using PaintDotNet.Camera.TUC;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Threading;
using System.Windows.Forms;

namespace PaintDotNet.Camera
{
    public class CameraManager
    {
        private static CameraManager _instance;
        protected List<ICamera> m_cameraList = new List<ICamera>();       // The list of cameras object
        private ICamera m_currentCamera;
        public static event Action<Bitmap> FrameCallback;
        static event Action<Bitmap> ShootCallback;
        /// <summary>
        /// 当发生相机切换，
        /// </summary>
        public static event Action<ICamera, ICamera> OnCameraChanged;

        private CameraManager()
        {
        }

        /// <summary>
        /// 返回相机数量
        /// </summary>
        /// <returns></returns>
        public int CameraCount => m_cameraList.Count;

        public static CameraManager GetInstance()
        {
            if (_instance == null)
            {
                _instance = new CameraManager();
                _instance.InitManager();
            }
            return _instance;
        }

        public static bool IsLive
        {
            get
            {
                if (CurrentCamera == null) return false;
                string sn;
                return CurrentCamera.ReadRegisterData(out sn);
            }
        }

        public static event Action OnCameraDrop;
        public void CheckDevices()
        {
            bool drop = false;
            for (int i = 0; i < m_cameraList.Count;)
            {
                string sn;
                if (m_cameraList[i].ReadRegisterData(out sn))
                {
                    i++;
                }
                else
                {
                    m_cameraList.RemoveAt(i);
                    drop = true;
                }
            }
            if (drop)
                OnCameraDrop?.Invoke();
        }

        /// <summary>
        /// 返回相机列表
        /// </summary>
        public List<ICamera> GetCameraList()
        {
            return m_cameraList;
        }
        /// <summary>
        /// 返回相机名称列表
        /// </summary>
        public List<string> GetCameraNameList()
        {
            var list = new List<string>();
            m_cameraList.ForEach((c) => list.Add(c.GetName()));
            return list;
        }

        public static ICamera CurrentCamera
        {
            get => _instance.m_currentCamera;
            private set
            {
                // CurrentCamera?.Close();
                value.Open();
                OnCameraChanged?.Invoke(_instance.m_currentCamera, value);
                _instance.m_currentCamera = value;
            }
        }

        public void InitManager()
        {
            Logs.Write("InitManager");
            m_cameraList.Clear();
            m_cameraList.AddRange(TUCamera.Init());
            if (m_cameraList.Count > 0)
            {
                CurrentCamera = m_cameraList[0];
            }
            else
            {
                _instance.m_currentCamera = new TUCamera(0);
            }
            new Thread(PreviewRuntime) { IsBackground = true }.Start();
            new Thread(PreviewMonitor) { IsBackground = true }.Start();

        }

        /// <summary>
        /// 设置当前使用相机
        /// </summary>
        /// <param name="idx"></param>
        public void SetCurrentCamera(int idx)
        {
            CurrentCamera = m_cameraList[idx];

        }

        public void UnInitManager()
        {
            Logs.Write("UnInitManager");
            Running = false;
            for (int i = 0; i < m_cameraList.Count; i++)
            {
                m_cameraList[i]?.Close();
            }
            m_cameraList.Clear();
            TUCamera.UnInit();
        }

        DateTime _timeWaitFrame;
        bool _waitingFrame;
        public static Action OnCaptureTimeOut;
        private void PreviewMonitor()
        {
            while (Running)
            {
                if (!_waitingFrame)
                { }
                else if ((DateTime.Now - _timeWaitFrame).TotalMilliseconds > CurrentCamera.ExposureTime + 1000)
                {
                    Logs.Write("相机拍摄超时");
                    _waitingFrame = false;
                    OnCaptureTimeOut?.Invoke();
                    CurrentCamera?.RepairPreview();
                }
                Thread.Sleep(200);
            }
        }

        private void WaitBegin()
        {
            _waitingFrame = true;
            _timeWaitFrame = DateTime.Now;
        }
        private void WaitEnd()
        {
            _waitingFrame = false;
        }
        bool Running;
        void PreviewRuntime()
        {
            Running = true;
            while (Running)
            {
                if (CurrentCamera == null || !CurrentCamera.IsOpen() || (FrameCallback == null && ShootCallback == null))
                {
                    ShootCallback = null;
                    Thread.Sleep(30); continue;
                }
                WaitBegin();
                var img = CurrentCamera.OneShoot();
                WaitEnd();
                if (img == null)
                { 
                    Logs.Write("获取图片失败");
                    continue;//added by songxk
                }

                ShootCallback?.Invoke((Bitmap)img?.Clone());
                ShootCallback = null;
                FrameCallback?.Invoke((Bitmap)img?.Clone());
            }
        }

        public static void Shoot(Action<Bitmap> callback)
        {
            ShootCallback += callback;
        }

    }
}