using Kean.Domain.Stock.Commands;
using Kean.Domain.Stock.Models;
using Kean.Domain.Stock.Repositories;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

namespace Kean.Domain.Stock.CommandHandlers
{
    /// <summary>
    /// 盘点命令处理程序
    /// </summary>
    public sealed class InventoryCommandHandler : CommandHandler<InventoryCommand>
    {
        private readonly ICommandBus _commandBus; // 命令总线
        private readonly INotification _notifications; // 总线通知
        private readonly IStockRepository _stockRepository; // 存储仓库

        /// <summary>
        /// 依赖注入
        /// </summary>
        public InventoryCommandHandler(
            ICommandBus commandBus,
            INotification notifications,
            IStockRepository stockRepository)
        {
            _commandBus = commandBus;
            _notifications = notifications;
            _stockRepository = stockRepository;
        }

        /// <summary>
        /// 处理程序
        /// </summary>
        public override async Task Handle(InventoryCommand command, CancellationToken cancellationToken)
        {
            if (command.ValidationResult.IsValid)
            {
                // 时间戳
                command.Timestamp ??= DateTime.Now;
                // 标签
                var innerTag = string.IsNullOrWhiteSpace(command.Tag) ? InventoryCommand.Feature : $"{InventoryCommand.Feature},{command.Tag}";
                // 拆分盈亏
                var profit = new List<StockLine>();
                var loss = new List<StockLine>();
                foreach (var item in await _stockRepository.TakeStock(command.Lines))
                {
                    if (item.Quantity > 0)
                    {
                        loss.Add(item);
                    }
                    else if (item.Quantity < 0)
                    {
                        profit.Add(item);
                    }
                }
                if (profit.Count > 0)
                {
                    // 盘盈出库
                    await _commandBus.Execute(new OutboundCommand
                    {
                        Barcode = command.Barcode,
                        Lines = profit,
                        Operator = command.Operator,
                        Tag = innerTag,
                        Timestamp = command.Timestamp
                    }, cancellationToken);
                }
                if (!_notifications.Any() && loss.Count > 0)
                {
                    // 盘亏入库
                    await _commandBus.Execute(new InboundCommand
                    {
                        Barcode = command.Barcode,
                        Lines = loss,
                        Operator = command.Operator,
                        Tag = innerTag,
                        Timestamp = command.Timestamp
                    }, cancellationToken);
                }
            }
            else
            {
                await _commandBus.Notify(command.ValidationResult,
                    cancellationToken: cancellationToken);
            }
        }
    }
}