import 'package:flutter/material.dart';
import 'package:apetrus/utils/Constantes.dart' as Constantes;
import 'package:shared_preferences/shared_preferences.dart';
import 'home_page.dart';
import 'package:http/http.dart' as http;
import 'dart:convert';
import 'dart:async';

class LoginPage extends StatefulWidget {
  @override
  _LoginPageState createState() => _LoginPageState();
}

class _LoginPageState extends State<LoginPage> {

  SharedPreferences prefs;
  bool checkvalue = false;
  TextEditingController usuario = new TextEditingController();
  TextEditingController senha = new TextEditingController();

  Map<String, dynamic> retornoJSON;
  bool _isLoading = false;
  final formKey = new GlobalKey<FormState>();
  final scaffoldKey = new GlobalKey<ScaffoldState>();
  String _usuario, _senha;

  @override
  initState() {
    _getDadosSalvos();
    super.initState();
  }

  void _submit() {
    final form = formKey.currentState;
    if(form.validate()) {
      form.save();
      setState(() {
        _isLoading = true;
      });
      _validaLogin(_usuario, _senha);
    }
  }

  _getDadosSalvos() async {
    prefs = await SharedPreferences.getInstance();
    setState(() {
      checkvalue = (prefs.getBool("_checkvalue") ?? false);
      usuario.text = (prefs.getString("_usuario") ?? "");
      senha.text = (prefs.getString("_senha") ?? "");
    });
  }

  _salvarLocal() async {
    prefs = await SharedPreferences.getInstance();
    if(checkvalue) {
      setState(() {
        prefs.setString("_usuario", _usuario);
        prefs.setString("_senha", _senha);
        prefs.setBool("_checkvalue", checkvalue);
      });
    } else {
      usuario.clear();
      senha.clear();
      prefs.clear();
    }
  }

  // Navigator.of(context).pushNamed('/homepage');

  Future<Null> _validaLogin(String email, String senha) async {
    Map<String, String> dadosUser = {
      'email': email,
      'senha': senha
    };

    var result = await http.post(Constantes.url + "loginMobile", body: dadosUser);
    String retornoBody = result.body;
    retornoJSON = json.decode(retornoBody);
    if(result.request.finalized) {
      setState(() {
        _isLoading = false;
      });
      if(retornoJSON['result'] == 'erro') {
        _showErro("Ops!","Erro ao acessar, revise seus dados!");
      } else {
        _salvarLocal();
        Navigator.push(
          context,
          MaterialPageRoute(builder: (context) => HomePage(retornoJSON['result'])),
        );
      }
    } else {
      _showErro("Ops!","Não foi possivel carregar!");
      setState(() {
        _isLoading = false;
      });
    }
  }

  _showErro(String titulo, String mensagem) {
    showDialog(
        context: context,
        builder: (BuildContext context) {
          return new AlertDialog(
            title: new Text(titulo),
            content: new Text(mensagem),
            actions: <Widget>[
              new FlatButton(
                  onPressed: () => Navigator.of(context).pop(),
                  child: new Text("OK")
              )
            ],
          );
        }
    );
  }

  @override
  Widget build(BuildContext context) {
    var loginBtn = new SizedBox(
      width: double.maxFinite,
      child: new RaisedButton(
        shape: new RoundedRectangleBorder(
            borderRadius: new BorderRadius.circular(20.0)
        ),
        onPressed: _submit,
        color: Theme.of(context).primaryColor,
        textColor: Colors.white,
        child: new Text("ENTRAR"),
      ),
    );

    var loginForm = new ListView(
      children: <Widget>[
        new Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: <Widget>[
            new Container(
              color: const Color(Constantes.CorPadrao),
              width: double.infinity,
              height: 200.0,
              child: new Padding(
                  padding: const EdgeInsets.all(30.0),
                  child: new Image.asset(
                    Constantes.logo
                  ),
              ),
            ),
            new Divider(
                height: 1.0,
                color: Theme.of(context).primaryColor,
            ),
            new Padding(
                padding: const EdgeInsets.all(20.0),
                child: new Form(
                    key: formKey,
                    child: new Column(
                      children: <Widget>[
                        new TextFormField(
                          controller: usuario,
                          onSaved: (val) => _usuario = val,
                          validator: (val) {
                            return val.isEmpty
                                ? "Digite seu e-mail"
                                : null;
                          },
                          decoration: new InputDecoration(labelText: "E-mail"),
                        ),
                        new Padding(
                            padding: const EdgeInsets.only(bottom: 10.0)
                        ),
                        new TextFormField(
                          controller: senha,
                          onSaved: (val) => _senha = val,
                          validator: (val) {
                            return val.isEmpty
                                ? "Digite sua senha"
                                : null;
                          },
                          obscureText: true,
                          decoration: new InputDecoration(labelText: "Senha"),
                        ),
                        new Padding(
                            padding: const EdgeInsets.only(bottom: 10.0)
                        ),
                        loginBtn,
                        new Row(
                          mainAxisAlignment: MainAxisAlignment.center,
                          children: <Widget>[
                            new Checkbox(
                                value: checkvalue,
                                onChanged: (bool newvalue) {
                                  setState(() {
                                    checkvalue = newvalue;
                                  });
                                }),
                            new Text("Salvar dados de acesso")
                          ],
                        ),
                      ],
                    )
                ),
            ),
          ],
        ),
      ],
    );
    var loader = new Center(
      child: new CircularProgressIndicator(),
    );
    return Scaffold(
      appBar: null,
      key: scaffoldKey,
      body: _isLoading ? loader : loginForm,
    );
  }
}