import {
  collectSqlDefaultFields,
  getDesignerBindingColumns,
  getDesignerCollectionProperty,
  getDesignerTabSlotValue,
  getDesignerDataSourceFilters,
  getDesignerNodeFilters,
  getSqlDataSourceColumnCount,
  getSqlDataSourceEndpointId,
  getSqlDataSourceKeyField,
  getSqlDataSourceKeyParam,
  getSqlDataSourceKeySource,
  getSqlDataSourceScriptedEvents,
  getSqlFormValueProperty,
  hasSqlDataSourceUrlParams,
  isDesignerDateComponent,
  isDesignerDateOnlyComponent,
  isDesignerDateProperty,
  isDesignerOptionComponent,
  isSqlDataSourceNode,
  isValuelessDesignerFilter,
  DESIGNER_FILTER_DX_OPERATORS,
  toDesignerFilterParamName,
  normalizeDesignerKeyList,
  DESIGNER_DROPDOWN_PLACEHOLDER,
  SQL_DATA_SOURCE_SLOTS,
  SQL_DEFAULT_VALUE_PROP,
  type DesignerDataSource,
  type DesignerDataSourceFilter,
  type DesignerDocument,
  type DesignerNode,
} from './types'

/**
 * Record scope opened by a SqlDataSource. The record state is named
 * `data_<nodeId>`, which is exactly what `bindingExpression` emits for a binding
 * whose `sourceId` is the container's node id — so children bind to columns
 * through the regular binding machinery and write back through `setterName`.
 */
interface FormScope {
  sourceId: string
  setterName: string
}

const safeIdentifier = (value: string) => {
  const cleaned = value.replace(/[^A-Za-z0-9_$]/g, '_')
  return /^[A-Za-z_$]/.test(cleaned) ? cleaned : `Component_${cleaned}`
}

/**
 * Whether the emitted component carries the `refs` runtime. It is switched on by
 * `generateDesignerCode` for the whole pass when a script actually addresses
 * another component, so a page that uses no refs keeps its previous output byte
 * for byte instead of paying for a state hook and a guard around every node.
 */
let refRuntimeEnabled = false

/** Prop that turns a component off; react-select spells it differently. */
const getDisabledProperty = (type: string) => (type === 'Select' ? 'isDisabled' : 'disabled')

/** A script with `await` in it has to be wrapped in an async function. */
export const usesAwait = (script: string) => /\bawait\b/.test(script || '')

const refPropsExpression = (ref: string) => `designerRefProps(${JSON.stringify(ref)})`

const isRefControlled = (node: DesignerNode) => refRuntimeEnabled && Boolean(node.ref)

const staticValueExpression = (value: unknown): string => {
  if (typeof value === 'string') {
    return value.startsWith('::') ? `translate(${JSON.stringify(value)})` : JSON.stringify(value)
  }
  if (Array.isArray(value)) return `[${value.map(staticValueExpression).join(', ')}]`
  if (value && typeof value === 'object') {
    return `{ ${Object.entries(value)
      .map(([key, item]) => `${JSON.stringify(key)}: ${staticValueExpression(item)}`)
      .join(', ')} }`
  }
  if (value === undefined) return 'undefined'
  return JSON.stringify(value)
}

const serializeValue = (value: unknown) => `{${staticValueExpression(value)}}`

const bindingExpression = (node: DesignerNode, propertyName: string, itemVariable?: string) => {
  const binding = node.bindings?.[propertyName]
  if (!binding?.sourceId) return ''
  const path = binding.path.trim()
  if (itemVariable && (path === '$item' || path.startsWith('$item.'))) {
    return `getByPath(${itemVariable}, ${JSON.stringify(path === '$item' ? '' : path.slice(6))})`
  }
  return `getByPath(data_${safeIdentifier(binding.sourceId)}, ${JSON.stringify(binding.path || '')})`
}

interface RuntimeStateSpec {
  propertyName: string
  eventName: string
  stateName: string
  setterName: string
  initialValue: unknown
}

const getRuntimeStateSpec = (node: DesignerNode): RuntimeStateSpec | null => {
  const configured: Record<string, { propertyName: string; eventName: string }> = {
    AutoComplete: { propertyName: 'value', eventName: 'onInputChange' },
    Dropdown: { propertyName: 'activeKey', eventName: 'onSelect' },
    Input: { propertyName: 'value', eventName: 'onChange' },
    ImageViewer: { propertyName: 'activeIndex', eventName: 'onIndexChange' },
    Menu: { propertyName: 'defaultActiveKeys', eventName: 'onSelect' },
    Pagination: { propertyName: 'currentPage', eventName: 'onChange' },
    'Radio.Group': { propertyName: 'value', eventName: 'onChange' },
    Select: { propertyName: 'value', eventName: 'onChange' },
    Steps: { propertyName: 'current', eventName: 'onChange' },
    Tabs: { propertyName: 'value', eventName: 'onChange' },
    Upload: { propertyName: 'fileList', eventName: 'onChange' },
  }
  const fallback =
    'checked' in node.props
      ? { propertyName: 'checked', eventName: 'onChange' }
      : 'value' in node.props
        ? { propertyName: 'value', eventName: 'onChange' }
        : null
  const state = configured[node.type] || fallback
  if (!state || node.bindings?.[state.propertyName]?.sourceId) return null

  let initialValue = node.props[state.propertyName]
  if (node.type === 'Select') {
    const options = Array.isArray(node.props.options) ? node.props.options : []
    initialValue = node.props.isMulti
      ? options.filter(
          (option) =>
            option &&
            typeof option === 'object' &&
            !Array.isArray(option) &&
            Array.isArray(node.props.value) &&
            node.props.value.includes((option as Record<string, unknown>).value),
        )
      : options.find(
          (option) =>
            option &&
            typeof option === 'object' &&
            !Array.isArray(option) &&
            (option as Record<string, unknown>).value === node.props.value,
        ) || null
  } else if (node.type === 'Menu') {
    initialValue = normalizeDesignerKeyList(initialValue)
  } else if (node.type === 'Tabs') {
    initialValue = initialValue === undefined || initialValue === null ? '' : String(initialValue)
  } else if (node.type === 'Pagination') {
    initialValue = Number(initialValue) || 1
  } else if (initialValue === undefined) {
    initialValue = state.propertyName === 'checked' ? false : ''
  }

  const identifier = safeIdentifier(node.id)
  return {
    ...state,
    stateName: `runtime_${identifier}_${safeIdentifier(state.propertyName)}`,
    setterName: `setRuntime_${identifier}_${safeIdentifier(state.propertyName)}`,
    initialValue,
  }
}

/** Prop of a node that the enclosing SqlDataSource writes the record back from. */
const getFormScopeField = (node: DesignerNode, formScope?: FormScope) => {
  if (!formScope) return null
  const propertyName = getSqlFormValueProperty(node, formScope.sourceId)
  if (!propertyName) return null
  return {
    propertyName,
    eventName: node.type === 'AutoComplete' ? 'onInputChange' : 'onChange',
    path: node.bindings[propertyName].path,
    setterName: formScope.setterName,
    sourceId: formScope.sourceId,
  }
}

const isOptionCollectionProperty = (node: DesignerNode, propertyName: string) =>
  isDesignerOptionComponent(node.type) && propertyName === getDesignerCollectionProperty(node.type)

/**
 * Options expression for a data component: the endpoint binding mapped through
 * `toSelectOptions` (honouring the configured label/value columns), otherwise the
 * static collection maintained in the designer.
 */
const optionCollectionExpression = (node: DesignerNode, itemVariable?: string) => {
  const collectionProperty = getDesignerCollectionProperty(node.type)
  const binding = node.bindings?.[collectionProperty]
  const boundExpression = binding?.sourceId
    ? bindingExpression(node, collectionProperty, itemVariable)
    : ''
  if (boundExpression) {
    return `toSelectOptions(${boundExpression}, ${JSON.stringify(binding?.labelPath || '')}, ${JSON.stringify(binding?.valuePath || '')})`
  }
  const staticOptions = node.props[collectionProperty]
  return staticValueExpression(Array.isArray(staticOptions) ? staticOptions : [])
}

/** Node stripped of its collection prop/binding; those are rendered as children. */
const withoutCollection = (node: DesignerNode) => {
  const collectionProperty = getDesignerCollectionProperty(node.type)
  const props = { ...node.props }
  const bindings = { ...(node.bindings || {}) }
  delete props[collectionProperty]
  delete bindings[collectionProperty]
  return { node: { ...node, props, bindings }, props, bindings }
}

const propsToCode = (
  node: DesignerNode,
  itemVariable?: string,
  omitProperties: string[] = [],
  formScope?: FormScope,
) => {
  const omitted = new Set(omitProperties)
  const runtimeState = getRuntimeStateSpec(node)
  const formField = getFormScopeField(node, formScope)
  const hasBoundInputValue = node.type === 'Input' && Boolean(node.bindings?.value?.sourceId)
  // Inside a SqlDataSource the bound value is editable: the change is written to
  // the record, so the input must not be forced read-only.
  const hasInputChangeHandler = Boolean(node.events?.onChange?.trim()) || Boolean(formField)
  const props = Object.entries(node.props)
    .filter(
      ([key, value]) =>
        key !== 'children' &&
        key !== runtimeState?.propertyName &&
        // Seeds a new SqlDataSource record; it is not a prop of the component.
        key !== SQL_DEFAULT_VALUE_PROP &&
        !omitted.has(key) &&
        !(node.type === 'Checkbox' && key === 'defaultChecked' && 'checked' in node.props) &&
        !(hasBoundInputValue && !hasInputChangeHandler && key === 'readOnly') &&
        // A field the SqlDataSource writes back must stay editable, whatever the
        // node happens to carry from the toolbox defaults.
        !(formField && (key === 'readOnly' || key === 'disabled')) &&
        !node.bindings?.[key]?.sourceId &&
        value !== '' &&
        value !== undefined,
    )
    .map(([key, value]) =>
      // Dates live in the document as ISO strings; pickers need Date instances.
      isDesignerDateProperty(node.type, key)
        ? `${key}={toDesignerDate(${staticValueExpression(value)}, ${isDesignerDateOnlyComponent(node.type)})}`
        : `${key}=${serializeValue(value)}`,
    )

  Object.keys(node.bindings || {}).forEach((propertyName) => {
    if (propertyName === 'children') return
    const expression = bindingExpression(node, propertyName, itemVariable)
    if (expression) {
      // Label/value columns come from the bound property itself; the collection
      // is named `items` on some data components and `options` on others.
      const binding = node.bindings?.[propertyName]
      const propertyExpression = isOptionCollectionProperty(node, propertyName)
        ? `toSelectOptions(${expression}, ${JSON.stringify(binding?.labelPath || '')}, ${JSON.stringify(binding?.valuePath || '')})`
        : // Pickers need a Date instance; an endpoint column is an ISO string.
          isDesignerDateProperty(node.type, propertyName)
          ? `toDesignerDate(${expression}, ${isDesignerDateOnlyComponent(node.type)})`
          : // Select is controlled by the option object, not by the raw column value.
            node.type === 'Select' && propertyName === 'value'
            ? `toSelectValue(${optionCollectionExpression(node, itemVariable)}, ${expression}, ${Boolean(node.props.isMulti)})`
            : // An empty record (New mode) would otherwise hand React `undefined`,
              // which flips the field to uncontrolled and makes it unusable.
              formField?.propertyName === propertyName
              ? `(${expression}) ?? ${propertyName === 'checked' ? 'false' : '""'}`
              : expression
      props.push(`${propertyName}={${propertyExpression}}`)
    }
  })

  if (hasBoundInputValue && !hasInputChangeHandler) props.push('readOnly={true}')

  if (runtimeState && !omitted.has(runtimeState.propertyName)) {
    props.push(`${runtimeState.propertyName}={${runtimeState.stateName}}`)
  }

  const handlerNames = new Set(
    Object.entries(node.events)
      .filter(([, script]) => script.trim())
      .map(([eventName]) => eventName),
  )
  if (runtimeState) handlerNames.add(runtimeState.eventName)
  if (formField) handlerNames.add(formField.eventName)
  handlerNames.forEach((eventName) =>
    props.push(`${eventName}={handle_${safeIdentifier(node.id)}_${eventName}}`),
  )

