using System;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;
using DualScreenDemo.Shared;
public class WatchDog
{
    
    private Func<VideoStatus> getVideoStatus;
    private Func<bool> isApplicationResponsive;
    private Thread watchdogThread;
    private bool running = false;
    private double lastPosition = -1;
    private int freezeCounter = 0;

    public WatchDog(Func<VideoStatus> getVideoPositionFunc, Func<bool> isAppResponsiveFunc)
    {
        getVideoStatus  = getVideoPositionFunc;
        isApplicationResponsive = isAppResponsiveFunc;
    }

    public void Start()
    {
        running = true;
        watchdogThread = new Thread(Run);
        watchdogThread.IsBackground = true;
        watchdogThread.Start();
    }

    public void Stop()
    {
        running = false;
        watchdogThread?.Join();
    }

    private void Run()
{
    while (running)
    {
        var status = getVideoStatus();  // 改用 getVideoStatus 取得完整狀態
        bool responsive = isApplicationResponsive();

        if (!status.IsGraphOk)
        {
            Log($"影片圖表異常: {status.LastError}");
        }
        else if(status.PlayState != "Paused")
        {
            double currentPosition = status.PositionSeconds;

            if (Math.Abs(currentPosition - lastPosition) < 0.001)
            {
                freezeCounter++;
                if (freezeCounter >= 3)
                {
                    Log($"影片疑似卡死（3次位置沒變）：位置={currentPosition:F2}秒，播放狀態={status.PlayState}");
                    freezeCounter = 0; // 記得 reset
                }
            }
            else
            {
                freezeCounter = 0;
            }

            lastPosition = currentPosition;
        }

        if (!responsive)
        {
            Log("UI 疑似卡死（Invoke 失敗）");
        }

        Thread.Sleep(5000);
    }
}


    private void Log(string message)
    {
        string logFilePath = Path.Combine("txt", "watchdog_log.txt");
        File.AppendAllText(logFilePath, $"{DateTime.Now}: {message}{Environment.NewLine}");
    }
}