using AutoMapper;
using Kean.Domain.Order.Commands;
using Kean.Domain.Order.Events;
using Kean.Domain.Order.Repositories;
using System.Threading;
using System.Threading.Tasks;

namespace Kean.Domain.Order.CommandHandlers
{
    /// <summary>
    /// 修改订单命令处理程序
    /// </summary>
    public sealed class ModifyOrderCommandHandler : CommandHandler<ModifyOrderCommand>
    {
        private readonly ICommandBus _commandBus; // 命令总线
        private readonly IMapper _mapper; // 模型映射
        private readonly IOrderRepository _orderRepository; // 订单仓库

        /// <summary>
        /// 依赖注入
        /// </summary>
        public ModifyOrderCommandHandler(
            ICommandBus commandBus,
            IMapper mapper,
            IOrderRepository orderRepository)
        {
            _commandBus = commandBus;
            _mapper = mapper;
            _orderRepository = orderRepository;
        }

        /// <summary>
        /// 处理程序
        /// </summary>
        public override async Task Handle(ModifyOrderCommand command, CancellationToken cancellationToken)
        {
            if (command.ValidationResult.IsValid)
            {
                if (!await _orderRepository.IsOrderExist(command.Id))
                {
                    await _commandBus.Notify(nameof(command.Id), "订单不存在", command.Id,
                        cancellationToken: cancellationToken);
                    return;
                }
                // 更新订单
                if (await _orderRepository.ModifyOrder(command.Id, command.Lines).ContinueWith(task =>
                {
                    if (task.Exception?.InnerException is RepositoryException ex)
                    {
                        task.Exception.Handle(_ => true);
                        _commandBus.Notify(ex.Member.Key, ex.Message, ex.Member.Value,
                            cancellationToken: cancellationToken).Wait();
                        return true;
                    }
                    return false;
                }))
                {
                    return;
                }
                var @event = _mapper.Map<ModifyOrderSuccessEvent>(command);
                await _commandBus.Trigger(@event, cancellationToken);
            }
            else
            {
                await _commandBus.Notify(command.ValidationResult,
                    cancellationToken: cancellationToken);
            }
        }
    }
}