  // Spread first so anything configured on the node overrides the defaults.
  const leading = node.type === 'Select' ? ['{...selectMenuProps}'] : []
  // …and the ref overrides spread last, because a script that disables or
  // refills a component has to win over both the defaults and the design values.
  const trailing = isRefControlled(node) ? [`{...${refPropsExpression(node.ref as string)}}`] : []
  const allProps = [...leading, ...props, ...trailing]
  return allProps.length ? ` ${allProps.join(' ')}` : ''
}

const indent = (text: string, level: number) =>
  text
    .split('\n')
    .map((line) => `${'  '.repeat(level)}${line}`)
    .join('\n')

const sqlIdentifiers = (node: DesignerNode) => {
  const identifier = safeIdentifier(node.id)
  return {
    identifier,
    record: `data_${identifier}`,
    setRecord: `setData_${identifier}`,
    rows: `sqlRows_${identifier}`,
    busy: `sqlBusy_${identifier}`,
    setBusy: `setSqlBusy_${identifier}`,
    error: `sqlError_${identifier}`,
    setError: `setSqlError_${identifier}`,
    key: `sqlKey_${identifier}`,
    keyParam: `sqlKeyParam_${identifier}`,
    hasKey: `sqlHasKey_${identifier}`,
    original: `sqlOriginal_${identifier}`,
    setOriginal: `setSqlOriginal_${identifier}`,
    mode: `sqlMode_${identifier}`,
    setMode: `setSqlMode_${identifier}`,
    index: `sqlIndex_${identifier}`,
    setIndex: `setSqlIndex_${identifier}`,
    selectUrl: `sqlSelectUrl_${identifier}`,
    filters: `sqlFilters_${identifier}`,
    filterKey: `sqlFilterKey_${identifier}`,
    urlKey: `sqlUrlKey_${identifier}`,
    setField: `sqlSetField_${identifier}`,
    reload: `sqlReload_${identifier}`,
    refresh: `sqlRefresh_${identifier}`,
    create: `sqlNew_${identifier}`,
    draft: `sqlDraft_${identifier}`,
    host: `sqlHost_${identifier}`,
    save: `sqlSave_${identifier}`,
    remove: `sqlDelete_${identifier}`,
    previous: `sqlPrev_${identifier}`,
    next: `sqlNext_${identifier}`,
    // Mirrors of the record/mode state, so an event handler declared further down
    // the component body reads the current value instead of a closed over one.
    recordRef: `sqlRecordRef_${identifier}`,
    modeRef: `sqlModeRef_${identifier}`,
    slot: (property: string) => `sql${property.replace(/Endpoint$/, '')}_${identifier}`,
  }
}

/** Handler name of a scripted SqlDataSource event, or `''` when it has no script. */
const sqlEventHandler = (node: DesignerNode, eventName: string) =>
  node.events?.[eventName]?.trim() ? `handle_${safeIdentifier(node.id)}_${eventName}` : ''

const hasSqlEvents = (node: DesignerNode) => getSqlDataSourceScriptedEvents(node).length > 0

/**
 * `await`ed call of an event script, emitted only when the event carries one.
 * `payload` is the object literal the script sees as `event`.
 */
const sqlEventCall = (node: DesignerNode, eventName: string, payload: string) => {
  const handler = sqlEventHandler(node, eventName)
  return handler ? `await ${handler}(${payload})` : ''
}

/**
 * Cancelable variant: the command stops when the script returns exactly `false`,
 * so a script that returns nothing (the common case) never blocks anything.
 */
const sqlCancelableEventCall = (node: DesignerNode, eventName: string, payload: string) => {
  const handler = sqlEventHandler(node, eventName)
  return handler ? `if ((await ${handler}(${payload})) === false) return` : ''
}

/** Same, but inside a `try` that already owns the busy flag — needs a reset. */
const sqlErrorEventCall = (node: DesignerNode, action: string) => {
  const handler = sqlEventHandler(node, 'onError')
  const names = sqlIdentifiers(node)
  return handler
    ? `\n      await ${handler}({ message: toSqlErrorMessage(error), action: ${JSON.stringify(action)}, error, record: ${names.recordRef}.current })`
    : ''
}

/**
 * Runtime expression a filter reads its value from. A `record` filter addresses
 * another SqlDataSource by its ref, which is what turns a master container and a
 * detail Grid into a filtered pair without a line of script.
 */
const filterValueExpression = (
  filter: DesignerDataSourceFilter,
  sqlRecordByRef: Map<string, string>,
) => {
  if (filter.source === 'static') return JSON.stringify(filter.value)
  if (filter.source === 'query' || filter.source === 'route') {
    return `readDesignerUrlValue(${JSON.stringify(filter.source)}, ${JSON.stringify(filter.value)})`
  }
  const [ref, ...rest] = String(filter.value).split('.')
  const record = sqlRecordByRef.get(ref)
  const column = rest.join('.')
  // A ref that no longer exists resolves to nothing; a required filter then
  // cancels the request instead of loading the whole collection.
  if (!record || !column) return '""'
  return `readSqlField(${record}, ${JSON.stringify(column)})`
}

/**
 * Filter descriptor array `buildPlatformFilterParams` consumes. A platform view
 * is filtered through a DevExtreme expression rather than through query
 * parameters, so the operator is emitted in its DevExtreme form.
 */
const platformFilterEntriesExpression = (
  node: DesignerNode,
  sqlRecordByRef: Map<string, string>,
) => {
  const filters = getDesignerNodeFilters(node)
  if (!filters.length) return ''
  return `[${filters
    .map(
      (filter) =>
        `{ field: ${JSON.stringify(filter.field)}, operator: ${JSON.stringify(
          DESIGNER_FILTER_DX_OPERATORS[filter.operator],
        )}, kind: ${JSON.stringify(filter.operator)}, value: ${
          isValuelessDesignerFilter(filter) ? '""' : filterValueExpression(filter, sqlRecordByRef)
        }, required: ${Boolean(filter.required)} }`,
    )
    .join(', ')}]`
}

/** Filter descriptor array `buildFilteredUrl` consumes, or `''` when there is none. */
const filterEntriesExpression = (
  source: DesignerDataSource | undefined,
  sqlRecordByRef: Map<string, string>,
) => {
  const filters = getDesignerDataSourceFilters(source)
  if (!filters.length) return ''
  return `[${filters
    .map(
      (filter) =>
        `{ param: ${JSON.stringify(toDesignerFilterParamName(filter))}, value: ${
          isValuelessDesignerFilter(filter) ? '"true"' : filterValueExpression(filter, sqlRecordByRef)
        }, required: ${Boolean(filter.required)} }`,
    )
    .join(', ')}]`
}

/** `{ url, method }` literal of an endpoint slot, or `null` when it is unset. */
const sqlSlotLiteral = (
  node: DesignerNode,
  property: string,
  method: string,
  dataSources: DesignerDataSource[],
) => {
  const source = dataSources.find(
    (candidate) => candidate.id === getSqlDataSourceEndpointId(node, property),
  )
  if (!source?.url.trim()) return 'null'
  return `{ url: ${JSON.stringify(source.url.trim())}, method: ${JSON.stringify(method)}, responsePath: ${JSON.stringify(source.responsePath || '')} }`
}

const sqlDataSourceHooks = (
  node: DesignerNode,
  dataSources: DesignerDataSource[],
  sqlRecordByRef: Map<string, string>,
) => {
  const names = sqlIdentifiers(node)
  const keyField = getSqlDataSourceKeyField(node)
  const selectSource = dataSources.find(
    (candidate) => candidate.id === getSqlDataSourceEndpointId(node, 'selectEndpoint'),
  )
  const selectFilters = filterEntriesExpression(selectSource, sqlRecordByRef)
  // The Select endpoint already owns a fetch hook, so the container reuses that
  // state instead of issuing a second request for the same URL.
  const selectData = selectSource ? `data_${safeIdentifier(selectSource.id)}` : 'null'
  // Must mirror the setter emitted by the data hooks, or the reload would call an
  // identifier that was never declared.
  const setSelectData =
    selectSource?.method === 'GET' && selectSource.url.trim().startsWith('/api/')
      ? `setData_${safeIdentifier(selectSource.id)}`
      : ''
  const keySource = getSqlDataSourceKeySource(node)
  const rowsExpression = `toSqlRows(${selectData}, ${JSON.stringify(String(node.props.collectionPath ?? ''))})`
  const slots = SQL_DATA_SOURCE_SLOTS.map(
    (slot) =>
      `  const ${names.slot(slot.property)} = ${sqlSlotLiteral(node, slot.property, slot.method, dataSources)}`,
  ).join('\n')

