main.dart

// Import MaterialApp and other widgets which we can use to quickly create a material app
import 'package:flutter/material.dart';
import 'package:google_sign_in/google_sign_in.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:graphql_flutter/graphql_flutter.dart';

// Code written in Dart starts exectuting from the main function. runApp is part of
// Flutter, and requires the component which will be our app's container. In Flutter,
// every component is known as a "widget".

// void main() => runApp(MyApp());

void main() {
  // ValueNotifier<Client> client = ValueNotifier(
  //   Client(
  //     endPoint: 'https://hasurainternship.herokuapp.com/v1alpha1/graphql',
  //     cache: InMemoryCache(),
  //     apiToken: '',
  //   ),
  // );

  //to run the application
  runApp(MyApp());
}

ValueNotifier<Client> client = ValueNotifier(
    Client(
      endPoint: 'https://hasurainternship.herokuapp.com/v1alpha1/graphql',
      cache: InMemoryCache(),
      apiToken: '',
    ),
  );

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return GraphqlProvider(
      client: client,
      child: MaterialApp(
        title: 'Flutter Demo',
        debugShowCheckedModeBanner: false,
        theme: ThemeData(
          primarySwatch: Colors.blue,
        ),
        home: new MyHomePage(),
      ),
    );
  }
}

//for normal query
String readTasks = """

  query{
    todolist{
      id
      tasks
    }
  }

""" .replaceAll('\n', ' ');

//for mutation
//change this accordingly to perform the action when the button is pressed and also to store the value which goes not some random text
String mutation = """

  mutation addTask(\$id: ID!) {
    addtask(input: {newtask: \$newtask}){
      todolist{
        tasks
      }
    }
  }
""".replaceAll('\n', ' ');



class MyHomePage extends StatelessWidget{

  final FirebaseAuth _auth = FirebaseAuth.instance;
  final GoogleSignIn googleSignIn = new GoogleSignIn();

  Future<FirebaseUser> _signIn() async{
    GoogleSignInAccount googleSignInAccount = await googleSignIn.signIn();
    GoogleSignInAuthentication gSA = await googleSignInAccount.authentication;
    
    FirebaseUser user = await _auth.signInWithGoogle(
      idToken: gSA.idToken,
      accessToken: gSA.accessToken
    );

    print("Username: ${user.displayName}");
    return user;
  }

  void _signOut(){
    googleSignIn.signOut();
    print("User Signed Out");
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text('Google Firebase Authentication'),
      ),
      body: new Padding(
        padding: const EdgeInsets.all(20.0),
        child: new Column(
          mainAxisAlignment: MainAxisAlignment.center,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[
            new RaisedButton(
              onPressed: (){  
                _signIn().then((FirebaseUser user)=> print(user)).catchError((e)=>print(e));
                Navigator.push(context,MaterialPageRoute(builder: (context) => TodoList()),);
              },
              child: new Text('Sign In'),
              color: Colors.green,
              shape: new RoundedRectangleBorder(borderRadius: new BorderRadius.circular(30.0)),
            ),
            new Padding(
              padding: const EdgeInsets.all(10.0),
            ),
            new RaisedButton(
              onPressed: _signOut,
              child: new Text('Sign Out'),
              color: Colors.red,
              shape: new RoundedRectangleBorder(borderRadius: new BorderRadius.circular(30.0)),
            ),
          ],
        ),
      ),
    );
  }
}

class TodoList extends StatefulWidget {
  @override
  createState() => new TodoListState();
}

class TodoListState extends State<TodoList> {
  List<String> _todoItems = [];

  void _addTodoItem(String task) {
    // Only add the task if the user actually entered something
    if(task.length > 0) {
      // Putting our code inside "setState" tells the app that our state has changed, and
      // it will automatically re-render the list
      setState(() => _todoItems.add(task));


