import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_markdown/flutter_markdown.dart';
import '../theme/app_colors.dart';

class ChangelogPage extends StatefulWidget {
  const ChangelogPage({super.key});

  @override
  State<ChangelogPage> createState() => _ChangelogPageState();
}

class _ChangelogPageState extends State<ChangelogPage>
    with SingleTickerProviderStateMixin {
  // ---------- 数据 ----------
  String _markdownContent = '';
  bool _isLoading = true;
  String? _error;

  // ---------- 滚动 ----------
  final ScrollController _scrollController = ScrollController();
  double _scrollProgress = 0.0;
  bool _isScrolling = false;

  // ---------- 呼吸动画 ----------
  late AnimationController _breathController;
  late Animation<double> _breathAnimation;

  // ---------- 原生刷新率控制 ----------
  static final _frameRateChannel = MethodChannel(
    'com.lxh.battery_health/frame_rate',
  );

  @override
  void initState() {
    super.initState();
    _loadChangelog();
    _frameRateChannel.invokeMethod('setHighRefreshRate');

    _breathController = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 500),
    )..repeat(reverse: true);

    _breathAnimation = Tween<double>(begin: 0.0, end: 0.03).animate(
      CurvedAnimation(parent: _breathController, curve: Curves.easeInOut),
    );

    _scrollController.addListener(() {
      _updateProgress();
      final isScrolling = _scrollController.position.isScrollingNotifier.value;
      if (isScrolling != _isScrolling) {
        setState(() {
          _isScrolling = isScrolling;
        });
        if (isScrolling) {
          _breathController.repeat(reverse: true);
        } else {
          _breathController.stop();
          _breathController.reset();
        }
      }
    });
  }

  @override
  void dispose() {
    _frameRateChannel.invokeMethod('clearRefreshRate');
    _scrollController.removeListener(_updateProgress);
    _scrollController.dispose();
    _breathController.dispose();
    super.dispose();
  }

  void _updateProgress() {
    if (!_scrollController.hasClients) return;
    final maxScroll = _scrollController.position.maxScrollExtent;
    final currentScroll = _scrollController.position.pixels;
    final progress = maxScroll > 0 ? currentScroll / maxScroll : 0.0;
    setState(() {
      _scrollProgress = progress;
    });
  }

  Future<void> _loadChangelog() async {
    try {
      final content = await rootBundle.loadString('assets/CHANGELOG.md');
      setState(() {
        _markdownContent = content;
        _isLoading = false;
      });
    } catch (e) {
      setState(() {
        _error = '无法加载更新日志: $e';
        _isLoading = false;
      });
    }
  }

  Widget _buildMarkdown(BuildContext context, String content) {
    final c = context.colors;
    return Markdown(
      data: content,
      shrinkWrap: true,
      physics: const NeverScrollableScrollPhysics(),
      styleSheet: MarkdownStyleSheet(
        h1: TextStyle(
          fontFamily: 'HarmonyOS_Sans_SC',
          fontSize: 24,
          fontWeight: FontWeight.w700,
          color: c.textPrimary,
        ),
        h2: TextStyle(
          fontFamily: 'HarmonyOS_Sans_SC',
          fontSize: 20,
          fontWeight: FontWeight.w600,
          color: c.textPrimary,
        ),
        h3: TextStyle(
          fontFamily: 'HarmonyOS_Sans_SC',
          fontSize: 18,
          fontWeight: FontWeight.w600,
          color: c.textSecondary,
        ),
        p: TextStyle(
          fontFamily: 'HarmonyOS_Sans_SC',
          fontSize: 16,
          color: c.textSecondary,
        ),
        listBullet: TextStyle(
          fontFamily: 'HarmonyOS_Sans_SC',
          fontSize: 16,
          color: c.textSecondary,
        ),
        code: TextStyle(
          fontFamily: 'HarmonyOS_Sans_SC',
          fontSize: 14,
          color: c.textSecondary,
          backgroundColor: c.surface,
        ),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    final c = context.colors;
    final breathOffset = _isScrolling ? _breathAnimation.value : 0.0;
    final displayProgress = (_scrollProgress + breathOffset).clamp(0.0, 1.0);

    return Scaffold(
      appBar: AppBar(
        title: Text(
          '更新日志',
          style: TextStyle(
            fontFamily: 'HarmonyOS_Sans_SC',
            color: c.textPrimary,
          ),
        ),
        elevation: 0,
        foregroundColor: c.textPrimary,
        iconTheme: IconThemeData(color: c.textPrimary),
        bottom: PreferredSize(
          preferredSize: const Size.fromHeight(2.0),
          child: LinearProgressIndicator(
            value: displayProgress,
            backgroundColor: c.divider,
            valueColor: AlwaysStoppedAnimation<Color>(c.progressBar),
            minHeight: 2.0,
          ),
        ),
      ),
      body: _isLoading
          ? const Center(child: CircularProgressIndicator())
          : _error != null
          ? Center(
              child: Text(
                _error!,
                style: TextStyle(
                  fontFamily: 'HarmonyOS_Sans_SC',
                  color: c.textTertiary,
                ),
              ),
            )
          : SingleChildScrollView(
              controller: _scrollController,
              padding: const EdgeInsets.all(16.0),
              child: _buildMarkdown(context, _markdownContent),
            ),
    );
  }
}