  return `${slots}
  const ${names.key} = ${JSON.stringify(keyField)}
  const ${names.keyParam} = ${JSON.stringify(getSqlDataSourceKeyParam(node))}
  const [${names.record}, ${names.setRecord}] = React.useState({})
  const [${names.original}, ${names.setOriginal}] = React.useState({})
  const [${names.mode}, ${names.setMode}] = React.useState("edit")
  const [${names.index}, ${names.setIndex}] = React.useState(0)
  const [${names.busy}, ${names.setBusy}] = React.useState(false)
  const [${names.error}, ${names.setError}] = React.useState("")
  // Container element, so New can hand the cursor to the first field of the form.
  const ${names.host} = React.useRef(null)${
    hasSqlEvents(node)
      ? `
  // Event scripts are declared after these hooks, so they read the record and the
  // mode through refs rather than through the closure they were created in.
  const ${names.recordRef} = React.useRef(${names.record})
  ${names.recordRef}.current = ${names.record}
  const ${names.modeRef} = React.useRef(${names.mode})`
      : ''
  }
  // The Select key can come from the page URL, which is how a detail page reads
  // /api/app/orders/{id} or /api/app/orders?id=… for a single record.
  const ${names.urlKey} = readUrlKey(${JSON.stringify(keySource)}, ${names.keyParam})
${
    selectFilters
      ? `  // Column filters configured on the Select source. They are rebuilt on every
  // render so a master record change reaches the URL, and the memo below is keyed
  // on their serialized form rather than on each value.
  const ${names.filters} = ${selectFilters}
  const ${names.filterKey} = JSON.stringify(${names.filters})
`
      : ''
  }  const ${names.selectUrl} = React.useMemo(() => {
    if (!${names.slot('selectEndpoint')}) return ""
    const base = ${names.urlKey}
      ? (() => {
          const bound = bindSqlUrl(${names.slot('selectEndpoint')}.url, { [${names.keyParam}]: ${names.urlKey} }, ${names.keyParam})
          return bound.keyBound ? bound.url : appendQueryParam(bound.url, ${names.keyParam}, ${names.urlKey})
        })()
      : ${names.slot('selectEndpoint')}.url
    ${
      selectFilters
        ? `// An unmet required filter yields no URL at all, which stops the Select
    // from loading the unfiltered collection.
    return buildFilteredUrl(base, ${names.filters})`
        : 'return base'
    }
  }, [${names.urlKey}${selectFilters ? `, ${names.filterKey}` : ''}])
  // A key in the page URL always narrows the result: a list endpoint ignores the
  // parameter server side, so the requested record is picked out here. Without a
  // key every row is kept and the navigation below takes over.
  const ${names.rows} = React.useMemo(
    () => filterSqlRowsByKey(${rowsExpression}, ${names.key}, ${names.urlKey}),
    [${selectData}, ${names.urlKey}],
  )
  // A fresh result set resets the position; New mode is left untouched so an
  // unsaved draft is not overwritten by a re-render.
  React.useEffect(() => {
    ${names.setIndex}((current) => (current < ${names.rows}.length ? current : 0))
  }, [${names.rows}])${
    sqlEventHandler(node, 'onLoad')
      ? `
  // Fires once the Select result has settled, whether it carries rows or not —
  // an empty result is exactly the case a script wants to react to.
  React.useEffect(() => {
    if (${selectData} === null || ${selectData} === undefined) return
    void ${sqlEventHandler(node, 'onLoad')}({ rows: ${names.rows}, count: ${names.rows}.length, record: ${names.rows}[${names.index}] ?? {}, index: ${names.index} })
  }, [${names.rows}])`
      : ''
  }
  React.useEffect(() => {
    const row = ${names.rows}[${names.index}]
    if (!row) return
    ${names.setRecord}(row)
    ${names.setOriginal}(row)
    ${names.setMode}("edit")${
      sqlEventHandler(node, 'onRecordChange')
        ? `
    void ${sqlEventHandler(node, 'onRecordChange')}({ record: row, index: ${names.index}, rows: ${names.rows}, count: ${names.rows}.length })`
        : ''
    }
  }, [${names.rows}, ${names.index}])${
    sqlEventHandler(node, 'onModeChange')
      ? `
  // The ref starts at the initial mode, so the first render is not reported as a
  // change; only real new/edit transitions reach the script.
  React.useEffect(() => {
    if (${names.modeRef}.current === ${names.mode}) return
    ${names.modeRef}.current = ${names.mode}
    void ${sqlEventHandler(node, 'onModeChange')}({ mode: ${names.mode}, record: ${names.recordRef}.current })
  }, [${names.mode}])`
      : ''
  }
  const ${names.hasKey} = (() => {
    const value = readSqlField(${names.record}, ${names.key})
    return value !== undefined && value !== null && value !== ""
  })()
  const ${names.setField} = React.useCallback(${
    sqlEventHandler(node, 'onFieldChange')
      ? `(path, value) => {
    ${names.setRecord}((current) => setSqlField(current, path, value))
    // The script is handed the record with the write already applied, so a
    // calculation can read the sibling columns without re-deriving the change.
    void ${sqlEventHandler(node, 'onFieldChange')}({ field: path, value, previous: getByPath(${names.recordRef}.current, path), record: setSqlField(${names.recordRef}.current, path, value) })
  }`
      : `(path, value) => ${names.setRecord}((current) => setSqlField(current, path, value))`
  }, [])
  const ${names.reload} = React.useCallback(async () => {${
    setSelectData
      ? `
    if (!${names.selectUrl}) return
    // Calling a URL that still holds a placeholder is a guaranteed 400, so the
    // missing key is reported in the component instead.
    if (hasSqlUrlParams(${names.selectUrl})) {
      throw new Error("Select endpointi " + ${names.keyParam} + " parametresini bekliyor; sayfa adresinde bulunamadı.")
    }
    const response = await apiService.fetchData({ url: ${names.selectUrl}, method: "GET" })
    ${setSelectData}(getByPath(response.data, ${names.slot('selectEndpoint')}.responsePath))`
      : ''
  }
  }, [${setSelectData ? names.selectUrl : ''}])
  // Reload wrapped with the busy/error handling the toolbar and mount effect need,
  // so a failing Select is reported in the component instead of the console.
  const ${names.refresh} = React.useCallback(async () => {
    ${names.setBusy}(true)
    ${names.setError}("")
    try {
      await ${names.reload}()
    } catch (error) {
      ${names.setError}(toSqlErrorMessage(error))${sqlErrorEventCall(node, 'reload')}
    } finally {
      ${names.setBusy}(false)
    }
  }, [${names.reload}])
  const ${names.create} = React.useCallback(${sqlEventHandler(node, 'onNewRecord') ? 'async ' : ''}() => {
    ${names.setError}("")
    // Defaults are resolved on every New, so an @today column carries the day the
    // record was opened rather than the day the component was generated.
    const ${names.draft} = buildSqlDefaults(${JSON.stringify(collectSqlDefaultFields(node))})
    ${names.setRecord}(${names.draft})
    ${names.setOriginal}({})
    ${names.setMode}("new")
    // After the re-render that paints the empty form, not before it.
    focusFirstSqlField(${names.host})${
      sqlEventHandler(node, 'onNewRecord')
        ? `
    ${sqlEventCall(node, 'onNewRecord', `{ record: ${names.draft} }`)}`
        : ''
    }
  }, [])
  const ${names.previous} = React.useCallback(() => ${names.setIndex}((current) => Math.max(0, current - 1)), [])
  const ${names.next} = React.useCallback(() => ${names.setIndex}((current) => Math.min(${names.rows}.length - 1, current + 1)), [${names.rows}])
  const ${names.save} = async () => {
    const isNew = ${names.mode} === "new"
    const target = isNew ? ${names.slot('insertEndpoint')} : ${names.slot('updateEndpoint')}
    if (!target) {
      ${names.setError}(isNew ? "Insert için POST endpointi tanımlı değil." : "Update için PUT endpointi tanımlı değil.")
      return
    }
    // Update carries only the edited columns plus the key; Insert sends the record.
    const payload = isNew ? ${names.record} : toSqlChanges(${names.original}, ${names.record}, ${names.key})
    if (!isNew && Object.keys(payload).filter((column) => column.toLowerCase() !== String(${names.key}).toLowerCase()).length === 0) {
      ${names.setError}("Kaydedilecek bir değişiklik yok.")
      return
    }${
      sqlEventHandler(node, 'onBeforeSave')
        ? `
    // Runs before the busy flag is raised: a vetoed save must leave the form in
    // exactly the state the user left it in.
    ${sqlCancelableEventCall(node, 'onBeforeSave', `{ record: ${names.record}, original: ${names.original}, payload, mode: ${names.mode}, isNew }`)}`
        : ''
    }
    ${names.setBusy}(true)
    ${names.setError}("")
    try {
      const response = await callSqlEndpoint(target, ${names.record}, ${names.key}, payload)
      // With a Select endpoint the reload is the source of truth and its effect
      // repopulates the form; without one, the response row is all there is.
      if (${names.slot('selectEndpoint')}) {
        await ${names.reload}()
      } else {
        const saved = toSqlRows(response?.data, "")[0]
        if (saved) {
          ${names.setRecord}(saved)
          ${names.setOriginal}(saved)
        }
      }
      ${names.setMode}("edit")${
        sqlEventHandler(node, 'onAfterSave')
          ? `
      ${sqlEventCall(node, 'onAfterSave', `{ record: ${names.record}, response: response?.data, mode: ${names.mode}, isNew }`)}`
          : ''
      }
    } catch (error) {
      ${names.setError}(toSqlErrorMessage(error))${sqlErrorEventCall(node, 'save')}
    } finally {
      ${names.setBusy}(false)
    }
  }
  const ${names.remove} = async () => {
    if (!${names.slot('deleteEndpoint')} || !${names.hasKey} || ${names.mode} === "new") return${
      sqlEventHandler(node, 'onBeforeDelete')
        ? `
    // Asked before the confirm dialog, so a script can block the delete without
    // the user ever being prompted.
    ${sqlCancelableEventCall(node, 'onBeforeDelete', `{ record: ${names.record}, key: readSqlField(${names.record}, ${names.key}) }`)}`
        : ''
    }
    // Deleting cannot be undone from the form, so it always asks first.
    const confirmMessage = ${names.key} + " = " + readSqlField(${names.record}, ${names.key}) + " kaydı silinecek.\\n\\nOnaylıyor musunuz?"
    if (typeof window !== "undefined" && !window.confirm(confirmMessage)) return
    ${names.setBusy}(true)
    ${names.setError}("")
    try {${
      sqlEventHandler(node, 'onAfterDelete')
        ? `
      const deleted = ${names.record}`
        : ''
    }
      await callSqlEndpoint(${names.slot('deleteEndpoint')}, ${names.record}, ${names.key})
      ${names.setRecord}({})
      ${names.setOriginal}({})
      ${names.setMode}("new")
      await ${names.reload}()${
        sqlEventHandler(node, 'onAfterDelete')
          ? `
      ${sqlEventCall(node, 'onAfterDelete', '{ record: deleted }')}`
          : ''
      }
    } catch (error) {
      ${names.setError}(toSqlErrorMessage(error))${sqlErrorEventCall(node, 'delete')}
    } finally {
      ${names.setBusy}(false)
    }
  }${
    node.props.autoLoad === false
      ? ''
      : `
  React.useEffect(() => { void ${names.refresh}() }, [${names.refresh}])`
  }`
}

const SQL_TOOLBAR_BUTTON_CLASS =
  'rounded-md px-3 py-1.5 text-xs font-semibold transition disabled:cursor-not-allowed disabled:opacity-40'

const sqlDataSourceToCode = (node: DesignerNode, level: number, itemVariable?: string) => {
  const names = sqlIdentifiers(node)
  const formScope: FormScope = { sourceId: node.id, setterName: names.setField }
  const columnCount = getSqlDataSourceColumnCount(node)
  const gap = Number(node.props.gap) || 0
  // Children sit one level deeper once they are wrapped in the column grid.
  const children = node.children
    .map((child) => nodeToCode(child, level + (columnCount > 1 ? 3 : 2), itemVariable, formScope))
    .join('\n')
  const className = JSON.stringify(String(node.props.className || ''))
  const style = `{ display: "flex", flexDirection: "column", gap: ${gap} }`
  // The toolbar and the error line stay in the outer column, so only the fields
  // are laid out side by side. A single column emits no wrapper at all, which
  // keeps the markup of every page saved before the setting existed unchanged.
  const gridStyle = `{ display: "grid", gridTemplateColumns: "repeat(${columnCount}, minmax(0, 1fr))", gap: ${gap}, alignItems: "start" }`
  const content =
    columnCount > 1
      ? `${indent(`<div style={${gridStyle}}>`, level + 2)}\n${children}\n${indent('</div>', level + 2)}`
      : children
  const plainButtonClass = `${SQL_TOOLBAR_BUTTON_CLASS} border border-slate-300 text-slate-600 hover:border-sky-400 hover:text-sky-700 dark:border-slate-700 dark:text-slate-300`
  // Navigation appears on its own whenever there is more than one record to walk.
  const navigation = `
${indent(`{${names.rows}.length > 1 ? (`, level + 3)}
${indent('<>', level + 4)}
${indent(`<button type="button" className="${plainButtonClass}" disabled={${names.busy} || ${names.index} <= 0} onClick={${names.previous}}>Önceki</button>`, level + 5)}
${indent(`<span className="text-xs text-slate-500">{\`\${${names.index} + 1} / \${${names.rows}.length}\`}</span>`, level + 5)}
${indent(`<button type="button" className="${plainButtonClass}" disabled={${names.busy} || ${names.index} >= ${names.rows}.length - 1} onClick={${names.next}}>Sonraki</button>`, level + 5)}
${indent('<span className="mx-1 h-5 w-px bg-slate-300 dark:bg-slate-700" />', level + 5)}
${indent('</>', level + 4)}
${indent(') : null}', level + 3)}`
  const toolbar =
    node.props.showToolbar === false
      ? ''
      : `
${indent('<div className="flex flex-wrap items-center gap-2 border-t border-slate-200 pt-3 dark:border-slate-800">', level + 2)}${navigation}
${indent(`<button type="button" className="${plainButtonClass}" disabled={${names.busy} || !${names.slot('insertEndpoint')}} onClick={${names.create}}>Yeni</button>`, level + 3)}
${indent(`<button type="button" className="${SQL_TOOLBAR_BUTTON_CLASS} bg-sky-600 text-white hover:bg-sky-700" disabled={${names.busy} || !(${names.mode} === "new" ? ${names.slot('insertEndpoint')} : ${names.slot('updateEndpoint')})} onClick={() => { void ${names.save}() }}>Kaydet</button>`, level + 3)}
${indent(`<button type="button" className="${SQL_TOOLBAR_BUTTON_CLASS} bg-red-600 text-white hover:bg-red-700" disabled={${names.busy} || !${names.slot('deleteEndpoint')} || !${names.hasKey} || ${names.mode} === "new"} onClick={() => { void ${names.remove}() }}>Sil</button>`, level + 3)}
${indent(`<button type="button" className="${plainButtonClass}" disabled={${names.busy} || !${names.slot('selectEndpoint')}} onClick={() => { void ${names.refresh}() }}>Yenile</button>`, level + 3)}
${indent(`<span className="ml-auto text-[10px] uppercase tracking-wider text-slate-400">{${names.mode} === "new" ? "Yeni kayıt" : "Düzenleme"}</span>`, level + 3)}
${indent('</div>', level + 2)}`
  const error = `
${indent(`{${names.error} ? <div className="rounded-md bg-red-50 px-3 py-2 text-xs text-red-700 dark:bg-red-950 dark:text-red-200">{${names.error}}</div> : null}`, level + 2)}`
  // A filled Title turns the container into a Card header; a `::` value is a
  // localization key, so `staticValueExpression` emits a translate() call for it
  // and the header follows the active language. The header extra carries the key
  // of the record on screen.
  const title = String(node.props.title ?? '').trim()
  const headerExtra = `{${names.hasKey} ? ${names.key} + ": " + readSqlField(${names.record}, ${names.key}) : ${names.mode} === "new" ? "Yeni kayıt" : ""}`
  const cardStart = title
    ? `<UiKit.Card bodyClass="p-4" header={${staticValueExpression(title)}} headerExtra={<span className="text-xs text-slate-500 dark:text-slate-400">${headerExtra}</span>}>`
    : '<UiKit.Card bodyClass="p-4">'

  return `${indent(cardStart, level)}
${indent(`<div ref={${names.host}} className=${className} style={${style}}>`, level + 1)}
${content}${toolbar}${error}
${indent('</div>', level + 1)}
${indent('</UiKit.Card>', level)}`
}

