import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.Signature;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Base64;
import android.util.Log;
import android.view.View;

import com.facebook.AccessToken;
import com.facebook.CallbackManager;
import com.facebook.FacebookCallback;
import com.facebook.FacebookException;
import com.facebook.Profile;
import com.facebook.login.LoginResult;
import com.facebook.login.widget.LoginButton;
import com.google.android.gms.auth.api.signin.GoogleSignIn;
import com.google.android.gms.auth.api.signin.GoogleSignInAccount;
import com.google.android.gms.auth.api.signin.GoogleSignInClient;
import com.google.android.gms.auth.api.signin.GoogleSignInOptions;
import com.google.android.gms.common.SignInButton;
import com.google.android.gms.common.api.ApiException;
import com.google.android.gms.tasks.Task;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class LoginActivity extends AppCompatActivity {
    CallbackManager callbackManager;
    GoogleSignInClient mGoogleSignInClient;
    int RC_SIGN_IN = 101;


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

        // Result returned from launching the Intent from GoogleSignInClient.getSignInIntent(...);
        if (requestCode == RC_SIGN_IN) {
            // The Task returned from this call is always completed, no need to attach
            // a listener.
            Task<GoogleSignInAccount> mTask = GoogleSignIn.getSignedInAccountFromIntent(data);
            handleSignInResult(mTask);

        }
    }



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        LoginButton loginButton = (LoginButton)findViewById(R.id.login_button);
        AccessToken accessToken = AccessToken.getCurrentAccessToken();
        boolean isLoggedIn = accessToken != null && !accessToken.isExpired();
        printKeyHash(this);
        loginButton.setReadPermissions("email");
        callbackManager = CallbackManager.Factory.create();
        loginButton.registerCallback(callbackManager, new FacebookCallback<LoginResult>() {
            @Override
            public void onSuccess(LoginResult loginResult) {
                Intent intent = new Intent(LoginActivity.this, HomeActivity.class);
                startActivity(intent);
            }
            @Override
            public void onCancel() {
                // App code
            }
            @Override
            public void onError(FacebookException exception) {
                // App code
            }
        });


        SignInButton signInButton = findViewById(R.id.sign_in_button);


        // Configure sign-in to request the user's ID, email address, and basic
        // profile. ID and basic profile are included in DEFAULT_SIGN_IN.
        GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                .requestEmail()
                .build();

        // Build a GoogleSignInClient with the options specified by gso.
        mGoogleSignInClient = GoogleSignIn.getClient(this, gso);

        // Check for existing Google Sign In account, if the user is already signed in
        // the GoogleSignInAccount will be non-null.
        GoogleSignInAccount mAccount = GoogleSignIn.getLastSignedInAccount(this);
        updateUI(mAccount);

        signInButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                signIn();
            }
        });
    }

    //Function to update UI
    public void updateUI(GoogleSignInAccount account){

        if(account != null){
            String personName = account.getDisplayName();
            String personGivenName = account.getGivenName();
            String personFamilyName = account.getFamilyName();
            String personEmail = account.getEmail();
            String personId = account.getId();
            //Uri personPhoto = account.getPhotoUrl();
            String personPhoto = String.valueOf(account.getPhotoUrl());

            Intent signInIntent = new Intent(LoginActivity.this, HomeActivity.class);
            signInIntent.putExtra("person_name",personName);
            signInIntent.putExtra("person_given_name", personGivenName);
            signInIntent.putExtra("person_family_name",personFamilyName);
            signInIntent.putExtra("person_email", personEmail);
            signInIntent.putExtra("person_id", personId);
            signInIntent.putExtra("person_photo", personPhoto);

            startActivity(signInIntent);

        }
    }

    //Function to sign in
    private void signIn() {
        Intent signInIntent = mGoogleSignInClient.getSignInIntent();
        startActivityForResult(signInIntent, RC_SIGN_IN);
    }

    //Function to handle sign in result
    public void handleSignInResult(Task<GoogleSignInAccount> completedTask){

        try {
            GoogleSignInAccount account = completedTask.getResult(ApiException.class);

            // Signed in successfully, show authenticated UI.
            updateUI(account);
        } catch (ApiException e) {
            // The ApiException status code indicates the detailed failure reason.
            // Please refer to the GoogleSignInStatusCodes class reference for more information.
            Log.w("SIGNINFAILED", "signInResult:failed code=" + e.getStatusCode());
            updateUI(null);
        }


    }

    public static String printKeyHash(Activity context) {
        PackageInfo packageInfo;
        String key = null;
        try {
            //getting application package name, as defined in manifest
            String packageName = context.getApplicationContext().getPackageName();

            //Retriving package info
            packageInfo = context.getPackageManager().getPackageInfo(packageName,
                    PackageManager.GET_SIGNATURES);

            Log.e("Package Name=", context.getApplicationContext().getPackageName());

            for (Signature signature : packageInfo.signatures) {
                MessageDigest md = MessageDigest.getInstance("SHA");
                md.update(signature.toByteArray());
                key = new String(Base64.encode(md.digest(), 0));

                // String key = new String(Base64.encodeBytes(md.digest()));
                Log.e("Key Hash=", key);
            }
        } 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());
        }

        return key;
    }

}```