import 'package:freezed_annotation/freezed_annotation.dart';
import 'package:worldhopper/models/link.dart';
import 'package:worldhopper/models/stream_link.dart';

part 'entry.freezed.dart';
part 'entry.g.dart';

/// Represents an entry in an OPDS feed (a publication or collection)
@freezed
class Entry with _$Entry {
  const factory Entry({
    /// Unique identifier for the entry
    required String id,

    /// Entry title
    required String title,

    /// Entry summary/description
    String? summary,

    /// Entry content (HTML description)
    String? content,

    /// Publication date
    DateTime? published,

    /// Last update date
    DateTime? updated,

    /// Authors
    @Default([]) List<String> authors,

    /// Categories/tags
    @Default([]) List<String> categories,

    /// All links associated with this entry
    @Default([]) List<Link> links,

    /// PSE stream link (if available)
    StreamLink? streamLink,

    /// Cover image URL
    String? coverUrl,

    /// Thumbnail image URL
    String? thumbnailUrl,

    /// Server-reported pages read (0-indexed current position). For EPUB
    /// entries this is the only place progress is exposed; for image streams
    /// it mirrors [StreamLink.lastRead].
    int? pagesRead,

    /// Server-reported total page count.
    int? totalPages,
  }) = _Entry;

  const Entry._();

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

  /// Check if this entry has a stream link (can be read page by page)
  bool get hasStreamLink => streamLink != null;

  /// Check if this entry is a navigation entry (leads to another feed)
  bool get isNavigation => links.any(
        (link) => link.rel == 'subsection' || link.rel.contains('navigation'),
      );

  /// Get the acquisition link (for download or reading)
  Link? get acquisitionLink => links.isEmpty
      ? null
      : links.cast<Link?>().firstWhere(
            (link) =>
                link!.rel.contains('acquisition') ||
                link.rel.contains('open-access'),
            orElse: () => links.first,
          );

  /// Get the self link
  Link? get selfLink => links.cast<Link?>().firstWhere(
        (link) => link?.rel == 'self',
        orElse: () => null,
      );

  /// Check if this entry is an EPUB publication
  bool get isEpub {
    final link = acquisitionLink;
    if (link == null) return false;
    return link.type?.toLowerCase().contains('epub') ?? false;
  }

  /// Check if this entry is an image stream (comic/manga)
  bool get isImageStream => hasStreamLink;

  /// Server-reported current page (0-indexed). Prefers the direct Entry field
  /// populated by Kavita for both EPUB and image streams; falls back to
  /// StreamLink.lastRead (OPDS PSE).
  int? get serverCurrentPage {
    if (pagesRead != null && pagesRead! >= 0) return pagesRead;
    return streamLink?.lastRead;
  }

  /// Server-reported total pages. Prefers Entry.totalPages; falls back to
  /// StreamLink.pageCount.
  int? get serverTotalPages {
    if (totalPages != null && totalPages! > 0) return totalPages;
    final pc = streamLink?.pageCount;
    return (pc != null && pc > 0) ? pc : null;
  }

  /// Server-reported progress as a percentage (0.0–1.0), or null when no
  /// usable progress is available. Treats a current page of 0 as "not
  /// started" so we do not show a spurious 1/N progress bar.
  double? get serverProgress {
    final cur = serverCurrentPage;
    final tot = serverTotalPages;
    if (cur == null || tot == null || tot <= 0 || cur <= 0) return null;
    return ((cur + 1) / tot).clamp(0.0, 1.0);
  }

  bool get hasServerProgress => serverProgress != null;
}