using BBWY.Common.Models;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Options;
using Microsoft.Extensions.Primitives;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace BBWY.Server.API.Middlewares
{
    public class ClientVersionValidationMiddleWare
    {
        /// <summary>
        /// 管道请求委托
        /// </summary>
        private RequestDelegate _next;

        private IDictionary<string, int> apiVersionDictionary;

        private IOptionsMonitor<List<ClientVersionValidationModel>> _monitor;

        public ClientVersionValidationMiddleWare(RequestDelegate requestDelegate, IOptionsMonitor<List<ClientVersionValidationModel>> monitor)
        {
            _next = requestDelegate;
            _monitor = monitor;
            apiVersionDictionary = new Dictionary<string, int>();
        }

        public async Task Invoke(HttpContext context)
        {
            try
            {
                Console.WriteLine(context.Request.Path);
                var apiRequirement = _monitor.CurrentValue.FirstOrDefault(x => x.Api.Equals(context.Request.Path, StringComparison.CurrentCultureIgnoreCase));
                if (apiRequirement != null)
                {
                    if (!context.Request.Headers.TryGetValue("ClientVersion", out StringValues clientVersionStr))
                        throw new BusinessException("未读取到ClientVersion");
                    if (!int.TryParse(clientVersionStr, out int clientVersion))
                        throw new BusinessException("非法ClientVersion");
                    if (clientVersion < apiRequirement.MinimumVersion)
                        throw new BusinessException("当前ClientVersion低于接口最低要求,请升级到最新版");
                }
                await _next(context);   //调用管道执行下一个中间件
            }
            catch
            {
                throw;
            }
        }
    }

    public class ClientVersionValidationModel
    {
        public string Api { get; set; }

        public int MinimumVersion { get; set; }
    }
}