using Model.Models;
using Prism.Events;
using System;
using System.Text;
using UIShare.PubEvent;
using ZLGUSBCANFD;

namespace UIShare.GlobalVariable
{
    /// <summary>
    /// CAN 信号广播器：订阅 ZLGCANFD.OnDbcMessageDecoded 事件，
    /// 将解码后的 DBC 信号值通过 HardwareDataReportedEvent 广播给监控系统。
    /// 由 DeviceManager 创建和管理，生命周期与 CAN 设备绑定。
    /// </summary>
    public class CANSignalBroadcaster : IDisposable
    {
        private readonly IEventAggregator _eventAggregator;
        private readonly string _scopeName;
        private ZLGCANFD? _canfd;
        private bool _disposed;

        public CANSignalBroadcaster(IEventAggregator eventAggregator, string scopeName)
        {
            _eventAggregator = eventAggregator;
            _scopeName = scopeName;
        }

        /// <summary>
        /// 绑定 CANFD 实例并订阅解码事件。
        /// </summary>
        public void Bind(ZLGCANFD canfd)
        {
            Unbind();
            _canfd = canfd;
            _canfd.OnDbcMessageDecoded += OnDbcMessageDecoded;
        }

        /// <summary>
        /// 取消订阅。
        /// </summary>
        public void Unbind()
        {
            if (_canfd != null)
            {
                _canfd.OnDbcMessageDecoded -= OnDbcMessageDecoded;
                _canfd = null;
            }
        }

        /// <summary>
        /// DBC 解码回调：提取所有信号并广播。
        /// </summary>
        private void OnDbcMessageDecoded(uint channel, ZDBC.DBCMessage msg)
        {
            if (_disposed) return;

            string fingerprint = $"CAN:{channel}";
            var now = DateTime.Now;

            for (int i = 0; i < msg.nSignalCount; i++)
            {
                var signal = msg.vSignals[i];
                string signalName = Encoding.Default.GetString(signal.strName).TrimEnd('\0');
                if (string.IsNullOrEmpty(signalName)) continue;

                // 计算物理值：physical = raw * factor + offset
                double physicalValue = signal.nRawvalue * signal.nFactor + signal.nOffset;

                // MethodName 格式："{MessageId:X}.{SignalName}"
                string methodName = $"{msg.nID:X}.{signalName}";

                _eventAggregator.GetEvent<HardwareDataReportedEvent>().Publish(new HardwareReportArgs
                {
                    Scope = _scopeName,
                    HardwareFingerprint = fingerprint,
                    MethodName = methodName,
                    Value = physicalValue,
                    Time = now
                });
            }
        }

        /// <summary>
        /// 生成 CAN 信号的 DisplayName 格式："{MessageName}.{SignalName}"
        /// </summary>
        public static string BuildDisplayName(string messageName, string signalName)
        {
            return $"{messageName}.{signalName}";
        }

        /// <summary>
        /// 生成 CAN 信号的 MethodName 格式："{MessageId:X}.{SignalName}"
        /// </summary>
        public static string BuildMethodName(uint messageId, string signalName)
        {
            return $"{messageId:X}.{signalName}";
        }

        /// <summary>
        /// 生成 CAN 信号的 Fingerprint 格式："CAN:{Channel}"
        /// </summary>
        public static string BuildFingerprint(uint channel)
        {
            return $"CAN:{channel}";
        }

        public void Dispose()
        {
            if (_disposed) return;
            _disposed = true;
            Unbind();
        }
    }
}