using System.Reflection;
using GFramework.SourceGenerators.Cqrs;
using GFramework.SourceGenerators.Tests.Core;

namespace GFramework.SourceGenerators.Tests.Cqrs;

/// <summary>
///     验证 CQRS 处理器注册生成器的输出与回退边界。
/// </summary>
[TestFixture]
public class CqrsHandlerRegistryGeneratorTests
{
    /// <summary>
    ///     验证生成器会为当前程序集中的 request、notification 和 stream 处理器生成稳定顺序的注册器。
    /// </summary>
    [Test]
    public async Task Generates_Assembly_Level_Cqrs_Handler_Registry()
    {
        const string source = """
                              using System;
                              using System.Collections.Generic;

                              namespace Microsoft.Extensions.DependencyInjection
                              {
                                  public interface IServiceCollection { }

                                  public static class ServiceCollectionServiceExtensions
                                  {
                                      public static void AddTransient(IServiceCollection services, Type serviceType, Type implementationType) { }
                                  }
                              }

                              namespace GFramework.Core.Abstractions.Logging
                              {
                                  public interface ILogger
                                  {
                                      void Debug(string msg);
                                  }
                              }

                              namespace GFramework.Cqrs.Abstractions.Cqrs
                              {
                                  public interface IRequest<TResponse> { }
                                  public interface INotification { }
                                  public interface IStreamRequest<TResponse> { }

                                  public interface IRequestHandler<in TRequest, TResponse> where TRequest : IRequest<TResponse> { }
                                  public interface INotificationHandler<in TNotification> where TNotification : INotification { }
                                  public interface IStreamRequestHandler<in TRequest, out TResponse> where TRequest : IStreamRequest<TResponse> { }
                              }

                              namespace GFramework.Cqrs
                              {
                                  public interface ICqrsHandlerRegistry
                                  {
                                      void Register(Microsoft.Extensions.DependencyInjection.IServiceCollection services, GFramework.Core.Abstractions.Logging.ILogger logger);
                                  }

                                  [AttributeUsage(AttributeTargets.Assembly, AllowMultiple = true)]
                                  public sealed class CqrsHandlerRegistryAttribute : Attribute
                                  {
                                      public CqrsHandlerRegistryAttribute(Type registryType) { }
                                  }
                              }

                              namespace TestApp
                              {
                                  using GFramework.Cqrs.Abstractions.Cqrs;

                                  public sealed record PingQuery() : IRequest<string>;
                                  public sealed record DomainEvent() : INotification;
                                  public sealed record NumberStream() : IStreamRequest<int>;

                                  public sealed class ZetaNotificationHandler : INotificationHandler<DomainEvent> { }
                                  public sealed class AlphaQueryHandler : IRequestHandler<PingQuery, string> { }
                                  public sealed class StreamHandler : IStreamRequestHandler<NumberStream, int> { }
                              }
                              """;

        const string expected = """
                                // <auto-generated />
                                #nullable enable

                                [assembly: global::GFramework.Cqrs.CqrsHandlerRegistryAttribute(typeof(global::GFramework.Generated.Cqrs.__GFrameworkGeneratedCqrsHandlerRegistry))]

                                namespace GFramework.Generated.Cqrs;

                                internal sealed class __GFrameworkGeneratedCqrsHandlerRegistry : global::GFramework.Cqrs.ICqrsHandlerRegistry
                                {
                                    public void Register(global::Microsoft.Extensions.DependencyInjection.IServiceCollection services, global::GFramework.Core.Abstractions.Logging.ILogger logger)
                                    {
                                        if (services is null)
                                            throw new global::System.ArgumentNullException(nameof(services));
                                        if (logger is null)
                                            throw new global::System.ArgumentNullException(nameof(logger));

