// ⏱️ 우리 학교 전용 "백품타" 공부 타이머 화면 (UI 전용).
// 서버 통신/상태는 lib/function/study_timer_controller.dart가 담당한다.
import 'package:flutter/material.dart';
import '../function/study_timer_controller.dart';
import '../theme/app_palette.dart';
import 'app_notice.dart';
import 'launchpad_transition.dart';
import 'study_preset_screen.dart';
import 'study_ranking_screen.dart';
import 'title_pill.dart';

class StudyTimerScreen extends StatefulWidget {
  final String studentId;
  final String studentName;
  final int? grade;

  const StudyTimerScreen({
    super.key,
    required this.studentId,
    required this.studentName,
    this.grade,
  });

  @override
  State<StudyTimerScreen> createState() => _StudyTimerScreenState();
}

class _StudyTimerScreenState extends State<StudyTimerScreen> {
  late final StudyTimerController _controller;

  @override
  void initState() {
    super.initState();
    _controller = StudyTimerController(
      studentId: widget.studentId,
      studentName: widget.studentName,
    );
    _controller.onPhaseChanged = _handlePhaseChanged;
    _controller.init();
  }

  void _handlePhaseChanged(String message) {
    if (!mounted) return;
    AppNotice.show(context, message, icon: Icons.timer_rounded);
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  String _formatHMS(int totalSeconds) {
    final h = totalSeconds ~/ 3600;
    final m = (totalSeconds % 3600) ~/ 60;
    final s = totalSeconds % 60;
    final hh = h.toString().padLeft(2, '0');
    final mm = m.toString().padLeft(2, '0');
    final ss = s.toString().padLeft(2, '0');
    return '$hh:$mm:$ss';
  }

  String _formatMinSec(int totalSeconds) {
    final s = totalSeconds < 0 ? 0 : totalSeconds;
    final m = s ~/ 60;
    final sec = s % 60;
    return '$m:${sec.toString().padLeft(2, '0')}';
  }

  String _statusLabel(bool isRunning, bool isPaused) {
    if (_controller.pomodoroEnabled && _controller.phase != null) {
      return _controller.phase == PomodoroPhase.study
          ? '뽀모도로 - 공부 중이에요'
          : '뽀모도로 - 쉬는 중이에요';
    }
    if (isRunning) return '지금 공부 중이에요';
    if (isPaused) return '일시정지 중이에요';
    return '공부를 시작해볼까요?';
  }

  String _formatHM(int totalSeconds) {
    final h = totalSeconds ~/ 3600;
    final m = (totalSeconds % 3600) ~/ 60;
    if (h > 0) return '$h시간 $m분';
    return '$m분';
  }

  Future<void> _runAction(
    Future<(bool success, String message)> Function() action,
  ) async {
    final (success, message) = await action();
    if (!mounted) return;
    AppNotice.show(
      context,
      message,
      icon: success ? Icons.check_circle_rounded : Icons.error_outline_rounded,
    );
  }

  Future<void> _showPomodoroSettings() async {
    bool enabled = _controller.pomodoroEnabled;
    int studyMinutes = _controller.studyMinutes;
    int breakMinutes = _controller.breakMinutes;
    final bool canEdit = _controller.isIdle;

