package org.thoughtcrime.securesms;

import android.Manifest;
import android.animation.Animator;
import android.annotation.SuppressLint;
import android.content.Context;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AlertDialog;
import android.text.Editable;
import android.text.TextUtils;
import android.text.TextWatcher;
import android.util.Pair;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.animation.OvershootInterpolator;
import android.view.inputmethod.InputMethodManager;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;

import com.dd.CircularProgressButton;

import net.sqlcipher.database.SQLiteDatabase;

import org.greenrobot.eventbus.EventBus;
import org.greenrobot.eventbus.Subscribe;
import org.greenrobot.eventbus.ThreadMode;
import org.thoughtcrime.securesms.animation.AnimationCompleteListener;
import org.thoughtcrime.securesms.backup.FullBackupBase;
import org.thoughtcrime.securesms.backup.FullBackupImporter;
import org.thoughtcrime.securesms.components.LabeledEditText;
import org.thoughtcrime.securesms.components.registration.CallMeCountDownView;
import org.thoughtcrime.securesms.components.registration.VerificationCodeView;
import org.thoughtcrime.securesms.components.registration.VerificationPinKeyboard;
import org.thoughtcrime.securesms.crypto.AttachmentSecretProvider;
import org.thoughtcrime.securesms.crypto.IdentityKeyUtil;
import org.thoughtcrime.securesms.crypto.PreKeyUtil;
import org.thoughtcrime.securesms.crypto.SessionUtil;
import org.thoughtcrime.securesms.crypto.UnidentifiedAccessUtil;
import org.thoughtcrime.securesms.database.Address;
import org.thoughtcrime.securesms.database.DatabaseFactory;
import org.thoughtcrime.securesms.database.IdentityDatabase;
import org.thoughtcrime.securesms.database.NoExternalStorageException;
import org.thoughtcrime.securesms.jobs.RotateCertificateJob;
import org.thoughtcrime.securesms.lock.RegistrationLockReminders;
import org.thoughtcrime.securesms.logging.Log;
import org.thoughtcrime.securesms.notifications.NotificationChannels;
import org.thoughtcrime.securesms.permissions.Permissions;
import org.thoughtcrime.securesms.push.AccountManagerFactory;
import org.thoughtcrime.securesms.registration.CaptchaActivity;
import org.thoughtcrime.securesms.service.RotateSignedPreKeyListener;
import org.thoughtcrime.securesms.util.BackupUtil;
import org.thoughtcrime.securesms.util.DateUtils;
import org.thoughtcrime.securesms.util.Dialogs;
import org.thoughtcrime.securesms.util.ServiceUtil;
import org.thoughtcrime.securesms.util.TextSecurePreferences;
import org.thoughtcrime.securesms.util.Util;
import org.thoughtcrime.securesms.util.concurrent.AssertedSuccessListener;
import org.whispersystems.libsignal.IdentityKeyPair;
import org.whispersystems.libsignal.state.PreKeyRecord;
import org.whispersystems.libsignal.state.SignedPreKeyRecord;
import org.whispersystems.libsignal.util.KeyHelper;
import org.whispersystems.libsignal.util.guava.Optional;
import org.whispersystems.signalservice.api.SignalServiceAccountManager;
import org.whispersystems.signalservice.api.push.exceptions.CaptchaRequiredException;
import org.whispersystems.signalservice.api.push.exceptions.RateLimitException;
import org.whispersystems.signalservice.api.util.PhoneNumberFormatter;
import org.whispersystems.signalservice.internal.push.LockedException;

import java.io.IOException;
import java.lang.ref.WeakReference;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.concurrent.TimeUnit;

import network.loki.messenger.R;

/**
 * The register account activity.  Prompts ths user for their registration information
 * and begins the account registration process.
 *
 * @author Moxie Marlinspike
 *
 */
public class RegistrationActivity extends BaseActionBarActivity implements VerificationCodeView.OnCodeEnteredListener {

  private static final int    PICK_COUNTRY              = 1;
  private static final int    CAPTCHA                   = 24601;
  private static final int    SCENE_TRANSITION_DURATION = 250;
  private static final int    DEBUG_TAP_TARGET          = 8;
  private static final int    DEBUG_TAP_ANNOUNCE        = 4;
  public static final  String RE_REGISTRATION_EXTRA     = "re_registration";