/**
 * Wraps a node in its visibility guard. Tabs is the one component emitted as a
 * braced expression rather than an element, so its outer `{…}` is turned into
 * parentheses — inside the ternary the code is read as an expression, not as a
 * JSX child.
 */
const withVisibilityGuard = (code: string, node: DesignerNode, level: number) => {
  if (!isRefControlled(node)) return code
  const trimmed = code.trim()
  const body =
    trimmed.startsWith('{') && trimmed.endsWith('}')
      ? code.replace(/^(\s*)\{/, '$1(').replace(/\}(\s*)$/, ')$1')
      : code
  return `${indent(`{designerRefHidden(${JSON.stringify(node.ref)}) ? null : (`, level)}
${body}
${indent(')}', level)}`
}

const nodeToCode = (
  node: DesignerNode,
  level = 0,
  itemVariable?: string,
  formScope?: FormScope,
): string =>
  withVisibilityGuard(
    renderNodeToCode(node, isRefControlled(node) ? level + 1 : level, itemVariable, formScope),
    node,
    level,
  )

const renderNodeToCode = (
  node: DesignerNode,
  level = 0,
  itemVariable?: string,
  formScope?: FormScope,
): string => {
  if (isSqlDataSourceNode(node.type)) return sqlDataSourceToCode(node, level, itemVariable)
  if (node.type === 'Spacer') {
    return indent(
      `<div aria-hidden="true" className=${JSON.stringify(String(node.props.className || ''))} style={{ height: ${Number(node.props.height) || 24} }} />`,
      level,
    )
  }

  if (node.type === 'FlexRow') {
    const style = `{ display: "flex", gap: ${Number(node.props.gap) || 0}, flexWrap: "${node.props.wrap ? 'wrap' : 'nowrap'}", alignItems: "${String(node.props.align || 'stretch')}" }`
    const className = node.props.className
      ? ` className=${JSON.stringify(node.props.className)}`
      : ''
    const children = node.children
      .map((child) => nodeToCode(child, level + 1, itemVariable, formScope))
      .join('\n')
    return `${indent(`<div${className} style={${style}}>`, level)}\n${children}\n${indent('</div>', level)}`
  }

  if (
    node.type === 'PageContainer' ||
    node.type === 'TwoColumns' ||
    node.type === 'SidebarContent' ||
    node.type === 'HeaderContent'
  ) {
    const gap = Number(node.props.gap) || 0
    const className = JSON.stringify(String(node.props.className || ''))
    const style =
      node.type === 'PageContainer'
        ? `{ display: "flex", flexDirection: "column", gap: ${gap}, margin: "0 auto", maxWidth: ${JSON.stringify(String(node.props.maxWidth || '1280px'))}, padding: ${Number(node.props.padding) || 0}, width: "100%" }`
        : node.type === 'HeaderContent'
          ? `{ display: "flex", flexDirection: "column", gap: ${gap} }`
          : `{ display: "grid", gap: ${gap}, gridTemplateColumns: ${JSON.stringify(node.type === 'SidebarContent' ? `${String(node.props.sidebarWidth || '280px')} minmax(0, 1fr)` : 'repeat(2, minmax(0, 1fr))')} }`
    const children = node.children
      .map((child) => nodeToCode(child, level + 1, itemVariable, formScope))
      .join('\n')
    return `${indent(`<div className=${className} style={${style}}>`, level)}\n${children}\n${indent('</div>', level)}`
  }

  if (node.type === 'Table') {
    const rowCount = Math.min(20, Math.max(1, Math.floor(Number(node.props.rowCount) || 2)))
    const columnCount = Math.min(20, Math.max(1, Math.floor(Number(node.props.columnCount) || 3)))
    const rows = Array.from({ length: rowCount }, (_, rowIndex) => {
      const cells = Array.from({ length: columnCount }, (_, columnIndex) => {
        const slot = `table:${rowIndex}:${columnIndex}`
        const cellChildren = node.children.filter(
          (child, childIndex) =>
            (child.slot ||
              `table:${Math.floor(childIndex / columnCount)}:${childIndex % columnCount}`) === slot,
        )
        const content = cellChildren.length
          ? cellChildren
              .map((child) => nodeToCode(child, level + 3, itemVariable, formScope))
              .join('\n')
          : indent('<span />', level + 3)
        return `${indent('<td>', level + 2)}\n${content}\n${indent('</td>', level + 2)}`
      }).join('\n')
      return `${indent('<tr>', level + 1)}\n${cells}\n${indent('</tr>', level + 1)}`
    }).join('\n')
    const className = JSON.stringify(String(node.props.className || ''))
    return `${indent(`<UiKit.Table className={${className} + " [&>tbody>tr>td]:!px-1.5 [&>tbody>tr>td]:!py-1.5"} borderlessRow compact={${Boolean(node.props.compact)}} hoverable={${node.props.hoverable !== false}} overflow={${node.props.overflow !== false}} style={{ minWidth: "100%", tableLayout: "fixed", width: "100%" }}>`, level)}
${indent('<tbody>', level + 1)}
${rows}
${indent('</tbody>', level + 1)}
${indent('</UiKit.Table>', level)}`
  }

  if (node.type === 'Grid') {
    const columns = Number(node.props.cols) || 3
    const gap = (Number(node.props.gap) || 0) * 4
    const itemsExpression =
      bindingExpression(node, 'items', itemVariable) ||
      (Array.isArray(node.props.items) ? JSON.stringify(node.props.items) : '')
    const itemsBinding = node.bindings?.items
    const sourceRootExpression =
      !itemVariable && itemsBinding?.sourceId ? `data_${safeIdentifier(itemsBinding.sourceId)}` : ''
    const collectionExpression =
      sourceRootExpression && sourceRootExpression !== itemsExpression
        ? `(Array.isArray(${itemsExpression}) ? ${itemsExpression} : Array.isArray(${sourceRootExpression}) ? ${sourceRootExpression} : null)`
        : itemsExpression
    const gridClassName = JSON.stringify(String(node.props.className || ''))
    const gridStart = `<div className=${gridClassName} style={{ display: "grid", gridTemplateColumns: "repeat(${columns}, minmax(0, 1fr))", gap: ${gap} }}>`

    if (collectionExpression && node.children.length === 0) {
      const identifier = safeIdentifier(node.id)
      const itemsVariable = `gridItems_${identifier}`
      const columnsVariable = `gridColumns_${identifier}`
      const itemVariable = `gridItem_${identifier}`
      const valueVariable = `cellValue_${identifier}`
      const configuredColumns = Array.isArray(node.props.dataColumns)
        ? node.props.dataColumns.filter((column): column is string => typeof column === 'string')
        : null
      const columnsExpression = configuredColumns
        ? JSON.stringify(configuredColumns)
        : `${itemsVariable}[0] && typeof ${itemsVariable}[0] === "object" && !Array.isArray(${itemsVariable}[0]) ? Object.keys(${itemsVariable}[0]) : ["value"]`
      const compact = Boolean(node.props.compact)
      const borderlessRow = Boolean(node.props.borderlessRow)
      const hoverable = node.props.hoverable !== false
      const overflow = node.props.overflow !== false
      const tableTextClass = compact ? 'text-[11px]' : 'text-xs'
      const cellSpacingClass = compact ? 'px-2 py-1' : 'px-3 py-2'
      const rowClass = [
        borderlessRow ? '' : 'border-b border-slate-100 last:border-b-0 dark:border-slate-800',
        hoverable ? 'transition-colors hover:bg-slate-50 dark:hover:bg-slate-800/70' : '',
      ]
        .filter(Boolean)
        .join(' ')
      const overflowClass = overflow ? 'overflow-auto' : 'overflow-visible'
      const table = `${indent('{(() => {', level + 1)}
${indent(`const ${itemsVariable} = ${collectionExpression}`, level + 2)}
${indent(`// Nothing loaded yet — an endpoint still in flight, or a required filter`, level + 2)}
${indent(`// holding the request back — is an empty grid, not a binding error.`, level + 2)}
${indent(`if (${itemsVariable} === null || ${itemsVariable} === undefined) return null`, level + 2)}
${indent(`if (!Array.isArray(${itemsVariable})) return <div className="rounded-lg border border-amber-300 bg-amber-50 p-3 text-xs text-amber-800 dark:border-amber-800 dark:bg-amber-950 dark:text-amber-200">Grid items bağlantısı bir koleksiyon döndürmelidir.</div>`, level + 2)}
${indent(`const ${columnsVariable} = ${columnsExpression}`, level + 2)}
${indent(`if (!${columnsVariable}.length) return <div className="rounded-lg border border-dashed border-slate-300 bg-slate-50 p-4 text-center text-xs text-slate-500 dark:border-slate-700 dark:bg-slate-900 dark:text-slate-400">Preview için en az bir sütun seçin.</div>`, level + 2)}
${indent('return (', level + 2)}
${indent(`<div className="min-w-0 ${overflowClass} rounded-lg border border-slate-200 bg-white shadow-sm dark:border-slate-700 dark:bg-slate-900" style={{ gridColumn: "1 / -1" }}>`, level + 3)}
${indent(`<table className="w-full border-collapse text-left ${tableTextClass}">`, level + 4)}
${indent('<thead className="bg-slate-100 text-slate-600 dark:bg-slate-800 dark:text-slate-200"><tr>', level + 5)}
${indent(`{${columnsVariable}.map((column) => <th key={column} className="whitespace-nowrap border-b border-slate-200 dark:border-slate-700 ${cellSpacingClass}">{column === "value" ? "Value" : column}</th>)}`, level + 6)}
${indent('</tr></thead>', level + 5)}
${indent('<tbody>', level + 5)}
${indent(`{${itemsVariable}.map((${itemVariable}, rowIndex) => (`, level + 6)}
${indent(`<tr key={rowIndex} className=${JSON.stringify(rowClass)}>`, level + 7)}
${indent(`{${columnsVariable}.map((column) => {`, level + 8)}
${indent(`const ${valueVariable} = column === "value" ? ${itemVariable} : getByPath(${itemVariable}, column)`, level + 9)}
${indent(`const text = typeof ${valueVariable} === "object" && ${valueVariable} !== null && !(${valueVariable} instanceof Date) ? JSON.stringify(${valueVariable}) : formatLocaleValue(${valueVariable}) || "—"`, level + 9)}
${indent(`return <td key={column} className="max-w-64 truncate text-slate-800 dark:text-slate-100 ${cellSpacingClass}" title={text}>{text}</td>`, level + 9)}
${indent('})}', level + 8)}
${indent('</tr>', level + 7)}
${indent('))}', level + 6)}
${indent('</tbody>', level + 5)}
${indent('</table>', level + 4)}
${indent('</div>', level + 3)}
${indent(')', level + 2)}
${indent('})()}', level + 1)}`
      return `${indent(gridStart, level)}\n${table}\n${indent('</div>', level)}`
    }

    const repeatedItemVariable = `item_${safeIdentifier(node.id)}`
    const staticChildren = node.children
      .map((child) => nodeToCode(child, level + 1, itemVariable, formScope))
      .join('\n')
    const repeatedChildren = node.children.length
      ? node.children
          .map((child) => nodeToCode(child, level + 4, repeatedItemVariable, formScope))
          .join('\n')
      : indent(
          `<pre className="min-w-0 overflow-auto rounded-lg border border-slate-200 bg-white p-3 text-xs text-slate-800 shadow-sm dark:border-slate-700 dark:bg-slate-900 dark:text-slate-100">{typeof ${repeatedItemVariable} === "string" ? ${repeatedItemVariable} : JSON.stringify(${repeatedItemVariable}, null, 2)}</pre>`,
          level + 4,
        )
    // The collection is read once into a local: it is tested for three cases
    // before it is mapped, and repeating the expression for each of them made
    // the emitted line unreadable.
    const repeatedRowsVariable = `rows_${safeIdentifier(node.id)}`
    const children = collectionExpression
      ? `${indent('{(() => {', level + 1)}
${indent(`const ${repeatedRowsVariable} = ${collectionExpression}`, level + 2)}
${indent(`// Nothing loaded yet — an endpoint still in flight, or a required filter`, level + 2)}
${indent(`// holding the request back — is an empty grid, not a binding error.`, level + 2)}
${indent(`if (${repeatedRowsVariable} === null || ${repeatedRowsVariable} === undefined) return null`, level + 2)}
${indent(`if (!Array.isArray(${repeatedRowsVariable})) return <div className="rounded-lg border border-amber-300 bg-amber-50 p-3 text-xs text-amber-800 dark:border-amber-800 dark:bg-amber-950 dark:text-amber-200">Grid items bağlantısı bir koleksiyon döndürmelidir.</div>`, level + 2)}
${indent(`return ${repeatedRowsVariable}.map((${repeatedItemVariable}, index) => (`, level + 2)}
${indent(`<React.Fragment key={${repeatedItemVariable}?.id ?? index}>`, level + 3)}
${repeatedChildren}
${indent('</React.Fragment>', level + 3)}
${indent('))', level + 2)}
${indent('})()}', level + 1)}`
      : staticChildren
    return `${indent(gridStart, level)}\n${children}\n${indent('</div>', level)}`
  }

