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

namespace BuildFlow.Workflow.Tests.Form;

public class FormVersionHandlerTests
{
    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;
    }

    #region CompareFormVersions

    [Fact]
    public async Task CompareFormVersions_WithSnapshot_PicksPreviousVersionAsOld()
    {
        await using var db = CreateDbContext();
        var formId = Guid.NewGuid();
        db.FormDefinitions.Add(new FormDefinition
        {
            Id = formId,
            Name = "Form",
            Code = "form",
            Version = 2,
            Status = FormStatus.Draft,
            SchemaJson = "{\"v\":2}"
        });
        db.FormDefinitionVersions.Add(new FormDefinitionVersion
        {
            Id = Guid.NewGuid(),
            FormDefinitionId = formId,
            Version = 1,
            SchemaJson = "{\"v\":1}",
            Source = "Update"
        });
        await db.SaveChangesAsync();

        var handler = new CompareFormVersionsQueryHandler(db);
        var query = new CompareFormVersionsQuery(formId, OldVersionId: null, NewVersionId: null);

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

        result.Should().NotBeNull();
        result.NewVersion.Should().NotBeNull();
        result.NewVersion!.Version.Should().Be(2);
        result.OldVersion.Should().NotBeNull();
        result.OldVersion!.Version.Should().Be(1);
        result.Diff.Should().NotBeNull();
    }

    [Fact]
    public async Task CompareFormVersions_MissingForm_ThrowsNotFound()
    {
        await using var db = CreateDbContext();
        var handler = new CompareFormVersionsQueryHandler(db);
        var query = new CompareFormVersionsQuery(Guid.NewGuid(), null, null);

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

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

    #endregion

    #region GetFormVersions

    [Fact]
    public async Task GetFormVersions_ReturnsOrderedList()
    {
        await using var db = CreateDbContext();
        var formId = Guid.NewGuid();
        db.FormDefinitions.Add(new FormDefinition
        {
            Id = formId,
            Name = "Form",
            Code = "form",
            Version = 3,
            Status = FormStatus.Draft
        });
        db.FormDefinitionVersions.Add(new FormDefinitionVersion
        {
            Id = Guid.NewGuid(),
            FormDefinitionId = formId,
            Version = 1,
            SchemaJson = "{\"v\":1}"
        });
        db.FormDefinitionVersions.Add(new FormDefinitionVersion
        {
            Id = Guid.NewGuid(),
            FormDefinitionId = formId,
            Version = 2,
            SchemaJson = "{\"v\":2}"
        });
        await db.SaveChangesAsync();

        var handler = new GetFormVersionsQueryHandler(db);
        var query = new GetFormVersionsQuery(formId);

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

        result.Should().NotBeNull();
        result.Should().HaveCount(2);
        result[0].Version.Should().Be(2);
        result[1].Version.Should().Be(1);
    }

    [Fact]
    public async Task GetFormVersions_MissingForm_ThrowsNotFound()
    {
        await using var db = CreateDbContext();
        var handler = new GetFormVersionsQueryHandler(db);
        var query = new GetFormVersionsQuery(Guid.NewGuid());

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

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

    #endregion
}