import 'package:flutter/material.dart';
import 'dart:async';
import 'dart:convert';
import 'package:http/http.dart' as http;


// class response json
class Response {
  final String status;
  final String message;

  Response({this.status, this.message});

  factory Response.fromJson(Map<String, dynamic> json) {
    return Response(
      status: json['status'],
      message: json['message'],
    );
  }
}

// fungsi untuk kirim http post
Future<Response> post(String url,var body)async{
  return await http
      .post(Uri.encodeFull(url), body: body, headers: {"Accept":"application/json"})
      .then((http.Response response) {

    final int statusCode = response.statusCode;

    if (statusCode < 200 || statusCode > 400 || json == null) {
      throw new Exception("Error while fetching data");
    }
    return Response.fromJson(json.decode(response.body));
  });
}

class Login extends StatefulWidget {
  @override
  LoginState createState() => new LoginState();
}

class LoginState extends State<Login> {

  // variabel member class
  final _username = TextEditingController();
  final _password = TextEditingController();

  // member response
  String _response = '';
  bool _apiCall = false;

  // fungsi panggil API
  void _callPostAPI() {
    post(
        'http://192.3.168.178/restapi/login.php',
        {
          'username': _username.text,
          'password': _password.text
        }).then((response) {
          // jika respon normal
          setState(() {
            _apiCall = false;
            _response = response.message;
          });

        },
          // jika respon error
          onError: (error) {
            _apiCall = false;
            _response = error.toString();
          }
    );
  }

  Widget progressWidget() {
    if (_apiCall)
      // jika masih proses kirim API
      return AlertDialog(
        content: new Column(
          children: <Widget>[
            CircularProgressIndicator(),
            Text("Please wait")
          ],
        ),
      );
    else
      // jika sudah selesai kirim API
      return Center(
        child: Text(
          _response,
          style: new TextStyle(fontSize: 15.0),
        ),
      );
  }

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: const Text("Welcome to Flutter"),
      ),
      body: SafeArea(
          child: ListView(
            padding: EdgeInsets.fromLTRB(20.0, 10.0, 20.0, 10.0),
            children: <Widget>[
              // nama
              TextField(
                controller: _username,
                decoration: InputDecoration(
                    filled: true,
                    labelText: 'Username'
                ),
              ),
              // spasi
              SizedBox(height: 5.0),
              // alamat
              TextField(
                controller: _password,
                decoration: InputDecoration(
                    filled: true,
                    labelText: 'Password'
                ),
                obscureText: true,
              ),
              // spasi
              SizedBox(height: 10.0),
              // tombol
              RaisedButton(
                child: Text('LOGIN'),
                onPressed: () {

                  setState(() {
                    _apiCall = true;
                  });
                  _callPostAPI();
/*
                  return showDialog(
                    context: context,
                    builder: (context) {
                      return AlertDialog(
                        content: Text('Username: ${_username.text}\nPassword: ${_password.text}'),
                      );
                    },
                  );
*/
                },
              ),

              // panggil loading widget
              progressWidget()
            ],
          )
      ),
    );
  }
}