import 'package:freezed_annotation/freezed_annotation.dart';

part 'opds_stream_link.freezed.dart';
part 'opds_stream_link.g.dart';

/// Represents an OPDS-PSE stream link for page-by-page reading
@freezed
class OPDSStreamLink with _$OPDSStreamLink {
  const factory OPDSStreamLink({
    /// URL template with {pageNumber} and optionally {maxWidth} placeholders
    /// This should be an absolute URL (resolved against server base URL during parsing)
    required String href,

    /// Image MIME type (image/jpeg, image/png, image/gif)
    required String type,

    /// Total number of pages
    required int pageCount,

    /// Last read page (0-indexed), null if never read
    int? lastRead,

    /// Last read timestamp
    DateTime? lastReadDate,
  }) = _OPDSStreamLink;

  const OPDSStreamLink._();

  /// Create OPDSStreamLink from JSON
  factory OPDSStreamLink.fromJson(Map<String, dynamic> json) =>
      _$OPDSStreamLinkFromJson(json);

  /// Check if the URL template supports maxWidth parameter
  bool get supportsMaxWidth => href.contains('{maxWidth}');

  /// Generate the URL for a specific page
  String getPageUrl(int pageNumber, {int? maxWidth}) {
    var url = href.replaceAll('{pageNumber}', pageNumber.toString());

    if (supportsMaxWidth && maxWidth != null) {
      url = url.replaceAll('{maxWidth}', maxWidth.toString());
    } else if (supportsMaxWidth) {
      // Remove maxWidth parameter if not provided
      url = url.replaceAll(RegExp(r'[?&]maxWidth=\{maxWidth\}'), '');
      url = url.replaceAll(RegExp(r'[?&]size=\{maxWidth\}'), '');
    }

    return url;
  }
}