using BuildFlow.Platform.Application.Menus.Commands;
using BuildFlow.Platform.Application.Menus.Handlers;
using BuildFlow.Platform.Application.Menus.Queries;
using BuildFlow.Platform.Domain.Entities.Menu;
using BuildFlow.Platform.Infrastructure.Persistence;
using BuildFlow.Shared.Domain.Errors;
using BuildFlow.Shared.Domain.Exceptions;
using FluentAssertions;
using Microsoft.EntityFrameworkCore;
using Xunit;

namespace BuildFlow.Platform.Tests.Menus;

/// <summary>
/// [SOP-PLATFORM] Menus 模块 5 个 Handler 覆盖测试。
/// 覆盖: Create / Update / Delete / GetTree / GetById。
/// 飞书矩阵: platform/Menus 子域(5 Handler 零覆盖→全补)。
/// </summary>
public class MenuHandlerTests
{
    private static PlatformDbContext CreateDb([System.Runtime.CompilerServices.CallerMemberName] string name = "")
        => PlatformTestDb.CreateDbContext(name);

    private static async Task<MenuEntity> SeedMenu(
        PlatformDbContext db,
        string code,
        string title,
        string? name = null,
        long? parentId = null,
        int order = 1)
    {
        var menu = PlatformTestDb.WithAudit(new MenuEntity
        {
            Name = name ?? code.Replace(".", ""),
            Code = code,
            Title = title,
            Path = "/" + code.Replace(".", "/"),
            Order = order,
            ParentId = parentId,
        });
        db.Menus.Add(menu);
        await db.SaveChangesAsync();
        return menu;
    }

    #region CreateMenu

    [Fact]
    public async Task CreateMenu_Valid_ReturnsDto()
    {
        var db = CreateDb();
        var result = await new CreateMenuCommandHandler(db).Handle(new CreateMenuCommand
        {
            Code = "sys.a",
            Title = "A",
            Path = "/sys/a",
        }, CancellationToken.None);
        result.Code.Should().Be("sys.a");
        (await db.Menus.CountAsync()).Should().Be(1);
    }

    [Fact]
    public async Task CreateMenu_DerivesNameFromCode_WhenNameOmitted()
    {
        var db = CreateDb();
        var result = await new CreateMenuCommandHandler(db).Handle(new CreateMenuCommand
        {
            Code = "system.user",
            Title = "用户",
            Path = "/system/user",
        }, CancellationToken.None);
        result.Name.Should().Be("SystemUser");
    }

    [Fact]
    public async Task CreateMenu_DuplicateCode_ThrowsBusiness()
    {
        var db = CreateDb();
        await SeedMenu(db, "sys.a", "A");
        var act = async () => await new CreateMenuCommandHandler(db).Handle(new CreateMenuCommand
        {
            Code = "sys.a",
            Title = "A2",
            Path = "/sys/a2",
        }, CancellationToken.None);
        var ex = await act.Should().ThrowAsync<BusinessException>();
        ex.Which.Code.Should().Be(ErrorCode.AlreadyExists);
    }

    [Fact]
    public async Task CreateMenu_ParentNotExists_ThrowsNotFound()
    {
        var db = CreateDb();
        var act = async () => await new CreateMenuCommandHandler(db).Handle(new CreateMenuCommand
        {
            Code = "sys.b",
            Title = "B",
            Path = "/sys/b",
            ParentId = 9999,
        }, CancellationToken.None);
        var ex = await act.Should().ThrowAsync<NotFoundException>();
        ex.Which.Code.Should().Be(ErrorCode.NotFound);
    }

    #endregion

    #region UpdateMenu

    [Fact]
    public async Task UpdateMenu_Existing_UpdatesTitle()
    {
        var db = CreateDb();
        var menu = await SeedMenu(db, "sys.a", "A");
        var result = await new UpdateMenuCommandHandler(db).Handle(new UpdateMenuCommand
        {
            Id = menu.Id,
            Title = "新标题",
        }, CancellationToken.None);
        result.Title.Should().Be("新标题");
    }

    [Fact]
    public async Task UpdateMenu_NonExistent_ThrowsNotFound()
    {
        var db = CreateDb();
        var act = async () => await new UpdateMenuCommandHandler(db).Handle(
            new UpdateMenuCommand { Id = 9999, Title = "x" }, CancellationToken.None);
        var ex = await act.Should().ThrowAsync<NotFoundException>();
        ex.Which.Code.Should().Be(ErrorCode.NotFound);
    }

