using BuildFlow.Shared.Domain.Common;
using BuildFlow.Shared.Infrastructure;
using File.Application.Common;
using File.Application.Features.Files.Commands;
using File.Application.Features.Files.Handlers;
using File.Domain.Entities;
using File.Infrastructure.Persistence;
using File.Infrastructure.Storage;
using FluentAssertions;
using Microsoft.EntityFrameworkCore;
using Moq;
using Xunit;

namespace BuildFlow.File.Tests;

/// <summary>
/// 删除文件命令处理器测试。核心回归：删除必须同时清理 S3 对象和 FileMeta 记录，
/// 否则文件夹视图（读 DB）仍显示已失效文件，或 S3 残留孤儿对象。
/// </summary>
public class DeleteFileCommandHandlerTests
{
    private const string Bucket = "build-flow";
    private const string Key = "multipart/abc123";

    /// <summary>测试用 bucket 解析器，固定返回与 <see cref="Bucket"/> 一致的桶名。</summary>
    private static IBucketResolver BucketResolver()
    {
        var mock = new Mock<IBucketResolver>();
        mock.Setup(r => r.GetDefaultBucketAsync(It.IsAny<CancellationToken>())).ReturnsAsync(Bucket);
        return mock.Object;
    }

    /// <summary>构造测试依赖：InMemory DB（挂审计拦截器自动填充非空字段）+ Mock S3 + Mock Mediator。</summary>
    private static (FileDbContext db, Mock<IS3StorageService> s3, Mock<MediatR.IMediator> mediator) CreateDeps(string dbName)
    {
        var user = new Mock<ICurrentUserContext>();
        user.SetupGet(u => u.UserId).Returns("user-001");
        user.SetupGet(u => u.IPAddress).Returns("127.0.0.1");
        var s3 = new Mock<IS3StorageService>();
        var mediator = new Mock<MediatR.IMediator>();
        var options = new DbContextOptionsBuilder<FileDbContext>()
            .UseInMemoryDatabase(dbName)
            .AddInterceptors(new AuditInterceptor(user.Object))
            .Options;
        return (new FileDbContext(options), s3, mediator);
    }

    /// <summary>构造一条 FileMeta 记录。</summary>
    private static FileMeta NewMeta(string bucket, string key, string owner = "user-001")
        => new()
        {
            Id = Guid.NewGuid(),
            Name = key,
            S3Key = key,
            S3Bucket = bucket,
            Size = 1024,
            ContentType = "text/plain",
            OwnerId = owner,
        };

    [Fact]
    public async Task Delete_存在FileMeta_同时删S3和数据库记录()
    {
        // Arrange：DB 有一条匹配的 FileMeta
        var (db, s3, mediator) = CreateDeps(nameof(Delete_存在FileMeta_同时删S3和数据库记录));
        db.Files.Add(NewMeta(Bucket, Key));
        await db.SaveChangesAsync();

        var handler = new DeleteFileCommandHandler(s3.Object, db, BucketResolver(), mediator.Object);

        // Act
        await handler.Handle(new DeleteFileCommand(Key), CancellationToken.None);

        // Assert：S3 对象已删
        s3.Verify(x => x.DeleteFileAsync(Bucket, Key, It.IsAny<CancellationToken>()), Times.Once);
        // Assert：FileMeta 记录已删（核心回归点——之前漏删导致文件夹视图仍显示）
        var remaining = await db.Files.ToListAsync();
        remaining.Should().BeEmpty("删除后 FileMeta 记录必须同步清理");
    }

    [Fact]
    public async Task Delete_无FileMeta记录_仍删S3对象_不报错()
    {
        // Arrange：DB 无匹配记录（如根目录直传未落库、或已被其他途径清理）
        var (db, s3, mediator) = CreateDeps(nameof(Delete_无FileMeta记录_仍删S3对象_不报错));
        var handler = new DeleteFileCommandHandler(s3.Object, db, BucketResolver(), mediator.Object);

        // Act
        await handler.Handle(new DeleteFileCommand(Key), CancellationToken.None);

