using MediatR;
using Microsoft.Extensions.Logging;
using CellularManagement.Domain.Common;
using CellularManagement.Domain.Entities.Device;
using CellularManagement.Domain.Repositories;
using CellularManagement.Domain.Repositories.Device;

namespace CellularManagement.Application.Features.Devices.Commands.CreateDevice;

/// <summary>
/// 创建设备命令处理器
/// </summary>
public class CreateDeviceCommandHandler : IRequestHandler<CreateDeviceCommand, OperationResult<CreateDeviceResponse>>
{
    private readonly ICellularDeviceRepository _deviceRepository;
    private readonly ILogger<CreateDeviceCommandHandler> _logger;

    /// <summary>
    /// 初始化命令处理器
    /// </summary>
    public CreateDeviceCommandHandler(
        ICellularDeviceRepository deviceRepository,
        ILogger<CreateDeviceCommandHandler> logger)
    {
        _deviceRepository = deviceRepository;
        _logger = logger;
    }

    /// <summary>
    /// 处理创建设备命令
    /// </summary>
    public async Task<OperationResult<CreateDeviceResponse>> Handle(CreateDeviceCommand request, CancellationToken cancellationToken)
    {
        try
        {
            _logger.LogInformation("开始创建设备，设备名称: {DeviceName}, 序列号: {SerialNumber}", 
                request.DeviceName, request.SerialNumber);

            // 检查序列号是否已存在
            if (await _deviceRepository.SerialNumberExistsAsync(request.SerialNumber, cancellationToken))
            {
                _logger.LogWarning("设备序列号已存在: {SerialNumber}", request.SerialNumber);
                return OperationResult<CreateDeviceResponse>.CreateFailure($"设备序列号 {request.SerialNumber} 已存在");
            }

            // 创建设备实体
            var device = CellularDevice.Create(
                name: request.DeviceName,
                serialNumber: request.SerialNumber,
                description: request.Comment,
                deviceTypeId: request.DeviceTypeId,
                statusId: request.StatusId,
                protocolVersionId: request.ProtocolVersionId,
                firmwareVersion: request.HardwareVersion);

            // 保存设备
            await _deviceRepository.AddDeviceAsync(device, cancellationToken);

            // 加载导航属性
            //await _deviceRepository.LoadNavigationPropertiesAsync(device, cancellationToken);

            // 构建响应
            var response = new CreateDeviceResponse
            {
                DeviceId = device.Id,
                DeviceName = device.Name,
                SerialNumber = device.SerialNumber,
                DeviceType = device.DeviceType?.Name ?? "未知",
                Status = device.Status?.Name ?? "未知",
                ProtocolVersion = device.ProtocolVersion?.Version ?? "未知",
                FirmwareVersion = device.FirmwareVersion,
                CreatedAt = device.CreatedAt
            };

            _logger.LogInformation("设备创建成功，设备ID: {DeviceId}, 设备名称: {DeviceName}, 序列号: {SerialNumber}", 
                device.Id, device.Name, device.SerialNumber);
            return OperationResult<CreateDeviceResponse>.CreateSuccess(response);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "创建设备时发生错误，设备名称: {DeviceName}, 序列号: {SerialNumber}", 
                request.DeviceName, request.SerialNumber);
            return OperationResult<CreateDeviceResponse>.CreateFailure($"创建设备时发生错误: {ex.Message}");
        }
    }
}