using Microsoft.Data.Sqlite;
using Microsoft.EntityFrameworkCore;
using Novelly.Api.Data;

namespace Novelly.Api.Tests;

/// <summary>
/// A throwaway SQLite database held in memory. Using real SQLite rather than the
/// in-memory provider means the tests exercise the same relational behaviour the app
/// ships with — cascade deletes, foreign keys and all.
/// </summary>
/// <remarks>
/// NUnit reuses one fixture instance across every test in a class, so this must be built
/// in <c>[SetUp]</c> and disposed in <c>[TearDown]</c>. A field initialiser would share
/// one database for the whole class and let tests see each other's rows.
/// </remarks>
public class TestDatabase : IDisposable
{
    private readonly SqliteConnection _connection;

    public TestDatabase()
    {
        _connection = new SqliteConnection("Data Source=:memory:");
        _connection.Open();

        Context = CreateContext();
        Context.Database.EnsureCreated();
    }

    public NovelDbContext Context { get; }

    /// <summary>A second context over the same database, for asserting on persisted state.</summary>
    public NovelDbContext CreateContext() =>
        new(new DbContextOptionsBuilder<NovelDbContext>().UseSqlite(_connection).Options);

    public void Dispose()
    {
        Context.Dispose();
        _connection.Dispose();
        GC.SuppressFinalize(this);
    }
}