using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;
using Sozsoft.Platform.Entities;
using Volo.Abp.Domain.Repositories;
using Volo.Abp.Domain.Services;
using Volo.Abp.MultiTenancy;

namespace Sozsoft.Mcp.Services;

/// <summary>
/// Sema bilgisinin tek kaynagi: <c>Sas_H_DbTableColumn</c> tablosundaki JSON veri sozlugu.
/// Sozluk kullaniciya gorunen basliklari ve lookup iliskilerini birlikte tasidigi icin canli
/// katalog yerine bu kullanilir — modelin gordugu adlar ekranda gorunen adlarla ayni olur.
/// </summary>
public interface IMcpSchemaDictionary
{
    /// <summary>Sozlugun bulunup bulunmadigi ve ne zaman tazelendigi; yoksa null.</summary>
    Task<McpDictionarySnapshot?> GetSnapshotAsync();

    /// <summary>Sozlukteki listeler; sozluk yoksa bos liste.</summary>
    Task<IReadOnlyList<McpDictionaryListForm>> GetListFormsAsync();

    /// <summary>
    /// Istegin kapsamina dusen sozluk kiraci adi. Sozluk ureten prosedurun
    /// <c>@TenantName</c> parametresiyle ayni degeri tasimasi gerekir.
    /// </summary>
    string ResolveTenantName();

    /// <summary>
    /// Aksan ve buyuk/kucuk harf duyarsiz karsilastirma anahtari; "Musteri" aramasi
    /// "Müşteri" basligini da bulur.
    /// </summary>
    string Normalize(string? value);
}

public class McpSchemaDictionary(
    IRepository<DbTableColumn, Guid> dictionaryRepository,
    ICurrentTenant currentTenant)
    : DomainService, IMcpSchemaDictionary
{
    private static readonly JsonSerializerOptions DictionaryJsonOptions = new()
    {
        PropertyNameCaseInsensitive = true
    };

    private static readonly CultureInfo TurkishCulture = CultureInfo.GetCultureInfo("tr-TR");

    public string ResolveTenantName()
        => currentTenant.Name ?? McpConsts.DefaultDictionaryTenantName;

    public async Task<McpDictionarySnapshot?> GetSnapshotAsync()
    {
        // Tazelik bilgisi icin JsonData (buyuk sozluklerde megabaytlar) okunmaz.
        using (currentTenant.Change(null))
        {
            var query = await ActiveRowsAsync(ResolveTenantName());

            return query
                .Select(row => new McpDictionarySnapshot(
                    row.CacheKey,
                    row.RefreshedAt,
                    row.FormCount,
                    row.FieldCount,
                    row.TenantName,
                    row.DefinitionCultureName,
                    row.UiCultureName))
                .FirstOrDefault();
        }
    }

    public async Task<IReadOnlyList<McpDictionaryListForm>> GetListFormsAsync()
    {
        var json = await GetJsonDataAsync();
        if (string.IsNullOrWhiteSpace(json))
        {
            return [];
        }

        var document = JsonSerializer.Deserialize<DictionaryDocument>(json, DictionaryJsonOptions);

        return document?.ListForms ?? [];
    }

    public string Normalize(string? value)
    {
        if (string.IsNullOrWhiteSpace(value))
        {
            return string.Empty;
        }

        var decomposed = value.ToLower(TurkishCulture).Normalize(NormalizationForm.FormD);
        var builder = new StringBuilder(decomposed.Length);

        foreach (var character in decomposed)
        {
            if (CharUnicodeInfo.GetUnicodeCategory(character) == UnicodeCategory.NonSpacingMark)
            {
                continue;
            }

            builder.Append(character switch
            {
                'ı' => 'i',
                'ğ' => 'g',
                'ş' => 's',
                _ => character
            });
        }

        return builder.ToString();
    }

    private async Task<string?> GetJsonDataAsync()
    {
        // Sozluk host kapsamli bir tabloda tutulur; kiraci ayrimi TenantName kolonundadir.
        using (currentTenant.Change(null))
        {
            var query = await ActiveRowsAsync(ResolveTenantName());

            return query.Select(row => row.JsonData).FirstOrDefault();
        }
    }

    private async Task<IQueryable<DbTableColumn>> ActiveRowsAsync(string tenantName)
    {
        var query = await dictionaryRepository.GetQueryableAsync();

        return query
            .Where(row => row.DictionaryType == McpConsts.DictionaryType
                       && row.IsActive
                       && row.TenantName == tenantName)
            .OrderByDescending(row => row.RefreshedAt);
    }

    /// <summary>Sozluk JSON'unun kok nesnesi.</summary>
    private sealed class DictionaryDocument
    {
        public List<McpDictionaryListForm>? ListForms { get; set; }
    }
}

/// <summary>Sozluk satirinin tazelik bilgisi.</summary>
public sealed record McpDictionarySnapshot(
    string? CacheKey,
    DateTime RefreshedAt,
    int FormCount,
    int FieldCount,
    string? TenantName,
    string? DefinitionCultureName,
    string? UiCultureName);

/// <summary>
/// Sozlukteki bir liste. Alan adlari <c>dbo.Sas_H_ListFormFieldsDictionaryJson</c> prosedurunun
/// urettigi JSON ile birebir ayni olmak zorundadir.
/// </summary>
public class McpDictionaryListForm
{
    public string? ListFormCode { get; set; }
    public string? DisplayName { get; set; }
    public string? Title { get; set; }
    public string? Description { get; set; }
    public string? TableName { get; set; }
    public string? SqlSourceName { get; set; }
    public string? SourceKind { get; set; }
    public string? KeyFieldName { get; set; }
    public string? SearchText { get; set; }
    public List<McpDictionaryField>? Fields { get; set; }
}

/// <summary>Sozlukteki bir sutun.</summary>
public class McpDictionaryField
{
    public string? Field { get; set; }
    public string? DisplayName { get; set; }
    public string? SqlDataType { get; set; }
    public bool IsVisible { get; set; }
    public bool IsBooleanColumn { get; set; }
    public string? LookupTableName { get; set; }
    public string? LookupValueColumn { get; set; }
    public string? LookupDisplayColumn { get; set; }
    public bool IsSensitive { get; set; }
    public bool IsDefaultSelectColumn { get; set; }
}