lib/main.dart

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:intl/intl.dart';
import 'models.dart';
import 'logic.dart';

void main() {
  runApp(
    ChangeNotifierProvider(
      create: (context) => TimeManager(),
      child: const TimeVoyagerApp(),
    ),
  );
}

class TimeVoyagerApp extends StatelessWidget {
  const TimeVoyagerApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'TimeVoyager',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.blue),
        useMaterial3: true,
      ),
      home: const ProjectListPage(),
    );
  }
}

class ProjectListPage extends StatelessWidget {
  const ProjectListPage({super.key});

  @override
  Widget build(BuildContext context) {
    final manager = context.watch<TimeManager>();

    return Scaffold(
      appBar: AppBar(
        title: const Text('TimeVoyager'),
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
      ),
      body: ListView.builder(
        itemCount: manager.projects.length,
        itemBuilder: (context, index) {
          final project = manager.projects[index];
          final isActive = manager.activeEntry?.projectId == project.id;

          return Card(
            margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
            child: ListTile(
              leading: CircleAvatar(
                backgroundColor: isActive ? Colors.green : Colors.blueGrey,
                child: Icon(isActive ? Icons.play_arrow : Icons.folder),
              ),
              title: Text(project.name),
              subtitle: Text('${project.hourlyRate} ${project.currency} / 小时'),
              trailing: isActive 
                ? const Text('正在计时...', style: TextStyle(color: Colors.green)) 
                : const Icon(Icons.chevron_right),
              onTap: () {
                Navigator.push(
                  context,
                  MaterialPageRoute(
                    builder: (context) => ProjectDetailPage(projectId: project.id),
                  ),
                );
              },
            ),
          );
        },
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
           // TODO: Implement Add Project Dialog
           ScaffoldMessenger.of(context).showSnackBar(
             const SnackBar(content: Text('演示模式：默认项目已预置')),
           );
        },
        child: const Icon(Icons.add),
      ),
    );
  }
}

class ProjectDetailPage extends StatelessWidget {
  final String projectId;

  const ProjectDetailPage({super.key, required this.projectId});

  @override
  Widget build(BuildContext context) {
    final manager = context.watch<TimeManager>();
    final project = manager.getProjectById(projectId);

    if (project == null) return const Scaffold(body: Center(child: Text('项目不存在')));

    final isActive = manager.activeEntry?.projectId == project.id;

    return Scaffold(
      appBar: AppBar(title: Text(project.name)),
      body: Padding(
        padding: const EdgeInsets.all(24.0),
        child: Column(
          children: [
            _buildStatusCard(context, project, manager, isActive),
            const SizedBox(height: 40),
            _buildControlButtons(context, project, manager, isActive),
          ],
        ),
      ),
    );
  }

  Widget _buildStatusCard(BuildContext context, Project project, TimeManager manager, bool isActive) {
    final duration = isActive ? manager.currentDuration : Duration.zero;
    final earnings = isActive ? manager.currentEarnings : 0.0;
    
    final formattedTime = _formatDuration(duration);
    final formattedEarnings = NumberFormat.currency(symbol: project.currency == 'CNY' ? '¥' : '\$')
        .format(earnings);

    return Container(
      width: double.infinity,
      padding: const EdgeInsets.all(32),
      decoration: BoxDecoration(
        color: isActive ? Colors.blue.shade50 : Colors.grey.shade100,
        borderRadius: BorderRadius.circular(24),
        border: Border.all(
          color: isActive ? Colors.blue.shade200 : Colors.transparent,
          width: 2,
        ),
      ),
      child: Column(
        children: [
          Text(
            isActive ? '工作中' : '就绪',
            style: TextStyle(
              color: isActive ? Colors.blue : Colors.grey,
              fontWeight: FontWeight.bold,
              letterSpacing: 1.2,
            ),
          ),
          const SizedBox(height: 16),
          Text(
            formattedTime,
            style: const TextStyle(
              fontSize: 64,
              fontFamily: 'Monospace',
              fontWeight: FontWeight.w300,
            ),
          ),
          const SizedBox(height: 8),
          Text(
            formattedEarnings,
            style: TextStyle(
              fontSize: 32,
              fontWeight: FontWeight.bold,
              color: isActive ? Colors.green : Colors.grey,
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildControlButtons(BuildContext context, Project project, TimeManager manager, bool isActive) {
    if (isActive) {
      return SizedBox(
        width: double.infinity,
        height: 60,
        child: ElevatedButton.icon(
          onPressed: () => manager.stopTracking(),
          style: ElevatedButton.styleFrom(
            backgroundColor: Colors.red.shade100,
            foregroundColor: Colors.red,
          ),
          icon: const Icon(Icons.stop_circle),
          label: const Text('停止计时', style: TextStyle(fontSize: 20)),
        ),
      );
    } else {
      // Check if another project is running
      final isOtherRunning = manager.isTracking && !isActive;
      
      return SizedBox(
        width: double.infinity,
        height: 60,
        child: ElevatedButton.icon(
          onPressed: isOtherRunning 
            ? () {
                ScaffoldMessenger.of(context).showSnackBar(
                  const SnackBar(content: Text('请先停止当前正在进行的项目')),
                );
              }
            : () => manager.startTracking(project),
          style: ElevatedButton.styleFrom(
            backgroundColor: isOtherRunning ? Colors.grey : Colors.green.shade100,
            foregroundColor: isOtherRunning ? Colors.white : Colors.green,
          ),
          icon: const Icon(Icons.play_circle),
          label: Text(
            isOtherRunning ? '其他项目进行中' : '开始工作', 
            style: const TextStyle(fontSize: 20)
          ),
        ),
      );
    }
  }

  String _formatDuration(Duration d) {
    String twoDigits(int n) => n.toString().padLeft(2, "0");
    String twoDigitMinutes = twoDigits(d.inMinutes.remainder(60));
    String twoDigitSeconds = twoDigits(d.inSeconds.remainder(60));
    return "${twoDigits(d.inHours)}:$twoDigitMinutes:$twoDigitSeconds";
  }
}