import 'package:flutter/material.dart';
import 'package:html/parser.dart' as html_parser;
import 'package:html/dom.dart' as dom;
import 'dart:convert';
import 'package:be_happy/di/service_locator.dart';
import '../../core/app_colors.dart';
import '../components/custom_app_bar.dart';
import '../../domain/usecase/get_news_by_id_usecase.dart';

class NewsDetailScreen extends StatefulWidget {
  final int newsId;
  final String title;

  const NewsDetailScreen({
    super.key,
    required this.newsId,
    required this.title,
  });

  @override
  State<NewsDetailScreen> createState() => _NewsDetailScreenState();
}

class _NewsDetailScreenState extends State<NewsDetailScreen> {
  bool _isLoading = true;
  String? _errorMessage;
  dynamic _news;

  @override
  void initState() {
    super.initState();
    _fetchNews();
  }

  Future<void> _fetchNews() async {
    try {
      final usecase = getIt<GetNewsByIdUsecase>();
      final news = await usecase(widget.newsId);

      if (mounted) {
        setState(() {
          _news = news;
          _isLoading = false;
        });
      }
    } catch (e) {
      if (mounted) {
        setState(() {
          _errorMessage = e.toString();
          _isLoading = false;
        });
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Container(
        decoration: const BoxDecoration(gradient: AppColors.phoneScreenBg),
        child: SafeArea(
          child: Column(
            children: [
              const SizedBox(height: 16),
              Padding(
                padding: const EdgeInsets.symmetric(horizontal: 20),
                child: CustomAppBar(title: widget.title),
              ),

              // 🔹 Контент
              Expanded(
                child: _isLoading
                    ? const Center(
                  child: CircularProgressIndicator(color: Colors.white),
                )
                    : _errorMessage != null
                    ? Center(
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: [
                      const Text(
                        'Ошибка загрузки новости',
                        style: TextStyle(
                          color: Colors.white,
                          fontSize: 16,
                          fontWeight: FontWeight.w600,
                        ),
                      ),
                      const SizedBox(height: 16),
                      Text(
                        _errorMessage!,
                        style: TextStyle(
                          color: Colors.white.withOpacity(0.6),
                          fontSize: 14,
                        ),
                        textAlign: TextAlign.center,
                      ),
                      const SizedBox(height: 24),
                      ElevatedButton(
                        onPressed: () {
                          setState(() {
                            _isLoading = true;
                            _errorMessage = null;
                            _fetchNews();
                          });
                        },
                        child: const Text('Повторить'),
                      ),
                    ],
                  ),
                )
                    : _news != null
                    ? _buildNewsContent(_news)
                    : const SizedBox.shrink(),
              ),
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildNewsContent(dynamic news) {
    return SingleChildScrollView(
      padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 20),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          
          // Текст новости: сначала проверяем textJson, потом text
          if (news.textJson != null)
            ..._parseJsonText(news.textJson)
          else if (news.text != null)
            ..._parseHtmlText(news.text),
        ],
      ),
    );
  }

  List<Widget> _parseHtmlText(String htmlText) {
    final parsedHtml = html_parser.parse(htmlText);
    final List<dom.Node> elements = parsedHtml.body?.nodes ?? [];

    return _parseHtmlElements(elements);
  }

  List<Widget> _parseHtmlElements(List<dom.Node> nodes) {
    List<Widget> widgets = [];

    for (final node in nodes) {
      if (node is dom.Element) {
        switch (node.localName) {
          case 'h1':
          case 'h2':
          case 'h3':
            widgets.add(
              Padding(
                padding: const EdgeInsets.symmetric(vertical: 8),
                child: Text(
                  node.text,
                  style: const TextStyle(
                    color: Colors.white,
                    fontSize: 18,
                    fontWeight: FontWeight.bold,
                  ),
                ),
              ),
            );
            break;
          case 'p':
            widgets.add(
              Padding(
                padding: const EdgeInsets.symmetric(vertical: 4),
                child: Text(
                  node.text,
                  style: const TextStyle(
                    color: Colors.white70,
                    fontSize: 14,
                    height: 1.5,
                  ),
                ),
              ),
            );
            break;
          case 'ul':
            widgets.add(
              Padding(
                padding: const EdgeInsets.symmetric(vertical: 4),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: node.children
                      .where((element) => element is dom.Element && element.localName == 'li')
                      .map((dom.Element li) => Padding(
                    padding: const EdgeInsets.only(left: 16, top: 4, bottom: 4),
                    child: Row(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        const Text('• ',
                            style: TextStyle(
                              color: Colors.white70,
                              fontSize: 14,
                            )),
                        Expanded(
                          child: Text(
                            li.text,
                            style: const TextStyle(
                              color: Colors.white70,
                              fontSize: 14,
                              height: 1.5,
                            ),
                          ),
                        ),
                      ],
                    ),
                  ))
                      .toList(),
                ),
              ),
            );
            break;
          default:
            widgets.add(
              Padding(
                padding: const EdgeInsets.symmetric(vertical: 4),
                child: Text(
                  node.text,
                  style: const TextStyle(
                    color: Colors.white70,
                    fontSize: 14,
                  ),
                ),
              ),
            );
        }
      } else if (node is dom.Text) {
        widgets.add(
          Text(
            node.text,
            style: const TextStyle(
              color: Colors.white70,
              fontSize: 14,
            ),
          ),
        );
      }
    }