                                        global::Microsoft.Extensions.DependencyInjection.ServiceCollectionServiceExtensions.AddTransient(
                                            services,
                                            typeof(global::GFramework.Cqrs.Abstractions.Cqrs.IRequestHandler<global::TestApp.PingQuery, string>),
                                            typeof(global::TestApp.AlphaQueryHandler));
                                        logger.Debug("Registered CQRS handler TestApp.AlphaQueryHandler as GFramework.Cqrs.Abstractions.Cqrs.IRequestHandler<TestApp.PingQuery, string>.");
                                        global::Microsoft.Extensions.DependencyInjection.ServiceCollectionServiceExtensions.AddTransient(
                                            services,
                                            typeof(global::GFramework.Cqrs.Abstractions.Cqrs.IStreamRequestHandler<global::TestApp.NumberStream, int>),
                                            typeof(global::TestApp.StreamHandler));
                                        logger.Debug("Registered CQRS handler TestApp.StreamHandler as GFramework.Cqrs.Abstractions.Cqrs.IStreamRequestHandler<TestApp.NumberStream, int>.");
                                        global::Microsoft.Extensions.DependencyInjection.ServiceCollectionServiceExtensions.AddTransient(
                                            services,
                                            typeof(global::GFramework.Cqrs.Abstractions.Cqrs.INotificationHandler<global::TestApp.DomainEvent>),
                                            typeof(global::TestApp.ZetaNotificationHandler));
                                        logger.Debug("Registered CQRS handler TestApp.ZetaNotificationHandler as GFramework.Cqrs.Abstractions.Cqrs.INotificationHandler<TestApp.DomainEvent>.");
                                    }
                                }

                                """;

        await GeneratorTest<CqrsHandlerRegistryGenerator>.RunAsync(
            source,
            ("CqrsHandlerRegistry.g.cs", expected));
    }

    /// <summary>
    ///     验证当程序集包含生成代码无法合法引用的私有嵌套处理器时，生成器会放弃产出并让运行时回退到反射扫描。
    /// </summary>
    [Test]
    public async Task Skips_Generation_When_Assembly_Contains_Private_Nested_Handler()
    {
        const string source = """
                              using System;

                              namespace Microsoft.Extensions.DependencyInjection
                              {
                                  public interface IServiceCollection { }

                                  public static class ServiceCollectionServiceExtensions
                                  {
                                      public static void AddTransient(IServiceCollection services, Type serviceType, Type implementationType) { }
                                  }
                              }

                              namespace GFramework.Core.Abstractions.Logging
                              {
                                  public interface ILogger
                                  {
                                      void Debug(string msg);
                                  }
                              }

                              namespace GFramework.Cqrs.Abstractions.Cqrs
                              {
                                  public interface IRequest<TResponse> { }
                                  public interface INotification { }
                                  public interface IStreamRequest<TResponse> { }

                                  public interface IRequestHandler<in TRequest, TResponse> where TRequest : IRequest<TResponse> { }
                                  public interface INotificationHandler<in TNotification> where TNotification : INotification { }
                                  public interface IStreamRequestHandler<in TRequest, out TResponse> where TRequest : IStreamRequest<TResponse> { }
                              }

                              namespace GFramework.Cqrs
                              {
                                  public interface ICqrsHandlerRegistry
                                  {
                                      void Register(Microsoft.Extensions.DependencyInjection.IServiceCollection services, GFramework.Core.Abstractions.Logging.ILogger logger);
                                  }

                                  [AttributeUsage(AttributeTargets.Assembly, AllowMultiple = true)]
                                  public sealed class CqrsHandlerRegistryAttribute : Attribute
                                  {
                                      public CqrsHandlerRegistryAttribute(Type registryType) { }
                                  }
                              }

                              namespace TestApp
                              {
                                  using GFramework.Cqrs.Abstractions.Cqrs;

                                  public sealed record VisibleRequest() : IRequest<string>;

                                  public sealed class Container
                                  {
                                      private sealed record HiddenRequest() : IRequest<string>;

                                      private sealed class HiddenHandler : IRequestHandler<HiddenRequest, string> { }
                                  }

                                  public sealed class VisibleHandler : IRequestHandler<VisibleRequest, string> { }
                              }
                              """;

        var test = new CSharpSourceGeneratorTest<CqrsHandlerRegistryGenerator, DefaultVerifier>
        {
            TestState =
            {
                Sources = { source }
            },
            DisabledDiagnostics = { "GF_Common_Trace_001" }
        };

        await test.RunAsync();
    }

    /// <summary>
    ///     验证日志字符串转义会覆盖换行、反斜杠和双引号，避免生成代码中的字符串字面量被意外截断。
    /// </summary>
    [Test]
    public void Escape_String_Literal_Handles_Control_Characters()
    {
        var method = typeof(CqrsHandlerRegistryGenerator).GetMethod(
            "EscapeStringLiteral",
            BindingFlags.NonPublic | BindingFlags.Static);

        Assert.That(method, Is.Not.Null);

        const string input = "line1\r\nline2\\\"";
        const string expected = "line1\\r\\nline2\\\\\\\"";
        var escaped = method!.Invoke(null, [input]) as string;

        Assert.That(escaped, Is.EqualTo(expected));
    }
}