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import android.content.Context;
import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.v4.app.FragmentActivity;
import android.util.Log;

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.api.GoogleApiClient;
import com.google.android.gms.common.api.OptionalPendingResult;
import com.google.android.gms.common.api.ResultCallback;
import com.google.android.gms.common.api.Status;

/**
 * Created by Kir on 05.10.2017.
 *
 * Deploying :
 *
 * public class SignInActivity extends AppCompatActivity { ... }
 * GoogleAuth googleAuth;
 * @Override protected void onCreate(Bundle savedInstanceState) {
 *     googleAuth = new GoogleAuth();
 *     googleAuth.configure(this,this, new GoogleAuth.Callback(){ ... }
 * }
 *
 * @Override
 * public void onStart() {
 *     super.onStart();
 *     googleAuth.start();
 * }
 * @Override
 * public void onActivityResult(int requestCode, int resultCode, Intent data) {
 *     super.onActivityResult(requestCode, resultCode, data);
 *     googleAuth.getResult(requestCode,data);
 * }
 *
 * Button actions :
 *      signIn()
 *      signOut()
 *      revokeAccess()
 *
 */

public class GoogleAuth {

    static final String TAG = "GoogleAuth";
    private static final int RC_SIGN_IN = 9001;

    private GoogleApiClient mGoogleApiClient;
    private Context context;
    private FragmentActivity fragment;

    public Callback callback;

    public void configure(Context c, FragmentActivity f, Callback cb){

        context = c;
        fragment = f;
        callback = cb;

        GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                .requestEmail()
                .build();

        GoogleApiClient.OnConnectionFailedListener failedListener = new GoogleApiClient.OnConnectionFailedListener() {
            @Override
            public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
                callback.connectionFailed(connectionResult);
            }
        };

        // Build a GoogleApiClient with access to the Google Sign-In API and the
        // options specified by gso.
        mGoogleApiClient = new GoogleApiClient.Builder(context)
                .enableAutoManage(fragment,failedListener)
                .addApi(Auth.GOOGLE_SIGN_IN_API, gso)
                .build();
    }

    public void start(){
        OptionalPendingResult<GoogleSignInResult> opr = Auth.GoogleSignInApi.silentSignIn(mGoogleApiClient);
        if (opr.isDone()) {
            // If the user's cached credentials are valid, the OptionalPendingResult will be "done"
            // and the GoogleSignInResult will be available instantly.
            Log.d(TAG, "Got cached sign-in");
            GoogleSignInResult result = opr.get();
            handleResult(result);
        } else {
            // If the user has not previously signed in on this device or the sign-in has expired,
            // this asynchronous branch will attempt to sign in the user silently.  Cross-device
            // single sign-on will occur in this branch.
            ///showProgressDialog();
            opr.setResultCallback(new ResultCallback<GoogleSignInResult>() {
                @Override
                public void onResult(GoogleSignInResult googleSignInResult) {
                    handleResult(googleSignInResult);
                }
            });
        }
    }

    public void signIn() {
        Intent signInIntent = Auth.GoogleSignInApi.getSignInIntent(mGoogleApiClient);
        fragment.startActivityForResult(signInIntent, RC_SIGN_IN);
    }

    public void signOut(){
        Auth.GoogleSignInApi.signOut(mGoogleApiClient).setResultCallback(
                new ResultCallback<Status>() {
                    @Override
                    public void onResult(Status status) {
                        callback.signOut(status);
                    }
                });
    }

    public void getResult(int requestCode, Intent data){
        // Result returned from launching the Intent from GoogleSignInApi.getSignInIntent(...);
        if (requestCode == RC_SIGN_IN) {
            GoogleSignInResult result = Auth.GoogleSignInApi.getSignInResultFromIntent(data);
            handleResult(result);
        }
    }

    private void handleResult(GoogleSignInResult result) {
        Log.d(TAG, "handleSignInResult:" + result.isSuccess());
        if (result.isSuccess()) {
            // Signed in successfully, show authenticated UI.
            GoogleSignInAccount acct = result.getSignInAccount();
            callback.success(acct);
        } else {
            // Signed out, show unauthenticated UI.
            callback.failed(result);
        }
    }

    /** Disconnect */
    public void revokeAccess() {
        Auth.GoogleSignInApi.revokeAccess(mGoogleApiClient).setResultCallback(
                new ResultCallback<Status>() {
                    @Override
                    public void onResult(Status status) {
                        callback.revokeAccess(status);
                    }
                });
    }

    public interface Callback {
        void connectionFailed(ConnectionResult c);
        void success(GoogleSignInAccount g);
        void revokeAccess(Status status);
        void failed(GoogleSignInResult result);
        void signOut(Status status);

    }
}