      // //also try to add the mutation here.**
      // Mutation(
      //       mutation,
      //       builder: (
      //         runMutation,{
      //           bool loading,
      //           var data,
      //           Exception error,
      //         }){
      //           return FloatingActionButton(
      //             onPressed: ()=>runMutation({
      //               'newtask': task,
      //             })
      //           );
      //         },
      //         onCompleted: (Map<String, dynamic> data){
      //           showDialog(
      //             context: context,
      //             builder: (BuildContext context){
      //               return AlertDialog(
      //                 title: Text('Task added'),
      //                 actions: <Widget>[
      //                   SimpleDialogOption(
      //                     child: Text('Dismiss'),
      //                     onPressed: (){
      //                       Navigator.of(context).pop();
      //                     },
      //                   )
      //                 ],
      //               );
      //             }
      //           );
      //         }
      //     );
    }
  }

  void _removeTodoItem(int index) {
    setState(() => _todoItems.removeAt(index));
  }

  void _promptRemoveTodoItem(int index) {
    showDialog(
      context: context,
      builder: (BuildContext context) {
        return new AlertDialog(
          title: new Text('Mark "${_todoItems[index]}" as done?'),
          actions: <Widget>[
            new FlatButton(
              child: new Text('CANCEL'),
              // The alert is actually part of the navigation stack, so to close it, we
              // need to pop it.
              onPressed: () => Navigator.of(context).pop()
            ),
            new FlatButton(
              child: new Text('MARK AS DONE'),
              onPressed: () {
                _removeTodoItem(index);
                Navigator.of(context).pop();
              }
            )
          ]
        );
      }
    );
  }

  // Build the whole list of todo items
  Widget _buildTodoList() {
    return new ListView.builder(
      itemBuilder: (context, index) {
        // itemBuilder will be automatically be called as many times as it takes for the
        // list to fill up its available space, which is most likely more than the
        // number of todo items we have. So, we need to check the index is OK.
        if(index < _todoItems.length) {
          return _buildTodoItem(_todoItems[index], index);
        }
      },
    );
  }

  // Build a single todo item
  Widget _buildTodoItem(String todoText, int index) {
    return new ListTile(
      title: new Text(todoText),
      onTap: () => _promptRemoveTodoItem(index)
    );
  }

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text('Todo List'),
        actions: <Widget>[
          new FlatButton(
            child: new Text('SignOut'),
            color: Colors.blue,
            textColor: Colors.white,
            onPressed: (){
              Navigator.of(context).pop();  
            },
          ),

          // Query(
          //   readTasks,
          //   builder: ({
          //     bool loading,
          //     var data,
          //     Exception error,
          //   }){
          //     if (error != null){
          //       return Text(error.toString());
          //     }
          //     if (loading){
          //       return Text('Loading');
          //     }

          //     List tasks = data['tasks'];
          //     return ListView.builder(
          //       itemCount: tasks.length,
          //       itemBuilder: (context,index){
          //         final taskList = tasks[index];
          //         return Text(taskList['name']);
          //       }
          //     );
          //   }  
          // ),
      
        ],
      ),
      body: _buildTodoList(),
      floatingActionButton: new FloatingActionButton(
        onPressed: _pushAddTodoScreen,
        tooltip: 'Add task',
        child: new Icon(Icons.add)
      ),
    );
  }

  void _pushAddTodoScreen() {
    // Push this page onto the stack
    Navigator.of(context).push(
      // MaterialPageRoute will automatically animate the screen entry, as well as adding
      // a back button to close it
      new MaterialPageRoute(
        builder: (context) {
          return new Scaffold(
            appBar: new AppBar(
              title: new Text('Add a new task')
            ),
            body: new TextField(
              autofocus: true,
              onSubmitted: (val) {
                _addTodoItem(val);
                Navigator.pop(context); // Close the add todo screen
              },
              decoration: new InputDecoration(
                hintText: 'Enter something to do...',
                contentPadding: const EdgeInsets.all(16.0)
              ),
            )
          );
        }
      )
    );
  }
}