  if (node.kind === 'platform') {
    const viewNames: Record<string, string> = {
      ListView: 'List',
      DataGridView: 'Grid',
      TreeView: 'Tree',
      GanttView: 'GanttView',
      TodoBoard: 'TodoBoard',
      CardView: 'CardView',
      SchedulerView: 'SchedulerView',
      PivotView: 'Pivot',
      ChartView: 'Chart',
    }
    const platformParams = `platformParams_${safeIdentifier(node.id)}`
    const hasFilters = getDesignerNodeFilters(node).length > 0
    const host = `<PlatformViewHost view=${JSON.stringify(viewNames[node.type] || node.type)} listFormCode=${JSON.stringify(String(node.props.listFormCode || ''))} height=${JSON.stringify(String(node.props.height || '420px'))}${hasFilters ? ` searchParams={${platformParams}}` : ''} />`
    if (!hasFilters) return indent(host, level)
    // A required filter without a value renders nothing: showing the unfiltered
    // list instead would read as a filter that is not applied.
    return `${indent(`{${platformParams} === null ? null : (`, level)}
${indent(host, level + 1)}
${indent(')}', level)}`
  }

  if (node.type === 'Menu') {
    const { node: menuNode, props: menuProps } = withoutCollection(node)
    delete menuProps.variant
    menuProps.defaultActiveKeys = normalizeDesignerKeyList(menuProps.defaultActiveKeys)
    menuProps.defaultExpandedKeys = normalizeDesignerKeyList(menuProps.defaultExpandedKeys)
    const menuPropsCode = propsToCode(menuNode, itemVariable, [], formScope)
    const optionsExpression = optionCollectionExpression(node, itemVariable)
    return `${indent(`<UiKit.Menu${menuPropsCode}>`, level)}\n${indent(`{${optionsExpression}.map((option, optionIndex) => <UiKit.Menu.MenuItem key={String(option.value ?? optionIndex)} eventKey={String(option.value ?? optionIndex)}>{String(option.label ?? option.value ?? \`Menü \${optionIndex + 1}\`)}</UiKit.Menu.MenuItem>)}`, level + 1)}\n${indent('</UiKit.Menu>', level)}`
  }

  if (node.type === 'Dropdown') {
    const { node: dropdownNode, props: dropdownProps, bindings } = withoutCollection(node)
    // Rendered from the active option below, so `title` must not also be emitted
    // by propsToCode — whether it is static or bound to an endpoint field.
    const boundTitle = bindings.title?.sourceId
      ? bindingExpression(node, 'title', itemVariable)
      : ''
    const fallbackTitleExpression = boundTitle || staticValueExpression(dropdownProps.title ?? '')
    delete dropdownProps.title
    delete bindings.title
    const dropdownPropsCode = propsToCode(dropdownNode, itemVariable, [], formScope)
    const optionsExpression = optionCollectionExpression(node, itemVariable)
    const activeKeyExpression =
      getRuntimeStateSpec(node)?.stateName ||
      bindingExpression(node, 'activeKey', itemVariable) ||
      staticValueExpression(node.props.activeKey ?? '')
    const titleExpression = `toDropdownTitle(${optionsExpression}, ${activeKeyExpression}, ${fallbackTitleExpression})`
    return `${indent(`<UiKit.Dropdown${dropdownPropsCode} title={${titleExpression}}>`, level)}\n${indent(`{${optionsExpression}.map((option, optionIndex) => <UiKit.Dropdown.Item key={String(option.value ?? optionIndex)} eventKey={String(option.value ?? optionIndex)} disabled={Boolean(option.disabled)}>{String(option.label ?? option.value ?? \`Öğe \${optionIndex + 1}\`)}</UiKit.Dropdown.Item>)}`, level + 1)}\n${indent('</UiKit.Dropdown>', level)}`
  }

  if (node.type === 'Pagination') {
    const { node: paginationNode } = withoutCollection(node)
    const paginationPropsCode = propsToCode(paginationNode, itemVariable, [], formScope)
    const optionsExpression = optionCollectionExpression(node, itemVariable)
    return indent(
      `<UiKit.Pagination${paginationPropsCode} total={${optionsExpression}.length} />`,
      level,
    )
  }

  if (node.type === 'Tabs') {
    const { node: tabsNode } = withoutCollection(node)
    // `value` is emitted below, resolved against the (possibly async) tab list.
    const tabsPropsCode = propsToCode(tabsNode, itemVariable, ['value'], formScope)
    const identifier = safeIdentifier(node.id)
    const optionsVariable = `tabItems_${identifier}`
    const activeVariable = `tabValue_${identifier}`
    const optionVariable = `tabItem_${identifier}`
    const activeStateExpression =
      getRuntimeStateSpec(node)?.stateName ||
      bindingExpression(node, 'value', itemVariable) ||
      staticValueExpression(node.props.value ?? '')
    const childrenVariable = `tabChildren_${identifier}`
    const fallbackVariable = `tabFallback_${identifier}`

    // Children are assigned to a tab through a `tab:<value>` slot. Building a
    // lookup keyed by tab value keeps this working when the tab list itself is
    // only known at runtime (endpoint driven tabs).
    const slotGroups = new Map<string, DesignerNode[]>()
    node.children.forEach((child) => {
      const key = getDesignerTabSlotValue(child.slot)
      const group = slotGroups.get(key)
      if (group) group.push(child)
      else slotGroups.set(key, [child])
    })
    const fragmentFor = (children: DesignerNode[], fragmentLevel: number) =>
      `${indent('<>', fragmentLevel)}\n${children
        .map((child) => nodeToCode(child, fragmentLevel + 1, itemVariable, formScope))
        .join('\n')}\n${indent('</>', fragmentLevel)}`

    const slottedEntries = [...slotGroups]
      .filter(([key]) => key !== '')
      .map(
        ([key, children]) =>
          `${indent(`${JSON.stringify(key)}: (`, level + 2)}\n${fragmentFor(children, level + 3)}\n${indent('),', level + 2)}`,
      )
      .join('\n')
    // Children saved before per-tab slots existed belong to the first tab.
    const fallbackChildren = slotGroups.get('') || []

    return `${indent('{(() => {', level)}
${indent(`const ${optionsVariable} = ${optionCollectionExpression(node, itemVariable)}`, level + 1)}
${indent(`const ${activeVariable} = toTabValue(${optionsVariable}, ${activeStateExpression})`, level + 1)}
${indent(`const ${childrenVariable} = {`, level + 1)}
${slottedEntries}
${indent('}', level + 1)}
${indent(`const ${fallbackVariable} = (`, level + 1)}
${fallbackChildren.length ? fragmentFor(fallbackChildren, level + 2) : indent('null', level + 2)}
${indent(')', level + 1)}
${indent('return (', level + 1)}
${indent(`<UiKit.Tabs${tabsPropsCode} value={${activeVariable}}>`, level + 2)}
${indent('<UiKit.Tabs.TabList>', level + 3)}
${indent(`{${optionsVariable}.map((${optionVariable}, tabIndex) => <UiKit.Tabs.TabNav key={String(${optionVariable}.value ?? tabIndex)} value={String(${optionVariable}.value ?? tabIndex)} disabled={Boolean(${optionVariable}.disabled)}>{String(${optionVariable}.label ?? ${optionVariable}.value ?? \`Sekme \${tabIndex + 1}\`)}</UiKit.Tabs.TabNav>)}`, level + 4)}
${indent('</UiKit.Tabs.TabList>', level + 3)}
${indent(`{${optionsVariable}.map((${optionVariable}, tabIndex) => (`, level + 3)}
${indent(`<UiKit.Tabs.TabContent key={String(${optionVariable}.value ?? tabIndex)} value={String(${optionVariable}.value ?? tabIndex)}>`, level + 4)}
${indent(`{${optionVariable}.content ? <div>{String(${optionVariable}.content)}</div> : null}`, level + 5)}
${indent(`{${childrenVariable}[String(${optionVariable}.value ?? tabIndex)] ?? null}`, level + 5)}
${indent(`{tabIndex === 0 ? ${fallbackVariable} : null}`, level + 5)}
${indent('</UiKit.Tabs.TabContent>', level + 4)}
${indent('))}', level + 3)}
${indent('</UiKit.Tabs>', level + 2)}
${indent(')', level + 1)}
${indent('})()}', level)}`
  }

  if (node.type === 'Radio.Group') {
    const { node: groupNode, props: groupProps } = withoutCollection(node)
    delete groupProps.checked
    delete groupProps.defaultChecked
    delete groupProps.readOnly
    const groupPropsCode = propsToCode(groupNode, itemVariable, [], formScope)
    const optionsExpression = optionCollectionExpression(node, itemVariable)
    return `${indent(`<UiKit.Radio.Group${groupPropsCode}>`, level)}\n${indent(`{${optionsExpression}.map((option, optionIndex) => <UiKit.Radio key={String(option.value ?? optionIndex)} value={option.value ?? optionIndex} disabled={Boolean(option.disabled)}>{String(option.label ?? option.value ?? \`Seçenek \${optionIndex + 1}\`)}</UiKit.Radio>)}`, level + 1)}\n${indent('</UiKit.Radio.Group>', level)}`
  }

  const tag =
    node.type === 'checkbox'
      ? 'input'
      : node.kind === 'ui'
        ? `UiKit.${node.type}`
        : node.kind === 'custom'
          ? safeIdentifier(node.type)
          : node.type
  const props = { ...node.props }
  if (node.type === 'checkbox') props.type = 'checkbox'
  const normalizedNode = { ...node, props }
  const propCode = propsToCode(normalizedNode, itemVariable, [], formScope)
  const childrenText = String(node.props.children ?? '')
  const childrenBinding = bindingExpression(node, 'children', itemVariable)
  const hasChildren = node.children.length > 0 || childrenText.length > 0 || !!childrenBinding
  const voidElement = ['input', 'img'].includes(tag)

  if (voidElement) return indent(`<${tag}${propCode} />`, level)
  if (!hasChildren) return indent(`<${tag}${propCode} />`, level)

  const nested = node.children
    .map((child) => nodeToCode(child, level + 1, itemVariable, formScope))
    .join('\n')
  // Static text is emitted through the ref override so `setText` reaches it: a
  // spread `children` prop loses to JSX children, which is what a label is.
  const staticText = isRefControlled(node)
    ? `${refPropsExpression(node.ref as string)}.children ?? ${staticValueExpression(childrenText)}`
    : staticValueExpression(childrenText)
  const text = childrenBinding
    ? indent(`{${childrenBinding}}`, level + 1)
    : childrenText
      ? indent(`{${staticText}}`, level + 1)
      : ''
  const body = [text, nested].filter(Boolean).join('\n')
  return `${indent(`<${tag}${propCode}>`, level)}\n${body}\n${indent(`</${tag}>`, level)}`
}

/** Every script of the document, so ref usage can be detected before emitting. */
const collectDesignerScripts = (document: DesignerDocument) => {
  const scripts: string[] = [document.lifecycle?.onMount || '']
  const visit = (nodes: DesignerNode[]) =>
    nodes.forEach((node) => {
      Object.values(node.events || {}).forEach((script) => scripts.push(script || ''))
      visit(node.children || [])
    })
  visit(document.nodes)
  return scripts.join('\n')
}

interface RefTarget {
  node: DesignerNode
  /** Reads the node's current value, whatever holds it. */
  getExpression: string
  /** Statement that writes a new value back to that same holder. */
  setStatement: string
  extras: string[]
}