        // Assert：S3 仍尝试删除（幂等，删不存在的对象也返回成功）
        s3.Verify(x => x.DeleteFileAsync(Bucket, Key, It.IsAny<CancellationToken>()), Times.Once);
    }

    [Fact]
    public async Task Delete_多条同bucket同key的FileMeta_全部清理()
    {
        // Arrange：极端场景——同 bucket+key 存在多条 FileMeta（历史数据或并发落库）
        var (db, s3, mediator) = CreateDeps(nameof(Delete_多条同bucket同key的FileMeta_全部清理));
        db.Files.Add(NewMeta(Bucket, Key, "user-001"));
        db.Files.Add(NewMeta(Bucket, Key, "user-002"));
        await db.SaveChangesAsync();

        var handler = new DeleteFileCommandHandler(s3.Object, db, BucketResolver(), mediator.Object);

        // Act
        await handler.Handle(new DeleteFileCommand(Key), CancellationToken.None);

        // Assert：两条记录都被清理
        var remaining = await db.Files.Where(f => f.S3Bucket == Bucket && f.S3Key == Key).ToListAsync();
        remaining.Should().BeEmpty("同 bucket+key 的所有 FileMeta 都应被清理");
    }

    [Fact]
    public async Task Delete_不影响其他文件的FileMeta()
    {
        // Arrange：删 A 文件，B 文件应不受影响
        var (db, s3, mediator) = CreateDeps(nameof(Delete_不影响其他文件的FileMeta));
        db.Files.Add(NewMeta(Bucket, "multipart/aaa"));
        db.Files.Add(NewMeta(Bucket, "multipart/bbb"));
        await db.SaveChangesAsync();

        var handler = new DeleteFileCommandHandler(s3.Object, db, BucketResolver(), mediator.Object);

        // Act：只删 aaa
        await handler.Handle(new DeleteFileCommand("multipart/aaa"), CancellationToken.None);

        // Assert：aaa 没了，bbb 还在
        var remaining = await db.Files.ToListAsync();
        remaining.Should().HaveCount(1);
        remaining[0].S3Key.Should().Be("multipart/bbb");
    }

    [Fact]
    public async Task Delete_S3删除失败_抛异常不删数据库()
    {
        // Arrange：S3 删除抛异常（网络故障/权限不足等）
        var (db, s3, mediator) = CreateDeps(nameof(Delete_S3删除失败_抛异常不删数据库));
        db.Files.Add(NewMeta(Bucket, Key));
        await db.SaveChangesAsync();
        s3.Setup(x => x.DeleteFileAsync(Bucket, Key, It.IsAny<CancellationToken>()))
          .ThrowsAsync(new Exception("S3 连接失败"));

        var handler = new DeleteFileCommandHandler(s3.Object, db, BucketResolver(), mediator.Object);

        // Act
        var act = () => handler.Handle(new DeleteFileCommand(Key), CancellationToken.None);

        // Assert：异常向上抛
        await act.Should().ThrowAsync<Exception>().WithMessage("S3 连接失败");
        // Assert：FileMeta 仍在（S3 删失败时不删库，避免库删了但对象还在的孤儿）
        var remaining = await db.Files.ToListAsync();
        remaining.Should().HaveCount(1, "S3 删除失败时不应清理数据库记录");
    }

    [Fact]
    public async Task Delete_发布FileDeletedEvent()
    {
        // Arrange
        var (db, s3, mediator) = CreateDeps(nameof(Delete_发布FileDeletedEvent));
        var handler = new DeleteFileCommandHandler(s3.Object, db, BucketResolver(), mediator.Object);

        // Act
        await handler.Handle(new DeleteFileCommand(Key), CancellationToken.None);

        // Assert：事件已发布（供其他模块响应，如清理缓存）
        mediator.Verify(
            x => x.Publish(It.IsAny<global::File.Application.Events.FileDeletedEvent>(), It.IsAny<CancellationToken>()),
            Times.Once);
    }
}