    await showModalBottomSheet<void>(
      context: context,
      isScrollControlled: true,
      backgroundColor: AppPalette.paper,
      shape: const RoundedRectangleBorder(
        borderRadius: BorderRadius.vertical(top: Radius.circular(20)),
      ),
      builder: (sheetContext) {
        return StatefulBuilder(
          builder: (sheetContext, setSheetState) {
            return Padding(
              padding: EdgeInsets.only(
                left: 20,
                right: 20,
                top: 20,
                bottom: MediaQuery.of(sheetContext).viewInsets.bottom + 20,
              ),
              child: Column(
                mainAxisSize: MainAxisSize.min,
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: [
                  Row(
                    children: [
                      const Expanded(
                        child: Text(
                          '뽀모도로 모드',
                          style: TextStyle(
                            fontWeight: FontWeight.bold,
                            fontSize: 16,
                          ),
                        ),
                      ),
                      Switch(
                        value: enabled,
                        activeThumbColor: AppPalette.ink,
                        onChanged: canEdit
                            ? (v) => setSheetState(() => enabled = v)
                            : null,
                      ),
                    ],
                  ),
                  const Text(
                    '공부/휴식 시간을 정해두면, 공부 시간이 끝났을 때 자동으로\n일시정지되고 휴식이 끝나면 자동으로 다시 시작해요.',
                    style: TextStyle(color: Colors.grey, fontSize: 12.5),
                  ),
                  if (!canEdit) ...[
                    const SizedBox(height: 10),
                    const Text(
                      '타이머가 멈춰있을 때만 설정을 바꿀 수 있어요.',
                      style: TextStyle(color: Colors.redAccent, fontSize: 12.5),
                    ),
                  ],
                  const SizedBox(height: 18),
                  _minuteStepper(
                    label: '공부 시간',
                    minutes: studyMinutes,
                    enabled: canEdit,
                    onChanged: (v) => setSheetState(() => studyMinutes = v),
                  ),
                  const SizedBox(height: 12),
                  _minuteStepper(
                    label: '휴식 시간',
                    minutes: breakMinutes,
                    enabled: canEdit,
                    onChanged: (v) => setSheetState(() => breakMinutes = v),
                  ),
                  const SizedBox(height: 10),
                  OutlinedButton.icon(
                    icon: const Icon(Icons.groups_rounded, size: 18),
                    label: const Text('친구들이 공유한 루틴 보기 / 공유하기'),
                    onPressed: () async {
                      final result = await pushLaunchpad<Map<String, int>>(
                        sheetContext,
                        (context) => StudyPresetScreen(
                          studentId: widget.studentId,
                          studentName: widget.studentName,
                          initialStudyMinutes: studyMinutes,
                          initialBreakMinutes: breakMinutes,
                        ),
                      );
                      if (result == null) return;
                      if (!canEdit) {
                        if (sheetContext.mounted) {
                          AppNotice.show(
                            sheetContext,
                            '타이머가 멈춰있을 때만 루틴을 적용할 수 있어요.',
                          );
                        }
                        return;
                      }
                      setSheetState(() {
                        studyMinutes = result['studyMinutes']!;
                        breakMinutes = result['breakMinutes']!;
                        enabled = true;
                      });
                    },
                  ),
                  const SizedBox(height: 18),
                  ElevatedButton(
                    style: ElevatedButton.styleFrom(
                      backgroundColor: AppPalette.ink,
                      foregroundColor: AppPalette.paper,
                      padding: const EdgeInsets.symmetric(vertical: 14),
                    ),
                    onPressed: !canEdit
                        ? null
                        : () async {
                            await _controller.setPomodoroSettings(
                              enabled: enabled,
                              studyMinutes: studyMinutes,
                              breakMinutes: breakMinutes,
                            );
                            if (sheetContext.mounted) {
                              Navigator.of(sheetContext).pop();
                            }
                          },
                    child: const Text('저장'),
                  ),
                ],
              ),
            );
          },
        );
      },
    );
  }

  Widget _minuteStepper({
    required String label,
    required int minutes,
    required bool enabled,
    required ValueChanged<int> onChanged,
  }) {
    return Row(
      children: [
        Expanded(
          child: Text(
            label,
            style: const TextStyle(fontWeight: FontWeight.w600),
          ),
        ),
        IconButton(
          icon: const Icon(Icons.remove_circle_outline_rounded),
          onPressed: enabled && minutes > 5
              ? () => onChanged(minutes - 5)
              : null,
        ),
        SizedBox(
          width: 48,
          child: Text(
            '$minutes분',
            textAlign: TextAlign.center,
            style: const TextStyle(fontWeight: FontWeight.bold),
          ),
        ),
        IconButton(
          icon: const Icon(Icons.add_circle_outline_rounded),
          onPressed: enabled && minutes < 120
              ? () => onChanged(minutes + 5)
              : null,
        ),
      ],
    );
  }

