MAINACTIVITY

package com.example.pbwi.actifitapp;

import android.app.ProgressDialog;
import android.content.Intent;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.Signature;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Base64;
import android.util.Log;
import android.util.Patterns;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.facebook.AccessToken;
import com.facebook.CallbackManager;
import com.facebook.FacebookCallback;
import com.facebook.FacebookException;
import com.facebook.login.LoginResult;
import com.facebook.login.widget.LoginButton;
import com.google.android.gms.auth.api.Auth;
import com.google.android.gms.auth.api.signin.GoogleSignInAccount;
import com.google.android.gms.auth.api.signin.GoogleSignInOptions;
import com.google.android.gms.auth.api.signin.GoogleSignInResult;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.SignInButton;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthCredential;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FacebookAuthProvider;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.auth.GoogleAuthProvider;
import com.facebook.FacebookSdk;
import com.facebook.appevents.AppEventsLogger;

import java.math.BigDecimal;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Currency;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivity";
    Button guzik_rejestracji;
    SignInButton googleSignInButton;
    LoginButton loginFbButton;

    //progress dialog
    private ProgressDialog progressDialog;
    //firebase auth object
    private FirebaseAuth firebaseAuth;
    private GoogleSignInOptions gso;
    private GoogleApiClient mGoogleSignInClient;
    private FirebaseAuth.AuthStateListener firebaseAuthListener;
    private CallbackManager mCallbackManager;
    //default value of request code
    static final int RC_SIGN_IN = 1;
    AppEventsLogger logger;

    @Override
    protected void onStart() {
        super.onStart();

        firebaseAuth.addAuthStateListener(firebaseAuthListener);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        firebaseAuth = FirebaseAuth.getInstance();
        FacebookSdk.sdkInitialize(getApplicationContext());
        setControls();
        loginFbButton.setReadPermissions("email", "public_profile");

        if (firebaseAuth.getCurrentUser() != null) {
            Intent intent=new Intent(MainActivity.this, ActivityDlaZalogowanych.class);
            intent.setFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
            startActivity(intent);
            finish();


        }
           //         PackageInfo info;
           // try {
           //     info = getPackageManager().getPackageInfo("com.example.pbwi.actifitapp", PackageManager.GET_SIGNATURES);
           //     for (Signature signature : info.signatures) {
           //         MessageDigest md;
           //         md = MessageDigest.getInstance("SHA");
           //         md.update(signature.toByteArray());
           //         String something = new String(Base64.encode(md.digest(), 0));
           //         //String something = new String(Base64.encodeBytes(md.digest()));
           //         Log.e("hash key", something);
           //     }
           // } catch (PackageManager.NameNotFoundException e1) {
           //     Log.e("name not found", e1.toString());
           // } catch (NoSuchAlgorithmException e) {
           //     Log.e("no such an algorithm", e.toString());
           // } catch (Exception e) {
           //     Log.e("exception", e.toString());
           // }
        mCallbackManager = CallbackManager.Factory.create();
        googleSignInButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                signIn();
            }
        });
        //if you off the app, this listener now that you have acco on firebase and next time you dont need to login
        firebaseAuthListener = new FirebaseAuth.AuthStateListener() {
            @Override
            public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
                if(firebaseAuth.getCurrentUser() !=null){
                    startActivity(new Intent(MainActivity.this, ActivityDlaZalogowanych.class));
            }
        }
        };

        //configure google sign in
         gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                .requestIdToken(getString(R.string.default_web_client_id))
                .requestEmail()
                .build();
        // Build a GoogleSignInClient with the options specified by gso.
        mGoogleSignInClient = new GoogleApiClient.Builder(this)
                .enableAutoManage(this, new GoogleApiClient.OnConnectionFailedListener() {
                    //if something went wrong
                    @Override
                    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
                        Toast.makeText(MainActivity.this, getString(R.string.authGoWrong), Toast.LENGTH_SHORT).show();
                    }
                })
                .addApi(Auth.GOOGLE_SIGN_IN_API, gso)
                .build();

        loginFbButton.registerCallback(mCallbackManager, new FacebookCallback<LoginResult>() {
            @Override
            public void onSuccess(LoginResult loginResult) {
                Log.d(TAG, "facebook:onSuccess:" + loginResult);
                Toast.makeText(MainActivity.this,"Logging in with fb. Please wait",Toast.LENGTH_LONG).show();
                handleFacebookAccessToken(loginResult.getAccessToken());
            }

            @Override
            public void onCancel() {
                Log.d(TAG, "facebook:onCancel");
                // [START_EXCLUDE]

                // [END_EXCLUDE]
            }

            @Override
            public void onError(FacebookException error) {
                Log.d(TAG, "facebook:onError", error);
                // [START_EXCLUDE]

