LoginActivity.java

package com.crime_mapping.sih2020.sos;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.annotation.TargetApi;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Build;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.Log;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.inputmethod.EditorInfo;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseAuthInvalidCredentialsException;
import com.google.firebase.auth.FirebaseAuthInvalidUserException;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class LoginActivity extends AppCompatActivity {


    private static final String TAG = "LoginActivity";
    private static final String EMAIL_LIST_KEY = "emailList";
    SharedPreferences sharedpreferences;
    private String MyPREFERENCES="SOS_DATA";

    Set<String> emails;
    List<String> emailList = new ArrayList<>();

    private FirebaseAuth mAuth;
    FirebaseDatabase database;
    DatabaseReference myRef;


    // UI references.
    private AutoCompleteTextView mEmailView;
    private EditText mPasswordView;
    private View mProgressView;
    private View mLoginFormView;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        sharedpreferences = getSharedPreferences(MyPREFERENCES, Context.MODE_PRIVATE);
        emails=sharedpreferences.getStringSet(EMAIL_LIST_KEY, new HashSet<String>());


        //firebase
        database = FirebaseDatabase.getInstance();
        myRef = database.getReference("Locations");


        mEmailView =  findViewById(R.id.email);
        populateAutoComplete();

        mPasswordView = findViewById(R.id.password);
        mPasswordView.setOnEditorActionListener(new TextView.OnEditorActionListener() {
            @Override
            public boolean onEditorAction(TextView textView, int id, KeyEvent keyEvent) {
                if (id == EditorInfo.IME_ACTION_DONE || id == EditorInfo.IME_NULL) {
                    attemptLogin();
                    return true;
                }
                return false;
            }
        });


        //get instance
        mAuth = FirebaseAuth.getInstance();

        Button mEmailSignInButton = findViewById(R.id.email_sign_in_button);
        mEmailSignInButton.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View view) {
                attemptLogin();
            }
        });

        mLoginFormView = findViewById(R.id.login_form);
        mProgressView = findViewById(R.id.login_progress);
    }

    private void populateAutoComplete() {
        for (String email:emails)
        {
            emailList.add(email);

        }
        ArrayAdapter<String> adapter =
                new ArrayAdapter<>(LoginActivity.this,
                        android.R.layout.simple_dropdown_item_1line,emailList );
        mEmailView.setAdapter(adapter);
        mEmailView.setThreshold(1);
    }

//    private boolean mayRequestContacts() {
//        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
//            return true;
//        }
//        if (checkSelfPermission(READ_CONTACTS) == PackageManager.PERMISSION_GRANTED) {
//            return true;
//        }
//        if (shouldShowRequestPermissionRationale(READ_CONTACTS)) {
//            Snackbar.make(mEmailView, R.string.permission_rationale, Snackbar.LENGTH_INDEFINITE)
//                    .setAction(android.R.string.ok, new View.OnClickListener() {
//                        @Override
//                        @TargetApi(Build.VERSION_CODES.M)
//                        public void onClick(View v) {
//                            requestPermissions(new String[]{READ_CONTACTS}, REQUEST_READ_CONTACTS);
//                        }
//                    });
//        } else {
//            requestPermissions(new String[]{READ_CONTACTS}, REQUEST_READ_CONTACTS);
//        }
//        return false;
//    }

    /**
     * Callback received when a permissions request has been completed.
     */

//    @Override
//    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
//                                           @NonNull int[] grantResults) {
//        if (requestCode == REQUEST_READ_CONTACTS) {
//            if (grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
//                populateAutoComplete();
//            }
//        }
//    }


    /**
     * Attempts to sign in or register the account specified by the login form.
     * If there are form errors (invalid email, missing fields, etc.), the
     * errors are presented and no actual login attempt is made.
     */

    private void attemptLogin() {

        // Reset errors.
        mEmailView.setError(null);
        mPasswordView.setError(null);

        // Store values at the time of the login attempt.
        String email = mEmailView.getText().toString();
        String password = mPasswordView.getText().toString();

        boolean cancel = false;
        View focusView = null;




