public class Account extends AppCompatActivity {

FirebaseUser mUser;
StorageReference mStorage;

ImageView displayProfilePhoto;

private static final int GALLERY_INTENT = 0;

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

    ImageButton Return = (ImageButton) findViewById(UserToHome);
    ImageButton editPhoto = (ImageButton) findViewById(R.id.editProfilePhoto);
    ImageButton editName = (ImageButton) findViewById(R.id.editName);
    ImageButton editEmail = (ImageButton) findViewById(R.id.editEmail);
    ImageButton editPass = (ImageButton) findViewById(R.id.editPassword);
    Button VerifyEmail = (Button) findViewById(R.id.DisplayVerification);

    Return.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            startActivity(new Intent(Account.this, Home.class));
        }
    });

    editPhoto.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            changePhoto();
        }
    });

    editName.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            startActivity(new Intent(Account.this, ChangeName.class));
        }
    });

    editEmail.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            startActivity(new Intent(Account.this, ChangeEmail.class));
        }
    });

    editPass.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            startActivity(new Intent(Account.this, ChangePassword.class));
        }
    });

    VerifyEmail.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            EmailVerification();
        }
    });

    getUserProfile();
}

private void getUserProfile() {
    mUser = FirebaseAuth.getInstance().getCurrentUser();
    mStorage = FirebaseStorage.getInstance().getReference();

    if (mUser != null) {
        Uri photoUrl = mUser.getPhotoUrl();
        String UID = mUser.getUid();
        String name = mUser.getDisplayName();
        String email = mUser.getEmail();
        Boolean verification = mUser.isEmailVerified();

        displayProfilePhoto = (ImageView) findViewById(R.id.ProfilePhoto);
        TextView displayUID = (TextView) findViewById(R.id.UserID);
        TextView displayName = (TextView) findViewById(R.id.DisplayName);
        TextView displayEmail = (TextView) findViewById(R.id.DisplayEmail);
        Button displayEmailVerification = (Button) findViewById(R.id.DisplayVerification);

        Picasso.with(Account.this).load(photoUrl).fit().centerCrop().into(displayProfilePhoto);
        displayUID.setText(UID);
        displayName.setText(name);
        displayEmail.setText(email);
        if(verification){
            displayEmailVerification.setText("Verified");
        }
        else{
            displayEmailVerification.setText("Not verified");
        }
    }
}

private void EmailVerification() {
    mUser = FirebaseAuth.getInstance().getCurrentUser();

    Boolean verification = mUser.isEmailVerified();
    if(verification){
        Toast.makeText(Account.this, "Email verified.",
                Toast.LENGTH_SHORT).show();
    }
    else{
        mUser.sendEmailVerification();
        Toast.makeText(Account.this, "Verification email sent.",
                Toast.LENGTH_SHORT).show();
    }
}

private void changePhoto() {
    mStorage = FirebaseStorage.getInstance().getReference();

    Intent intent = new Intent(Intent.ACTION_PICK);
    intent.setType("image/*");

    startActivityForResult(intent, GALLERY_INTENT);
}

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

    mUser = FirebaseAuth.getInstance().getCurrentUser();
    String UID = mUser.getUid();

    displayProfilePhoto = (ImageView) findViewById(R.id.ProfilePhoto);

    if(requestCode == GALLERY_INTENT && resultCode == RESULT_OK) {
        Uri uri = data.getData();

        final StorageReference childRef = mStorage.child("Profile Pictures")
                .child(UID)
                .child(uri.getLastPathSegment());

        childRef.putFile(uri).addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
            @Override
            public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                @SuppressWarnings("VisibleForTests") final
                Uri downloadUri = taskSnapshot.getDownloadUrl();
                String stringUri = downloadUri.toString();


                UserProfileChangeRequest profileUpdates = new UserProfileChangeRequest.Builder()
                        .setPhotoUri(Uri.parse(stringUri))
                        .build();

                mUser.updateProfile(profileUpdates)
                        .addOnCompleteListener(new OnCompleteListener<Void>() {
                            @Override
                            public void onComplete(@NonNull Task<Void> task) {
                                if (!task.isSuccessful()) {
                                    Toast.makeText(Account.this, "Profile update failed. Please try again.",
                                            Toast.LENGTH_SHORT).show();
                                }
                                else
                                {
                                    Picasso.with(Account.this).load(downloadUri).fit().centerCrop().into(displayProfilePhoto);

                                    Toast.makeText(Account.this, "Profile picture updated.",
                                            Toast.LENGTH_SHORT).show();
                                }
                            }
                        });
            }
        }).addOnFailureListener(new OnFailureListener() {
            @Override
            public void onFailure(@NonNull Exception e) {
                Toast.makeText(Account.this, "Photo upload failed. Please try again.",
                        Toast.LENGTH_SHORT).show();
            }
        });
    }
}
}