using Prism.Events;
using System.Text.Json;
using YY.Admin.Core;
using YY.Admin.Core.Events;
using YY.Admin.Core.Services;

namespace YY.Admin.Services.Service.Vehicle;

/// <summary>
/// 监听 STOMP 收到的车辆变更信号，转发为桌面端 Prism 事件，触发列表刷新。
/// </summary>
public class VehicleSyncCoordinator : ISingletonDependency
{
    private readonly IEventAggregator _eventAggregator;
    private readonly ILoggerService _logger;
    private SubscriptionToken? _remoteCommandToken;
    private SubscriptionToken? _networkStatusToken;

    public VehicleSyncCoordinator(IEventAggregator eventAggregator, ILoggerService logger)
    {
        _eventAggregator = eventAggregator;
        _logger = logger;
        _remoteCommandToken = _eventAggregator
            .GetEvent<RemoteCommandReceivedEvent>()
            .Subscribe(OnRemoteCommand, ThreadOption.BackgroundThread);
        // 断线重连后补拉一次，覆盖离线期间漏掉的 STOMP 事件
        _networkStatusToken = _eventAggregator
            .GetEvent<NetworkStatusChangedEvent>()
            .Subscribe(OnNetworkStatusChanged, ThreadOption.BackgroundThread);
        _logger.Information("[车辆推送] VehicleSyncCoordinator 已启动，开始监听 RemoteCommandReceivedEvent");
    }

    private void OnNetworkStatusChanged(NetworkStatusChangedPayload payload)
    {
        if (!payload.IsOnline) return;
        _logger.Information("[车辆推送] 网络恢复，触发补偿刷新");
        _eventAggregator.GetEvent<VehicleChangedEvent>().Publish(new VehicleChangedPayload { Action = "reconnect" });
    }

    private void OnRemoteCommand(RemoteCommandPayload payload)
    {
        try
        {
            var json = payload.CommandJson ?? string.Empty;
            if (string.IsNullOrWhiteSpace(json))
            {
                _logger.Information("[车辆推送] 收到空命令，忽略");
                return;
            }

            using var doc = JsonDocument.Parse(json);
            if (!doc.RootElement.TryGetProperty("cmd", out var cmdEl))
            {
                _logger.Information("[车辆推送] 命令无cmd字段，忽略");
                return;
            }
            var cmd = cmdEl.GetString() ?? string.Empty;
            if (!cmd.Equals("MES_VEHICLE_CHANGED", StringComparison.OrdinalIgnoreCase))
            {
                _logger.Information($"[车辆推送] 非车辆命令 cmd={cmd}，忽略");
                return;
            }

            doc.RootElement.TryGetProperty("action", out var actionEl);
            doc.RootElement.TryGetProperty("vehicleId", out var idEl);

            var changedPayload = new VehicleChangedPayload
            {
                Action = actionEl.GetString() ?? string.Empty,
                VehicleId = idEl.ValueKind == JsonValueKind.String ? idEl.GetString() : null,
            };

            _logger.Information($"收到车辆变更信号: action={changedPayload.Action}, vehicleId={changedPayload.VehicleId}");
            _eventAggregator.GetEvent<VehicleChangedEvent>().Publish(changedPayload);
        }
        catch (Exception ex)
        {
            _logger.Warning($"处理 STOMP 车辆变更信号失败: {ex.Message}");
        }
    }
}