import 'package:flutter/material.dart';
import 'package:flutter_markdown/flutter_markdown.dart';

import '../core/app_colors.dart';
import '../core/app_design_tokens.dart';

class AiContent {
  AiContent._();

  static String clean(String text) {
    var t = text;
    t = t.replaceAll(RegExp(r'\$\d+'), '');
    t = t.replaceAll(RegExp(r'<[^>]+>'), '');
    t = t.replaceAllMapped(RegExp(r'^#{4,}\s', multiLine: true), (_) => '### ');
    t = t.replaceAll(RegExp(r'\n{3,}'), '\n\n');
    return t.trim();
  }

  static String plain(String text) {
    final cleaned = clean(text);
    return cleaned
        .replaceAll(RegExp(r'\*\*(.*?)\*\*'), r'$1')
        .replaceAll(RegExp(r'__(.*?)__'), r'$1')
        .replaceAll(RegExp(r'`([^`]+)`'), r'$1')
        .replaceAll(RegExp(r'^\s*[-*]\s+', multiLine: true), '• ')
        .trim();
  }
}

class AiMarkdownView extends StatelessWidget {
  final String data;
  final bool selectable;
  final void Function(String text, String? href, String title)? onTapLink;

  const AiMarkdownView({
    super.key,
    required this.data,
    this.selectable = true,
    this.onTapLink,
  });

  @override
  Widget build(BuildContext context) {
    return MarkdownBody(
      data: AiContent.clean(data),
      selectable: selectable,
      onTapLink: onTapLink,
      styleSheet: MarkdownStyleSheet(
        p: AppTextStyles.chatBody,
        a: AppTextStyles.chatBody.copyWith(
          color: AppColors.primary,
          fontWeight: FontWeight.w600,
          decoration: TextDecoration.underline,
          decorationColor: AppColors.primary,
        ),
        strong: AppTextStyles.chatBody.copyWith(fontWeight: FontWeight.w600),
        h1: AppTextStyles.chatTitle.copyWith(fontSize: 20),
        h2: AppTextStyles.chatTitle.copyWith(fontSize: 20),
        h3: AppTextStyles.chatTitle.copyWith(fontSize: 19),
        listBullet: AppTextStyles.chatBody.copyWith(
          fontSize: 21,
          fontWeight: FontWeight.w700,
        ),
        listBulletPadding: const EdgeInsets.only(right: 8),
        blockquote: AppTextStyles.chatBody.copyWith(
          color: AppColors.textSecondary,
        ),
      ),
    );
  }
}

class AiGeneratedNote extends StatelessWidget {
  const AiGeneratedNote({super.key});

  @override
  Widget build(BuildContext context) => const Padding(
    padding: EdgeInsets.only(top: 10),
    child: Text('内容由 AI 生成', style: AppTextStyles.aiNote),
  );
}