using System;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using Sozsoft.Platform.EntityFrameworkCore;
using Volo.Abp.Data;
using Volo.Abp.DependencyInjection;
using Volo.Abp.EntityFrameworkCore;
using static Sozsoft.Settings.SettingsConsts;

namespace Sozsoft.Platform.Data.Seeds;

/// <summary>
/// SqlTableDesigner üzerinden deploy edilen tabloları Seeds/SqlData/*.sql dosyalarından okuyarak veritabanına uygular.
/// Her dosya, tek bir tabloya (veya ilgili ALTER/INDEX script'lerine) ait IF OBJECT_ID kontrolü içeren T-SQL batch'leri içermelidir.
/// Veritabanı silinip yeniden oluşturulduğunda bu seeder tüm tablo scriptlerini yeniden çalıştırır.
/// </summary>
public class SqlDataSeeder : IDataSeedContributor, ITransientDependency
{
    private readonly IDbContextProvider<PlatformDbContext> _dbContextProvider;
    private readonly ILogger<SqlDataSeeder> _logger;

    public SqlDataSeeder(
        IDbContextProvider<PlatformDbContext> dbContextProvider,
        ILogger<SqlDataSeeder> logger)
    {
        _dbContextProvider = dbContextProvider;
        _logger = logger;
    }

    public async Task SeedAsync(DataSeedContext context)
    {
        var dataDirectoryName = GetDataDirectoryName();
        var sqlDataPath = Path.Combine(Directory.GetCurrentDirectory(), "Seeds", dataDirectoryName);
        if (!Directory.Exists(sqlDataPath))
        {
            _logger.LogInformation("Seeds/{DirectoryName} directory not found, skipping SqlDataSeeder.", dataDirectoryName);
            return;
        }

        var isHostSeed = context.TenantId == null;
        var sqlFiles = GetSqlFiles(sqlDataPath, isHostSeed);

        if (sqlFiles.Length == 0)
        {
            _logger.LogInformation("No .sql files found in Seeds/{DirectoryName} directory, skipping SqlDataSeeder.", dataDirectoryName);
            return;
        }

        _logger.LogInformation(
            "SqlDataSeeder started for provider '{Provider}' from Seeds/{DirectoryName}. Seed target: {SeedTarget}. {Count} file(s) to be processed.",
            DefaultDatabaseProvider,
            dataDirectoryName,
            isHostSeed ? "Host" : "Tenant",
            sqlFiles.Length);

        var dbContext = await _dbContextProvider.GetDbContextAsync();

        foreach (var filePath in sqlFiles)
        {
            var fileName = Path.GetFileName(filePath);
            try
            {
                var sqlContent = await File.ReadAllTextAsync(filePath);

                // Split by GO batch separators (SQL Server convention)
                var batches = Regex.Split(sqlContent, @"^\s*GO\s*$",
                    RegexOptions.Multiline | RegexOptions.IgnoreCase);

                foreach (var batch in batches)
                {
                    var sql = batch.Trim();
                    if (string.IsNullOrWhiteSpace(sql))
                        continue;

                    try
                    {
                        var (action, objectName, objectType) = ExtractSqlInfo(sql);

                        if (!string.IsNullOrEmpty(objectName))
                            _logger.LogInformation("Executing: {Action} {ObjectType} {ObjectName}", action, objectType, objectName);
                        else
                            _logger.LogInformation("Executing SQL batch from {FileName}", fileName);

                        await dbContext.Database.ExecuteSqlRawAsync(sql);
                    }
                    catch (Exception ex)
                    {
                        _logger.LogError(ex, "SQL batch failed in file {FileName}: {Sql}", fileName, sql);
                        throw;
                    }
                }
            }
            catch (Exception ex) when (ex is not InvalidOperationException)
            {
                _logger.LogError(ex, "Failed to process SQL seed file: {FileName}", fileName);
                throw;
            }
        }

        _logger.LogInformation("SqlDataSeeder completed. {Count} file(s) processed.", sqlFiles.Length);
    }

    private static string GetDataDirectoryName()
    {
        return DefaultDatabaseProvider == DatabaseProvider.PostgreSql
            ? "PostgresData"
            : "SqlData";
    }

    private static string[] GetSqlFiles(string dataDirectoryPath, bool includeHostData)
    {
        var sqlFiles = Directory.GetFiles(dataDirectoryPath, "*.sql")
            .OrderBy(f => Path.GetFileName(f))
            .ToList();

        if (includeHostData)
        {
            var hostDataPath = Path.Combine(dataDirectoryPath, "HostData");
            if (Directory.Exists(hostDataPath))
            {
                sqlFiles.AddRange(Directory.GetFiles(hostDataPath, "*.sql")
                    .OrderBy(f => Path.GetFileName(f)));
            }
        }

        return sqlFiles.ToArray();
    }

    private static (string Action, string? ObjectName, string? ObjectType) ExtractSqlInfo(string sql)
    {
        var patterns = new[]
        {
            (@"CREATE\s+TABLE\s+(\[?\w+\]?\.?\[?\w+\]?)", "CREATE", "TABLE"),
            (@"CREATE\s+VIEW\s+(\[?\w+\]?\.?\[?\w+\]?)", "CREATE", "VIEW"),
            (@"CREATE\s+PROCEDURE\s+(\[?\w+\]?\.?\[?\w+\]?)", "CREATE", "PROCEDURE"),
            (@"CREATE\s+FUNCTION\s+(\[?\w+\]?\.?\[?\w+\]?)", "CREATE", "FUNCTION"),
            (@"ALTER\s+TABLE\s+(\[?\w+\]?\.?\[?\w+\]?)", "ALTER", "TABLE"),
            (@"ALTER\s+VIEW\s+(\[?\w+\]?\.?\[?\w+\]?)", "ALTER", "VIEW"),
            (@"ALTER\s+PROCEDURE\s+(\[?\w+\]?\.?\[?\w+\]?)", "ALTER", "PROCEDURE"),
            (@"ALTER\s+FUNCTION\s+(\[?\w+\]?\.?\[?\w+\]?)", "ALTER", "FUNCTION"),
            (@"CREATE\s+(UNIQUE\s+)?INDEX\s+(\[?\w+\]?)", "CREATE", "INDEX"),
            (@"CREATE\s+TRIGGER\s+(\[?\w+\]?\.?\[?\w+\]?)", "CREATE", "TRIGGER"),
            (@"DROP\s+TABLE\s+(\[?\w+\]?\.?\[?\w+\]?)", "DROP", "TABLE"),
            (@"DROP\s+VIEW\s+(\[?\w+\]?\.?\[?\w+\]?)", "DROP", "VIEW"),
            (@"DROP\s+PROCEDURE\s+(\[?\w+\]?\.?\[?\w+\]?)", "DROP", "PROCEDURE"),
            (@"DROP\s+FUNCTION\s+(\[?\w+\]?\.?\[?\w+\]?)", "DROP", "FUNCTION"),
        };

        foreach (var (pattern, action, type) in patterns)
        {
            var match = Regex.Match(sql, pattern, RegexOptions.IgnoreCase);
            if (match.Success)
            {
                var captured = match.Groups[match.Groups.Count - 1].Value;
                return (action, captured, type);
            }
        }

        return ("UNKNOWN", null, null);
    }
}