import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:pad_scanner/services/api_service.dart';

class SettingsPage extends StatefulWidget {
  const SettingsPage({super.key});

  @override
  State<SettingsPage> createState() => _SettingsPageState();
}

class _SettingsPageState extends State<SettingsPage> {
  final _controller = TextEditingController();
  final _apiService = ApiService();
  bool _saving = false;
  bool _testing = false;

  @override
  void initState() {
    super.initState();
    _loadUrl();
  }

  Future<void> _loadUrl() async {
    final prefs = await SharedPreferences.getInstance();
    final url = prefs.getString('api_url') ?? '';
    _controller.text = url;
  }

  Future<void> _saveUrl() async {
    final url = _controller.text.trim();
    if (url.isEmpty) {
      _showSnackBar('请输入 API 地址', isError: true);
      return;
    }
    setState(() => _saving = true);
    final prefs = await SharedPreferences.getInstance();
    await prefs.setString('api_url', url);
    setState(() => _saving = false);
    if (mounted) {
      _showSnackBar('设置已保存');
    }
  }

  Future<void> _testConnection() async {
    final url = _controller.text.trim();
    if (url.isEmpty) {
      _showSnackBar('请先输入 API 地址', isError: true);
      return;
    }
    setState(() => _testing = true);
    final ok = await _apiService.testConnection(url);
    setState(() => _testing = false);
    if (mounted) {
      _showSnackBar(
        ok ? '连接成功' : '连接失败，请检查地址和网络',
        isError: !ok,
      );
    }
  }

  void _showSnackBar(String message, {bool isError = false}) {
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(
        content: Text(message),
        backgroundColor: isError ? Colors.red.shade700 : Colors.green.shade700,
        duration: const Duration(seconds: 2),
      ),
    );
  }

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('设置')),
      body: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            const Text('API 服务器地址', style: TextStyle(fontSize: 14)),
            const SizedBox(height: 8),
            TextField(
              controller: _controller,
              decoration: const InputDecoration(
                hintText: 'http://192.168.1.100:8000',
                border: OutlineInputBorder(),
              ),
              keyboardType: TextInputType.url,
            ),
            const SizedBox(height: 20),
            ElevatedButton.icon(
              onPressed: _saving ? null : _saveUrl,
              icon: _saving
                  ? const SizedBox(
                      width: 18,
                      height: 18,
                      child: CircularProgressIndicator(strokeWidth: 2),
                    )
                  : const Icon(Icons.save),
              label: const Text('保存设置'),
            ),
            const SizedBox(height: 8),
            OutlinedButton.icon(
              onPressed: _testing ? null : _testConnection,
              icon: _testing
                  ? const SizedBox(
                      width: 18,
                      height: 18,
                      child: CircularProgressIndicator(strokeWidth: 2),
                    )
                  : const Icon(Icons.wifi),
              label: const Text('测试连接'),
            ),
          ],
        ),
      ),
    );
  }
}