import 'dart:async';
import 'dart:io';

import 'package:dio/dio.dart';
import 'package:docx_viewer/docx_viewer.dart';
import 'package:flutter/material.dart';
import 'package:path_provider/path_provider.dart';
import 'package:pdfx/pdfx.dart';
import 'package:qhd_prevention/pages/my_appbar.dart';

class ReadFilePage extends StatefulWidget {
  final String fileUrl;
  final int countdownSeconds;

  const ReadFilePage({
    Key? key,
    required this.fileUrl,
    this.countdownSeconds = 3,
  }) : super(key: key);

  @override
  State<ReadFilePage> createState() => _ReadFilePageState();
}

class _ReadFilePageState extends State<ReadFilePage> {
  String? _localPath;
  bool _isLoading = true;
  bool _hasScrolledToBottom = false;
  bool _timerFinished = false;
  late int _secondsRemaining;
  Timer? _countdownTimer;
  PdfControllerPinch? _pdfController;
  int _totalPages = 0;
  bool _isDocxFile = false;

  @override
  void initState() {
    super.initState();
    _secondsRemaining = widget.countdownSeconds;
    _startCountdown();
    _prepareFile();
  }

  bool _isDocxUrl(String url) {
    final path = Uri.parse(url).path.toLowerCase();
    return path.endsWith('.docx') || path.endsWith('.doc');
  }

  bool _isPdfUrl(String url) {
    final path = Uri.parse(url).path.toLowerCase();
    return path.endsWith('.pdf');
  }

  Future<void> _prepareFile() async {
    final url = widget.fileUrl;

    if (_isDocxUrl(url)) {
      if (!mounted) return;
      setState(() {
        _isDocxFile = true;
        _isLoading = false;
      });
      return;
    }

    if (!_isPdfUrl(url)) {
      if (!mounted) return;
      setState(() {
        _isLoading = false;
      });
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('目前仅支持 PDF、DOCX、DOC 文件预览')),
      );
      return;
    }

    await _downloadAndLoadPdf();
  }

  Future<void> _downloadAndLoadPdf() async {
    try {
      final url = widget.fileUrl;
      final uri = Uri.parse(url);
      final filename = uri.pathSegments.isNotEmpty ? uri.pathSegments.last : 'temp.pdf';

      final dir = await getTemporaryDirectory();
      final filePath = '${dir.path}/$filename';

      final dio = Dio();
      await dio.download(url, filePath);

      if (!mounted) return;

      _pdfController = PdfControllerPinch(
        document: PdfDocument.openFile(filePath),
      );

      setState(() {
        _localPath = filePath;
        _isLoading = false;
      });
    } catch (e) {
      if (!mounted) return;

      setState(() {
        _isLoading = false;
      });

      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('文件加载失败：$e')),
      );
    }
  }

  void _startCountdown() {
    _countdownTimer?.cancel();
    _countdownTimer = Timer.periodic(const Duration(seconds: 1), (timer) {
      if (!mounted) return;

      setState(() {
        if (_secondsRemaining > 1) {
          _secondsRemaining--;
        } else {
          _secondsRemaining = 0;
          _timerFinished = true;
          _countdownTimer?.cancel();
        }
      });
    });
  }

  @override
  void dispose() {
    _countdownTimer?.cancel();
    _pdfController?.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final isButtonEnabled = _timerFinished && _hasScrolledToBottom;

    return Scaffold(
      appBar: MyAppbar(title: '文件详情'),
      backgroundColor: Colors.white,
      body: SafeArea(
        child: Column(
          children: [
            Expanded(
              child: _isLoading
                  ? const Center(child: CircularProgressIndicator())
                  : _isDocxFile
                  ? DocxView(
                filePath: widget.fileUrl,
                fontSize: 16,
                onError: (error) {
                  ScaffoldMessenger.of(context).showSnackBar(
                    SnackBar(content: Text('DOCX 加载失败：$error')),
                  );
                },
              )
                  : _pdfController == null
                  ? const Center(
                child: Text('文件无法预览，请确认链接有效且为 PDF 文件'),
              )
                  : PdfViewPinch(
                controller: _pdfController!,
                scrollDirection: Axis.vertical,
                onDocumentLoaded: (document) {
                  setState(() {
                    _totalPages = document.pagesCount;
                  });
                },
                onPageChanged: (page) {
                  if (_totalPages > 0 && page == _totalPages - 1) {
                    setState(() => _hasScrolledToBottom = true);
                  }
                },
              ),
            ),
            // Padding(
            //   padding: const EdgeInsets.all(16),
            //   child: ElevatedButton(
            //     onPressed: isButtonEnabled
            //         ? () {
            //       Navigator.pop(context);
            //     }
            //         : null,
            //     child: Text(
            //       isButtonEnabled
            //           ? '我已学习完毕'
            //           : _secondsRemaining == 0
            //           ? '请阅读完成'
            //           : '（$_secondsRemaining s）我已学习完毕',
            //     ),
            //   ),
            // ),
          ],
        ),
      ),
    );
  }
}