using System;
using NetMQ;
using NetMQ.Sockets;
using SHH.Contracts;

namespace SHH.NetMQ
{
    /// <summary>
    /// 视频转发客户端 (Pusher)
    /// 特性：主动推送、断线重连、非阻塞
    /// </summary>
    public class ForwarderClient : IDisposable
    {
        private PushSocket _pushSocket;
        private readonly object _lock = new object();
        private bool _isInitialized = false;

        // 同样设置 50 帧的缓存限制
        private const int HWM_LIMIT = 50;

        public ForwarderClient(string remoteAddress)
        {
            if (string.IsNullOrEmpty(remoteAddress)) return;

            _pushSocket = new PushSocket();

            // 1. 防堆积设置
            _pushSocket.Options.SendHighWatermark = HWM_LIMIT;

            try
            {
                // NetMQ 会自动在后台处理重连，无需人工干预
                _pushSocket.Connect(remoteAddress);
                _isInitialized = true;
            }
            catch (Exception ex)
            {
                Console.WriteLine($"[Client Error] 连接失败: {ex.Message}");
                _isInitialized = false;
            }
        }

        public void Push(VideoPayload payload)
        {
            if (!_isInitialized || payload == null) return;

            if (payload.DispatchTime == DateTime.MinValue)
                payload.DispatchTime = DateTime.Now;

            var msg = new NetMQMessage();
            msg.Append(payload.GetMetadataJson());
            msg.Append(payload.OriginalImageBytes ?? new byte[0]);
            msg.Append(payload.TargetImageBytes ?? new byte[0]);

            lock (_lock)
            {
                // 2. 非阻塞推送
                // 如果对方挂了，或者网络断了，缓冲区满后这里的 TrySend 会立即返回 false
                // 保证 SDK 采集不受影响
                bool sent = _pushSocket.TrySendMultipartMessage(TimeSpan.Zero, msg);
            }
        }

        public void Dispose()
        {
            _pushSocket?.Dispose();
        }
    }
}