using System.IO;
using System.Linq;

using SongTidy.Services;

namespace SongTidy.Tests;

/// <summary>
/// Contains tests for <see cref="AudioFileScanner"/>.
/// </summary>
[TestClass]
public sealed class AudioFileScannerTests {
    private string _tempDirectory = string.Empty;

    /// <summary>
    /// Creates a unique temporary directory for the current test.
    /// </summary>
    [TestInitialize]
    public void Initialize() {
        _tempDirectory = Path.Combine(Path.GetTempPath(), $"SongTidy Scanner {Guid.NewGuid():N}");
        Directory.CreateDirectory(_tempDirectory);
    }

    /// <summary>
    /// Removes the temporary directory created for the current test.
    /// </summary>
    [TestCleanup]
    public void Cleanup() {
        Directory.Delete(_tempDirectory, recursive: true);
    }

    /// <summary>
    /// Verifies that supported extensions are matched case-insensitively and others are ignored.
    /// </summary>
    [TestMethod]
    public void ScansSupportedExtensionsCaseInsensitively() {
        CreateFile("a.mp3");
        CreateFile("b.FLAC");
        CreateFile("c.txt");

        IReadOnlyList<string> files = AudioFileScanner.Scan(_tempDirectory);

        Assert.HasCount(2, files);
        Assert.IsTrue(files.Any(file => file.EndsWith("a.mp3", StringComparison.OrdinalIgnoreCase)));
        Assert.IsTrue(files.Any(file => file.EndsWith("b.FLAC", StringComparison.OrdinalIgnoreCase)));
    }

    /// <summary>
    /// Verifies that subdirectories are not scanned.
    /// </summary>
    [TestMethod]
    public void DoesNotScanSubdirectories() {
        CreateFile("root.mp3");
        CreateFile(Path.Combine("sub", "nested.wav"));

        IReadOnlyList<string> files = AudioFileScanner.Scan(_tempDirectory);

        Assert.HasCount(1, files);
        Assert.IsTrue(files[0].EndsWith("root.mp3", StringComparison.OrdinalIgnoreCase));
    }

    /// <summary>
    /// Creates an empty file inside the test directory.
    /// </summary>
    /// <param name="fileName">The relative file name, which may include a subdirectory.</param>
    private void CreateFile(string fileName) {
        string path = Path.Combine(_tempDirectory, fileName);
        string directory = Path.GetDirectoryName(path) ?? _tempDirectory;

        Directory.CreateDirectory(directory);
        File.WriteAllText(path, string.Empty);
    }
}