using System;
using System.Collections.Generic;
using System.IO.Ports;
using System.Linq;
using System.Threading;

namespace IvfTl.Hardware.Impl
{
    /// <summary>
    /// 统一硬件访问层单例（13 §3.1）。全进程唯一持有每个 COM 口与每台相机句柄。
    /// 合并后由宿主(operate 主进程)在启动时初始化一次(Instance)，并在 control StartRun 之前 ScanDevices()。
    /// 字典缓存 + 锁保证：GetSerial(port)/GetCamera(index) 重复调用返回同一实例——杜绝同口重复 Open / 同相机重复 Init。
    /// 代码隔离原则(01 §5)：内部包装旧 ComBin/Camera/Channel，不改其内部逻辑。
    /// ⚠ 线程安全见 V-009：所有字典访问经 _lock；单例用 Lazy 双检。
    /// </summary>
    public sealed class HardwareAccessLayer : IHardwareAccessLayer
    {
        private static readonly Lazy<HardwareAccessLayer> _instance =
            new Lazy<HardwareAccessLayer>(() => new HardwareAccessLayer(), LazyThreadSafetyMode.ExecutionAndPublication);

        /// <summary>进程级单例。</summary>
        public static HardwareAccessLayer Instance => _instance.Value;

        private readonly object _lock = new object();
        private readonly Dictionary<string, ISerialChannel> _serials = new Dictionary<string, ISerialChannel>(StringComparer.OrdinalIgnoreCase);
        private readonly Dictionary<int, ICamera> _cameras = new Dictionary<int, ICamera>();
        private readonly Dictionary<int, IHouseGate> _gates = new Dictionary<int, IHouseGate>();

        // 设备发现结果：houseSn → 设备信息（port + 配对相机 index）。
        private readonly Dictionary<int, HouseDeviceInfo> _houses = new Dictionary<int, HouseDeviceInfo>();

        private readonly CameraGateImpl _cameraGate = new CameraGateImpl();

        /// <summary>日志回调（宿主可注入到 LogService）。</summary>
        public Action<string> Log { get; set; }

        private HardwareAccessLayer() { }

        public ICameraGate CameraGate => _cameraGate;

        // ── 唯一持有：串口 ──
        public ISerialChannel GetSerial(string portName) => GetSerial(0, portName);

        public ISerialChannel GetSerial(int houseId, string portName)
        {
            if (string.IsNullOrEmpty(portName)) throw new ArgumentNullException(nameof(portName));
            lock (_lock)
            {
                if (!_serials.TryGetValue(portName, out var ch))
                {
                    // houseId 仅用于 ComBin 内部日志；唯一持有以 portName 为键。
                    ch = new SerialChannelImpl(houseId, portName);
                    _serials[portName] = ch;
                }
                return ch;
            }
        }

        // ── 唯一持有：相机 ──
        public ICamera GetCamera(int cameraIndex) => GetCamera(cameraIndex, 1600, 1200, 400);

        public ICamera GetCamera(int cameraIndex, int width, int height, int exposure)
        {
            lock (_lock)
            {
                if (!_cameras.TryGetValue(cameraIndex, out var cam))
                {
                    cam = new CameraImpl(cameraIndex, width, height, exposure, _cameraGate);
                    _cameras[cameraIndex] = cam;
                }
                return cam;
            }
        }

        // ── 按舱取句柄组 ──
        public IHouseHandle GetHouse(int houseSn)
        {
            lock (_lock)
            {
                if (!_houses.TryGetValue(houseSn, out var info))
                {
                    throw new InvalidOperationException($"舱 {houseSn} 未在 ScanDevices 中发现，无法取句柄组。请先 ScanDevices()。");
                }
                ISerialChannel serial = GetSerialNoLock(info.PortName);
                ICamera camera = info.CcdIndex >= 0 ? GetCameraNoLock(info.CcdIndex) : null;
                IHouseGate gate = GetHouseGateNoLock(houseSn, info);
                return new HouseHandle(houseSn, serial, camera, gate);
            }
        }

        public IHouseGate GetHouseGate(int houseSn)
        {
            lock (_lock)
            {
                _houses.TryGetValue(houseSn, out var info);
                return GetHouseGateNoLock(houseSn, info);
            }
        }

        private ISerialChannel GetSerialNoLock(string portName)
        {
            if (!_serials.TryGetValue(portName, out var ch))
            {
                ch = new SerialChannelImpl(0, portName);
                _serials[portName] = ch;
            }
            return ch;
        }

        private ICamera GetCameraNoLock(int cameraIndex)
        {
            if (!_cameras.TryGetValue(cameraIndex, out var cam))
            {
                cam = new CameraImpl(cameraIndex, 1600, 1200, 400, _cameraGate);
                _cameras[cameraIndex] = cam;
            }
            return cam;
        }

        private IHouseGate GetHouseGateNoLock(int houseSn, HouseDeviceInfo info)
        {
            if (!_gates.TryGetValue(houseSn, out var gate))
            {
                string port = info?.PortName;
                int idx = info?.CcdIndex ?? -1;
                gate = new HouseGateImpl(
                    houseSn,
                    () => port != null ? GetSerialNoLock(port) : null,
                    () => idx >= 0 ? GetCameraNoLock(idx) : null);
                _gates[houseSn] = gate;
            }
            return gate;
        }

