import 'package:flutter/material.dart';
import 'package:instruction_app/screens/home_page.dart';

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

  @override
  State<AuthorizationPage> createState() => _AuthorizationPage();
}

class _AuthorizationPage extends State<AuthorizationPage> {
  final TextEditingController _loginController = new TextEditingController();
  final TextEditingController _passwordController = new TextEditingController();
  final _formKey = GlobalKey<FormState>();
  final borederRadius = BorderRadius.all(Radius.circular(10));
  bool passwordVisible = false;

  void _login(){
    if (_formKey.currentState!.validate()) {
      final String login = _loginController.text;
      final String password  = _passwordController.text;

      if (login == 'admin' && password == '123456') {
        Navigator.of(context).push(MaterialPageRoute(
          builder: (ctx) => HomePage())
        );
      }
    }
  }

  String? _validatePassword(String? password){
    if (password == null || password.isEmpty)
      return 'Введите пароль';
    if (password != '123456')
      return 'Пароль: 123456';
    return null;
  }

    String? _validateLogin(String? login){
    if (login == null || login.isEmpty)
      return 'Введите логин';
    if (login != 'admin')
      return 'Логин: admin';
    return null;
  }

  @override
  void dispose() {
    super.dispose();
    _loginController.dispose();
    _passwordController.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Авторизация"),
      ),
      body: Padding(
        padding: EdgeInsets.all(80),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          crossAxisAlignment: CrossAxisAlignment.center,
          children: [
            _buildFormWidget(context),
            SizedBox(height: 25,),
            TextButton(
              style: ButtonStyle(
                backgroundColor: WidgetStateProperty.all(Colors.blue),
                foregroundColor: WidgetStateProperty.all(Colors.white),
                ),
              onPressed: () => _login(), 
              child: Text("Войти") 
              )
          ],
        )
      )
    );
  }

  Widget _buildFormWidget(BuildContext context) {
    return Form(
      key: _formKey,
      child: Column(
        children: [
          TextFormField(
            controller: _loginController,
            decoration: InputDecoration(
              prefixIcon: Icon(Icons.account_circle),
              border: OutlineInputBorder(
                borderRadius: borederRadius
              ), 
              labelText: 'Логин'),
              validator: (text) => _validateLogin(text),
          ),
          SizedBox(height: 25,),
          TextFormField(
            controller: _passwordController,
            obscureText: !passwordVisible,
            decoration: InputDecoration(
              prefixIcon: Icon(Icons.lock),
              border: OutlineInputBorder(
                borderRadius: borederRadius
              ), 
              labelText: 'Пароль',
              suffixIcon: IconButton(
                icon: Icon(
                  passwordVisible ? Icons.visibility : Icons.visibility_off),
              onPressed: () => setState(() => passwordVisible = !passwordVisible),
            )),
            validator: (text) => _validatePassword(text),
        ),
        ],
      )
    );
  }
}