using System;
using System.IO;
using System.Linq;
using Migrato.Core;
using Xunit;

namespace Migrato.Tests;

public class MigrationLoaderTests : IDisposable
{
    private readonly string _tempDirectory = Directory.CreateTempSubdirectory("migrato-tests-").FullName;

    [Fact]
    public void LoadFromDirectory_ReturnsMigrationsOrderedByVersion()
    {
        WriteFile("20260103000000_third.sql");
        WriteFile("20260101000000_first.sql");
        WriteFile("20260102000000_second.sql");

        var migrations = MigrationLoader.LoadFromDirectory(_tempDirectory);

        Assert.Equal(
            new[] { "first", "second", "third" },
            migrations.Select(m => m.Name).ToArray());
    }

    [Fact]
    public void LoadFromDirectory_MissingDirectory_Throws()
    {
        var missingDirectory = Path.Combine(_tempDirectory, "does-not-exist");

        Assert.Throws<DirectoryNotFoundException>(() => MigrationLoader.LoadFromDirectory(missingDirectory));
    }

    [Fact]
    public void LoadFromDirectory_DuplicateVersions_Throws()
    {
        WriteFile("20260101000000_first.sql");
        WriteFile("20260101000000_also_first.sql");

        Assert.Throws<MigrationFormatException>(() => MigrationLoader.LoadFromDirectory(_tempDirectory));
    }

    private void WriteFile(string fileName)
    {
        var path = Path.Combine(_tempDirectory, fileName);
        File.WriteAllText(path, "-- +migrato Up\nSELECT 1;\n-- +migrato Down\nSELECT 2;\n");
    }

    public void Dispose()
    {
        Directory.Delete(_tempDirectory, recursive: true);
    }
}