allstarr/allstarr.Tests/FuzzyMatcherTests.cs

using Xunit;
using allstarr.Services.Common;

namespace allstarr.Tests;

public class FuzzyMatcherTests
{

    [Theory]
    [InlineData("Mr. Brightside", "Mr. Brightside", 100)]
    [InlineData("Mr Brightside", "Mr. Brightside", 100)]
    [InlineData("Mr. Brightside", "Mr Brightside", 100)]
    [InlineData("The Killers", "Killers", 85)]
    [InlineData("Dua Lipa", "Dua-Lipa", 100)]
    public void CalculateSimilarity_ExactAndNearMatches_ReturnsHighScore(string str1, string str2, int expectedMin)
    {
        // Act
        var score = FuzzyMatcher.CalculateSimilarity(str1, str2);

        // Assert
        Assert.True(score >= expectedMin, $"Expected score >= {expectedMin}, got {score}");
    }

    [Theory]
    [InlineData("Mr. Brightside", "Somebody Told Me", 20)]
    [InlineData("The Killers", "The Beatles", 40)]
    [InlineData("Hot Fuss", "Sam's Town", 20)]
    public void CalculateSimilarity_DifferentStrings_ReturnsLowScore(string str1, string str2, int expectedMax)
    {
        // Act
        var score = FuzzyMatcher.CalculateSimilarity(str1, str2);

        // Assert
        Assert.True(score <= expectedMax, $"Expected score <= {expectedMax}, got {score}");
    }

    [Fact]
    public void CalculateSimilarity_IgnoresPunctuation()
    {
        // Arrange
        var str1 = "Don't Stop Believin'";
        var str2 = "Dont Stop Believin";

        // Act
        var score = FuzzyMatcher.CalculateSimilarity(str1, str2);

        // Assert
        Assert.True(score >= 95, $"Expected high score for punctuation differences, got {score}");
    }

    [Fact]
    public void CalculateSimilarity_IgnoresCase()
    {
        // Arrange
        var str1 = "Mr. Brightside";
        var str2 = "mr. brightside";

        // Act
        var score = FuzzyMatcher.CalculateSimilarity(str1, str2);

        // Assert
        Assert.Equal(100, score);
    }

    [Fact]
    public void CalculateSimilarity_HandlesArticles()
    {
        // Arrange
        var str1 = "The Killers";
        var str2 = "Killers";

        // Act
        var score = FuzzyMatcher.CalculateSimilarity(str1, str2);

        // Assert
        Assert.True(score >= 80, $"Expected high score when 'The' is removed, got {score}");
    }

    [Fact]
    public void CalculateSimilarity_HandlesFeaturedArtists()
    {
        // Arrange
        var str1 = "Song Title (feat. Artist)";
        var str2 = "Song Title";

        // Act
        var score = FuzzyMatcher.CalculateSimilarity(str1, str2);

        // Assert
        Assert.True(score >= 70, $"Expected decent score for featured artist variations, got {score}");
    }

    [Fact]
    public void CalculateSimilarity_HandlesRemixes()
    {
        // Arrange
        var str1 = "Song Title - Radio Edit";
        var str2 = "Song Title";

        // Act
        var score = FuzzyMatcher.CalculateSimilarity(str1, str2);

        // Assert
        Assert.True(score >= 70, $"Expected decent score for remix/edit variations, got {score}");
    }

    [Theory]
    [InlineData("", "", 0)]
    [InlineData("Test", "", 0)]
    [InlineData("", "Test", 0)]
    public void CalculateSimilarity_EmptyStrings_ReturnsZero(string str1, string str2, int expected)
    {
        // Act
        var score = FuzzyMatcher.CalculateSimilarity(str1, str2);

        // Assert
        Assert.Equal(expected, score);
    }

    [Fact]
    public void CalculateSimilarity_TokenOrder_DoesNotMatter()
    {
        // Arrange
        var str1 = "Bright Side Mr";
        var str2 = "Mr Bright Side";

        // Act
        var score = FuzzyMatcher.CalculateSimilarity(str1, str2);

        // Assert
        Assert.True(score >= 90, $"Expected high score regardless of token order, got {score}");
    }

    [Fact]
    public void CalculateSimilarity_PartialTokenMatch_ReturnsModerateScore()
    {
        // Arrange
        var str1 = "Mr. Brightside";
        var str2 = "Mr. Brightside (Live)";

        // Act
        var score = FuzzyMatcher.CalculateSimilarity(str1, str2);

        // Assert
        Assert.True(score >= 70 && score < 100, $"Expected moderate score for partial match, got {score}");
    }

    [Fact]
    public void CalculateSimilarity_SpecialCharacters_AreNormalized()
    {
        // Arrange
        var str1 = "Café del Mar";
        var str2 = "Cafe del Mar";

        // Act
        var score = FuzzyMatcher.CalculateSimilarity(str1, str2);

        // Assert
        Assert.True(score >= 90, $"Expected high score for accented characters, got {score}");
    }

}