using System;
using System.Text.Json;
using System.Threading;
using System.Threading.Tasks;
using Jellyfin.Plugin.JellyLMS.Models;
using MediaBrowser.Controller.Entities;
using MediaBrowser.Controller.Library;
using MediaBrowser.Controller.Session;
using MediaBrowser.Model.Session;
using Microsoft.Extensions.Logging;

namespace Jellyfin.Plugin.JellyLMS.Services;

/// <summary>
/// Session controller for LMS player devices.
/// Enables Jellyfin to send playback commands to LMS players via the cast interface.
/// </summary>
public class LmsSessionController : ISessionController, IDisposable
{
    private readonly ILogger _logger;
    private readonly ILmsApiClient _lmsClient;
    private readonly LmsPlayer _player;
    private readonly SessionInfo _session;
    private readonly ISessionManager _sessionManager;
    private readonly ILibraryManager _libraryManager;
    private Timer? _progressTimer;
    private bool _disposed;
    private BaseItem? _currentItem;

    /// <summary>
    /// Initializes a new instance of the <see cref="LmsSessionController"/> class.
    /// </summary>
    /// <param name="logger">The logger instance.</param>
    /// <param name="lmsClient">The LMS API client.</param>
    /// <param name="player">The LMS player this controller manages.</param>
    /// <param name="session">The Jellyfin session associated with this controller.</param>
    /// <param name="sessionManager">The session manager for reporting playback events.</param>
    /// <param name="libraryManager">The library manager for item lookups.</param>
    public LmsSessionController(
        ILogger logger,
        ILmsApiClient lmsClient,
        LmsPlayer player,
        SessionInfo session,
        ISessionManager sessionManager,
        ILibraryManager libraryManager)
    {
        _logger = logger;
        _lmsClient = lmsClient;
        _player = player;
        _session = session;
        _sessionManager = sessionManager;
        _libraryManager = libraryManager;
    }

    /// <summary>
    /// Gets or sets the currently playing item ID.
    /// </summary>
    public Guid? CurrentItemId { get; set; }

    /// <summary>
    /// Gets or sets a value indicating whether playback is currently active.
    /// </summary>
    public bool IsPlaying { get; set; }

    /// <summary>
    /// Gets or sets a value indicating whether playback is paused.
    /// </summary>
    public bool IsPaused { get; set; }

    /// <inheritdoc />
    public bool IsSessionActive => _player.IsConnected;

    /// <inheritdoc />
    public bool SupportsMediaControl => true;

    /// <summary>
    /// Gets the MAC address of the LMS player.
    /// </summary>
    public string PlayerMac => _player.MacAddress;

    /// <inheritdoc />
    public async Task SendMessage<T>(
        SessionMessageType name,
        Guid messageId,
        T data,
        CancellationToken cancellationToken)
    {
        _logger.LogInformation(
            "LMS Session Controller received message {MessageType} for player {PlayerName} ({Mac})",
            name,
            _player.Name,
            _player.MacAddress);

        try
        {
            switch (name)
            {
                case SessionMessageType.Play:
                    await HandlePlayCommandAsync(data, cancellationToken).ConfigureAwait(false);
                    break;

                case SessionMessageType.Playstate:
                    await HandlePlaystateCommandAsync(data, cancellationToken).ConfigureAwait(false);
                    break;

                case SessionMessageType.GeneralCommand:
                    await HandleGeneralCommandAsync(data, cancellationToken).ConfigureAwait(false);
                    break;

                default:
                    _logger.LogDebug("Unhandled message type: {MessageType}", name);
                    break;
            }
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Error handling message {MessageType} for player {PlayerName}", name, _player.Name);
        }
    }

    private async Task HandlePlayCommandAsync<T>(T data, CancellationToken cancellationToken)
    {
        if (data is not PlayRequest playRequest)
        {
            _logger.LogWarning("Expected PlayRequest but got {Type}", data?.GetType().Name);
            return;
        }

        _logger.LogInformation(
            "Play command received for player {PlayerName}: {ItemCount} items",
            _player.Name,
            playRequest.ItemIds.Length);

        // Power on the player if needed
        if (!_player.IsPoweredOn)
        {
            await _lmsClient.PowerOnAsync(_player.MacAddress).ConfigureAwait(false);
        }

        // For now, play the first item
        // TODO: Support playlists/queues
        if (playRequest.ItemIds.Length > 0)
        {
            var itemId = playRequest.ItemIds[0];
            var streamUrl = BuildStreamUrl(itemId);

            _logger.LogInformation("Playing stream URL: {Url}", streamUrl);
            await _lmsClient.PlayUrlAsync(_player.MacAddress, streamUrl).ConfigureAwait(false);

            // Track current playback state
            CurrentItemId = itemId;
            IsPlaying = true;
            IsPaused = false;

            // Look up the item for duration info
            _currentItem = _libraryManager.GetItemById(itemId);

