//
// Just a rough implementation of the document index
//
import 'package:flutter/material.dart';
import 'package:pdfrx/pdfrx.dart';

class OutlineView extends StatelessWidget {
  const OutlineView({
    super.key,
    required this.outline,
    required this.controller,
  });

  final List<PdfOutlineNode>? outline;
  final PdfViewerController controller;

  @override
  Widget build(BuildContext context) {
    final list = _getOutlineList(outline, 0).toList();
    return SizedBox(
      width: list.isEmpty ? 0 : 200,
      child: ListView.builder(
        itemCount: list.length,
        itemBuilder: (context, index) {
          final item = list[index];
          return InkWell(
            onTap: () => controller.goToDest(item.node.dest),
            child: Container(
              margin: EdgeInsets.only(
                left: item.level * 16.0 + 8,
                top: 8,
                bottom: 8,
              ),
              child: Text(
                item.node.title,
                softWrap: false,
              ),
            ),
          );
        },
      ),
    );
  }

  /// Recursively create outline indent structure
  Iterable<({PdfOutlineNode node, int level})> _getOutlineList(
      List<PdfOutlineNode>? outline, int level) sync* {
    if (outline == null) return;
    for (var node in outline) {
      yield (node: node, level: level);
      yield* _getOutlineList(node.children, level + 1);
    }
  }
}