import 'package:worldhopper/models/opds_server.dart';
import 'package:worldhopper/services/opds_service.dart';
import 'package:worldhopper/services/server_handlers/kavita_handler.dart';
import 'package:worldhopper/services/server_handlers/opds_server_handler.dart';

/// Detects the software running behind an OPDS server.
///
/// Fetches the root feed once and iterates all registered handlers,
/// returning the identifier of the first match (or null).
class ServerSoftwareDetector {
  static final List<OPDSServerHandler> handlers = [
    KavitaHandler(),
  ];

  /// Attempt to detect the server software for [server].
  ///
  /// Returns the handler identifier (e.g. "kavita") on match, or null.
  Future<String?> detect(OPDSServer server) async {
    try {
      final parsedFeed = await OPDSService().fetchRootFeed(server);
      final feed = parsedFeed.feed;

      for (final handler in handlers) {
        if (await handler.detect(server, feed)) {
          return handler.identifier;
        }
      }
    } catch (_) {
      // Detection is best-effort; return null on any failure.
    }
    return null;
  }

  /// Get the human-readable display name for a handler identifier.
  static String? displayName(String identifier) {
    for (final handler in handlers) {
      if (handler.identifier == identifier) {
        return handler.displayName;
      }
    }
    return null;
  }

  /// All known server software types for use in UI dropdowns.
  static List<({String identifier, String displayName})> get knownTypes {
    return handlers
        .map((h) => (identifier: h.identifier, displayName: h.displayName))
        .toList();
  }
}