    return widgets;
  }

  // 🔹 Парсинг JSON-текста (новый метод)
  List<Widget> _parseJsonText(String jsonString) {
    try {
      final dynamic data = jsonDecode(jsonString);
      return _parseJsonNode(data);
    } catch (e) {
      return [
        const Text(
          'Ошибка отображения текста новости',
          style: TextStyle(color: Colors.red, fontSize: 14),
        ),
      ];
    }
  }

  List<Widget> _parseJsonNode(dynamic node) {
    List<Widget> widgets = [];

    if (node is List) {
      // Если корень — массив, парсим каждый элемент
      for (final item in node) {
        widgets.addAll(_parseJsonNode(item));
      }
    } else if (node is Map<String, dynamic>) {
      final type = node['type'] as String?;
      final content = node['content'];

      switch (type) {
        case 'div':
          if (content is List) {
            widgets.addAll(_parseJsonNode(content));
          }
          break;
        case 'h2':
          widgets.add(
            Padding(
              padding: const EdgeInsets.symmetric(vertical: 8),
              child: Text(
                (content is List)
                    ? content.join(' ')
                    : content?.toString() ?? '',
                style: const TextStyle(
                  color: Colors.white,
                  fontSize: 18,
                  fontWeight: FontWeight.bold,
                ),
              ),
            ),
          );
          break;
        case 'p':
          widgets.add(
            Padding(
              padding: const EdgeInsets.symmetric(vertical: 4),
              child: Text(
                (content is List)
                    ? content.join(' ')
                    : content?.toString() ?? '',
                style: const TextStyle(
                  color: Colors.white70,
                  fontSize: 14,
                  height: 1.5,
                ),
              ),
            ),
          );
          break;
        case 'ul':
          if (content is List) {
            widgets.add(
              Padding(
                padding: const EdgeInsets.symmetric(vertical: 4),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: content
                      .where((item) => item is Map<String, dynamic>)
                      .map((item) => item as Map<String, dynamic>)
                      .where((item) => item['type'] == 'li')
                      .map((li) => Padding(
                    padding: const EdgeInsets.only(left: 16, top: 4, bottom: 4),
                    child: Row(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        const Text('• ',
                            style: TextStyle(
                              color: Colors.white70,
                              fontSize: 14,
                            )),
                        Expanded(
                          child: Text(
                            (li['content'] is List)
                                ? li['content'].join(' ')
                                : li['content']?.toString() ?? '',
                            style: const TextStyle(
                              color: Colors.white70,
                              fontSize: 14,
                              height: 1.5,
                            ),
                          ),
                        ),
                      ],
                    ),
                  ))
                      .toList(),
                ),
              ),
            );
          }
          break;
        default:
        // Если тип неизвестен, просто выводим текст
          widgets.add(
            Padding(
              padding: const EdgeInsets.symmetric(vertical: 4),
              child: Text(
                (content is List)
                    ? content.join(' ')
                    : content?.toString() ?? type ?? 'unknown',
                style: const TextStyle(
                  color: Colors.white70,
                  fontSize: 14,
                ),
              ),
            ),
          );
      }
    }

    return widgets;
  }

  String _formatDate(DateTime? date) {
    if (date == null) return '';
    final localDate = date.toLocal();
    return '${localDate.day.toString().padLeft(2, '0')}.${localDate.month.toString().padLeft(2, '0')}.${localDate.year}';
  }
}