using Microsoft.AspNetCore.Mvc.Testing;
using Microsoft.AspNetCore.TestHost;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Caching.Memory;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
using Moq;
using StackExchange.Redis;
using Xunit;
using YarpGateway.Data;
using YarpGateway.DynamicProxy;
using YarpGateway.Services;

namespace YarpGateway.Tests.Integration;

/// <summary>
/// 集成测试基类
/// 提供 WebApplicationFactory 和 HttpClient 的共享实例
/// </summary>
public class TestFixture : IAsyncLifetime
{
    public WebApplicationFactory<Program> Factory { get; private set; } = null!;
    public HttpClient Client { get; private set; } = null!;
    public IServiceProvider Services { get; private set; } = null!;

    public async Task InitializeAsync()
    {
        Factory = new WebApplicationFactory<Program>()
            .WithWebHostBuilder(builder =>
            {
                builder.UseEnvironment("Testing");
                builder.ConfigureServices((context, services) =>
                {
                    // 移除所有与 GatewayDbContext 相关的服务
                    var descriptorsToRemove = services
                        .Where(d => d.ServiceType.Name.Contains("DbContext") || 
                                   d.ServiceType.Name.Contains("GatewayDbContext"))
                        .ToList();
                    foreach (var descriptor in descriptorsToRemove)
                    {
                        services.Remove(descriptor);
                    }

                    // 使用内存数据库替换
                    services.AddDbContextFactory<GatewayDbContext>(options =>
                    {
                        options.UseInMemoryDatabase($"YarpGateway_Test_{Guid.NewGuid()}");
                    });

                    // 移除 PgSqlConfigChangeListener（因为内存数据库不支持 NOTIFY）
                    var listenerDescriptor = services.SingleOrDefault(
                        d => d.ServiceType == typeof(Microsoft.Extensions.Hosting.IHostedService) &&
                             d.ImplementationType == typeof(PgSqlConfigChangeListener));
                    if (listenerDescriptor != null)
                    {
                        services.Remove(listenerDescriptor);
                    }

                    // 移除 Redis 相关服务（测试环境不需要）
                    services.RemoveAll(typeof(StackExchange.Redis.IConnectionMultiplexer));
                    services.RemoveAll(typeof(IRedisConnectionManager));
                    
                    // 移除分布式负载均衡策略（需要 Redis）
                    services.RemoveAll(typeof(Yarp.ReverseProxy.LoadBalancing.ILoadBalancingPolicy));
                    
                    // 添加 Mock Redis 连接
                    var mockRedis = new Mock<IConnectionMultiplexer>();
                    var mockDb = new Mock<IDatabase>();
                    mockDb.Setup(db => db.StringSet(It.IsAny<RedisKey>(), It.IsAny<RedisValue>(), It.IsAny<TimeSpan?>(), It.IsAny<When>(), It.IsAny<CommandFlags>())).Returns(true);
                    mockDb.Setup(db => db.StringGet(It.IsAny<RedisKey>(), It.IsAny<CommandFlags>())).Returns(RedisValue.Null);
                    mockDb.Setup(db => db.ScriptEvaluate(It.IsAny<string>(), It.IsAny<RedisKey[]>(), It.IsAny<RedisValue[]>(), It.IsAny<CommandFlags>())).Returns(RedisResult.Create(1));
                    mockRedis.Setup(r => r.GetDatabase(It.IsAny<int>(), It.IsAny<object?>())).Returns(mockDb.Object);
                    services.AddSingleton(mockRedis.Object);
                    
                    // 添加内存缓存
                    services.AddMemoryCache();
                    
                    // 确保 RouteCache 被正确注册
                    services.RemoveAll(typeof(IRouteCache));
                    services.AddSingleton<IRouteCache, RouteCache>();
                });
            });

        Client = Factory.CreateClient();
        Services = Factory.Services;

        // 初始化数据库种子数据
        await SeedDatabaseAsync();
    }

    public async Task DisposeAsync()
    {
        Client?.Dispose();
        if (Factory != null)
        {
            await Factory.DisposeAsync();
        }
    }

    /// <summary>
    /// 获取新的数据库上下文实例
    /// </summary>
    public GatewayDbContext CreateDbContext()
    {
        var factory = Services.GetRequiredService<IDbContextFactory<GatewayDbContext>>();
        return factory.CreateDbContext();
    }

    /// <summary>
    /// 获取 RouteCache 实例
    /// </summary>
    public IRouteCache GetRouteCache()
    {
        return Services.GetRequiredService<IRouteCache>();
    }

    /// <summary>
    /// 获取 DynamicProxyConfigProvider 实例
    /// </summary>
    public DynamicProxyConfigProvider GetConfigProvider()
    {
        return Services.GetRequiredService<DynamicProxyConfigProvider>();
    }

    /// <summary>
    /// 获取内存缓存实例
    /// </summary>
    public IMemoryCache GetMemoryCache()
    {
        return Services.GetRequiredService<IMemoryCache>();
    }

    /// <summary>
    /// 重新加载配置
    /// </summary>
    public async Task ReloadConfigurationAsync()
    {
        var routeCache = GetRouteCache();
        await routeCache.ReloadAsync();

        var configProvider = GetConfigProvider();
        configProvider.UpdateConfig();
    }

    /// <summary>
    /// 初始化数据库种子数据
    /// </summary>
    private async Task SeedDatabaseAsync()
    {
        using var scope = Services.CreateScope();
        var dbContext = scope.ServiceProvider.GetRequiredService<GatewayDbContext>();

        // 添加测试租户
        await TestData.SeedTenantsAsync(dbContext);
        
        // 添加测试路由
        await TestData.SeedRoutesAsync(dbContext);
        
        // 添加测试集群和目标
        await TestData.SeedClustersAsync(dbContext);

        await dbContext.SaveChangesAsync();

        // 初始化 RouteCache（注意：不要在初始化后调用 UpdateConfig，
        // 因为 DynamicProxyConfigProvider 构造函数中已经调用了它，
        // 额外的调用可能导致 YARP 配置管理器的递归问题）
        var routeCache = scope.ServiceProvider.GetRequiredService<IRouteCache>();
        await routeCache.InitializeAsync();
    }
}

/// <summary>
/// 集合定义，确保使用 TestFixture 的测试不会并行执行
/// </summary>
[CollectionDefinition("Integration Tests")]
public class IntegrationTestCollection : ICollectionFixture<TestFixture>
{
}