using Apimanager_backend.Models;
using System.Reflection;
using System;
using Apimanager_backend.Data;
using Microsoft.EntityFrameworkCore;
using Apimanager_backend.Exceptions;
using Apimanager_backend.Dtos;
using Public;
using Apimanager_backend.Services;

namespace Apimanager_backend.Tools
{
    public class BillableApiDispatcher
    {
        private readonly IServiceProvider _serviceProvider;
        private readonly ApiContext _db;
        private PluginLoaderService _pluginLoaderService;

        public BillableApiDispatcher(IServiceProvider sp, ApiContext db,PluginLoaderService pluginLoaderService)
        {
            _serviceProvider = sp;
            _db = db;
            _pluginLoaderService = pluginLoaderService;
        }

        public async Task<object> DispatchAsync(string webPath,int apiId,string code, ApiCallContext context)
        {
            //_pluginLoaderService.LoadPlugins(new ServiceCollection());
            // 1. 安全验证
            string dllPath = webPath + "\\ApiHandler\\" + code + ".dll";
            if (!System.IO.File.Exists(dllPath))
                throw new BaseException(3002, "接口实现未找到");

            // 2. 加载程序集
            var assembly = Assembly.LoadFrom(dllPath); // 或使用 AssemblyLoadContext.Default.LoadFromAssemblyPath

            // 3. 查找实现类
            var type = assembly.GetTypes()
                .FirstOrDefault(t =>
                    typeof(IBillableApiHandler).IsAssignableFrom(t) &&
                    !t.IsInterface &&
                    !t.IsAbstract &&
                    t.Name.Equals(code, StringComparison.OrdinalIgnoreCase));
            if (type == null)
                throw new BaseException(3002,"接口实现未找到");

            List<UserPackage> userPackages = context.HttpContext.Items["userPackages"] as List<UserPackage>;
            List<UserPackage> userPackageList = null;

            if (userPackages == null || !(userPackages is IEnumerable<UserPackage>))
            {
                throw new BaseException(3004, "未购买该API套餐或权限不足");
            }

            userPackageList = ((IEnumerable<UserPackage>)userPackages).ToList();

            userPackageList = userPackageList.Where(x => x.ExpiryDate > DateTime.Now).ToList();

            if (userPackageList.Count == 0)
            {
                throw new BaseException(3004, "未购买该API套餐或权限不足");
            }


            var maxCountUserPackage = userPackageList.MaxBy(x => x.RemainingCalls);

            if (maxCountUserPackage.RemainingCalls <= 0)
            {
                throw new BaseException(3004, "套餐可用额度不足");
            }

            var uPackage = await _db.UserPackages.SingleOrDefaultAsync(x => x.Id == maxCountUserPackage.Id);
            if (uPackage == null)
            {
                throw new BaseException(3004, "未购买该API套餐或权限不足");
            }

            uPackage.RemainingCalls -= 1;

            _db.UserPackages.Update(uPackage);

            var handler = (IBillableApiHandler)Activator.CreateInstance(type)!;

            // 执行接口
            var result = await handler.ExecuteAsync(context);

            // 记录调用日志
            _db.CallLogs.Add(new ApiCallLog
            {
                ApiId = apiId,
                UserId = context.UserId,
                CallTime = DateTime.UtcNow
            });

            await _db.SaveChangesAsync();
            return result;
        }

    }
}