using BuildFlow.Shared.Domain.Errors;
using FluentAssertions;
using Microsoft.EntityFrameworkCore;
using Workflow.Application.Form.ComponentRegistry.Commands;
using Workflow.Application.Form.ComponentRegistry.Handlers;
using Workflow.Application.Form.ComponentRegistry.Queries;
using Workflow.Domain.Entities;
using Xunit;

namespace BuildFlow.Workflow.Tests.Form;

public class FormComponentHandlerTests
{
    private static WorkflowDbContext CreateDbContext()
    {
        var options = new DbContextOptionsBuilder<WorkflowDbContext>()
            .UseInMemoryDatabase(Guid.NewGuid().ToString())
            .Options;
        var db = new WorkflowDbContext(options);
        db.SavingChanges += AuditStub.OnSave;
        return db;
    }

    private static FormComponentRegistry SeedComponent(WorkflowDbContext db, string name, string category)
    {
        var entity = new FormComponentRegistry
        {
            Id = Guid.NewGuid(),
            Name = name,
            DisplayName = name,
            Category = category,
            Icon = "icon",
            DefaultSchema = "{}",
            SupportedProps = "{}"
        };
        db.FormComponentRegistries.Add(entity);
        return entity;
    }

    #region CreateFormComponent

    [Fact]
    public async Task CreateFormComponent_SavesAndReturnsDto()
    {
        await using var db = CreateDbContext();
        var handler = new CreateFormComponentCommandHandler(db);
        var command = new CreateFormComponentCommand(
            Name: "input",
            DisplayName: "Input",
            Category: "basic",
            Icon: "i",
            DefaultSchema: "{}",
            SupportedProps: "{}");

        var result = await handler.Handle(command, CancellationToken.None);

        result.Should().NotBeNull();
        result.Name.Should().Be("input");
        result.Category.Should().Be("basic");
        (await db.FormComponentRegistries.CountAsync()).Should().Be(1);
    }

    [Fact]
    public async Task CreateFormComponent_DuplicateName_ThrowsAlreadyExists()
    {
        await using var db = CreateDbContext();
        SeedComponent(db, "input", "basic");
        await db.SaveChangesAsync();

        var handler = new CreateFormComponentCommandHandler(db);
        var command = new CreateFormComponentCommand(
            Name: "input",
            DisplayName: "Input",
            Category: "basic",
            Icon: "i",
            DefaultSchema: "{}",
            SupportedProps: "{}");

        var act = async () => await handler.Handle(command, CancellationToken.None);

        var ex = await act.Should().ThrowAsync<BusinessException>();
        ex.Which.Code.Should().Be(ErrorCode.AlreadyExists);
    }

    #endregion

    #region UpdateFormComponent

    [Fact]
    public async Task UpdateFormComponent_UpdatesFields()
    {
        await using var db = CreateDbContext();
        var entity = SeedComponent(db, "input", "basic");
        await db.SaveChangesAsync();

        var handler = new UpdateFormComponentCommandHandler(db);
        var command = new UpdateFormComponentCommand(
            Id: entity.Id,
            DisplayName: "Renamed",
            Category: "advanced",
            Icon: "x",
            DefaultSchema: "{\"a\":1}",
            SupportedProps: "{\"b\":2}",
            IsActive: false);

        var result = await handler.Handle(command, CancellationToken.None);

        result.DisplayName.Should().Be("Renamed");
        result.IsActive.Should().BeFalse();
        var stored = await db.FormComponentRegistries.FindAsync(entity.Id);
        stored!.Category.Should().Be("advanced");
    }

    [Fact]
    public async Task UpdateFormComponent_Missing_ThrowsNotFound()
    {
        await using var db = CreateDbContext();
        var handler = new UpdateFormComponentCommandHandler(db);
        var command = new UpdateFormComponentCommand(
            Id: Guid.NewGuid(),
            DisplayName: "Renamed",
            Category: "advanced",
            Icon: "x",
            DefaultSchema: "{}",
            SupportedProps: "{}",
            IsActive: true);

        var act = async () => await handler.Handle(command, CancellationToken.None);

        var ex = await act.Should().ThrowAsync<NotFoundException>();
        ex.Which.Code.Should().Be(ErrorCode.NotFound);
    }

    #endregion

    #region DeleteFormComponent

    [Fact]
    public async Task DeleteFormComponent_SoftDeletes()
    {
        await using var db = CreateDbContext();
        var entity = SeedComponent(db, "input", "basic");
        await db.SaveChangesAsync();

        var handler = new DeleteFormComponentCommandHandler(db);
        await handler.Handle(new DeleteFormComponentCommand(entity.Id), CancellationToken.None);

        var stored = await db.FormComponentRegistries.FindAsync(entity.Id);
        stored!.IsDeleted.Should().BeTrue();
    }

    [Fact]
    public async Task DeleteFormComponent_Missing_ThrowsNotFound()
    {
        await using var db = CreateDbContext();
        var handler = new DeleteFormComponentCommandHandler(db);

        var act = async () => await handler.Handle(new DeleteFormComponentCommand(Guid.NewGuid()), CancellationToken.None);

        var ex = await act.Should().ThrowAsync<NotFoundException>();
        ex.Which.Code.Should().Be(ErrorCode.NotFound);
    }

    #endregion

    #region GetFormComponentById

    [Fact]
    public async Task GetFormComponentById_ReturnsDto()
    {
        await using var db = CreateDbContext();
        var entity = SeedComponent(db, "input", "basic");
        await db.SaveChangesAsync();

        var handler = new GetFormComponentByIdQueryHandler(db);
        var result = await handler.Handle(new GetFormComponentByIdQuery(entity.Id), CancellationToken.None);

        result.Should().NotBeNull();
        result.Id.Should().Be(entity.Id);
        result.Name.Should().Be("input");
    }

    [Fact]
    public async Task GetFormComponentById_Missing_ThrowsNotFound()
    {
        await using var db = CreateDbContext();
        var handler = new GetFormComponentByIdQueryHandler(db);

        var act = async () => await handler.Handle(new GetFormComponentByIdQuery(Guid.NewGuid()), CancellationToken.None);

        var ex = await act.Should().ThrowAsync<NotFoundException>();
        ex.Which.Code.Should().Be(ErrorCode.NotFound);
    }

    #endregion

    #region GetFormComponents

    [Fact]
    public async Task GetFormComponents_FiltersByCategory()
    {
        await using var db = CreateDbContext();
        SeedComponent(db, "a", "basic");
        SeedComponent(db, "b", "advanced");
        await db.SaveChangesAsync();

        var handler = new GetFormComponentsQueryHandler(db);
        var result = await handler.Handle(new GetFormComponentsQuery(Category: "basic", IsActive: null), CancellationToken.None);

        result.Should().HaveCount(1);
        result[0].Name.Should().Be("a");
    }

    [Fact]
    public async Task GetFormComponents_Empty_WhenNoMatch()
    {
        await using var db = CreateDbContext();
        SeedComponent(db, "a", "basic");
        await db.SaveChangesAsync();

        var handler = new GetFormComponentsQueryHandler(db);
        var result = await handler.Handle(new GetFormComponentsQuery(Category: "missing", IsActive: null), CancellationToken.None);

        result.Should().BeEmpty();
    }

    #endregion
}