/**
 * `refs.<name>` entry of a node: the value accessor is wired to whichever state
 * actually owns the value — the enclosing SqlDataSource record, the node's own
 * runtime state, or the ref override store for a component that has neither.
 */
const refTargetFor = (
  node: DesignerNode,
  formField: ReturnType<typeof getFormScopeField>,
  runtimeState: RuntimeStateSpec | null,
): RefTarget => {
  const ref = node.ref as string
  const extras: string[] = []
  if (isSqlDataSourceNode(node.type)) {
    const names = sqlIdentifiers(node)
    extras.push(
      `      getRecord: () => ${names.record}`,
      `      setRecord: (record) => ${names.setRecord}(record || {})`,
      `      getField: (path) => getByPath(${names.record}, path)`,
      `      setField: (path, value) => ${names.setField}(path, value)`,
      // A patch is the readable way to write several columns at once; each write
      // still goes through setField so onFieldChange fires for every column.
      `      setFields: (patch) => Object.entries(patch || {}).forEach(([path, value]) => ${names.setField}(path, value))`,
      `      clearFields: (...paths) => paths.flat().forEach((path) => ${names.setField}(path, null))`,
      `      getOriginal: () => ${names.original}`,
      `      getChanges: () => toSqlChanges(${names.original}, ${names.record}, ${names.key})`,
      `      hasChanges: () => Object.keys(toSqlChanges(${names.original}, ${names.record}, ${names.key})).filter((column) => column.toLowerCase() !== String(${names.key}).toLowerCase()).length > 0`,
      `      getKey: () => readSqlField(${names.record}, ${names.key})`,
      `      getKeyField: () => ${names.key}`,
      `      getRows: () => ${names.rows}`,
      `      getRowCount: () => ${names.rows}.length`,
      `      getIndex: () => ${names.index}`,
      `      getMode: () => ${names.mode}`,
      `      isNew: () => ${names.mode} === "new"`,
      `      isBusy: () => ${names.busy}`,
      `      getError: () => ${names.error}`,
      `      setError: (message) => ${names.setError}(message == null ? "" : String(message))`,
      `      goToRow: (index) => ${names.setIndex}(Number(index) || 0)`,
      `      nextRow: () => ${names.next}()`,
      `      prevRow: () => ${names.previous}()`,
      `      firstRow: () => ${names.setIndex}(0)`,
      `      lastRow: () => ${names.setIndex}(Math.max(0, ${names.rows}.length - 1))`,
      `      reload: () => ${names.refresh}()`,
      `      newRecord: () => ${names.create}()`,
      `      save: () => ${names.save}()`,
      `      remove: () => ${names.remove}()`,
    )
    return {
      node,
      getExpression: names.record,
      setStatement: `${names.setRecord}(value)`,
      extras,
    }
  }
  const valueProperty =
    'checked' in node.props ? 'checked' : 'value' in node.props ? 'value' : 'children'
  const base = formField
    ? {
        getExpression: `getByPath(data_${safeIdentifier(formField.sourceId)}, ${JSON.stringify(formField.path)})`,
        setStatement: `${formField.setterName}(${JSON.stringify(formField.path)}, value)`,
      }
    : runtimeState
      ? {
          getExpression: runtimeState.stateName,
          setStatement: `${runtimeState.setterName}(value)`,
        }
      : {
          getExpression: `${refPropsExpression(ref)}.${valueProperty} ?? ${staticValueExpression(node.props[valueProperty])}`,
          setStatement: `patchDesignerRef(${JSON.stringify(ref)}, { props: { ${valueProperty}: value } })`,
        }

  // Select/AutoComplete/Menu ekranda yalnızca Label gösterir, ama seçenek nesnesi
  // kaynak satırın bütün sütunlarını taşır. Bu erişimciler sayesinde bir script
  // görünmeyen sütunları okuyup başka bir komponente ya da kayda yazabilir.
  if (isDesignerOptionComponent(node.type)) {
    const optionsExpression = optionCollectionExpression(node)
    const selected = `findDesignerOption(${optionsExpression}, ${base.getExpression})`
    const columns = getDesignerBindingColumns(node.bindings?.[getDesignerCollectionProperty(node.type)])
    extras.push(
      `      getOptions: () => ${optionsExpression}`,
      `      getSelectedOption: () => ${selected}`,
      `      getColumn: (path) => readDesignerOptionColumn(${selected}, path)`,
      `      getLabel: () => readDesignerOptionColumn(${selected}, "label") ?? ""`,
      // Tasarımda bildirilen ek sütunlar; bir script hangi sütunların garanti
      // altında olduğunu buradan öğrenebilir.
      `      getColumnNames: () => ${JSON.stringify(columns)}`,
    )
  }

  return { node, ...base, extras }
}

/**
 * The `refs` object handed to every event script and to `onMount`. Overrides are
 * kept in one state map keyed by ref name, so a script can change any prop of any
 * other component without that component needing a hook of its own.
 */
const refRuntimeCode = (targets: RefTarget[]) => {
  const entries = targets
    .map((target) => {
      const ref = target.node.ref as string
      const key = JSON.stringify(ref)
      const disabledProperty = JSON.stringify(getDisabledProperty(target.node.type))
      return `    ${key}: {
      name: ${key},
      type: ${JSON.stringify(target.node.type)},
      getValue: () => ${target.getExpression},
      setValue: (value) => { ${target.setStatement} },
      getProps: () => designerRefProps(${key}),
      setProps: (patch) => patchDesignerRef(${key}, { props: patch || {} }),
      setProp: (property, value) => patchDesignerRef(${key}, { props: { [property]: value } }),
      isVisible: () => !designerRefHidden(${key}),
      setVisible: (visible) => patchDesignerRef(${key}, { hidden: visible === false }),
      show: () => patchDesignerRef(${key}, { hidden: false }),
      hide: () => patchDesignerRef(${key}, { hidden: true }),
      isEnabled: () => (designerRefProps(${key})[${disabledProperty}] ?? ${JSON.stringify(Boolean(target.node.props[getDisabledProperty(target.node.type)]))}) !== true,
      setEnabled: (enabled) => patchDesignerRef(${key}, { props: { [${disabledProperty}]: enabled === false } }),
      setReadOnly: (readOnly) => patchDesignerRef(${key}, { props: { readOnly: readOnly !== false } }),
      setText: (text) => patchDesignerRef(${key}, { props: { children: text } }),
      reset: () => patchDesignerRef(${key}, { props: null, hidden: false }),${
        target.extras.length ? `\n${target.extras.join(',\n')},` : ''
      }
    }`
    })
    .join(',\n')

  // Only emitted when an option component is actually addressable by ref.
  const optionHelpers = targets.some((target) => isDesignerOptionComponent(target.node.type))
    ? `  // Seçili option nesnesi: bir Select değeri kimi zaman option'ın kendisi, kimi
  // zaman kayda yazılan ham value olur; ikisi de aynı nesneye çözülür.
  const findDesignerOption = (options, value) => {
    const list = Array.isArray(options) ? options : []
    if (Array.isArray(value)) return value.map((item) => findDesignerOption(list, item)).filter(Boolean)
    if (value && typeof value === "object") return value
    return list.find((option) => option?.value === value)
      ?? list.find((option) => String(option?.value ?? "") === String(value ?? ""))
      ?? null
  }
  const readDesignerOptionColumn = (option, path) => {
    if (Array.isArray(option)) return option.map((item) => readDesignerOptionColumn(item, path))
    return String(path || "").split(".").filter(Boolean).reduce((current, key) => current?.[key], option)
  }
`
    : ''

  return `${optionHelpers}  // Component references. Every node on the canvas is addressable by its ref,
  // so an event script can read or change another component without prop drilling.
  const [designerRefState, setDesignerRefState] = React.useState({})
  const designerRefProps = (name) => designerRefState[name]?.props || {}
  const designerRefHidden = (name) => Boolean(designerRefState[name]?.hidden)
  const patchDesignerRef = (name, patch) => setDesignerRefState((current) => ({
    ...current,
    [name]: {
      ...current[name],
      ...patch,
      // \`props: null\` resets the overrides; anything else is merged on top.
      props: patch.props === null ? {} : { ...(current[name]?.props || {}), ...(patch.props || {}) },
    },
  }))
  const refs = {
${entries}
  }`
}

/**
 * `api` and `notify`, the two helpers an event script needs to do something that
 * is not just moving values between components. `apiService`, `toast` and
 * `Notification` are already in the compiled component's scope, so this is only
 * about giving the scripts a small, obvious surface over them.
 */
const SCRIPT_API_CODE = `  const api = {
    get: (url, params) => apiService.fetchData({ url, method: "GET", params }).then((response) => response.data),
    post: (url, data, params) => apiService.fetchData({ url, method: "POST", data, params }).then((response) => response.data),
    put: (url, data, params) => apiService.fetchData({ url, method: "PUT", data, params }).then((response) => response.data),
    patch: (url, data, params) => apiService.fetchData({ url, method: "PATCH", data, params }).then((response) => response.data),
    delete: (url, params) => apiService.fetchData({ url, method: "DELETE", params }).then((response) => response.data),
    remove: (url, params) => apiService.fetchData({ url, method: "DELETE", params }).then((response) => response.data),
    request: (config) => apiService.fetchData(config).then((response) => response.data),
    errorMessage: (error) => error?.response?.data?.error?.message || error?.response?.data?.message || error?.message || "İşlem tamamlanamadı.",
  }`

const SCRIPT_NOTIFY_CODE = `  const notify = (message, type = "info") => toast.push(
    <Notification type={type} duration={2500}>{typeof message === "string" ? message : JSON.stringify(message)}</Notification>,
    { placement: "bottom-end" },
  )`

export const generateDesignerCode = (name: string, document: DesignerDocument) => {
  const componentName = safeIdentifier(name || 'VisualComponent')
  const scripts = collectDesignerScripts(document)
  // Only pages whose scripts address a ref pay for the ref runtime.
  refRuntimeEnabled = /\brefs\b/.test(scripts)
  const scriptHelpers = [
    /\bapi\b/.test(scripts) ? SCRIPT_API_CODE : '',
    /\bnotify\b/.test(scripts) ? SCRIPT_NOTIFY_CODE : '',
  ]
    .filter(Boolean)
    .join('\n\n')
  const refTargets: RefTarget[] = []
  const handlers: string[] = []
  const runtimeStateHooks: string[] = []
  let hasSelect = false
  let hasDataTable = false
  let hasDropdown = false
  let hasSelectComponent = false
  let hasDatePicker = false
  let hasTabs = false
  const sqlDataSourceNodes: DesignerNode[] = []
  /** Platform views carrying their own filters; they get a params hook each. */
  const platformFilterNodes: DesignerNode[] = []
  /** Sources loaded by a SqlDataSource; their own mount fetch would duplicate it. */
  const sqlManagedSelectSourceIds = new Set<string>()

