using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json.Linq;

namespace CoreAgent.ProtocolClient.ProtocolEngineCore
{
    /// <summary>
    /// 管理所有与统计信息相关的操作
    /// 职责：
    /// 1. 定时轮询获取统计信息 (stats)。
    /// 2. 管理统计信息的配置 (samples, rf)。
    /// 3. 管理轮询的定时器 (_statsTimer)。
    /// 4. 触发统计信息相关的事件。
    /// </summary>
    public class StatsManager : IDisposable
    {
        private readonly ILogger _logger;
        private readonly Func<JObject, Action<JObject>?, bool, long> _sendMessage;
        private readonly string _clientName;
        private bool _enableSamples = false;
        private bool _enableRf = false;
        private int _statsPollDelay = 1000;
        private Timer? _statsTimer;
        private bool _isFirstStatsUpdate = true;
        private bool _disposed = false;
        private bool _isConnected = false;

        public event EventHandler<JObject>? StatsReceived;

        public StatsManager(string clientName, ILogger logger, Func<JObject, Action<JObject>?, bool, long> sendMessage)
        {
            _clientName = clientName;
            _logger = logger;
            _sendMessage = sendMessage;
        }

        public void HandleMessage(JObject message)
        {
            // The "stats" response is handled via callback in UpdateStats,
            // but a generic handler could be placed here if needed in the future.
            var messageType = message["message"]?.ToString();
            if (messageType == "stats")
            {
                StatsReceived?.Invoke(this, message);
            }
        }

        public void SetConnectionState(bool isConnected)
        {
            _isConnected = isConnected;
            if (!_isConnected)
            {
                StopStatsTimer();
            }
        }

        public void TriggerStatsUpdate()
        {
            UpdateStats();
        }

        public void ResetStatistics()
        {
            var resetStats = new JObject { ["cpu"] = new JObject { ["global"] = 0 } };
            _logger.LogDebug($"[{_clientName}] 重置统计信息");
            // This was a local-only operation in the original code.
            // If it needs to send a message, it should be done here.
        }

        public void SetStatisticsConfig(bool enableSamples, bool enableRf)
        {
            _enableSamples = enableSamples;
            _enableRf = enableRf;
            _logger.LogInformation($"[{_clientName}] 设置统计配置: samples={enableSamples}, rf={enableRf}");
        }

        public (bool samples, bool rf) GetStatisticsConfig()
        {
            return (_enableSamples, _enableRf);
        }

        public void SetRefreshDelay(int delay)
        {
            _statsPollDelay = delay;
        }

        public void Start(bool first = false)
        {
            if (first)
            {
                _isFirstStatsUpdate = true;
            }
            UpdateStats(first);
        }

        private void UpdateStats(bool first = false)
        {
            if (_disposed || !_isConnected) return;

            var msg = new JObject { ["message"] = "stats", ["samples"] = _enableSamples, ["rf"] = _enableRf };
            _sendMessage(msg, response =>
            {
                if (_disposed) return;

                if (first || _isFirstStatsUpdate)
                {
                    ResetStatistics();
                    _isFirstStatsUpdate = false;
                    StartStatsTimer();
                    // In the original, the first response is not propagated.
                    return;
                }

                StatsReceived?.Invoke(this, response);
                StartStatsTimer(); // Schedule next update
            }, false);
        }

        private void StartStatsTimer()
        {
            if (_statsTimer != null) { _statsTimer.Dispose(); }
            _statsTimer = new Timer(_ => UpdateStats(), null, _statsPollDelay, Timeout.Infinite);
        }

        public void StopStatsTimer()
        {
            _statsTimer?.Dispose();
            _statsTimer = null;
        }

        public void Dispose()
        {
            if (_disposed) return;
            _disposed = true;
            StopStatsTimer();
        }
    }
}