using System;
using System.Runtime.InteropServices;
using System.Text;

namespace AutoFocusTool.Camera
{
    /// <summary>
    /// Microview MVC2000 相机封装。精简自原工程 aivfo_ccd\Util\Camera.cs +
    /// ivf_tl_CameraHelper\Camera.cs，只保留自动对焦测试程序需要的能力：
    /// 连接 / 采集模式 / 抓单帧 / 调曝光增益 / 取像素 / 转 WPF 位图 / 序列号。
    ///
    /// 重要：所有原生调用用同一把锁串行化（SDK 非线程安全）。
    /// 多舱室共用同一 SDK，跨相机操作也走这把全局锁。
    /// </summary>
    public class Camera : IDisposable
    {
        private static readonly object Locker = new object();

        private readonly int _width;
        private readonly int _height;
        private int _index;
        private int _exposure;

        private CapInfoStruct _capInfo;
        private IntPtr _hImager;     // MV_Usb2Init 返回的设备句柄
        private IntPtr _pDest;       // RGB 输出缓冲（width*height*3）

        public int Index => _index;
        public int Width => _width;
        public int Height => _height;
        public int Exposure => _exposure;
        public string SerialNumber { get; private set; } = "";
        public bool IsInit { get; private set; }
        public bool IsStart { get; private set; }

        /// <param name="index">相机枚举索引 0..9（MV_Usb2Init 用）</param>
        /// <param name="width">分辨率宽，默认 1600</param>
        /// <param name="height">分辨率高，默认 1200</param>
        /// <param name="exposure">曝光时间，单位 100us</param>
        public Camera(int index, int width = 1600, int height = 1200, int exposure = 400)
        {
            _index = index;
            _width = width;
            _height = height;
            _exposure = exposure;
            _pDest = Marshal.AllocCoTaskMem(_width * _height * 3);
        }

        /// <summary>初始化相机。执行后需立即 SetOpMode 才能抓图。返回 0 成功。</summary>
        public int Init(byte redGain = 25, byte greenGain = 14, byte blueGain = 25)
        {
            _capInfo.Buffer = Marshal.AllocCoTaskMem(_width * _height * 3);
            _capInfo.Width = _width;
            _capInfo.Height = _height;
            _capInfo.HorizontalOffset = 0;
            _capInfo.VerticalOffset = 0;
            _capInfo.Exposure = _exposure;
            _capInfo.Gain = new byte[] { redGain, greenGain, blueGain };
            _capInfo.Control = 0x04;
            _capInfo.Reserved = new byte[8];

            int result;
            lock (Locker)
            {
                result = MVCAPI.MV_Usb2Init("MVC2000", out _index, ref _capInfo, out _hImager);
            }
            IsInit = result == 0;
            return result;
        }

        /// <summary>设置采集模式：0=拍照(单帧，对焦用)，1=实时图像。返回 0 成功。</summary>
        public int SetOpMode(byte mode = 0, bool strobe = false)
        {
            if (!IsInit) return -1;
            int result;
            lock (Locker)
            {
                result = MVCAPI.MV_Usb2SetOpMode(_hImager, mode, strobe);
            }
            IsStart = result == 0;
            return result;
        }

        /// <summary>读相机序列号到 SerialNumber。返回 0 成功。</summary>
        public int ReadSerial()
        {
            try
            {
                lock (Locker)
                {
                    var sb = new StringBuilder(125);
                    int r = MVCAPI.MV_Usb2GetSerial(_hImager, sb);
                    SerialNumber = sb.ToString();
                    return r;
                }
            }
            catch { return -2; }
        }

        /// <summary>抓取一帧 RGB 到内部缓冲。返回 0 成功，之后用 GetSourceBuffer / GetBitmapSource 取。</summary>
        public int GrabRgb()
        {
            if (!IsStart) return -1;
            lock (Locker)
            {
                return MVCAPI.MV_Usb2GetRgbData(_hImager, ref _capInfo, _pDest);
            }
        }

        /// <summary>设置曝光时间（单位 100us）。返回 0 成功。</summary>
        public int SetExposure(int exposure100us)
        {
            _exposure = exposure100us;
            _capInfo.Exposure = exposure100us;
            lock (Locker)
            {
                return MVCAPI.MV_Usb2SetPartOfCapInfo(_hImager, ref _capInfo);
            }
        }

        /// <summary>设置 RGB 三通道增益（0-255）。返回 0 成功。</summary>
        public int SetGain(byte red, byte green, byte blue)
        {
            if (_capInfo.Gain == null) _capInfo.Gain = new byte[3];
            _capInfo.Gain[0] = red;
            _capInfo.Gain[1] = green;
            _capInfo.Gain[2] = blue;
            lock (Locker)
            {
                return MVCAPI.MV_Usb2SetPartOfCapInfo(_hImager, ref _capInfo);
            }
        }

        /// <summary>取当前帧像素（24bpp BGR，width*height*3 字节，未翻转）。</summary>
        public byte[] GetSourceBuffer()
        {
            byte[] buf = new byte[_width * _height * 3];
            Marshal.Copy(_pDest, buf, 0, buf.Length);
            return buf;
        }

        /// <summary>卸载相机。</summary>
        public int UnInit()
        {
            int result = 0;
            lock (Locker)
            {
                if (_hImager != IntPtr.Zero)
                    result = MVCAPI.MV_Usb2Uninit(ref _hImager);
            }
            IsInit = false;
            IsStart = false;
            return result;
        }

        public void Dispose()
        {
            try { UnInit(); } catch { }
            if (_pDest != IntPtr.Zero) { Marshal.FreeCoTaskMem(_pDest); _pDest = IntPtr.Zero; }
            if (_capInfo.Buffer != IntPtr.Zero) { Marshal.FreeCoTaskMem(_capInfo.Buffer); _capInfo.Buffer = IntPtr.Zero; }
        }
    }
}