    [Fact]
    public async Task UpdateMenu_ParentPointsToSelf_ThrowsCircular()
    {
        var db = CreateDb();
        var menu = await SeedMenu(db, "sys.a", "A");
        var act = async () => await new UpdateMenuCommandHandler(db).Handle(
            new UpdateMenuCommand { Id = menu.Id, ParentId = menu.Id }, CancellationToken.None);
        var ex = await act.Should().ThrowAsync<BusinessException>();
        ex.Which.Code.Should().Be(ErrorCode.CircularReference);
    }

    [Fact]
    public async Task UpdateMenu_ParentNotExists_ThrowsNotFound()
    {
        var db = CreateDb();
        var menu = await SeedMenu(db, "sys.a", "A");
        var act = async () => await new UpdateMenuCommandHandler(db).Handle(
            new UpdateMenuCommand { Id = menu.Id, ParentId = 8888 }, CancellationToken.None);
        var ex = await act.Should().ThrowAsync<NotFoundException>();
        ex.Which.Code.Should().Be(ErrorCode.NotFound);
    }

    [Fact]
    public async Task UpdateMenu_DuplicateName_ThrowsBusiness()
    {
        var db = CreateDb();
        await SeedMenu(db, "sys.a", "A", name: "Same");
        var other = await SeedMenu(db, "sys.b", "B");
        var act = async () => await new UpdateMenuCommandHandler(db).Handle(
            new UpdateMenuCommand { Id = other.Id, Name = "Same" }, CancellationToken.None);
        var ex = await act.Should().ThrowAsync<BusinessException>();
        ex.Which.Code.Should().Be(ErrorCode.AlreadyExists);
    }

    #endregion

    #region DeleteMenu

    [Fact]
    public async Task DeleteMenu_Leaf_Removes()
    {
        var db = CreateDb();
        var menu = await SeedMenu(db, "sys.a", "A");
        await new DeleteMenuCommandHandler(db).Handle(new DeleteMenuCommand(menu.Id), CancellationToken.None);
        (await db.Menus.CountAsync()).Should().Be(0);
    }

    [Fact]
    public async Task DeleteMenu_HasChildren_ThrowsBusiness()
    {
        var db = CreateDb();
        var parent = await SeedMenu(db, "sys", "Sys", order: 1);
        await SeedMenu(db, "sys.a", "A", parentId: parent.Id, order: 2);
        var act = async () => await new DeleteMenuCommandHandler(db)
            .Handle(new DeleteMenuCommand(parent.Id), CancellationToken.None);
        var ex = await act.Should().ThrowAsync<BusinessException>();
        ex.Which.Code.Should().Be(ErrorCode.HasChildren);
    }

    [Fact]
    public async Task DeleteMenu_NonExistent_ThrowsNotFound()
    {
        var db = CreateDb();
        var act = async () => await new DeleteMenuCommandHandler(db)
            .Handle(new DeleteMenuCommand(7777), CancellationToken.None);
        var ex = await act.Should().ThrowAsync<NotFoundException>();
        ex.Which.Code.Should().Be(ErrorCode.NotFound);
    }

    #endregion

    #region GetMenuTree

    [Fact]
    public async Task GetMenuTree_BuildsHierarchy()
    {
        var db = CreateDb();
        var parent = await SeedMenu(db, "sys", "Sys", order: 1);
        await SeedMenu(db, "sys.a", "A", parentId: parent.Id, order: 2);
        var tree = await new GetMenuTreeQueryHandler(db).Handle(new GetMenuTreeQuery(), CancellationToken.None);
        tree.Should().HaveCount(1);
        tree[0].MenuEntity.Code.Should().Be("sys");
        tree[0].Children.Should().HaveCount(1);
        tree[0].Children[0].MenuEntity.Code.Should().Be("sys.a");
    }

    [Fact]
    public async Task GetMenuTree_Empty_ReturnsEmpty()
    {
        var db = CreateDb();
        var tree = await new GetMenuTreeQueryHandler(db).Handle(new GetMenuTreeQuery(), CancellationToken.None);
        tree.Should().BeEmpty();
    }

    #endregion

    #region GetMenuById

    [Fact]
    public async Task GetMenuById_Existing_ReturnsDto()
    {
        var db = CreateDb();
        var menu = await SeedMenu(db, "sys.a", "A");
        var result = await new GetMenuByIdQueryHandler(db)
            .Handle(new GetMenuByIdQuery(menu.Id), CancellationToken.None);
        result.Code.Should().Be("sys.a");
    }

    [Fact]
    public async Task GetMenuById_NonExistent_ThrowsNotFound()
    {
        var db = CreateDb();
        var act = async () => await new GetMenuByIdQueryHandler(db)
            .Handle(new GetMenuByIdQuery(12345), CancellationToken.None);
        var ex = await act.Should().ThrowAsync<NotFoundException>();
        ex.Which.Code.Should().Be(ErrorCode.NotFound);
    }

    #endregion
}