using MediaBrowser.Controller.Library;

namespace Jellyfin.Plugin.Vanguard.Services;

/// <summary>Splits a media path into (series folder, dock title or null, file stem) relative to its library root.</summary>
public sealed class LibraryPaths
{
    private readonly ILibraryManager _library;
    public LibraryPaths(ILibraryManager library) { _library = library; }

    public sealed record Parts(string SeriesFolder, string? Title, string Stem);

    public Parts? Split(string path)
    {
        var full = Path.GetFullPath(path);
        string? root = null;
        foreach (var vf in _library.GetVirtualFolders())
        {
            foreach (var loc in vf.Locations ?? [])
            {
                var l = Path.GetFullPath(loc).TrimEnd(Path.DirectorySeparatorChar);
                if (full.StartsWith(l + Path.DirectorySeparatorChar, StringComparison.Ordinal) && (root is null || l.Length > root.Length)) root = l;
            }
        }
        if (root is null) return null;
        var rel = full[(root.Length + 1)..].Split(Path.DirectorySeparatorChar, StringSplitOptions.RemoveEmptyEntries);
        if (rel.Length < 2) return null;
        var stem = Path.GetFileNameWithoutExtension(rel[^1]);
        if (rel.Length >= 3) return new Parts(rel[0], rel[^2], stem);           // legacy: <user>/<Title>/<ts>.mp4
        var sep = stem.IndexOf("__", StringComparison.Ordinal);                   // flat: <user>/<Title>__<ts>.mp4
        return sep > 0 ? new Parts(rel[0], stem[..sep], stem[(sep + 2)..]) : new Parts(rel[0], null, stem);
    }
}