namespace VFXReviewWorker;

/// <summary>
/// Translates canonical UNC paths from manifests to this machine's local
/// drive mappings (§7.8 pathMappings). Comparison is case-insensitive and
/// slash-direction tolerant; the first matching mapping wins.
/// </summary>
public sealed class PathMapper
{
    private readonly List<(string From, string To)> _mappings;

    public PathMapper(IEnumerable<PathMapping> mappings)
    {
        _mappings = mappings
            .Where(m => !string.IsNullOrWhiteSpace(m.From))
            .Select(m => (Normalize(m.From), m.To))
            .ToList();
    }

    private static string Normalize(string p) => p.Replace('\\', '/');

    public string Map(string path)
    {
        if (string.IsNullOrEmpty(path)) return path;
        var normalized = Normalize(path);
        foreach (var (from, to) in _mappings)
        {
            if (normalized.StartsWith(from, StringComparison.OrdinalIgnoreCase))
            {
                var mapped = to + normalized[from.Length..];
                return mapped.Replace('/', Path.DirectorySeparatorChar);
            }
        }
        return path.Replace('/', Path.DirectorySeparatorChar);
    }
}