using BuildFlow.Shared.Domain.Common;
using BuildFlow.Shared.Infrastructure;
using File.Application.Features.Files.Handlers;
using File.Application.Features.Files.Queries;
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>
/// 秒传预检测试。验证查重三维度（同用户/跨用户/防碰撞）+ S3 存在性校验（孤儿清理）。
/// </summary>
public class CheckFileQueryHandlerTests
{
    private const string OwnerId = "user-001";
    private const string Sha = "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824";

    private static (FileDbContext db, Mock<IS3StorageService> s3, Mock<ICurrentUserContext> user) CreateDeps(string dbName)
    {
        var user = new Mock<ICurrentUserContext>();
        user.SetupGet(u => u.UserId).Returns(OwnerId);
        user.SetupGet(u => u.IPAddress).Returns("127.0.0.1");
        var s3 = new Mock<IS3StorageService>();
        // 默认对象存在；个别测试覆盖 false
        s3.Setup(x => x.ObjectExistsAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
          .ReturnsAsync(true);

        var options = new DbContextOptionsBuilder<FileDbContext>()
            .UseInMemoryDatabase(dbName)
            .AddInterceptors(new AuditInterceptor(user.Object))
            .Options;
        return (new FileDbContext(options), s3, user);
    }

    private static FileMeta NewFile(string owner, string hash, long size, string name = "a.txt")
        => new()
        {
            Name = name,
            S3Key = Guid.NewGuid().ToString(),
            S3Bucket = "files",
            Size = size,
            ContentType = "text/plain",
            ContentHash = hash,
            OwnerId = owner,
        };

    [Fact]
    public async Task Check_同用户同哈希同大小_S3对象存在_命中秒传()
    {
        var (db, s3, user) = CreateDeps(nameof(Check_同用户同哈希同大小_S3对象存在_命中秒传));
        db.Files.Add(NewFile(OwnerId, Sha, 100));
        await db.SaveChangesAsync();

        var handler = new CheckFileQueryHandler(db, s3.Object, user.Object);

        var result = await handler.Handle(new CheckFileQuery(Sha, 100), CancellationToken.None);

        result.Exists.Should().BeTrue();
        result.File.Should().NotBeNull();
        result.File!.Size.Should().Be(100);
        result.File.OwnerId.Should().Be(OwnerId);
    }

    [Fact]
    public async Task Check_无匹配_返回未命中()
    {
        var (db, s3, user) = CreateDeps(nameof(Check_无匹配_返回未命中));
        var handler = new CheckFileQueryHandler(db, s3.Object, user.Object);

        var result = await handler.Handle(new CheckFileQuery(Sha, 100), CancellationToken.None);

        result.Exists.Should().BeFalse();
        result.File.Should().BeNull();
    }

    [Fact]
    public async Task Check_他人文件不命中_所有权隔离()
    {
        var (db, s3, user) = CreateDeps(nameof(Check_他人文件不命中_所有权隔离));
        db.Files.Add(NewFile("another-user", Sha, 100));
        await db.SaveChangesAsync();
        var handler = new CheckFileQueryHandler(db, s3.Object, user.Object);

        var result = await handler.Handle(new CheckFileQuery(Sha, 100), CancellationToken.None);

        result.Exists.Should().BeFalse("他人文件不应被秒传命中（所有权隔离）");
    }

    [Fact]
    public async Task Check_大小不匹配不命中_防哈希碰撞()
    {
        var (db, s3, user) = CreateDeps(nameof(Check_大小不匹配不命中_防哈希碰撞));
        db.Files.Add(NewFile(OwnerId, Sha, 100));
        await db.SaveChangesAsync();
        var handler = new CheckFileQueryHandler(db, s3.Object, user.Object);

        var result = await handler.Handle(new CheckFileQuery(Sha, 999), CancellationToken.None);

        result.Exists.Should().BeFalse("大小不同不应命中（防哈希碰撞）");
    }

    [Fact]
    public async Task Check_文件无哈希不命中()
    {
        var (db, s3, user) = CreateDeps(nameof(Check_文件无哈希不命中));
        db.Files.Add(NewFile(OwnerId, hash: null!, 100));
        await db.SaveChangesAsync();
        var handler = new CheckFileQueryHandler(db, s3.Object, user.Object);

        var result = await handler.Handle(new CheckFileQuery(Sha, 100), CancellationToken.None);

        result.Exists.Should().BeFalse("无哈希的老文件不参与秒传查重");
    }

    [Fact]
    public async Task Check_S3对象已丢失_清理孤儿FileMeta_返回未命中()
    {
        // 缺陷E回归：FileMeta 存在但 S3 对象被外部删除，应清理孤儿并返回未命中（而非误报秒传成功）
        var (db, s3, user) = CreateDeps(nameof(Check_S3对象已丢失_清理孤儿FileMeta_返回未命中));
        db.Files.Add(NewFile(OwnerId, Sha, 100));
        await db.SaveChangesAsync();
        s3.Setup(x => x.ObjectExistsAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CancellationToken>()))
          .ReturnsAsync(false); // S3 对象不存在
        var handler = new CheckFileQueryHandler(db, s3.Object, user.Object);

        var result = await handler.Handle(new CheckFileQuery(Sha, 100), CancellationToken.None);

        result.Exists.Should().BeFalse("S3 对象丢失不应误报秒传成功");
        // 孤儿 FileMeta 应被清理
        var remaining = await db.Files.ToListAsync();
        remaining.Should().BeEmpty("孤儿 FileMeta 应被清理");
    }
}