优化项目结构

lib/data/epub/reader_models.dart

@@ -0,0 +1,74 @@
+/// EPUB 解析结果数据模型
+library;
+
+class EpubBookInfo {
+  final String title;
+  final String author;
+  final List<String> authors;
+  final String? description;
+  final String? coverHref;
+  final String opfRootPath;
+  final String epubVersion;
+  final List<SpineItem> spine;
+  final List<TocEntry> toc;
+
+  EpubBookInfo({
+    required this.title,
+    required this.author,
+    required this.authors,
+    this.description,
+    this.coverHref,
+    required this.opfRootPath,
+    required this.epubVersion,
+    required this.spine,
+    required this.toc,
+  });
+}
+
+class SpineItem {
+  final int index;
+  final String href;
+  final String idref;
+  final bool linear;
+
+  SpineItem({
+    required this.index,
+    required this.href,
+    required this.idref,
+    this.linear = true,
+  });
+}
+
+class TocEntry {
+  final String label;
+  final String href;
+  final int spineIndex;
+  final List<TocEntry> children;
+
+  TocEntry({
+    required this.label,
+    required this.href,
+    this.spineIndex = -1,
+    this.children = const [],
+  });
+
+  /// 递归展平为列表（保留层级信息通过 depth）
+  List<FlatTocItem> flatten() {
+    final result = <FlatTocItem>[];
+    _flattenRecursive(result, 0);
+    return result;
+  }
+
+  void _flattenRecursive(List<FlatTocItem> list, int depth) {
+    list.add(FlatTocItem(entry: this, depth: depth));
+    for (final child in children) {
+      child._flattenRecursive(list, depth + 1);
+    }
+  }
+}
+
+class FlatTocItem {
+  final TocEntry entry;
+  final int depth;
+  FlatTocItem({required this.entry, required this.depth});
+}