git.stella-ops.org/src/StellaOps.Scanner.Analyzers.Lang/Core/LanguageUsageHints.cs

namespace StellaOps.Scanner.Analyzers.Lang;

public sealed class LanguageUsageHints
{
    private static readonly StringComparer Comparer = OperatingSystem.IsWindows()
        ? StringComparer.OrdinalIgnoreCase
        : StringComparer.Ordinal;

    private readonly ImmutableHashSet<string> _usedPaths;

    public static LanguageUsageHints Empty { get; } = new(Array.Empty<string>());

    public LanguageUsageHints(IEnumerable<string> usedPaths)
    {
        if (usedPaths is null)
        {
            throw new ArgumentNullException(nameof(usedPaths));
        }

        _usedPaths = usedPaths
            .Select(Normalize)
            .Where(static path => path.Length > 0)
            .ToImmutableHashSet(Comparer);
    }

    public bool IsPathUsed(string path)
    {
        if (string.IsNullOrWhiteSpace(path))
        {
            return false;
        }

        var normalized = Normalize(path);
        return _usedPaths.Contains(normalized);
    }

    private static string Normalize(string path)
    {
        if (string.IsNullOrWhiteSpace(path))
        {
            return string.Empty;
        }

        var full = Path.GetFullPath(path);
        return OperatingSystem.IsWindows()
            ? full.Replace('\\', '/').TrimEnd('/')
            : full;
    }
}