using System;
using System.Threading.Tasks;
using FinlyticCore.Dtos.Logging;
using FinlyticCore.Models.Settings;
using Microsoft.Extensions.Logging;

namespace FinlyticCore.Services;

/// <summary>
/// Globaler Broadcaster für strukturierte Logs in Echtzeit.
/// </summary>
public static class FinlyticLogBroadcaster
{
    public static Func<LogMessageDto, Task>? OnLogPublished { get; set; }

    public static void Broadcast(LogMessageDto dto)
    {
        if (OnLogPublished != null)
        {
            _ = Task.Run(async () =>
            {
                try
                {
                    await OnLogPublished(dto);
                }
                catch
                {
                    // Ignore broadcast errors to never disrupt execution
                }
            });
        }
    }
}

/// <summary>
/// Bietet kanalbasierte, dynamisch steuerbare Logging-Funktionalitäten über den <see cref="ISettingsService"/>.
/// </summary>
/// <typeparam name="TContextClass">Die aufrufende Klasse (für Log-Kategorien).</typeparam>
public interface IFinlyticLogger<TContextClass>
{
    // --- Debug ---
    Task LogDebugAsync(SettingKey<bool> channelKey, string message, params object[] args);
    Task LogDebugAsync(SettingKey<bool> channelKey, Exception? exception, string message, params object[] args);

    // --- Info ---
    Task LogInfoAsync(SettingKey<bool> channelKey, string message, params object[] args);
    Task LogInfoAsync(SettingKey<bool> channelKey, Exception? exception, string message, params object[] args);

    // --- Warning ---
    Task LogWarningAsync(SettingKey<bool> channelKey, string message, params object[] args);
    Task LogWarningAsync(SettingKey<bool> channelKey, Exception? exception, string message, params object[] args);

    // --- Error ---
    Task LogErrorAsync(SettingKey<bool> channelKey, string message, params object[] args);
    Task LogErrorAsync(SettingKey<bool> channelKey, Exception? exception, string message, params object[] args);

    // --- Trace & Critical ---
    Task LogTraceAsync(SettingKey<bool> channelKey, string message, params object[] args);
    Task LogCriticalAsync(SettingKey<bool> channelKey, Exception? exception, string message, params object[] args);
}

/// <summary>
/// Kanalbasierte Logger-Implementierung, die Einstellungen und Stummschaltungen 
/// in Echtzeit aus dem <see cref="ISettingsService"/> bezieht.
/// </summary>
public class FinlyticLogger<TContextClass> : IFinlyticLogger<TContextClass>
{
    private static readonly string ServiceName = typeof(TContextClass).Assembly.GetName().Name ?? "Finlytic";
    private readonly ILogger<TContextClass> _logger;
    private readonly ISettingsService _settingsService;

    public FinlyticLogger(
        ILogger<TContextClass> logger,
        ISettingsService settingsService)
    {
        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
        _settingsService = settingsService ?? throw new ArgumentNullException(nameof(settingsService));
    }

    private void DispatchBroadcast(SettingKey<bool> channelKey, LogLevel level, string message, Exception? exception, params object[] args)
    {
        try
        {
            string formattedMsg = args != null && args.Length > 0 ? string.Format(message, args) : message;
            FinlyticLogBroadcaster.Broadcast(new LogMessageDto(
                Timestamp: DateTime.UtcNow,
                ServiceName: ServiceName,
                Channel: channelKey.Name,
                Level: level.ToString(),
                Message: formattedMsg,
                Exception: exception?.ToString()
            ));
        }
        catch
        {
            FinlyticLogBroadcaster.Broadcast(new LogMessageDto(
                Timestamp: DateTime.UtcNow,
                ServiceName: ServiceName,
                Channel: channelKey.Name,
                Level: level.ToString(),
                Message: message,
                Exception: exception?.ToString()
            ));
        }
    }

