// ⏱️ 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_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.init();
  }

  @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 _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,
    );
  }

  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.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(
                          isRunning
                              ? '지금 공부 중이에요'
                              : isPaused
                              ? '일시정지 중이에요'
                              : '공부를 시작해볼까요?',
                          style: const TextStyle(
                            fontSize: 15,
                            color: Colors.grey,
                          ),
                        ),
                        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: '공부 시작',
        color: AppPalette.ink,
        onTap: () => _runAction(_controller.start),
      );
    }
    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),
          ),
        ],
      ),
    );
  }
}