using Microsoft.AspNetCore.SignalR.Client;
using Microsoft.Extensions.Options;
using DeviceAgent.Models;

namespace DeviceAgent.Services;

/// <summary>
/// SignalR 信令客户端 - 连接到服务器接收质量控制指令
/// </summary>
public class SignalingClientService : IDisposable
{
    private readonly ILogger<SignalingClientService> _logger;
    private readonly AgentConfig _config;
    private readonly DeviceInfoService _deviceInfoService;
    private ScreenStreamService? _screenStreamService;
    private HubConnection? _connection;
    private bool _isConnected;
    private CancellationTokenSource? _reconnectCts;

    public SignalingClientService(
        ILogger<SignalingClientService> logger,
        IOptions<AgentConfig> config,
        DeviceInfoService deviceInfoService)
    {
        _logger = logger;
        _config = config.Value;
        _deviceInfoService = deviceInfoService;
    }
    
    /// <summary>
    /// 设置 ScreenStreamService 引用（避免循环依赖）
    /// </summary>
    public void SetScreenStreamService(ScreenStreamService screenStreamService)
    {
        _screenStreamService = screenStreamService;
    }

    public async Task StartAsync(CancellationToken cancellationToken)
    {
        if (!_config.ScreenStreamEnabled)
        {
            _logger.LogInformation("屏幕流已禁用，跳过信令连接");
            return;
        }

        try
        {
            var hubUrl = $"{_config.ServerUrl}/hubs/stream-signaling";
            _logger.LogInformation("连接到信令服务器: {HubUrl}", hubUrl);

            _connection = new HubConnectionBuilder()
                .WithUrl(hubUrl)
                .WithAutomaticReconnect(new[] { TimeSpan.Zero, TimeSpan.FromSeconds(2), TimeSpan.FromSeconds(5), TimeSpan.FromSeconds(10) })
                .Build();

            // 注册事件处理器
            RegisterHandlers();

            // 连接事件
            _connection.Reconnecting += error =>
            {
                _logger.LogWarning("信令连接断开，正在重连...");
                _isConnected = false;
                return Task.CompletedTask;
            };

            _connection.Reconnected += async connectionId =>
            {
                _logger.LogInformation("信令连接已恢复: {ConnectionId}", connectionId);
                _isConnected = true;
                await RegisterDeviceAsync();
            };

            _connection.Closed += async error =>
            {
                _logger.LogWarning("信令连接关闭: {Error}", error?.Message);
                _isConnected = false;
                
                // 自动重连
                await Task.Delay(5000, cancellationToken);
                if (!cancellationToken.IsCancellationRequested)
                {
                    await StartAsync(cancellationToken);
                }
            };

            // 启动连接
            await _connection.StartAsync(cancellationToken);
            _isConnected = true;
            _logger.LogInformation("信令连接已建立");

            // 注册设备
            await RegisterDeviceAsync();
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "启动信令客户端失败");
        }
    }

    private void RegisterHandlers()
    {
        if (_connection == null) return;

        // 服务器通知切换质量
        _connection.On<string>("SetQuality", async (quality) =>
        {
            _logger.LogInformation("收到质量切换指令: {Quality}", quality);
            
            if (_screenStreamService != null)
            {
                var profile = quality.ToLower() == "high" 
                    ? StreamQualityProfile.High 
                    : StreamQualityProfile.Low;
                
                _screenStreamService.SetQuality(profile);
            }
        });

        // 服务器通知开始推流
        _connection.On<string>("StartStreaming", async (quality) =>
        {
            _logger.LogInformation("收到开始推流指令: {Quality}", quality);
            
            if (_screenStreamService != null)
            {
                var profile = quality.ToLower() == "high" 
                    ? StreamQualityProfile.High 
                    : StreamQualityProfile.Low;
                
                _screenStreamService.SetQuality(profile);
            }
            // 注意：ScreenStreamService 已经在运行，这里只是切换质量
        });

        // 服务器通知停止推流
        _connection.On("StopStreaming", async () =>
        {
            _logger.LogInformation("收到停止推流指令");
            // 切换到低质量，实际推流由客户端连接数控制
            if (_screenStreamService != null)
            {
                _screenStreamService.SetQuality(StreamQualityProfile.Low);
            }
        });

        // 批量设备质量控制
        _connection.On<List<string>, string>("DevicesNeedStream", async (deviceUuids, quality) =>
        {
            var myUuid = _deviceInfoService.GetDeviceInfo().Uuid;
            if (deviceUuids.Contains(myUuid) && _screenStreamService != null)
            {
                _logger.LogInformation("设备在监控列表中，质量: {Quality}", quality);
                var profile = quality.ToLower() == "high" 
                    ? StreamQualityProfile.High 
                    : StreamQualityProfile.Low;
                _screenStreamService.SetQuality(profile);
            }
        });

        _connection.On<List<string>>("DevicesStopStream", async (deviceUuids) =>
        {
            var myUuid = _deviceInfoService.GetDeviceInfo().Uuid;
            if (deviceUuids.Contains(myUuid) && _screenStreamService != null)
            {
                _logger.LogInformation("设备停止监控");
                _screenStreamService.SetQuality(StreamQualityProfile.Low);
            }
        });

        _connection.On<string, string>("DeviceQualityChange", async (deviceUuid, quality) =>
        {
            var myUuid = _deviceInfoService.GetDeviceInfo().Uuid;
            if (deviceUuid == myUuid && _screenStreamService != null)
            {
                _logger.LogInformation("设备质量切换: {Quality}", quality);
                var profile = quality.ToLower() == "high" 
                    ? StreamQualityProfile.High 
                    : StreamQualityProfile.Low;
                _screenStreamService.SetQuality(profile);
            }
        });
    }

    private async Task RegisterDeviceAsync()
    {
        if (_connection == null || !_isConnected) return;

        try
        {
            var uuid = _deviceInfoService.GetDeviceInfo().Uuid;
            await _connection.InvokeAsync("RegisterDevice", uuid);
            _logger.LogInformation("设备已注册到信令服务器: {Uuid}", uuid);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "注册设备失败");
        }
    }

    public async Task StopAsync()
    {
        if (_connection != null)
        {
            try
            {
                var uuid = _deviceInfoService.GetDeviceInfo().Uuid;
                await _connection.InvokeAsync("UnregisterDevice", uuid);
                _logger.LogInformation("设备已从信令服务器注销");
            }
            catch { }

            await _connection.StopAsync();
            await _connection.DisposeAsync();
            _connection = null;
        }

        _isConnected = false;
        _logger.LogInformation("信令客户端已停止");
    }

    public void Dispose()
    {
        _reconnectCts?.Cancel();
        _reconnectCts?.Dispose();
        _connection?.DisposeAsync().AsTask().Wait();
    }
}