            // Seek to start position if specified
            var startPositionTicks = 0L;
            if (playRequest.StartPositionTicks.HasValue && playRequest.StartPositionTicks.Value > 0)
            {
                startPositionTicks = playRequest.StartPositionTicks.Value;
                var positionSeconds = startPositionTicks / TimeSpan.TicksPerSecond;
                await _lmsClient.SeekAsync(_player.MacAddress, positionSeconds).ConfigureAwait(false);
            }

            // Report playback start to Jellyfin
            await ReportPlaybackStartAsync(itemId, startPositionTicks).ConfigureAwait(false);

            // Start progress reporting timer (every 2 seconds)
            StartProgressTimer();
        }
    }

    private async Task ReportPlaybackStartAsync(Guid itemId, long positionTicks)
    {
        try
        {
            var startInfo = new PlaybackStartInfo
            {
                ItemId = itemId,
                SessionId = _session.Id,
                PositionTicks = positionTicks,
                PlayMethod = PlayMethod.DirectStream,
                CanSeek = true,
                IsPaused = false,
                IsMuted = false
            };

            _logger.LogInformation(
                "Reporting playback start for item {ItemId}, duration: {Duration}",
                itemId,
                _currentItem?.RunTimeTicks);
            await _sessionManager.OnPlaybackStart(startInfo).ConfigureAwait(false);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to report playback start");
        }
    }

    private void StartProgressTimer()
    {
        // Stop any existing timer
        _progressTimer?.Dispose();

        // Report progress every 2 seconds
        _progressTimer = new Timer(
            async _ => await ReportPlaybackProgressAsync().ConfigureAwait(false),
            null,
            TimeSpan.FromSeconds(2),
            TimeSpan.FromSeconds(2));
    }

    private void StopProgressTimer()
    {
        _progressTimer?.Dispose();
        _progressTimer = null;
    }

    private async Task ReportPlaybackProgressAsync()
    {
        if (!IsPlaying || !CurrentItemId.HasValue)
        {
            return;
        }

        try
        {
            var status = await _lmsClient.GetPlayerStatusAsync(_player.MacAddress).ConfigureAwait(false);
            if (status == null)
            {
                return;
            }

            var positionTicks = (long)(status.Time * TimeSpan.TicksPerSecond);
            var isPaused = status.Mode == "pause";

            // Update our local state from LMS
            IsPaused = isPaused;

            // Check if playback has stopped on LMS side
            if (status.Mode == "stop")
            {
                _logger.LogInformation("LMS playback stopped, reporting to Jellyfin");
                await ReportPlaybackStoppedAsync().ConfigureAwait(false);
                return;
            }

            var progressInfo = new PlaybackProgressInfo
            {
                ItemId = CurrentItemId.Value,
                SessionId = _session.Id,
                IsPaused = isPaused,
                PositionTicks = positionTicks,
                PlayMethod = PlayMethod.DirectStream,
                CanSeek = true,
                IsMuted = status.Volume == 0,
                VolumeLevel = status.Volume
            };

            await _sessionManager.OnPlaybackProgress(progressInfo).ConfigureAwait(false);
        }
        catch (Exception ex)
        {
            _logger.LogDebug(ex, "Error reporting playback progress");
        }
    }

    private async Task ReportPlaybackStoppedAsync()
    {
        if (!CurrentItemId.HasValue)
        {
            return;
        }

        try
        {
            StopProgressTimer();

            var stopInfo = new PlaybackStopInfo
            {
                ItemId = CurrentItemId.Value,
                SessionId = _session.Id
            };

            _logger.LogInformation("Reporting playback stopped for item {ItemId}", CurrentItemId.Value);
            await _sessionManager.OnPlaybackStopped(stopInfo).ConfigureAwait(false);

            IsPlaying = false;
            IsPaused = false;
            CurrentItemId = null;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to report playback stopped");
        }
    }

    private async Task HandlePlaystateCommandAsync<T>(T data, CancellationToken cancellationToken)
    {
        if (data is not PlaystateRequest playstateRequest)
        {
            _logger.LogWarning("Expected PlaystateRequest but got {Type}", data?.GetType().Name);
            return;
        }

