using System.Net.WebSockets;
using CoreAgent.WebSocketTransport.Interfaces;
using Microsoft.Extensions.Logging;

namespace CoreAgent.WebSocketTransport.Services;

/// <summary>
/// WebSocket 连接实现
/// 单一职责：负责网络连接管理
/// </summary>
public class WebSocketConnection : IWebSocketConnection
{
    private ClientWebSocket _webSocket;
    private readonly ILogger<WebSocketConnection> _logger;
    private readonly object _lock = new object();

    public WebSocketState State => _webSocket.State;
    public bool IsConnected => _webSocket.State == WebSocketState.Open;

    public WebSocketConnection(ILogger<WebSocketConnection> logger)
    {
        _webSocket = new ClientWebSocket();
        _logger = logger;
    }

    public async Task ConnectAsync(Uri uri, CancellationToken cancellationToken = default)
    {
        lock (_lock)
        {
            // 如果连接已关闭或处于CloseReceived状态，需要重新创建WebSocket实例
            if (_webSocket.State == WebSocketState.Closed || 
                _webSocket.State == WebSocketState.CloseReceived ||
                _webSocket.State == WebSocketState.CloseSent)
            {
                _logger.LogInformation("WebSocket 处于关闭状态，重新创建连接实例");
                _webSocket?.Dispose();
                _webSocket = new ClientWebSocket();
            }
            
            if (_webSocket.State == WebSocketState.Open)
            {
                _logger.LogInformation("WebSocket 已连接");
                return;
            }
        }

        _logger.LogInformation("正在连接 WebSocket 服务器: {Uri}", uri);
        // 👇 这行：跳过所有证书验证（只用于开发测试）
        _webSocket.Options.RemoteCertificateValidationCallback += (sender, cert, chain, sslPolicyErrors) => true;
        await _webSocket.ConnectAsync(uri, cancellationToken);
        _logger.LogInformation("WebSocket 连接成功");
    }

    public async Task SendAsync(ArraySegment<byte> buffer, WebSocketMessageType messageType, bool endOfMessage, CancellationToken cancellationToken = default)
    {
        if (_webSocket.State != WebSocketState.Open)
        {
            throw new InvalidOperationException($"WebSocket 未连接，当前状态: {_webSocket.State}");
        }

        await _webSocket.SendAsync(buffer, messageType, endOfMessage, cancellationToken);
    }

    public async Task<WebSocketReceiveResult> ReceiveAsync(ArraySegment<byte> buffer, CancellationToken cancellationToken = default)
    {
        if (_webSocket.State != WebSocketState.Open)
        {
            throw new InvalidOperationException($"WebSocket 未连接，当前状态: {_webSocket.State}");
        }

        return await _webSocket.ReceiveAsync(buffer, cancellationToken);
    }

    public async Task CloseAsync(WebSocketCloseStatus closeStatus, string statusDescription, CancellationToken cancellationToken = default)
    {
        _logger.LogInformation("开始关闭 WebSocket 连接 - 关闭状态: {CloseStatus}, 状态描述: {StatusDescription}, 当前连接状态: {CurrentState}", 
            closeStatus, statusDescription, _webSocket.State);
        
        if (_webSocket.State == WebSocketState.Open)
        {
            _logger.LogDebug("WebSocket 连接处于打开状态，执行正常关闭流程");
            try
            {
                await _webSocket.CloseAsync(closeStatus, statusDescription, cancellationToken);
                _logger.LogInformation("WebSocket 连接关闭成功 - 关闭状态: {CloseStatus}, 状态描述: {StatusDescription}", 
                    closeStatus, statusDescription);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "WebSocket 连接关闭失败 - 关闭状态: {CloseStatus}, 状态描述: {StatusDescription}, 错误信息: {ErrorMessage}", 
                    closeStatus, statusDescription, ex.Message);
                throw;
            }
        }
        else
        {
            _logger.LogWarning("WebSocket 连接未处于打开状态，跳过关闭操作 - 当前状态: {CurrentState}", _webSocket.State);
        }
    }

    /// <summary>
    /// 强制关闭连接并重新创建WebSocket实例
    /// </summary>
    public void ForceClose()
    {
        lock (_lock)
        {
            _logger.LogInformation("强制关闭 WebSocket 连接并重新创建实例");
            _webSocket?.Dispose();
            _webSocket = new ClientWebSocket();
        }
    }

    public void Dispose()
    {
        lock (_lock)
        {
            _webSocket?.Dispose();
        }
        GC.SuppressFinalize(this);
    }
}