import 'package:flutter/material.dart';
import './todo_api.dart';
import './todo_model.dart';
import './todo_detail.dart'; // 稍後創建
// import './main.dart'; // 確保可以訪問 MainMenu

class TodoManager extends StatefulWidget {
  // 實際應用中，這裡應該傳入當前用戶 ID
  final String currentUserId;
  const TodoManager({this.currentUserId = 'admin', super.key});

  @override
  State<StatefulWidget> createState() {
    return _TodoManagerState();
  }
}

class _TodoManagerState extends State<TodoManager> {
  late TodoApiService _apiService;
  late Future<List<Todo>> _todosFuture;

  @override
  void initState() {
    super.initState();
    _apiService = TodoApiService(currentUserId: widget.currentUserId);
    // 頁面加載時自動開始獲取資料
    _todosFuture = _apiService.fetchTodos();
  }

  // 刷新資料的函數
  void _refreshTodos() {
    setState(() {
      _todosFuture = _apiService.fetchTodos();
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('我的待辦事項'),
        actions: <Widget>[
          IconButton(
            icon: const Icon(Icons.refresh),
            tooltip: '刷新列表',
            onPressed: _refreshTodos,
          ),
          // 假設這裡使用 Navigator.pop(context) 即可返回 MainMenu
          IconButton(
            icon: const Icon(Icons.home),
            tooltip: '返回主頁',
            onPressed: () => Navigator.pop(context),
          ),
        ],
      ),
      body: FutureBuilder<List<Todo>>(
        future: _todosFuture,
        builder: (context, snapshot) {
          if (snapshot.connectionState == ConnectionState.waiting) {
            return const Center(child: CircularProgressIndicator());
          } else if (snapshot.hasError) {
            return Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Text('載入失敗: ${snapshot.error}', textAlign: TextAlign.center),
                  const SizedBox(height: 16),
                  ElevatedButton(onPressed: _refreshTodos, child: const Text('重試')),
                ],
              ),
            );
          } else if (snapshot.hasData && snapshot.data!.isNotEmpty) {
            return TodoList(todos: snapshot.data!);
          } else {
            return const Center(child: Text('目前沒有待辦事項。工作很輕鬆！'));
          }
        },
      ),
    );
  }
}

// -----------------------------------------------------------
// 列表顯示小部件 (TodoList)
// -----------------------------------------------------------

class TodoList extends StatelessWidget {
  final List<Todo> todos;

  const TodoList({required this.todos, super.key});

  @override
  Widget build(BuildContext context) {
    return ListView.builder(
      itemCount: todos.length,
      itemBuilder: (BuildContext context, int index) {
        final item = todos[index];

        return Card(
          elevation: 3,
          margin: const EdgeInsets.symmetric(vertical: 6.0, horizontal: 16.0),
          child: InkWell(
            onTap: () {
              // 點擊項目：導航到詳細頁面
              Navigator.push(
                context,
                MaterialPageRoute(
                  builder: (context) => TodoDetail(todo: item),
                ),
              );
            },
            child: ListTile(
              // 左側狀態指示器
              leading: Container(
                width: 10,
                decoration: BoxDecoration(
                  color: item.statusColor,
                  borderRadius: BorderRadius.circular(5),
                ),
              ),
              title: Text(
                item.taskName,
                style: const TextStyle(fontWeight: FontWeight.bold),
              ),
              subtitle: Text(
                '分類: ${item.className} | 優先級: ${item.priority ?? '一般'}',
                style: const TextStyle(fontSize: 12),
              ),
              trailing: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                crossAxisAlignment: CrossAxisAlignment.end,
                children: [
                  Text(
                    '截止日',
                    style: TextStyle(fontSize: 10, color: item.statusColor),
                  ),
                  Text(
                    item.formattedEndDate,
                    style: const TextStyle(fontSize: 13, fontWeight: FontWeight.w600),
                  ),
                ],
              ),
            ),
          ),
        );
      },
    );
  }
}