                // [END_EXCLUDE]
            }
        });
        // [END initialize_fblogin]








    final Button button = (Button) findViewById(R.id.guzik_logowania_id);
        progressDialog = new ProgressDialog(this);


        button.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                userLogin();
            }

        });
        guzik_rejestracji = (Button) findViewById(R.id.guzik_rejestracja_id);
        guzik_rejestracji.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, RegisterPanel.class);
                startActivity(intent);
            }
        });





    }
    private void handleFacebookAccessToken(AccessToken token) {
        Log.d(TAG, "handleFacebookAccessToken:" + token);
        // [START_EXCLUDE silent]


        // [END_EXCLUDE]

        AuthCredential credential = FacebookAuthProvider.getCredential(token.getToken());
        firebaseAuth.signInWithCredential(credential)
                .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        if (task.isSuccessful()) {
                            // Sign in success, update UI with the signed-in user's information
                            Log.d(TAG, "signInWithCredential:success");
                            FirebaseUser user = firebaseAuth.getCurrentUser();
                            finish();
                            startActivity(new Intent(getApplicationContext(), ActivityDlaZalogowanych.class));
                        } else {
                            // If sign in fails, display a message to the user.
                            Log.w(TAG, "signInWithCredential:failure", task.getException());
                            Toast.makeText(MainActivity.this, "Authentication failed.",
                                    Toast.LENGTH_SHORT).show();

                        }

                        // [START_EXCLUDE]
                        // [END_EXCLUDE]
                    }
                });
    }





    //method for user login
    private void userLogin(){

        EditText _email = (EditText) findViewById(R.id.input_email_id);
        EditText _password = (EditText) findViewById(R.id.input_haslo_id);

        String email = _email.getText().toString().trim();
        String password  = _password.getText().toString().trim();


        //checking if email and passwords are empty
        if (_email.getText().toString().length() == 0)
            _email.setError("Email required.");
        else if (!Patterns.EMAIL_ADDRESS.matcher(_email.getText().toString()).matches()) {
            _email.setError("This is not a valid email address.");
        }
        if (_password.getText().toString().length() == 0){
            _password.setError("Password required.");
            return;
        }

        //if the email and password are not empty
        //displaying a progress dialog

        progressDialog.setMessage("Please Wait...");
        progressDialog.show();

        //logging in the user
        firebaseAuth.signInWithEmailAndPassword(email, password)
                .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        progressDialog.dismiss();
                        //if the task is successfull
                        if(task.isSuccessful()){
                            //start the profile activity
                            finish();
                            startActivity(new Intent(getApplicationContext(), ActivityDlaZalogowanych.class));
                        }
                        else{
                            Toast.makeText(getApplicationContext(), "Błędne dane", Toast.LENGTH_LONG).show();
                        }
                    }
                });

    }

    public void setControls(){
        googleSignInButton = (SignInButton) findViewById(R.id.sign_in_button);
        loginFbButton=(LoginButton)findViewById(R.id.login_button_fb);
    }

    //Google Sign In methods
    private void signIn() {
        Intent signInIntent = Auth.GoogleSignInApi.getSignInIntent(mGoogleSignInClient);
        startActivityForResult(signInIntent, RC_SIGN_IN);
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        // Result returned from launching the Intent from GoogleSignInApi.getSignInIntent(...);
        if (requestCode == RC_SIGN_IN) {
            GoogleSignInResult result = Auth.GoogleSignInApi.getSignInResultFromIntent(data);
          if(result.isSuccess()) {
              //get google account
              GoogleSignInAccount account = result.getSignInAccount();
              firebaseAuthWithGoogle(account);
          } else {
              Toast.makeText(getApplicationContext(), getString(R.string.authGoWrong), Toast.LENGTH_LONG).show();
          }
        }else
        mCallbackManager.onActivityResult(requestCode, resultCode, data);
    }

    private void firebaseAuthWithGoogle(GoogleSignInAccount account) {
        AuthCredential credential = GoogleAuthProvider.getCredential(account.getIdToken(), null);
        firebaseAuth.signInWithCredential(credential)
                .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        if (task.isSuccessful()) {
                            // Sign in success, update UI with the signed-in user's information
                            Log.d("TAG", "signInWithCredential:success");
                            FirebaseUser user = firebaseAuth.getCurrentUser();
                            //updateUI(user);
                        } else {
                            // If sign in fails, display a message to the user.
                            Log.w("TAG", "signInWithCredential:failure", task.getException());
                            Toast.makeText(MainActivity.this, getString(R.string.authGoWrong),
                                    Toast.LENGTH_SHORT).show();
                           // updateUI(null);
                        }

                        // ...
                    }
                });
    }

}