Nexus.Reader/tests/NexusReader.Application.Tests/Commands/SubmitQuizResultCommandHandlerTests.cs

using System;
using System.Threading;
using System.Threading.Tasks;
using FluentAssertions;
using Microsoft.Data.Sqlite;
using Microsoft.EntityFrameworkCore;
using Moq;
using NexusReader.Application.Commands.Quiz;
using NexusReader.Data.Persistence;
using NexusReader.Domain.Entities;
using Xunit;

namespace NexusReader.Application.Tests.Commands;

public class SubmitQuizResultCommandHandlerTests : IDisposable
{
    private readonly SqliteConnection _connection;
    private readonly DbContextOptions<AppDbContext> _contextOptions;
    private readonly Mock<IDbContextFactory<AppDbContext>> _dbContextFactoryMock;

    public SubmitQuizResultCommandHandlerTests()
    {
        _connection = new SqliteConnection("DataSource=:memory:");
        _connection.Open();

        _contextOptions = new DbContextOptionsBuilder<AppDbContext>()
            .UseSqlite(_connection)
            .Options;

        using var context = new AppDbContext(_contextOptions);
        context.Database.EnsureCreated();

        _dbContextFactoryMock = new Mock<IDbContextFactory<AppDbContext>>();
        _dbContextFactoryMock.Setup(f => f.CreateDbContextAsync(It.IsAny<CancellationToken>()))
            .ReturnsAsync(() => new AppDbContext(_contextOptions));
    }

    [Fact]
    public async Task Handle_WithValidRequest_PersistsQuizResultToDatabase()
    {
        // Arrange
        using (var context = new AppDbContext(_contextOptions))
        {
            var user = new NexusUser
            {
                Id = "user-abc",
                UserName = "testuser",
                Email = "test@example.com",
                TenantId = "tenant-xyz",
                SubscriptionPlanId = 1
            };
            context.Users.Add(user);
            await context.SaveChangesAsync();
        }

        var command = new SubmitQuizResultCommand(
            UserId: "user-abc",
            Topic: "Sprawdzian: .NET 10",
            Score: 4,
            TotalQuestions: 5
        );

        var handler = new SubmitQuizResultCommandHandler(_dbContextFactoryMock.Object);

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

        // Assert
        result.IsSuccess.Should().BeTrue();

        using (var context = new AppDbContext(_contextOptions))
        {
            var quizResult = await context.QuizResults.FirstOrDefaultAsync(q => q.UserId == "user-abc");
            quizResult.Should().NotBeNull();
            quizResult!.Topic.Should().Be("Sprawdzian: .NET 10");
            quizResult.Score.Should().Be(4);
            quizResult.TotalQuestions.Should().Be(5);
            quizResult.TenantId.Should().Be("tenant-xyz");
        }
    }

    [Fact]
    public async Task Handle_WithNonExistentUser_ReturnsFailureResult()
    {
        // Arrange
        var command = new SubmitQuizResultCommand(
            UserId: "non-existent",
            Topic: "Sprawdzian: .NET 10",
            Score: 4,
            TotalQuestions: 5
        );

        var handler = new SubmitQuizResultCommandHandler(_dbContextFactoryMock.Object);

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

        // Assert
        result.IsFailed.Should().BeTrue();
        result.Errors.Should().ContainSingle(e => e.Message == "User not found.");
    }

    public void Dispose()
    {
        _connection.Dispose();
    }
}