using System;
using System.Timers;
using leak_test_project.Infrastructure;
using leak_test_project.Utils;

namespace leak_test_project.Services
{
    /// <summary>
    /// Sentinel C28 기기와의 통신 프로토콜을 관리하는 서비스.
    /// 자동 재연결(Auto-Reconnect) 및 예외 처리 포함.
    /// </summary>
    public class SentinelC28Service : IDisposable
    {
        private readonly ICommunication _communication;
        private int _sequence = 1;
        private Timer _reconnectTimer;
        private bool _shouldBeConnected = false;

        public event EventHandler<string> RawDataReceived;
        public event EventHandler<string> ResultReceived; 
        public event EventHandler<string> StreamingReceived; 
        public event EventHandler<bool> ConnectionChanged;
        
        /// <summary> 파싱된 최종 검사 결과 알림 </summary>
        public event EventHandler<Models.ParsedData> OnFinalResultParsed;
        
        /// <summary> 파싱된 실시간 스트리밍 데이터 알림 </summary>
        public event EventHandler<Models.ParsedData> OnStreamingParsed;

        public SentinelC28Service(ICommunication communication)
        {
            _communication = communication;
            _communication.DataReceived += OnDataReceived;
            _communication.ConnectionStatusChanged += (s, isConnected) => {
                ConnectionChanged?.Invoke(this, isConnected);
                if (!isConnected && _shouldBeConnected) StartReconnectTimer();
            };

            // 1초(1000ms)마다 연결 상태를 확인하고 재연결 시도
            _reconnectTimer = new Timer(1000);
            _reconnectTimer.AutoReset = false; // 재진입 방지
            _reconnectTimer.Elapsed += (s, e) => {
                if (_shouldBeConnected && !_communication.IsOpen)
                {
                    Console.WriteLine($"[Service] Attempting to reconnect to {_communication.Name}...");
                    if (!_communication.Open())
                    {
                        // 실패 시 다시 타이머 시작
                        if (_shouldBeConnected) _reconnectTimer.Start();
                    }
                }
                else if (_shouldBeConnected)
                {
                    _reconnectTimer.Start();
                }
            };
        }

        public bool Connect() 
        {
            _shouldBeConnected = true;
            bool opened = _communication.Open();
            if (!opened) StartReconnectTimer();
            return opened;
        }

        public void Disconnect() 
        {
            _shouldBeConnected = false;
            _reconnectTimer.Stop();
            _communication.Close();
        }

        private void StartReconnectTimer()
        {
            if (!_reconnectTimer.Enabled) _reconnectTimer.Start();
        }

        public void SendCommand(string command, string dataTypeCode)
        {
            if (!_communication.IsOpen) return;

            try {
                string sequenceHex = _sequence.ToString("X2");
                string lengthHex = command.Length.ToString("X3");
                string payload = $"{sequenceHex}{lengthHex} {dataTypeCode}\t{command}";
                string crc = SentinelCrc8.CalculateHex(payload);
                
                if (!_communication.Write($"{crc}{payload}\r\n"))
                {
                    FileLogger.Log("ERROR", "[SentinelC28] Failed to send command: Communication channel closed.");
                }
                
                _sequence = (_sequence >= 255) ? 1 : _sequence + 1;
            } catch (Exception ex) {
                FileLogger.Log("ERROR", $"[SentinelC28] Error sending command: {ex.Message}");
            }
        }

        private void OnDataReceived(object sender, string rawData)
        {
            try {
                RawDataReceived?.Invoke(this, rawData);
                
                if (string.IsNullOrWhiteSpace(rawData)) return;

                // 헤더 분석 및 본문 추출
                string body = SentinelParser.ExtractBody(rawData, out char typeCode);

                switch (typeCode)
                {
                    case 'R': // 최종 결과 (Result Value)
                        ResultReceived?.Invoke(this, rawData);
                        var finalParsed = SentinelParser.ParseFinalResult(rawData);
                        OnFinalResultParsed?.Invoke(this, finalParsed);
                        break;

                    case 'S': // 스트리밍 데이터 (Streaming Value)
                        StreamingReceived?.Invoke(this, rawData);
                        var streamParsed = SentinelParser.ParseStreamingValue(rawData);
                        OnStreamingParsed?.Invoke(this, streamParsed);
                        break;

                    case 'M': // 일반 메시지
                        FileLogger.Log("INFO", $"[SentinelC28 Message] {body}");
                        break;
                }
            } catch (Exception ex) {
                FileLogger.Log("ERROR", $"[SentinelC28] Error parsing received data: {ex.Message}");
            }
        }

        public void Dispose()
        {
            Disconnect();
            _reconnectTimer?.Stop();
            _reconnectTimer?.Dispose();
            _reconnectTimer = null;
        }
    }
}