using System.Collections.Concurrent;
using System.Diagnostics;
using System.Net;
using System.Text;
using NewLife.Http;
using NewLife.Net;
using NewLife.Reflection;
using NewLife.Security;

namespace NewLife.Log;

/// <summary>网络日志</summary>
public class NetworkLog : Logger, IDisposable
{
    /// <summary>服务端</summary>
    public String? Server { get; set; }

    /// <summary>应用标识</summary>
    public String? AppId { get; set; }

    /// <summary>客户端标识</summary>
    public String? ClientId { get; set; }

    private ISocketRemote? _client;
    private HttpClient? _http;
    private readonly ConcurrentQueue<String> _Logs = new();
    private volatile Int32 _logCount;
    private Int32 _writing;

    /// <summary>实例化网络日志。默认广播到514端口</summary>
    public NetworkLog() => Server = new NetUri(NetType.Udp, IPAddress.Broadcast, 514) + "";

    /// <summary>指定日志服务器地址来实例化网络日志</summary>
    /// <param name="server"></param>
    public NetworkLog(String server) => Server = server;

    /// <summary>销毁</summary>
    public void Dispose()
    {
        // 销毁前把队列日志输出
        if (_logCount > 0)
        {
            if (Interlocked.CompareExchange(ref _writing, 1, 0) == 0)
                PushLog();
            else
                Thread.Sleep(500);
        }

        _client.TryDispose();
        _http.TryDispose();
    }

    private void Send(String value)
    {
        if (_client != null)
            _client.Send(value);
        else
            _http?.PostAsync("", new StringContent(value)).Wait(30_000);
    }

    private Boolean _inited;
    private void Init()
    {
        if (_inited) return;

        //var sys = SysConfig.Current;
        if (AppId.IsNullOrEmpty()) AppId = AssemblyX.Entry?.Name;
        if (ClientId.IsNullOrEmpty())
        {
            try
            {
                ClientId = NetHelper.MyIP() + "@" + Process.GetCurrentProcess().Id;
            }
            catch
            {
                ClientId = Rand.NextString(8);
            }
        }

        if (!Server.IsNullOrEmpty())
        {
            var uri = new NetUri(Server);
            switch (uri.Type)
            {
                case NetType.Unknown:
                    break;
                case NetType.Tcp:
                case NetType.Udp:
                    _client = uri.CreateRemote();
                    break;
                case NetType.Http:
                case NetType.Https:
                case NetType.WebSocket:
                    var handler = HttpHelper.CreateHandler(false, false);
                    var http = new HttpClient(handler)
                    {
                        BaseAddress = new Uri(Server)
                    };
                    http.DefaultRequestHeaders.Add("X-AppId", AppId);
                    http.DefaultRequestHeaders.Add("X-ClientId", ClientId);

                    // 默认UserAgent
                    http.SetUserAgent();

                    _http = http;
                    break;
                default:
                    break;
            }
        }
        if (_client == null && _http == null) return;

        // 首先发送日志头
        Send(GetHead());

        _inited = true;
    }

    /// <summary>写日志</summary>
    /// <param name="level"></param>
    /// <param name="format"></param>
    /// <param name="args"></param>
    protected override void OnWrite(LogLevel level, String format, params Object?[] args)
    {
        if (_logCount > 100) return;

        var e = WriteLogEventArgs.Current.Set(level);
        // 特殊处理异常对象
        if (/*args != null &&*/ args.Length == 1 && args[0] is Exception ex && (format.IsNullOrEmpty() || format == "{0}"))
            e = e.Set(null, ex);
        else
            e = e.Set(Format(format, args), null);

        // 推入队列
        _Logs.Enqueue(e.GetAndReset());
        Interlocked.Increment(ref _logCount);

        // 异步写日志，实时。即使这里错误，定时器那边仍然会补上
        if (Interlocked.CompareExchange(ref _writing, 1, 0) == 0)
        {
            ThreadPool.UnsafeQueueUserWorkItem(s =>
            {
                try
                {
                    PushLog();
                }
                catch { }
                finally
                {
                    _writing = 0;
                }
            }, null);
        }
    }

    private void PushLog()
    {
        Init();

        // Tcp/Udp 和 Http 推送日志时需要不同的包大小
        var max = _http != null ? 8192 : 1460;

        var sb = new StringBuilder();
        while (_Logs.TryDequeue(out var msg))
        {
            Interlocked.Decrement(ref _logCount);

            if (sb.Length > 0 && sb.Length + msg.Length >= max)
            {
                Send(sb.ToString());
                sb.Clear();
            }

            if (sb.Length > 0) sb.AppendLine();
            sb.Append(msg);
        }

        if (sb.Length > 0) Send(sb.ToString());
    }
}