// Type definitions
interface LocalizationResource {
  texts: Record<string, string>
  baseResources: string[]
}

interface LocalizationState {
  resources: Record<string, LocalizationResource>
}

interface LocalizationKey {
  key: string
  defaultValue?: string
}

const getBaseResources = (state: LocalizationState, resourceNames: string[]): Record<string, string> => {
  if (!resourceNames.length) {
    return {}
  }

  // [{}, {}, {}]
  const texts = resourceNames.map((resourceName: string) => {
    const resource = state.resources[resourceName]
    return {
      ...resource.texts,
      ...getBaseResources(state, resource.baseResources),
    }
  })

  return Object.assign({}, ...texts)
}

export const setLocalization = (state: LocalizationState): Record<string, Record<string, string>> => {
  const values: Record<string, Record<string, string>> = {}
  Object.entries(state.resources).forEach(([key, value]) => {
    values[key] = {
      ...value.texts,
      ...getBaseResources(state, value.baseResources),
    }
  })

  return values
}

// 🔑 Interpolation helper
const interpolate = (text: string, params: Record<string, string | number>) => {
  if (!params || typeof params !== 'object') return text

  return Object.entries(params).reduce((acc, [key, value]) => {
    const pattern = new RegExp(`{{\\s*${key}\\s*}}`, 'g')
    return acc.replace(pattern, String(value))
  }, text)
}

export const getLocalization = (
  texts: Record<string, Record<string, string>>,
  defaultResourceName: string | undefined,
  key: string | LocalizationKey,
  params?: Record<string, string | number>
): string => {
  let keyString = ''
  let defaultValue = ''

  if (typeof key === 'string') {
    keyString = key || ''
  } else {
    defaultValue = key.defaultValue || ''
    keyString = key.key
  }

  const keys = keyString.split('::')
  const warn = (message: string) => {
    if (import.meta.env.DEV) console.warn(message)
  }

  if (keys.length < 2) {
    warn('The localization source separator (::) not found.')
    return defaultValue || keyString
  }
  if (!texts) return defaultValue || keys[1]

  const sourceName = keys[0] || defaultResourceName
  const sourceKey = keys[1]

  if (sourceName === '_') {
    return defaultValue || sourceKey
  }

  if (!sourceName) {
    warn('Localization source name is not specified and the defaultResourceName was not defined!')
    return defaultValue || sourceKey
  }

  const source = texts[sourceName]
  if (!source) {
    warn('Could not find localization source: ' + sourceName)
    return defaultValue || sourceKey
  }

  let localization = source[sourceKey]
  if (typeof localization === 'undefined') {
    return defaultValue || sourceKey
  }

  if (typeof localization !== 'string') localization = ''

  // ✅ Interpolation using the helper function
  if (localization && params && typeof params === 'object') {
    localization = interpolate(localization, params)
  }

  return localization || defaultValue || keyString
}