        //check for empty password
        if (TextUtils.isEmpty(password)){

            mPasswordView.setError("Please set Password");
            focusView = mPasswordView;
            cancel = true;
        }
        else if(!isPasswordValid(password)){ // Check for a valid password, if the user entered one.
            mPasswordView.setError(getString(R.string.error_invalid_password));
            focusView=mPasswordView;
            cancel=true;
        }

        // Check for a valid email address.

        if (TextUtils.isEmpty(email)) {
            mEmailView.setError(getString(R.string.error_field_required));
            focusView = mEmailView;
            cancel = true;
        } else if (!isEmailValid(email)) {
            mEmailView.setError(getString(R.string.error_invalid_email));
            focusView = mEmailView;
            cancel = true;
        }

        if (cancel) {
            focusView.requestFocus();
        } else {
            showProgress(true);
            SharedPreferences.Editor et= sharedpreferences.edit();
            emails.add(email);
            et.putStringSet(EMAIL_LIST_KEY,emails);
            et.apply();
            performFirebaseLogin(email,password);
        }
    }

    private boolean isEmailValid(String email) {
        return email.contains("@");
    }

    private boolean isPasswordValid(String password) {
        return password.length() > 5;
    }

    private  void performFirebaseLogin(final String mEmail, final String mPassword)
    {

        mAuth.signInWithEmailAndPassword(mEmail, mPassword)
                .addOnCompleteListener(LoginActivity.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, "signInWithEmail:success");
                            FirebaseUser user = mAuth.getCurrentUser();

                            startActivity(new Intent(LoginActivity.this, MainActivity.class));
                            finish();


                        } else {
                            Log.w(TAG, "signInWithEmail:failure", task.getException());

                            try {
                                throw (task.getException());
                            }
                            catch (FirebaseAuthInvalidUserException e) {
                                Toast.makeText(LoginActivity.this, "Registering..", Toast.LENGTH_SHORT).show();
                                Log.w(TAG, "onComplete: registering user" );
                                mAuth.createUserWithEmailAndPassword(mEmail, mPassword)
                                        .addOnCompleteListener(LoginActivity.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, "createUserWithEmail:success");
                                                    FirebaseUser user = mAuth.getCurrentUser();
                                                    myRef.child(user.getUid()).child("email").setValue(mEmail);
                                                    startActivity(new Intent(LoginActivity.this, MainActivity.class));
                                                    showProgress(false);
                                                    finish();
                                                    Log.d(TAG, "onComplete: user registered" );

                                                }
                                                else {
                                                    // If sign in fails, display a message to the user.
                                                    Log.w(TAG, "createUserWithEmail:failure", task.getException());
                                                    Toast.makeText(LoginActivity.this, "Authentication failed.",
                                                            Toast.LENGTH_SHORT).show();

                                                }
                                            }
                                        });

                            }

                            catch (FirebaseAuthInvalidCredentialsException e) {
                                Toast.makeText(LoginActivity.this, "Invalid Password", Toast.LENGTH_SHORT).show();
                                mPasswordView.setError(getString(R.string.error_incorrect_password));
                                mPasswordView.requestFocus();
                                Log.e(TAG, e.getMessage());
                            }
                            catch (Exception e) {
                                Toast.makeText(LoginActivity.this, "FireBase Authentication Failed", Toast.LENGTH_SHORT).show();
                                Log.e(TAG, e.getMessage());
                            }
                            showProgress(false);

                        }

                    }
                });
    }

    /**
     * Shows the progress UI and hides the login form.
     */
    @TargetApi(Build.VERSION_CODES.HONEYCOMB_MR2)
    private void showProgress(final boolean show) {

            int shortAnimTime = getResources().getInteger(android.R.integer.config_shortAnimTime);

            mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
            mLoginFormView.animate().setDuration(shortAnimTime).alpha(
                    show ? 0 : 1).setListener(new AnimatorListenerAdapter() {
                @Override
                public void onAnimationEnd(Animator animation) {
                    mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
                }
            });

            mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
            mProgressView.animate().setDuration(shortAnimTime).alpha(
                    show ? 1 : 0).setListener(new AnimatorListenerAdapter() {
                @Override
                public void onAnimationEnd(Animator animation) {
                    mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
                }
            });

    }
}