  const visit = (nodes: DesignerNode[], formScope?: FormScope) => {
    nodes.forEach((node) => {
      if (isDesignerOptionComponent(node.type)) hasSelect = true
      if (node.type === 'Select') hasSelectComponent = true
      if (node.type === 'Dropdown') hasDropdown = true
      if (node.type === 'Grid') hasDataTable = true
      if (node.type === 'Tabs') hasTabs = true
      if (isDesignerDateComponent(node.type)) hasDatePicker = true
      if (node.kind === 'platform' && getDesignerNodeFilters(node).length) {
        platformFilterNodes.push(node)
      }
      if (isSqlDataSourceNode(node.type)) {
        sqlDataSourceNodes.push(node)
        const selectId = getSqlDataSourceEndpointId(node, 'selectEndpoint')
        if (selectId) sqlManagedSelectSourceIds.add(selectId)
      }
      const formField = getFormScopeField(node, formScope)
      const runtimeState = getRuntimeStateSpec(node)
      if (refRuntimeEnabled && node.ref) {
        refTargets.push(refTargetFor(node, formField, runtimeState))
      }
      if (runtimeState) {
        // Date pickers hold a Date in state but an ISO string in the document.
        const initialExpression = isDesignerDateProperty(node.type, runtimeState.propertyName)
          ? `toDesignerDate(${JSON.stringify(runtimeState.initialValue ?? null)}, ${isDesignerDateOnlyComponent(node.type)})`
          : JSON.stringify(runtimeState.initialValue)
        runtimeStateHooks.push(
          `  const [${runtimeState.stateName}, ${runtimeState.setterName}] = React.useState(${initialExpression})`,
        )
      }
      // A SqlDataSource event is not a React prop: it is called by the container's
      // own runtime with a single payload object, and always awaited so a script
      // can veto a command or finish an API call before the save continues.
      if (isSqlDataSourceNode(node.type)) {
        getSqlDataSourceScriptedEvents(node).forEach((event) => {
          const script = node.events[event.name].trim()
          handlers.push(
            `  const handle_${safeIdentifier(node.id)}_${event.name} = async (event) => {\n${indent(script, 2)}\n  }`,
          )
        })
        visit(node.children, { sourceId: node.id, setterName: sqlIdentifiers(node).setField })
        return
      }
      const eventNames = new Set(
        Object.entries(node.events)
          .filter(([, script]) => script.trim())
          .map(([eventName]) => eventName),
      )
      if (runtimeState) eventNames.add(runtimeState.eventName)
      if (formField) eventNames.add(formField.eventName)
      eventNames.forEach((eventName) => {
        const script = node.events[eventName]?.trim() || ''
        // A form scoped field replaces the local state update: the edit belongs
        // to the SqlDataSource record, which is what Save posts back.
        const formUpdate =
          formField?.eventName === eventName
            ? `${formField.setterName}(${JSON.stringify(formField.path)}, ${
                node.type === 'Select'
                  ? 'Array.isArray(valueOrEvent) ? valueOrEvent.map((option) => option?.value ?? option) : (valueOrEvent?.value ?? null)'
                  : formField.propertyName === 'checked'
                    ? 'typeof originalEvent === "object" && originalEvent?.target ? Boolean(originalEvent.target.checked) : typeof valueOrEvent === "object" && valueOrEvent?.target ? Boolean(valueOrEvent.target.checked) : Boolean(valueOrEvent)'
                    : isDesignerDateComponent(node.type)
                      ? `fromDesignerDate(valueOrEvent ?? null, ${isDesignerDateOnlyComponent(node.type)})`
                      : node.type === 'AutoComplete'
                        ? 'valueOrEvent ?? ""'
                        : 'valueOrEvent?.target?.value ?? valueOrEvent'
              })`
            : ''
        const stateUpdate =
          formUpdate ||
          (runtimeState?.eventName === eventName
            ? node.type === 'Select'
              ? `${runtimeState.setterName}(valueOrEvent)`
              : node.type === 'AutoComplete'
                ? `${runtimeState.setterName}(valueOrEvent ?? "")`
                : node.type === 'Menu'
                  ? `${runtimeState.setterName}([String(valueOrEvent ?? "")])`
                  : node.type === 'Tabs'
                    ? `${runtimeState.setterName}(String(valueOrEvent ?? ""))`
                    : node.type === 'Dropdown'
                      ? `${runtimeState.setterName}(String(valueOrEvent ?? ""))`
                      : node.type === 'Pagination'
                        ? `${runtimeState.setterName}(Number(valueOrEvent) || 1)`
                        : node.type === 'Steps' || node.type === 'ImageViewer'
                          ? `${runtimeState.setterName}(Number(valueOrEvent) || 0)`
                          : node.type === 'Upload'
                            ? `${runtimeState.setterName}(Array.isArray(originalEvent) ? originalEvent : [])`
                            : runtimeState.propertyName === 'checked'
                              ? `${runtimeState.setterName}(typeof originalEvent === "object" && originalEvent?.target ? Boolean(originalEvent.target.checked) : typeof valueOrEvent === "object" && valueOrEvent?.target ? Boolean(valueOrEvent.target.checked) : Boolean(valueOrEvent))`
                              : node.type === 'Input' || node.kind === 'html'
                                ? `${runtimeState.setterName}(valueOrEvent?.target?.value ?? valueOrEvent)`
                                : `${runtimeState.setterName}(valueOrEvent)`
            : '')
        const eventDeclaration =
          node.type === 'Checkbox' && eventName === 'onChange'
            ? '    const event = { checked: Boolean(valueOrEvent), originalEvent, target: originalEvent?.target }'
            : '    const event = valueOrEvent'
        // A script that awaits an API call needs an async handler, otherwise the
        // `await` is a syntax error the user only finds out about at compile time.
        const asyncPrefix = usesAwait(script) ? 'async ' : ''
        handlers.push(
          `  const handle_${safeIdentifier(node.id)}_${eventName} = ${asyncPrefix}(valueOrEvent, originalEvent) => {\n${stateUpdate ? `    ${stateUpdate}\n` : ''}${eventDeclaration}${script ? `\n${indent(script, 2)}` : ''}\n  }`,
        )
      })
      visit(
        node.children,
        isSqlDataSourceNode(node.type)
          ? { sourceId: node.id, setterName: sqlIdentifiers(node).setField }
          : formScope,
      )
    })
  }
  visit(document.nodes)

