using BuildFlow.Application.Document.Queries;
using BuildFlow.Application.Document.Handlers;
using BuildFlow.Application.Embedding.Commands;
using BuildFlow.Application.Embedding.Handlers;
using BuildFlow.Application.Chat.Commands;
using BuildFlow.Application.Chat.Handlers;
using BuildFlow.Application.Chat.Queries;
using BuildFlow.Domain.Entities.ChatMessage;
using BuildFlow.Domain.Entities.Conversation;
using BuildFlow.Domain.Entities.Document;
using BuildFlow.Domain.Enums;
using BuildFlow.Domain.Interfaces;
using BuildFlow.Infrastructure.Persistence;
using BuildFlow.Rag.Tests.Stub;
using BuildFlow.Shared.Domain.Errors;
using BuildFlow.Shared.Domain.Exceptions;
using BuildFlow.Shared.Infrastructure;
using FluentAssertions;
using Microsoft.EntityFrameworkCore;
using Xunit;

namespace BuildFlow.Rag.Tests;

/// <summary>
/// [SOP-RAG] Embedding Command + DocumentEntity/Chat Query Handler 补测。
/// 覆盖:EmbedText/EmbedBatch / GetDocuments / GetConversationDetail / GetConversations / DeleteConversation。
/// </summary>
public class EmbeddingAndQueryTests
{
    private static RagDbContext CreateDb([System.Runtime.CompilerServices.CallerMemberName] string name = "")
    {
        var userContext = new TestCurrentUserContext();
        var options = new DbContextOptionsBuilder<RagDbContext>()
            .UseInMemoryDatabase($"rag-misc-{name}-{Guid.NewGuid():N}")
            .AddInterceptors(new AuditInterceptor(userContext))
            .Options;
        return new RagDbContext(options);
    }

    // ===== Embedding =====

    [Fact]
    public async Task EmbedText_ReturnsVectorAndDimensions()
    {
        var embedding = new StubEmbeddingService();
        var handler = new EmbedTextCommandHandler(embedding);

        var result = await handler.Handle(new EmbedTextCommand("测试文本"), CancellationToken.None);

        result.Vector.Should().HaveCount(StubEmbeddingService.Dimensions);
        result.Dimensions.Should().Be(StubEmbeddingService.Dimensions);
    }

    [Fact]
    public async Task EmbedBatch_ReturnsVectorsInOrder()
    {
        var embedding = new StubEmbeddingService();
        var handler = new EmbedBatchCommandHandler(embedding);

        var result = await handler.Handle(
            new EmbedBatchCommand(["文本A", "文本B", "文本C"]), CancellationToken.None);

        result.Vectors.Should().HaveCount(3);
        result.Vectors[0].Should().HaveCount(StubEmbeddingService.Dimensions);
        result.Dimensions.Should().Be(StubEmbeddingService.Dimensions);
    }

    // ===== DocumentEntity Queries =====

    [Fact]
    public async Task GetDocuments_ByKnowledgeBase_ReturnsOnlyMatching()
    {
        var db = CreateDb();
        var kbId = Guid.NewGuid();
        var otherKbId = Guid.NewGuid();
        db.Documents.Add(new DocumentEntity { KnowledgeBaseId = kbId, Title = "doc1", FileName = "a.md", FilePath = "a", ContentType = "text", Status = DocumentStatusEnum.Completed });
        db.Documents.Add(new DocumentEntity { KnowledgeBaseId = kbId, Title = "doc2", FileName = "b.md", FilePath = "b", ContentType = "text", Status = DocumentStatusEnum.Pending });
        db.Documents.Add(new DocumentEntity { KnowledgeBaseId = otherKbId, Title = "other", FileName = "c.md", FilePath = "c", ContentType = "text", Status = DocumentStatusEnum.Completed });
        await db.SaveChangesAsync();

        var handler = new GetDocumentsQueryHandler(db);
        var result = await handler.Handle(new GetDocumentsQuery(kbId), CancellationToken.None);

        result.Should().HaveCount(2);
        result.Should().OnlyContain(d => d.KnowledgeBaseId == kbId);
    }

    // ===== Chat Queries =====

    [Fact]
    public async Task GetConversations_ReturnsCurrentUserOnly()
    {
        var db = CreateDb();
        var userContext = new TestCurrentUserContext();
        var myId = Guid.Parse(userContext.UserId);
        db.Conversations.Add(new ConversationEntity { Title = "我的", UserId = myId });
        db.Conversations.Add(new ConversationEntity { Title = "他人的", UserId = Guid.NewGuid() });
        await db.SaveChangesAsync();

        var handler = new GetConversationsQueryHandler(db, userContext);
        var result = await handler.Handle(new GetConversationsQuery(), CancellationToken.None);

