using Strata.SqlTools.SqlBreakdown.Utilities;

namespace Strata.SqlTools.SqlBreakdown.Tests.Utilities;

[TestFixture]
public class StringUtilsTests
{
    [TestCase('a', -842352705)]
    [TestCase('z', -842352730)]
    [TestCase('A', -842352673)]
    [TestCase('Z', -842352698)]
    [TestCase('0', -842352768)]
    [TestCase('9', -842352759)]
    [TestCase(' ', -842352737)]
    [TestCase('-', -842352782)]
    public void GetHashCode32Bit_KnownCharacters_ReturnsHardcodedHash(char c, int expected)
    {
        // Act & Assert
        Assert.That(StringUtils.GetHashCode32Bit(c), Is.EqualTo(expected));
    }

    [Test]
    public void GetHashCode32Bit_UnmappedCharacter_UsesConsistentFallback()
    {
        // Arrange - '!' is not in the hardcoded table
        const char c = '!';
        var expected = -842352737 - (int)c;

        // Act & Assert
        Assert.That(StringUtils.GetHashCode32Bit(c), Is.EqualTo(expected));
    }

    [Test]
    public void GetHashCode32Bit_SameCharacter_IsDeterministic()
    {
        // Act & Assert - critical: TranslateTextToGuid relies on stable hashing
        Assert.That(StringUtils.GetHashCode32Bit('q'), Is.EqualTo(StringUtils.GetHashCode32Bit('q')));
    }
}