English/kouyu_english/lib/features/lesson/steps/independent_step.dart

part of '../lesson_flow.dart';

class _IndependentStep extends StatefulWidget {
  const _IndependentStep({
    required this.state,
    required this.segmentId,
    required this.keepRecording,
    required this.activity,
    required this.controller,
    required this.showHelp,
    required this.canContinue,
    required this.onChanged,
    required this.onNeedHelp,
    required this.onLookup,
    required this.onContinue,
    required this.onLater,
  });
  final AppState state;
  final LessonActivity activity;
  final String segmentId;
  final bool keepRecording;
  final TextEditingController controller;
  final bool showHelp;
  final bool canContinue;
  final VoidCallback onChanged;
  final VoidCallback onNeedHelp;
  final VoidCallback onLookup;
  final void Function(bool spoken, String? recordingPath) onContinue;
  final VoidCallback onLater;

  @override
  State<_IndependentStep> createState() => _IndependentStepState();
}

class _IndependentStepState extends State<_IndependentStep>
    with VoiceAnswerMixin<_IndependentStep> {
  bool usedVoice = false;
  bool transcriptEdited = false;
  String lastTranscript = '';
  String? validationError;

  @override
  AppState get voiceState => widget.state;

  @override
  void dispose() {
    disposeVoiceAnswer(keepRecording: widget.keepRecording);
    super.dispose();
  }

  void _submit() {
    if (!matchesSegmentIndependent(widget.segmentId, widget.controller.text)) {
      setState(() => validationError = '这次还没有用上本段要练的内容。查看帮助后补充一次。');
      return;
    }
    widget.onContinue(
      usedVoice && !transcriptEdited,
      widget.keepRecording ? recordingPath : null,
    );
  }

  Future<void> _toggleMic() async {
    if (aiVoiceRecording) {
      await finishVoiceInput(
        onTranscript: (text) {
          widget.controller.text = text;
          usedVoice = true;
          lastTranscript = text;
          transcriptEdited = false;
        },
        afterTranscribe: widget.onChanged,
      );
      return;
    }

    if (listening) {
      await VoiceService.instance.stopListening();
      if (mounted) setState(() => listening = false);
      return;
    }

    final ready = await VoiceService.instance.startListening(
      (text, _) {
        if (!mounted) return;
        setState(() {
          widget.controller.text = text;
          usedVoice = true;
          lastTranscript = text;
          transcriptEdited = false;
        });
        widget.onChanged();
      },
      onStatus: (status) {
        if (mounted && (status == 'notListening' || status == 'done')) {
          setState(() => listening = false);
        }
      },
      onError: (err) {
        if (mounted) {
          setState(() => listening = false);
        }
      },
    );

    if (!ready) {
      final recordStarted = await startVoiceInput();
      if (recordStarted && mounted) {
        showVoiceMessage('已启动麦克风录音，说完后再次点击，AI 将自动转写为英文。');
      }
      return;
    }

    if (mounted) setState(() => listening = ready);
  }

  @override
  Widget build(BuildContext context) => _LessonScaffold(
    step: 6,
    child: SpacedColumn(
      children: [
        const Eyebrow('试着自己写 / 说一次 · 约 1 分钟'),
        Text('现在不看句框。', style: Theme.of(context).textTheme.headlineMedium),
        Text(widget.activity.independentPrompt),
        if (widget.showHelp)
          SectionCard(
            tint: AppColors.warm,
            child: Text(
              '帮助：${widget.activity.independentHelp}',
              style: TextStyle(color: AppColors.warmInk),
            ),
          ),
        TextField(
          controller: widget.controller,
          onChanged: (value) {
            if (usedVoice && value != lastTranscript) transcriptEdited = true;
            setState(() {});
            widget.onChanged();
          },
          minLines: 2,
          maxLines: 4,
          decoration: InputDecoration(
            hintText: '输入完整英文句子',
            filled: true,
            fillColor: AppColors.surface,
            prefixIcon: IconButton(
              tooltip: listening ? '停止录音' : '语音输入',
              icon: Icon(
                listening ? Icons.stop_circle_outlined : Icons.mic_none,
              ),
              onPressed: _toggleMic,
            ),
            border: OutlineInputBorder(),
          ),
        ),
        SectionCard(
          tint: AppColors.surfaceMuted,
          child: SpacedColumn(
            spacing: 8,
            children: [
              Text(
                widget.keepRecording
                    ? '可录下这次尝试并保存在本机；不会发送给 AI。'
                    : '可录下这次尝试并回听；离开本页后会自动删除。',
              ),
              RecordingControls(
                recording: recording,
                playing: playingRecording,
                hasRecording: recordingPath != null,
                onToggleRecording: toggleRecording,
                onPlay: playRecording,
                onDelete: deleteRecording,
              ),
            ],
          ),
        ),
        if (usedVoice)
          SectionCard(
            tint: transcriptEdited ? AppColors.warm : AppColors.softGreen,
            child: Text(
              transcriptEdited
                  ? '你修改了设备转写：这次会按文字练习保存，不计口语练习。'
                  : '这是设备转写。未修改并确认后，会保留为本次语音练习记录。',
              style: TextStyle(
                color: transcriptEdited ? AppColors.warmInk : AppColors.green,
              ),
            ),
          ),
        if (validationError != null)
          SectionCard(
            tint: AppColors.warm,
            child: Text(
              validationError!,
              style: const TextStyle(color: AppColors.warmInk),
            ),
          ),
        if (!widget.showHelp)
          Wrap(
            spacing: 8,
            children: [
              TextButton(
                onPressed: widget.onNeedHelp,
                child: const Text('需要帮助'),
              ),
              TextButton(
                onPressed: widget.onLookup,
                child: const Text('查词或短语'),
              ),
            ],
          )
        else
          TextButton(onPressed: widget.onLookup, child: const Text('查词或短语')),
        PrimaryButton(
          label: widget.showHelp ? '带帮助完成' : '独立完成',
          onPressed: widget.canContinue ? _submit : null,
        ),
        TextButton(onPressed: widget.onLater, child: const Text('稍后继续')),
      ],
    ),
  );
}