import 'dart:convert';
import 'dart:io';
import 'dart:math';

import 'package:firebase_auth/firebase_auth.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'package:path_provider/path_provider.dart';
import 'package:record/record.dart';

// Your deployed function URL, e.g. https://assess-xxxx-uc.a.run.app
const functionUrl = String.fromEnvironment('ASSESS_URL');
const sentence = {'text': '我想买书', 'language': 'zh-CN'};

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp(); // run `flutterfire configure` first
  await FirebaseAuth.instance.signInAnonymously();
  runApp(const MaterialApp(home: ScorePage()));
}

class ScorePage extends StatefulWidget {
  const ScorePage({super.key});
  @override
  State<ScorePage> createState() => _ScorePageState();
}

class _ScorePageState extends State<ScorePage> {
  final _recorder = AudioRecorder();
  bool _recording = false, _busy = false;
  Map<String, dynamic>? _result;

  Future<void> _toggle() async {
    if (!_recording) {
      if (!await _recorder.hasPermission()) return;
      final dir = await getTemporaryDirectory();
      await _recorder.start(const RecordConfig(encoder: AudioEncoder.aacLc), path: '${dir.path}/take.m4a');
      setState(() => _recording = true);
      return;
    }
    final path = await _recorder.stop();
    setState(() {
      _recording = false;
      _busy = true;
    });
    try {
      final token = await FirebaseAuth.instance.currentUser!.getIdToken();
      final response = await http.post(Uri.parse(functionUrl),
          headers: {
            'Authorization': 'Bearer $token',
            'Content-Type': 'application/json',
            'Idempotency-Key': 'take-${DateTime.now().microsecondsSinceEpoch}-${Random().nextInt(1 << 30)}',
          },
          body: jsonEncode({...sentence, 'audio_base64': base64Encode(await File(path!).readAsBytes())}));
      setState(() => _result = jsonDecode(utf8.decode(response.bodyBytes)) as Map<String, dynamic>);
    } catch (e) {
      setState(() => _result = {'error': {'message': 'Network error: $e'}});
    } finally {
      setState(() => _busy = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    final r = _result;
    final words = (r?['words'] as List?) ?? const [];
    return Scaffold(
      appBar: AppBar(title: Text('Say: ${sentence['text']}')),
      body: ListView(padding: const EdgeInsets.all(24), children: [
        FilledButton(onPressed: _busy ? null : _toggle, child: Text(_recording ? 'Stop' : _busy ? 'Scoring…' : 'Record')),
        if (r?['error'] != null) Text('${r!['error']['message']}'),
        if (r != null && r['error'] == null && r['assessable'] == false) Text('Could not score that recording (${r['reason']}).'),
        for (final w in words)
          ListTile(
            title: Text('${w['text'] ?? ''} ${w['pinyin'] ?? ''}'),
            subtitle: Text(() {
              final tone = (w['units'] as List).cast<Map>().where((u) => u['dimension'] == 'tone');
              return tone.isEmpty ? '' : 'tone ${tone.first['expected']} → ${tone.first['heard'] ?? '?'}';
            }()),
            trailing: Text('${w['score'] ?? '—'}'),
          ),
        if (r?['test'] == true) const Text('Test key: fixed example result.'),
      ]),
    );
  }
}