using Dapper;
using MySqlConnector;
using IBKRTrader.Core.Logging;
using IBKRTrader.Core.Settings;

namespace IBKRTrader.Core.Database;

/// <summary>
/// Zentraler Datenbankzugriff via MySqlConnector + Dapper.
/// Jede Methode öffnet eine eigene Connection (Connection-Pooling via MySqlConnector).
/// </summary>
public class DatabaseService
{
    private readonly SettingsService _settings;
    private readonly LoggingService  _logger;

    public DatabaseService(SettingsService settings, LoggingService logger)
    {
        _settings = settings;
        _logger   = logger;

        // Dapper support for DateOnly
        SqlMapper.AddTypeHandler(new DateOnlyTypeHandler());
    }

    private class DateOnlyTypeHandler : SqlMapper.TypeHandler<DateOnly>
    {
        public override void SetValue(System.Data.IDbDataParameter parameter, DateOnly value)
        {
            parameter.Value = value.ToString("yyyy-MM-dd");
        }

        public override DateOnly Parse(object value)
        {
            if (value is DateTime dt) return DateOnly.FromDateTime(dt);
            if (value is string s && DateOnly.TryParse(s, out var d)) return d;
            return DateOnly.FromDateTime(Convert.ToDateTime(value));
        }
    }


    // ─── Connection ───────────────────────────────────────────────────────────

    public MySqlConnection CreateConnection()
        => new(_settings.Settings.Database.BuildConnectionString());

    public async Task<bool> TestConnectionAsync()
    {
        try
        {
            await using var conn = CreateConnection();
            await conn.OpenAsync();
            _logger.Info("Core", "Datenbankverbindung erfolgreich hergestellt.");
            return true;
        }
        catch (Exception ex)
        {
            _logger.Error("Core", "Datenbankverbindung fehlgeschlagen.", ex);
            return false;
        }
    }

    // ─── Abfragen (Dapper) ────────────────────────────────────────────────────

    public async Task<IEnumerable<T>> QueryAsync<T>(string sql, object? param = null)
    {
        await using var conn = CreateConnection();
        return await conn.QueryAsync<T>(sql, param);
    }

    public async Task<T?> QueryFirstOrDefaultAsync<T>(string sql, object? param = null)
    {
        await using var conn = CreateConnection();
        return await conn.QueryFirstOrDefaultAsync<T>(sql, param);
    }

    public async Task<int> ExecuteAsync(string sql, object? param = null)
    {
        await using var conn = CreateConnection();
        return await conn.ExecuteAsync(sql, param);
    }

    public async Task<T> ExecuteScalarAsync<T>(string sql, object? param = null)
    {
        await using var conn = CreateConnection();
#pragma warning disable CS8603
        return await conn.ExecuteScalarAsync<T>(sql, param);
#pragma warning restore CS8603
    }

    // ─── Worker-Log Hilfsmethoden ─────────────────────────────────────────────

    /// <summary>Legt einen neuen Worker-Log-Eintrag an und gibt die neue ID zurück.</summary>
    public async Task<long> BeginWorkerLogAsync(string workerName, string module)
    {
        const string sql =
            @"INSERT INTO `core_worker_log` (worker_name, module, started_at, status)
              VALUES (@workerName, @module, @now, 'Running');
              SELECT LAST_INSERT_ID();";
        return await ExecuteScalarAsync<long>(sql,
            new { workerName, module, now = DateTime.UtcNow });
    }

    /// <summary>Schließt einen Worker-Log-Eintrag ab (Success oder Error).</summary>
    public async Task EndWorkerLogAsync(long logId, bool success, string? message = null)
    {
        const string sql =
            @"UPDATE `core_worker_log`
              SET finished_at = @now, status = @status, message = @msg
              WHERE id = @id";
        await ExecuteAsync(sql, new
        {
            id     = logId,
            now    = DateTime.UtcNow,
            status = success ? "Success" : "Error",
            msg    = message
        });
    }
}