        result.Should().HaveCount(1);
        result[0].Title.Should().Be("我的");
    }

    [Fact]
    public async Task GetConversationDetail_Existing_ReturnsWithMessages()
    {
        var db = CreateDb();
        var convId = Guid.NewGuid();
        var userContext = new TestCurrentUserContext();
        var userId = Guid.Parse(userContext.UserId);
        db.Conversations.Add(new ConversationEntity { Id = convId, Title = "详情", UserId = userId });
        db.ChatMessages.Add(new ChatMessageEntity { ConversationId = convId, Role = ChatRoleEnum.User, Content = "你好" });
        db.ChatMessages.Add(new ChatMessageEntity { ConversationId = convId, Role = ChatRoleEnum.Assistant, Content = "回复" });
        await db.SaveChangesAsync();

        var cache = new StubChatMessageCache();
        var handler = new GetConversationDetailQueryHandler(db, cache, userContext);
        var result = await handler.Handle(new GetConversationDetailQuery(convId), CancellationToken.None);

        result.Title.Should().Be("详情");
        result.Messages.Should().HaveCount(2);
    }

    [Fact]
    public async Task DeleteConversation_RemovesFromDbAndCache()
    {
        var db = CreateDb();
        var convId = Guid.NewGuid();
        var userContext = new TestCurrentUserContext();
        var userId = Guid.Parse(userContext.UserId);
        db.Conversations.Add(new ConversationEntity { Id = convId, Title = "待删", UserId = userId });
        await db.SaveChangesAsync();

        var cache = new StubChatMessageCache();
        await cache.SetMessagesAsync(convId, [new CachedChatMessage(Guid.NewGuid(), "user", "hi", null, DateTime.UtcNow)]);

        var handler = new DeleteConversationCommandHandler(db, cache, userContext);
        await handler.Handle(new DeleteConversationCommand(convId), CancellationToken.None);

        (await db.Conversations.AnyAsync(c => c.Id == convId)).Should().BeFalse();
        cache.Count(convId).Should().Be(0, "cache 也应清除");
    }

    [Fact]
    public async Task GetConversationDetail_OtherUsersConversation_ThrowsNotFound()
    {
        await using var db = CreateDb();
        var userContext = new TestCurrentUserContext();
        var conversationId = Guid.NewGuid();
        db.Conversations.Add(new ConversationEntity
        {
            Id = conversationId,
            Title = "他人的详情",
            UserId = Guid.NewGuid(),
        });
        await db.SaveChangesAsync();
        var handler = new GetConversationDetailQueryHandler(
            db,
            new StubChatMessageCache(),
            userContext);
        var request = new GetConversationDetailQuery(conversationId);

        var act = () => handler.Handle(request, CancellationToken.None);

        await act.Should().ThrowAsync<NotFoundException>()
            .Where(x => x.Code == ErrorCode.NotFound && x.Message == "会话不存在");
    }

    [Fact]
    public async Task UpdateConversation_OtherUsersConversation_DoesNotChangeTitle()
    {
        await using var db = CreateDb();
        var userContext = new TestCurrentUserContext();
        var conversation = new ConversationEntity
        {
            Id = Guid.NewGuid(),
            Title = "原始标题",
            UserId = Guid.NewGuid(),
        };
        db.Conversations.Add(conversation);
        await db.SaveChangesAsync();
        var handler = new UpdateConversationCommandHandler(db, userContext);
        var request = new UpdateConversationCommand(conversation.Id, "越权更新", null);

        var act = () => handler.Handle(request, CancellationToken.None);

        await act.Should().ThrowAsync<NotFoundException>()
            .Where(x => x.Code == ErrorCode.NotFound && x.Message == "会话不存在");
        conversation.Title.Should().Be("原始标题");
    }

    [Fact]
    public async Task DeleteConversation_OtherUsersConversation_LeavesDbAndCacheUntouched()
    {
        await using var db = CreateDb();
        var userContext = new TestCurrentUserContext();
        var conversationId = Guid.NewGuid();
        db.Conversations.Add(new ConversationEntity
        {
            Id = conversationId,
            Title = "不可删除",
            UserId = Guid.NewGuid(),
        });
        await db.SaveChangesAsync();
        var cache = new StubChatMessageCache();
        await cache.SetMessagesAsync(conversationId,
            [new CachedChatMessage(Guid.NewGuid(), "user", "保留", null, DateTime.UtcNow)]);
        var handler = new DeleteConversationCommandHandler(db, cache, userContext);
        var request = new DeleteConversationCommand(conversationId);

        var act = () => handler.Handle(request, CancellationToken.None);

        await act.Should().ThrowAsync<NotFoundException>()
            .Where(x => x.Code == ErrorCode.NotFound && x.Message == "会话不存在");
        (await db.Conversations.AnyAsync(x => x.Id == conversationId)).Should().BeTrue();
        cache.Count(conversationId).Should().Be(1);
    }
}