        // ── 设备发现 ──
        public IReadOnlyList<HouseDeviceInfo> ScanDevices()
        {
            // 复刻 af DeviceScanner.ScanAll / control SerialBin.UpdataCamera+Start：
            //   ① 枚举相机 0..9 读 SN，得 ccdSn → cameraIndex；
            //   ② 扫描 COM 口握手得 houseSn + 读 EEPROM 得该舱 CCDSN；
            //   ③ 按 CCDSN 把舱与相机 index 配对。
            // ⚠ 13 §⑤ V7 / V-009：index/COM 每次开机可变，必须现场重扫，禁止写死。
            var result = new List<HouseDeviceInfo>();

            // ① 相机 SN → index
            // 用临时相机实例读 SN（不进 HAL 缓存）：避免以默认分辨率缓存相机，
            // 采集端随后用各舱实际 ccdWidth/ccdHeight 经 GetCamera(index,w,h,exp) 惰性创建正确实例。
            var snToIndex = new Dictionary<string, int>();
            for (int i = 0; i < 10; i++)
            {
                ICamera cam = new CameraImpl(i, 100, 100, 100, _cameraGate);
                try
                {
                    if (cam.Init() == 0)
                    {
                        cam.ReadSerial();
                        string sn = cam.SerialNumber;
                        if (!string.IsNullOrEmpty(sn) && !snToIndex.ContainsKey(sn))
                            snToIndex[sn] = i;
                        cam.UnInit();
                    }
                }
                catch (Exception ex)
                {
                    Log?.Invoke($"[HAL] 枚举相机 {i} 异常: {ex.Message}");
                }
                finally
                {
                    try { cam.Dispose(); } catch { }
                }
            }

            // ② / ③ 扫 COM 口握手 + 配对
            string[] ports;
            try { ports = SerialPort.GetPortNames(); }
            catch { ports = Array.Empty<string>(); }

            foreach (var port in ports)
            {
                if (port == "COM1" || port == "COM2" || !port.Contains("COM")) continue;
                ISerialChannel ch = GetSerial(port);
                try
                {
                    if (!ch.Open()) { Log?.Invoke($"[HAL] {port} 打开失败"); continue; }
                    int houseSn = ch.ShakeHandsWait();
                    if (houseSn < 0) { Log?.Invoke($"[HAL] {port} 握手失败"); continue; }

                    string ccdSn = null;
                    int ccdIndex = -1;
                    if (houseSn != 11) // 11 = 缓冲瓶/总控模块，无相机
                    {
                        int ccd = ch.ReadCcdSnWait();
                        if (ccd >= 0)
                        {
                            ccdSn = ccd.ToString();
                            if (snToIndex.TryGetValue(ccdSn, out int idx)) ccdIndex = idx;
                        }
                    }

                    var info = new HouseDeviceInfo
                    {
                        HouseSn = houseSn,
                        PortName = port,
                        CcdSn = ccdSn,
                        CcdIndex = ccdIndex
                    };
                    lock (_lock) { _houses[houseSn] = info; }
                    result.Add(info);
                    Log?.Invoke($"[HAL] 发现舱 {houseSn} @ {port}, CCDSN={ccdSn}, index={ccdIndex}");
                }
                catch (Exception ex)
                {
                    Log?.Invoke($"[HAL] 扫描 {port} 异常: {ex.Message}");
                }
                finally
                {
                    try { ch.Close(); } catch { }
                }
            }

            return result;
        }

        // ── 采集端补登记设备表（ScanDevices 现场漏扫某舱时的双保险；T1.4）──
        public void RegisterHouse(int houseSn, string portName, int ccdIndex)
        {
            if (string.IsNullOrEmpty(portName)) return;
            lock (_lock)
            {
                // ScanDevices(登录后由 MainWindow 调)若已发现本舱，以其现场实时枚举结果为准、不覆盖；
                // 仅补 ScanDevices 漏扫(如该舱握手失败)但采集端有服务器配置的舱，使其借用仍可用。
                if (_houses.ContainsKey(houseSn)) return;
                _houses[houseSn] = new HouseDeviceInfo
                {
                    HouseSn = houseSn,
                    PortName = portName,
                    CcdSn = null,
                    CcdIndex = ccdIndex
                };
                _gates.Remove(houseSn);
            }
        }

        // ── 统一关闭 ──
        public void ShutdownAll()
        {
            lock (_lock)
            {
                foreach (var c in _cameras.Values) { try { c.Dispose(); } catch { } }
                foreach (var s in _serials.Values) { try { s.Dispose(); } catch { } }
                _cameras.Clear();
                _serials.Clear();
                _gates.Clear();
                _houses.Clear();
            }
        }

        private sealed class HouseHandle : IHouseHandle
        {
            public HouseHandle(int sn, ISerialChannel serial, ICamera camera, IHouseGate gate)
            {
                HouseSn = sn; Serial = serial; Camera = camera; Gate = gate;
            }
            public int HouseSn { get; }
            public ISerialChannel Serial { get; }
            public ICamera Camera { get; }
            public IHouseGate Gate { get; }
        }
    }
}