  void _openRanking() {
    if (widget.grade == null) {
      AppNotice.show(context, '학년 정보가 없어 랭킹을 볼 수 없어요.');
      return;
    }
    pushLaunchpad(
      context,
      (context) => StudyRankingScreen(
        grade: widget.grade!,
        myStudentId: widget.studentId,
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return ListenableBuilder(
      listenable: _controller,
      builder: (context, _) {
        final bool isRunning = _controller.isRunning;
        final bool isPaused = _controller.isPaused;
        return Scaffold(
          backgroundColor: AppPalette.mist,
          appBar: AppBar(
            backgroundColor: Colors.transparent,
            foregroundColor: AppPalette.ink,
            elevation: 0,
            centerTitle: true,
            title: const TitlePill('백품타'),
            actions: [
              IconButton(
                icon: const Icon(Icons.tune_rounded),
                tooltip: '뽀모도로 설정',
                onPressed: _showPomodoroSettings,
              ),
              IconButton(
                icon: const Icon(Icons.leaderboard_rounded),
                tooltip: '학년 랭킹',
                onPressed: _openRanking,
              ),
            ],
          ),
          body: _controller.isLoading
              ? const Center(child: CircularProgressIndicator())
              : Center(
                  child: SingleChildScrollView(
                    padding: const EdgeInsets.all(24),
                    child: Column(
                      mainAxisSize: MainAxisSize.min,
                      children: [
                        Text(
                          _statusLabel(isRunning, isPaused),
                          style: const TextStyle(
                            fontSize: 15,
                            color: Colors.grey,
                          ),
                        ),
                        if (_controller.pomodoroEnabled &&
                            _controller.phase != null) ...[
                          const SizedBox(height: 4),
                          Text(
                            '${_controller.phase == PomodoroPhase.study ? '다음 휴식까지' : '다음 공부까지'} '
                            '${_formatMinSec(_controller.phaseSecondsLeft)} · '
                            '완료 ${_controller.completedCycles}회',
                            style: const TextStyle(
                              fontSize: 12.5,
                              color: Colors.grey,
                              fontWeight: FontWeight.w600,
                            ),
                          ),
                        ],
                        const SizedBox(height: 12),
                        Text(
                          _formatHMS(_controller.liveElapsedSeconds),
                          style: TextStyle(
                            fontSize: 52,
                            fontWeight: FontWeight.bold,
                            color: isPaused ? Colors.grey : AppPalette.ink,
                          ),
                        ),
                        const SizedBox(height: 36),
                        _buildActionButtons(isRunning, isPaused),
                        const SizedBox(height: 40),
                        Row(
                          mainAxisAlignment: MainAxisAlignment.center,
                          children: [
                            _statBox(
                              '오늘',
                              _formatHM(_controller.todaySecondsLive),
                            ),
                            const SizedBox(width: 12),
                            _statBox(
                              '이번주',
                              _formatHM(_controller.weekSecondsLive),
                            ),
                            const SizedBox(width: 12),
                            _statBox(
                              '전체',
                              _formatHM(_controller.totalSecondsLive),
                            ),
                          ],
                        ),
                      ],
                    ),
                  ),
                ),
        );
      },
    );
  }

  Widget _buildActionButtons(bool isRunning, bool isPaused) {
    if (!isRunning && !isPaused) {
      return _circleButton(
        size: 140,
        icon: Icons.play_arrow_rounded,
        label: _controller.pomodoroEnabled ? '뽀모도로 시작' : '공부 시작',
        color: AppPalette.ink,
        onTap: () => _runAction(_controller.start),
      );
    }
    if (_controller.pomodoroEnabled && _controller.phase != null) {
      // 뽀모도로 자동 전환 중에는 일시정지/재개는 자동으로 일어나니 종료 버튼만 보여준다.
      return _circleButton(
        size: 140,
        icon: Icons.stop_rounded,
        label: '공부 종료',
        color: Colors.red[400]!,
        onTap: () => _runAction(_controller.stop),
      );
    }
    return Row(
      mainAxisAlignment: MainAxisAlignment.center,
      children: [
        _circleButton(
          size: 110,
          icon: isPaused ? Icons.play_arrow_rounded : Icons.pause_rounded,
          label: isPaused ? '재개' : '일시정지',
          color: isPaused ? AppPalette.ink : Colors.amber[700]!,
          onTap: () =>
              _runAction(isPaused ? _controller.resume : _controller.pause),
        ),
        const SizedBox(width: 20),
        _circleButton(
          size: 110,
          icon: Icons.stop_rounded,
          label: '공부 종료',
          color: Colors.red[400]!,
          onTap: () => _runAction(_controller.stop),
        ),
      ],
    );
  }

  Widget _circleButton({
    required double size,
    required IconData icon,
    required String label,
    required Color color,
    required VoidCallback onTap,
  }) {
    return GestureDetector(
      onTap: _controller.isBusy ? null : onTap,
      child: Container(
        width: size,
        height: size,
        decoration: BoxDecoration(
          shape: BoxShape.circle,
          color: color,
          boxShadow: [
            BoxShadow(
              color: color.withValues(alpha: 0.3),
              blurRadius: 20,
              offset: const Offset(0, 8),
            ),
          ],
        ),
        child: Center(
          child: _controller.isBusy
              ? const CircularProgressIndicator(color: Colors.white)
              : Column(
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    Icon(icon, color: Colors.white, size: size > 120 ? 36 : 28),
                    Text(
                      label,
                      style: TextStyle(
                        color: Colors.white,
                        fontWeight: FontWeight.bold,
                        fontSize: size > 120 ? 14 : 12.5,
                      ),
                    ),
                  ],
                ),
        ),
      ),
    );
  }

  Widget _statBox(String label, String value) {
    return Container(
      width: 100,
      padding: const EdgeInsets.symmetric(vertical: 14),
      decoration: BoxDecoration(
        color: AppPalette.paper,
        borderRadius: BorderRadius.circular(16),
        border: Border.all(color: AppPalette.sage),
      ),
      child: Column(
        children: [
          Text(label, style: TextStyle(color: Colors.grey[600], fontSize: 12)),
          const SizedBox(height: 4),
          Text(
            value,
            style: const TextStyle(fontWeight: FontWeight.bold, fontSize: 15),
          ),
        ],
      ),
    );
  }
}