    #region Debug

    public async Task LogDebugAsync(SettingKey<bool> channelKey, string message, params object[] args)
    {
        if (await ShouldLogAsync(channelKey, LogLevel.Debug))
        {
            _logger.LogDebug(message, args);
            DispatchBroadcast(channelKey, LogLevel.Debug, message, null, args);
        }
    }

    public async Task LogDebugAsync(SettingKey<bool> channelKey, Exception? exception, string message, params object[] args)
    {
        if (await ShouldLogAsync(channelKey, LogLevel.Debug))
        {
            if (exception != null)
                _logger.LogDebug(exception, message, args);
            else
                _logger.LogDebug(message, args);
            DispatchBroadcast(channelKey, LogLevel.Debug, message, exception, args);
        }
    }

    #endregion

    #region Info

    public async Task LogInfoAsync(SettingKey<bool> channelKey, string message, params object[] args)
    {
        if (await ShouldLogAsync(channelKey, LogLevel.Information))
        {
            _logger.LogInformation(message, args);
            DispatchBroadcast(channelKey, LogLevel.Information, message, null, args);
        }
    }

    public async Task LogInfoAsync(SettingKey<bool> channelKey, Exception? exception, string message, params object[] args)
    {
        if (await ShouldLogAsync(channelKey, LogLevel.Information))
        {
            if (exception != null)
                _logger.LogInformation(exception, message, args);
            else
                _logger.LogInformation(message, args);
            DispatchBroadcast(channelKey, LogLevel.Information, message, exception, args);
        }
    }

    #endregion

    #region Warning

    public async Task LogWarningAsync(SettingKey<bool> channelKey, string message, params object[] args)
    {
        if (await ShouldLogAsync(channelKey, LogLevel.Warning))
        {
            _logger.LogWarning(message, args);
            DispatchBroadcast(channelKey, LogLevel.Warning, message, null, args);
        }
    }

    public async Task LogWarningAsync(SettingKey<bool> channelKey, Exception? exception, string message, params object[] args)
    {
        if (await ShouldLogAsync(channelKey, LogLevel.Warning))
        {
            if (exception != null)
                _logger.LogWarning(exception, message, args);
            else
                _logger.LogWarning(message, args);
            DispatchBroadcast(channelKey, LogLevel.Warning, message, exception, args);
        }
    }

    #endregion

    #region Error

    public async Task LogErrorAsync(SettingKey<bool> channelKey, string message, params object[] args)
    {
        if (await ShouldLogAsync(channelKey, LogLevel.Error))
        {
            _logger.LogError(message, args);
            DispatchBroadcast(channelKey, LogLevel.Error, message, null, args);
        }
    }

    public async Task LogErrorAsync(SettingKey<bool> channelKey, Exception? exception, string message, params object[] args)
    {
        if (await ShouldLogAsync(channelKey, LogLevel.Error))
        {
            if (exception != null)
                _logger.LogError(exception, message, args);
            else
                _logger.LogError(message, args);
            DispatchBroadcast(channelKey, LogLevel.Error, message, exception, args);
        }
    }

    #endregion

    #region Trace & Critical

    public async Task LogTraceAsync(SettingKey<bool> channelKey, string message, params object[] args)
    {
        if (await ShouldLogAsync(channelKey, LogLevel.Trace))
        {
            _logger.LogTrace(message, args);
            DispatchBroadcast(channelKey, LogLevel.Trace, message, null, args);
        }
    }

    public async Task LogCriticalAsync(SettingKey<bool> channelKey, Exception? exception, string message, params object[] args)
    {
        if (await ShouldLogAsync(channelKey, LogLevel.Critical))
        {
            if (exception != null)
                _logger.LogCritical(exception, message, args);
            else
                _logger.LogCritical(message, args);
            DispatchBroadcast(channelKey, LogLevel.Critical, message, exception, args);
        }
    }

    #endregion

    private async Task<bool> ShouldLogAsync(SettingKey<bool> channelKey, LogLevel level)
    {
        ArgumentNullException.ThrowIfNull(channelKey);

        try
        {
            return await _settingsService.GetSettingAsync(channelKey);
        }
        catch
        {
            return channelKey.DefaultValue;
        }
    }
}