        _logger.LogInformation(
            "Playstate command {Command} for player {PlayerName} ({Mac})",
            playstateRequest.Command,
            _player.Name,
            _player.MacAddress);

        switch (playstateRequest.Command)
        {
            case PlaystateCommand.Stop:
                var stopResult = await _lmsClient.StopAsync(_player.MacAddress).ConfigureAwait(false);
                _logger.LogInformation("Stop command result: {Result}", stopResult);
                await ReportPlaybackStoppedAsync().ConfigureAwait(false);
                break;

            case PlaystateCommand.Pause:
                var pauseResult = await _lmsClient.PauseAsync(_player.MacAddress).ConfigureAwait(false);
                _logger.LogInformation("Pause command result: {Result}", pauseResult);
                IsPaused = true;
                break;

            case PlaystateCommand.Unpause:
                var playResult = await _lmsClient.PlayAsync(_player.MacAddress).ConfigureAwait(false);
                _logger.LogInformation("Unpause/Play command result: {Result}", playResult);
                IsPaused = false;
                break;

            case PlaystateCommand.PlayPause:
                // Toggle play/pause - check current state first
                var currentState = await _lmsClient.GetPlayerStatusAsync(_player.MacAddress).ConfigureAwait(false);
                if (currentState?.Mode == "play")
                {
                    var togglePauseResult = await _lmsClient.PauseAsync(_player.MacAddress).ConfigureAwait(false);
                    _logger.LogInformation("PlayPause toggle (pause) result: {Result}", togglePauseResult);
                    IsPaused = true;
                }
                else
                {
                    var togglePlayResult = await _lmsClient.PlayAsync(_player.MacAddress).ConfigureAwait(false);
                    _logger.LogInformation("PlayPause toggle (play) result: {Result}", togglePlayResult);
                    IsPaused = false;
                }

                break;

            case PlaystateCommand.Seek:
                if (playstateRequest.SeekPositionTicks.HasValue)
                {
                    var positionSeconds = playstateRequest.SeekPositionTicks.Value / TimeSpan.TicksPerSecond;
                    _logger.LogInformation(
                        "Seeking player {PlayerName} to {Seconds} seconds",
                        _player.Name,
                        positionSeconds);
                    await _lmsClient.SeekAsync(_player.MacAddress, positionSeconds).ConfigureAwait(false);
                }

                break;

            case PlaystateCommand.NextTrack:
            case PlaystateCommand.PreviousTrack:
                // TODO: Implement playlist navigation
                _logger.LogDebug("Track navigation not yet implemented");
                break;

            default:
                _logger.LogDebug("Unhandled playstate command: {Command}", playstateRequest.Command);
                break;
        }
    }

    private async Task HandleGeneralCommandAsync<T>(T data, CancellationToken cancellationToken)
    {
        if (data is not GeneralCommand command)
        {
            _logger.LogWarning("Expected GeneralCommand but got {Type}", data?.GetType().Name);
            return;
        }

        _logger.LogDebug(
            "General command {CommandName} for player {PlayerName}",
            command.Name,
            _player.Name);

        switch (command.Name)
        {
            case GeneralCommandType.SetVolume:
                if (command.Arguments.TryGetValue("Volume", out var volumeStr) &&
                    int.TryParse(volumeStr, out var volume))
                {
                    await _lmsClient.SetVolumeAsync(_player.MacAddress, volume).ConfigureAwait(false);
                }

                break;

            case GeneralCommandType.VolumeUp:
                var currentStatus = await _lmsClient.GetPlayerStatusAsync(_player.MacAddress).ConfigureAwait(false);
                if (currentStatus != null)
                {
                    var newVolume = Math.Min(100, currentStatus.Volume + 5);
                    await _lmsClient.SetVolumeAsync(_player.MacAddress, newVolume).ConfigureAwait(false);
                }

                break;

            case GeneralCommandType.VolumeDown:
                var status = await _lmsClient.GetPlayerStatusAsync(_player.MacAddress).ConfigureAwait(false);
                if (status != null)
                {
                    var newVolume = Math.Max(0, status.Volume - 5);
                    await _lmsClient.SetVolumeAsync(_player.MacAddress, newVolume).ConfigureAwait(false);
                }

                break;

            case GeneralCommandType.Mute:
                await _lmsClient.SetVolumeAsync(_player.MacAddress, 0).ConfigureAwait(false);
                break;

            case GeneralCommandType.ToggleMute:
                // TODO: Track mute state to toggle properly
                break;

            default:
                _logger.LogDebug("Unhandled general command: {Command}", command.Name);
                break;
        }
    }

    private string BuildStreamUrl(Guid itemId)
    {
        var config = Plugin.Instance?.Configuration;
        var jellyfinUrl = config?.JellyfinServerUrl?.TrimEnd('/') ?? "http://localhost:8096";
        var apiKey = config?.JellyfinApiKey ?? string.Empty;

        // Build audio stream URL that LMS can fetch
        // Use direct stream endpoint - simpler and more compatible
        var url = $"{jellyfinUrl}/Audio/{itemId}/stream?static=true";

        if (!string.IsNullOrEmpty(apiKey))
        {
            url += $"&api_key={apiKey}";
        }

        return url;
    }

    /// <inheritdoc />
    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    /// <summary>
    /// Disposes managed resources.
    /// </summary>
    /// <param name="disposing">Whether to dispose managed resources.</param>
    protected virtual void Dispose(bool disposing)
    {
        if (_disposed)
        {
            return;
        }

        if (disposing)
        {
            StopProgressTimer();
        }

        _disposed = true;
    }
}