  const dataSources = document.dataSources || []
  // Ref → record state variable of every SqlDataSource on the page. A `record`
  // filter addresses its master through this map, so a detail source can be
  // filtered by the row the container currently shows.
  const sqlRecordByRef = new Map<string, string>(
    sqlDataSourceNodes
      .filter((node) => node.ref)
      .map((node) => [String(node.ref), sqlIdentifiers(node).record] as const),
  )
  const hasDataSourceFilters = dataSources.some(
    (source) => getDesignerDataSourceFilters(source).length > 0,
  )
  const hasFilters = hasDataSourceFilters || platformFilterNodes.length > 0
  const selectHelpers = hasSelect
    ? `  const toSelectOptions = (value, labelPath = "", valuePath = "") => {
    if (!Array.isArray(value)) return []
    return value.map((item, index) => {
      if (item === null || typeof item !== "object" || Array.isArray(item)) return { label: String(item ?? ""), value: item ?? index }
      const primitiveKeys = Object.keys(item).filter((key) => item[key] === null || ["string", "number", "boolean"].includes(typeof item[key]))
      const labelKey = ["label", "children", "name", "title", "text", "description"].find((key) => item[key] !== undefined)
      const valueKey = ["value", "eventKey", "id", "code", "key"].find((key) => item[key] !== undefined)
      const optionLabel = labelPath ? getByPath(item, labelPath) : item[labelKey ?? primitiveKeys[0]]
      const optionValue = valuePath ? getByPath(item, valuePath) : item[valueKey ?? primitiveKeys[1] ?? primitiveKeys[0]]
      return { ...item, label: String(optionLabel ?? \`Seçenek \${index + 1}\`), value: optionValue ?? index }
    })
  }`
    : ''
  // A bound Select receives a raw column value, but react-select is controlled by
  // the option object itself.
  const selectValueHelpers = hasSelectComponent
    ? `  const toSelectValue = (options, value, isMulti) => {
    if (isMulti) return options.filter((option) => Array.isArray(value) && value.includes(option.value))
    return options.find((option) => option.value === value) ?? null
  }`
    : ''
  // Dropdown paints its toggle from `title`; `activeKey` only marks the item
  // inside the closed menu, so the label of the active option is resolved here.
  const dropdownHelpers = hasDropdown
    ? `  const toDropdownTitle = (options, activeKey, fallbackTitle) => {
    const key = activeKey === undefined || activeKey === null ? "" : String(activeKey)
    const selected = key ? options.find((option) => String(option?.value ?? "") === key) : undefined
    if (selected) return String(selected.label ?? selected.value ?? key)
    return String(fallbackTitle ?? "") || ${JSON.stringify(DESIGNER_DROPDOWN_PLACEHOLDER)}
  }`
    : ''
  // Falls back to the first tab while an endpoint driven tab list is still empty
  // or when the stored value no longer exists.
  const tabHelpers = hasTabs
    ? `  const toTabValue = (options, value) => {
    const key = value === undefined || value === null ? "" : String(value)
    if (key && options.some((option) => String(option?.value ?? "") === key)) return key
    return options.length ? String(options[0]?.value ?? "") : ""
  }`
    : ''
  // Grid cells print raw endpoint columns, so dates and decimals are localised
  // here — the culture is published on `<html lang>` because a runtime compiled
  // component has neither hooks nor imports to reach the store.
  const localeHelpers = hasDataTable
    ? `  const localeCulture = () => (typeof document !== "undefined" && document.documentElement.lang) || "en"
  const localeDateOptions = { year: "numeric", month: "2-digit", day: "2-digit" }
  const localeTimeOptions = { year: "numeric", month: "2-digit", day: "2-digit", hour: "2-digit", minute: "2-digit" }
  const localeIsoPattern = /^(\\d{4})-(\\d{2})-(\\d{2})(?:[T ](\\d{2}):(\\d{2})(?::(\\d{2})(?:\\.\\d+)?)?(Z|[+-]\\d{2}:?\\d{2})?)?$/
  const formatLocaleValue = (value) => {
    if (value === null || value === undefined) return ""
    const culture = localeCulture()
    if (typeof value === "number") {
      if (!Number.isFinite(value)) return String(value)
      return new Intl.NumberFormat(culture, { useGrouping: false, maximumFractionDigits: 20 }).format(value)
    }
    if (value instanceof Date) {
      return Number.isNaN(value.getTime()) ? "" : new Intl.DateTimeFormat(culture, localeTimeOptions).format(value)
    }
    if (typeof value !== "string") return String(value)
    const parts = localeIsoPattern.exec(value.trim())
    if (!parts) return value
    const parsed = new Date(value)
    if (Number.isNaN(parsed.getTime())) return value
    if (parts[4] === undefined) {
      const day = new Date(Number(parts[1]), Number(parts[2]) - 1, Number(parts[3]))
      return new Intl.DateTimeFormat(culture, localeDateOptions).format(day)
    }
    return new Intl.DateTimeFormat(culture, localeTimeOptions).format(parsed)
  }`
    : ''
  // Pickers check `instanceof Date`, but the document only stores ISO strings.
  // Both directions stay on the local wall clock: a date column carries no
  // timezone, so converting through UTC would move 29/07 to 28/07.
  const dateHelpers = hasDatePicker
    ? `  const sqlPad = (value) => String(value).padStart(2, "0")
  const isoDateTime = /^(\\d{4})-(\\d{2})-(\\d{2})(?:[T ](\\d{2}):(\\d{2})(?::(\\d{2}))?)?/
  const toDesignerDate = (value, dateOnly) => {
    if (Array.isArray(value)) return value.map((entry) => toDesignerDate(entry, dateOnly))
    if (value instanceof Date) return Number.isNaN(value.getTime()) ? null : value
    if (typeof value !== "string" || !value.trim()) return null
    const parts = isoDateTime.exec(value.trim())
    const midnight = parts && dateOnly && !Number(parts[4]) && !Number(parts[5]) && !Number(parts[6])
    if (parts && (parts[4] === undefined || midnight)) {
      return new Date(Number(parts[1]), Number(parts[2]) - 1, Number(parts[3]))
    }
    const parsed = new Date(value)
    return Number.isNaN(parsed.getTime()) ? null : parsed
  }
  const fromDesignerDate = (value, dateOnly) => {
    if (Array.isArray(value)) return value.map((entry) => fromDesignerDate(entry, dateOnly))
    if (value instanceof Date) {
      if (Number.isNaN(value.getTime())) return null
      const day = value.getFullYear() + "-" + sqlPad(value.getMonth() + 1) + "-" + sqlPad(value.getDate())
      if (dateOnly) return day
      return day + "T" + sqlPad(value.getHours()) + ":" + sqlPad(value.getMinutes()) + ":" + sqlPad(value.getSeconds())
    }
    return typeof value === "string" && value.trim() ? value : null
  }`
    : ''
  // Select renders its menu inline, so a scrollable/clipped ancestor (Grid, Table,
  // Card) would cut it off. A body portal keeps the menu fully visible.
  const selectMenuHelpers = hasSelectComponent
    ? `  const selectMenuProps = {
    menuPosition: "fixed",
    menuPortalTarget: typeof window === "undefined" ? null : window.document.body,
    styles: { menuPortal: (base) => ({ ...base, zIndex: 60 }) },
  }`
    : ''
  // Shared SqlDataSource runtime: row extraction, record writes, URL parameter
  // binding and the actual Insert/Update/Delete calls.
  const sqlHelpers = sqlDataSourceNodes.length
    ? `  const readSqlField = (record, field) => {
    if (!record || typeof record !== "object" || Array.isArray(record)) return undefined
    if (field in record) return record[field]
    const matched = Object.keys(record).find((key) => key.toLowerCase() === String(field).toLowerCase())
    return matched === undefined ? undefined : record[matched]
  }
  const toSqlRows = (value, collectionPath) => {
    const source = collectionPath ? getByPath(value, collectionPath) : value
    const rows = Array.isArray(source)
      ? source
      : source && typeof source === "object"
        ? (Array.isArray(source.items) ? source.items : [source])
        : []
    return rows.filter((item) => item && typeof item === "object" && !Array.isArray(item))
  }
  const setSqlField = (record, path, value) => {
    const keys = String(path || "").split(".").filter(Boolean)
    if (!keys.length) return record
    const next = { ...(record || {}) }
    let target = next
    for (let index = 0; index < keys.length - 1; index += 1) {
      const child = target[keys[index]]
      target[keys[index]] = child && typeof child === "object" && !Array.isArray(child) ? { ...child } : {}
      target = target[keys[index]]
    }
    target[keys[keys.length - 1]] = value
    return next
  }
  const bindSqlUrl = (url, record, keyField) => {
    let keyBound = false
    const boundUrl = String(url).replace(/\\{([^}]+)\\}|(?<=\\/):([A-Za-z_][A-Za-z0-9_]*)/g, (match, braced, colon) => {
      const name = (braced || colon || "").trim()
      if (!name) return match
      const value = readSqlField(record, name) ?? readSqlField(record, keyField)
      if (value === undefined || value === null || value === "") return match
      if (name.toLowerCase() === String(keyField).toLowerCase()) keyBound = true
      return encodeURIComponent(String(value))
    })
    return { url: boundUrl, keyBound }
  }
  const appendQueryParam = (url, name, value) =>
    url + (url.includes("?") ? "&" : "?") + encodeURIComponent(name) + "=" + encodeURIComponent(value)
  const hasSqlUrlParams = (url) => /\\{[^}]+\\}|(?<=\\/):[A-Za-z_][A-Za-z0-9_]*/.test(String(url))
  const readUrlKey = (source, name) => {
    if (typeof window === "undefined") return ""
    if (source === "query") return new URLSearchParams(window.location.search).get(name) ?? ""
    const segments = window.location.pathname.split("/").filter(Boolean)
    return segments.length ? decodeURIComponent(segments[segments.length - 1]) : ""
  }
  const filterSqlRowsByKey = (rows, keyField, keyValue) => {
    if (!keyValue) return rows
    const matched = rows.filter((row) => String(readSqlField(row, keyField) ?? "") === String(keyValue))
    // No match means the endpoint already filtered server side, or the key column
    // is named differently — keeping the rows beats showing an empty form.
    return matched.length ? matched : rows
  }
  // Update payload: only the columns the user actually edited, plus the key.
  const toSqlChanges = (original, current, keyField) => {
    const changes = {}
    const isSame = (left, right) => JSON.stringify(left ?? null) === JSON.stringify(right ?? null)
    Object.keys(current || {}).forEach((column) => {
      if (!isSame(original ? original[column] : undefined, current[column])) changes[column] = current[column]
    })
    const keyColumn = Object.keys(current || {}).find((column) => column.toLowerCase() === String(keyField).toLowerCase())
    if (keyColumn !== undefined && changes[keyColumn] === undefined) changes[keyColumn] = current[keyColumn]
    return changes
  }
  const callSqlEndpoint = (target, record, keyField, payload) => {
    // The URL is always bound from the full record: a placeholder may reference a
    // column that the update payload does not carry.
    const bound = bindSqlUrl(target.url, record, keyField)
    const request = { url: bound.url, method: target.method }
    if (target.method === "POST" || target.method === "PUT") request.data = payload === undefined ? record : payload
    const keyValue = readSqlField(record, keyField)
    const hasKey = keyValue !== undefined && keyValue !== null && keyValue !== ""
    // The key still has to reach the endpoint when the URL carries no placeholder.
    if (!bound.keyBound && hasKey && target.method !== "POST") request.params = { [keyField]: keyValue }
    return apiService.fetchData(request)
  }
  // A new record starts at the top of the form: the first enabled editor takes the
  // cursor, so a Yeni click is immediately followed by typing.
  const focusFirstSqlField = (host) => {
    if (typeof window === "undefined") return
    window.requestAnimationFrame(() => {
      const field = host.current?.querySelector("input:not([type='hidden']):not([disabled]):not([readonly]), textarea:not([disabled]):not([readonly]), select:not([disabled])")
      if (!field) return
      field.focus()
      if (typeof field.select === "function") field.select()
    })
  }
  // Defaults declared on the bound children; only a new record starts from them.
  const buildSqlDefaults = (fields) => fields.reduce((record, field) => setSqlField(record, field.path, resolveSqlDefault(field)), {})
  const resolveSqlDefault = (field) => {
    if (field.token !== "today" && field.token !== "now") return field.value
    const now = new Date()
    const pad = (value) => String(value).padStart(2, "0")
    const day = now.getFullYear() + "-" + pad(now.getMonth() + 1) + "-" + pad(now.getDate())
    if (field.token === "today" || field.dateOnly) return day
    return day + "T" + pad(now.getHours()) + ":" + pad(now.getMinutes()) + ":" + pad(now.getSeconds())
  }
  const toSqlErrorMessage = (error) => error?.response?.data?.error?.message || error?.response?.data?.message || error?.message || "İşlem tamamlanamadı."`
    : ''
  const filterHelpers = hasFilters
    ? `  // Value of a filter that reads the page URL: a query string parameter, or a
  // path segment — the one after a segment named like the parameter, otherwise
  // the last one, which is the /orders/{id} detail page shape.
  const readDesignerUrlValue = (kind, name) => {
    if (typeof window === "undefined") return ""
    if (kind === "query") return new URLSearchParams(window.location.search).get(name) ?? ""
    const segments = window.location.pathname.split("/").filter(Boolean)
    if (!segments.length) return ""
    const index = name ? segments.findIndex((segment) => segment.toLowerCase() === String(name).toLowerCase()) : -1
    if (index >= 0 && index < segments.length - 1) return decodeURIComponent(segments[index + 1])
    return decodeURIComponent(segments[segments.length - 1])
  }
  // Filters are appended as query parameters: \`Column\` for an equality and
  // \`Column.operator\` for anything else, which is what the endpoint parses.
  // Returns "" when a required filter has no value yet — the caller must skip the
  // request instead of loading the unfiltered collection.
  const buildFilteredUrl = (url, filters) => {
    const parts = []
    for (const filter of filters || []) {
      const value = filter.value === undefined || filter.value === null ? "" : String(filter.value)
      if (!value) {
        if (filter.required) return ""
        continue
      }
      parts.push(encodeURIComponent(filter.param) + "=" + encodeURIComponent(value))
    }
    if (!parts.length) return url
    return url + (url.includes("?") ? "&" : "?") + parts.join("&")
  }`
    : ''
  // A platform view is filtered through the same `filter` expression a list form
  // page carries in its address, so an embedded view needs no change to the list
  // form itself. Returns null when a required filter has no value yet.
  const platformFilterHelpers = platformFilterNodes.length
    ? `  const buildPlatformFilterParams = (filters) => {
    const expressions = []
    for (const filter of filters || []) {
      if (filter.kind === "isnull" || filter.kind === "notnull") {
        expressions.push([filter.field, filter.operator, null])
        continue
      }
      const value = filter.value === undefined || filter.value === null ? "" : String(filter.value)
      if (!value) {
        if (filter.required) return null
        continue
      }
      if (filter.kind === "in") {
        const entries = value.split(",").map((entry) => entry.trim()).filter(Boolean).map((entry) => [filter.field, "=", entry])
        if (!entries.length) continue
        expressions.push(entries.reduce((result, entry) => (result ? [result, "or", entry] : entry), null))
        continue
      }
      expressions.push([filter.field, filter.operator, value])
    }
    const params = new URLSearchParams()
    const merged = expressions.reduce((result, expression) => (result ? [result, "and", expression] : expression), null)
    if (merged) params.set("filter", JSON.stringify(merged))
    return params
  }`
    : ''
  // Declared after the SqlDataSource hooks: a filter may read the record of the
  // container the view sits next to.
  const platformFilterHooks = platformFilterNodes
    .map((node) => {
      const identifier = safeIdentifier(node.id)
      return `  const platformFilters_${identifier} = ${platformFilterEntriesExpression(node, sqlRecordByRef)}
  const platformKey_${identifier} = JSON.stringify(platformFilters_${identifier})
  // The views keep the params object in their own state and write back to it, so
  // it must stay the same object until a filter value actually changes.
  const platformParams_${identifier} = React.useMemo(() => buildPlatformFilterParams(platformFilters_${identifier}), [platformKey_${identifier}])`
    })
    .join('\n\n')
  const sqlHooks = sqlDataSourceNodes
    .map((node) => sqlDataSourceHooks(node, dataSources, sqlRecordByRef))
    .join('\n\n')
  const dataHelpers =
    dataSources.length || hasDataTable || sqlDataSourceNodes.length
      ? `  const getByPath = (value, path) => {
    if (!path) return value
    const readPath = (target, targetPath) => targetPath.split('.').filter(Boolean).reduce((current, key) => current?.[key], target)
    const directValue = readPath(value, path)
    if (directValue !== undefined) return directValue
    if (path.startsWith('result.')) return readPath(value, path.slice('result.'.length))
    return value?.result === undefined ? undefined : readPath(value.result, path)
  }`
      : ''
  // The state of every source is declared before the SqlDataSource hooks, which
  // write through the setters; the fetch effects come after them, because a
  // filtered source may read the record a container owns.
  const dataStateHooks = dataSources
    .map((source) => {
      const identifier = safeIdentifier(source.id)
      // POST/PUT/DELETE sources are only ever invoked by a SqlDataSource command;
      // they hold no readable state and must never be written to.
      if (source.method !== 'GET' || !source.url.trim().startsWith('/api/')) {
        return `  const [data_${identifier}] = React.useState(null)`
      }
      return `  const [data_${identifier}, setData_${identifier}] = React.useState(null)`
    })
    .join('\n')
  const dataFetchHooks = dataSources
    .map((source) => {
      const identifier = safeIdentifier(source.id)
      if (source.method !== 'GET' || !source.url.trim().startsWith('/api/')) return ''
      // A GetById style URL is not fetched on mount — requesting a literal `{id}`
      // is a guaranteed 400 — and neither is a source the owning SqlDataSource
      // loads itself, through the setter declared above.
      if (hasSqlDataSourceUrlParams(source.url) || sqlManagedSelectSourceIds.has(source.id)) {
        return ''
      }
      const entries = filterEntriesExpression(source, sqlRecordByRef)
      // Without filters the source keeps its previous mount-only fetch, byte for
      // byte; with them the effect re-runs whenever a filter value changes.
      if (!entries) {
        return `  React.useEffect(() => {
    let active = true
    apiService.fetchData({ url: ${JSON.stringify(source.url)}, method: 'GET' }).then((response) => {
      if (active) setData_${identifier}(getByPath(response.data, ${JSON.stringify(source.responsePath || '')}))
    }).catch((error) => console.error(${JSON.stringify(`${source.name} endpoint error:`)}, error))
    return () => { active = false }
  }, [])`
      }
      return `  const filters_${identifier} = ${entries}
  const filterKey_${identifier} = JSON.stringify(filters_${identifier})
  React.useEffect(() => {
    const url = buildFilteredUrl(${JSON.stringify(source.url)}, filters_${identifier})
    // An unmet required filter leaves the component empty on purpose.
    if (!url) {
      setData_${identifier}(null)
      return
    }
    let active = true
    apiService.fetchData({ url, method: 'GET' }).then((response) => {
      if (active) setData_${identifier}(getByPath(response.data, ${JSON.stringify(source.responsePath || '')}))
    }).catch((error) => console.error(${JSON.stringify(`${source.name} endpoint error:`)}, error))
    return () => { active = false }
  }, [filterKey_${identifier}])`
    })
    .filter(Boolean)
    .join('\n\n')

  // Declared after the data/SQL/runtime state it reads, and before the handlers
  // and the mount effect that call into it.
  const refRuntime = refTargets.length ? refRuntimeCode(refTargets) : ''
  // An effect callback must not return a promise, so an awaiting onMount is run
  // through an async IIFE instead of being made async itself.
  const mount = document.lifecycle.onMount.trim()
    ? usesAwait(document.lifecycle.onMount)
      ? `  React.useEffect(() => {\n    void (async () => {\n${indent(document.lifecycle.onMount, 3)}\n    })()\n  }, [])`
      : `  React.useEffect(() => {\n${indent(document.lifecycle.onMount, 2)}\n  }, [])`
    : ''
  const body = document.nodes.map((node) => nodeToCode(node, 3)).join('\n')

  const designerBackup = encodeURIComponent(JSON.stringify(document))

  return `/*__SOZSOFT_VISUAL_DESIGNER__${designerBackup}__*/\nconst ${componentName} = () => {\n${[dataHelpers, scriptHelpers,selectHelpers, dropdownHelpers, selectValueHelpers, selectMenuHelpers, localeHelpers, dateHelpers, tabHelpers, sqlHelpers, filterHelpers, platformFilterHelpers, dataStateHooks, sqlHooks, dataFetchHooks, platformFilterHooks, ...runtimeStateHooks, refRuntime, mount, ...handlers].filter(Boolean).join('\n\n')}\n\n  return (\n    <>\n${body}\n    </>\n  )\n}\n\nexport default ${componentName}\n`
}