  private static final String TAG = RegistrationActivity.class.getSimpleName();

  private ArrayAdapter<String>   countrySpinnerAdapter;
  private Spinner                countrySpinner;
  private LabeledEditText        countryCode;
  private LabeledEditText        number;
  private CircularProgressButton createButton;
  private TextView               title;
  private TextView               subtitle;
  private View                   registrationContainer;
  private View                   verificationContainer;

  private View                   restoreContainer;
  private TextView               restoreBackupTime;
  private TextView               restoreBackupSize;
  private TextView               restoreBackupProgress;
  private CircularProgressButton restoreButton;

  private View                   pinContainer;
  private EditText               pin;
  private CircularProgressButton pinButton;
  private TextView               pinForgotButton;
  private View                   pinClarificationContainer;

  private CallMeCountDownView         callMeCountDownView;
  private View                        wrongNumberButton;
  private VerificationPinKeyboard     keyboard;
  private VerificationCodeView        verificationCodeView;
  private RegistrationState           registrationState;
  private SignalServiceAccountManager accountManager;
  private int                         debugTapCounter;


  @Override
  public void onCreate(Bundle icicle) {
    super.onCreate(icicle);
    setContentView(R.layout.registration_activity);

    initializeResources();
    initializeSpinner();
    initializeNumber();
    initializeBackupDetection();
  }

  @Override
  public void onDestroy() {
    super.onDestroy();
    markAsVerifying(false);
    EventBus.getDefault().unregister(this);
  }

  @Override
  protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == PICK_COUNTRY && resultCode == RESULT_OK && data != null) {
      this.countryCode.setText(String.valueOf(data.getIntExtra("country_code", 1)));
      setCountryDisplay(data.getStringExtra("country_name"));
    } else if (requestCode == CAPTCHA && resultCode == RESULT_OK && data != null) {
      registrationState = new RegistrationState(Optional.fromNullable(data.getStringExtra(CaptchaActivity.KEY_TOKEN)), registrationState);

      if (data.getBooleanExtra(CaptchaActivity.KEY_IS_SMS, true)) {
        handleRegister();
      } else {
        handlePhoneCallRequest();
      }
    } else if (requestCode == CAPTCHA) {
      Toast.makeText(this, R.string.RegistrationActivity_failed_to_verify_the_captcha, Toast.LENGTH_LONG).show();
      createButton.setIndeterminateProgressMode(false);
      createButton.setProgress(0);
    }
  }

  private void initializeResources() {
    TextView skipButton        = findViewById(R.id.skip_button);
    TextView restoreSkipButton = findViewById(R.id.skip_restore_button);

    this.countrySpinner        = findViewById(R.id.country_spinner);
    this.countryCode           = findViewById(R.id.country_code);
    this.number                = findViewById(R.id.number);
    this.createButton          = findViewById(R.id.registerButton);
    this.title                 = findViewById(R.id.verify_header);
    this.subtitle              = findViewById(R.id.verify_subheader);
    this.registrationContainer = findViewById(R.id.registration_container);
    this.verificationContainer = findViewById(R.id.verification_container);

    this.verificationCodeView = findViewById(R.id.code);
    this.keyboard             = findViewById(R.id.keyboard);
    this.callMeCountDownView  = findViewById(R.id.call_me_count_down);
    this.wrongNumberButton    = findViewById(R.id.wrong_number);

    this.restoreContainer      = findViewById(R.id.restore_container);
    this.restoreBackupSize     = findViewById(R.id.backup_size_text);
    this.restoreBackupTime     = findViewById(R.id.backup_created_text);
    this.restoreBackupProgress = findViewById(R.id.backup_progress_text);
    this.restoreButton         = findViewById(R.id.restore_button);

    this.pinContainer              = findViewById(R.id.pin_container);
    this.pin                       = findViewById(R.id.pin);
    this.pinButton                 = findViewById(R.id.pinButton);
    this.pinForgotButton           = findViewById(R.id.forgot_button);
    this.pinClarificationContainer = findViewById(R.id.pin_clarification_container);

    this.registrationState    = new RegistrationState(RegistrationState.State.INITIAL, null, null, Optional.absent(), Optional.absent());

    this.countryCode.getInput().addTextChangedListener(new CountryCodeChangedListener());
    this.number.getInput().addTextChangedListener(new NumberChangedListener());
    this.createButton.setOnClickListener(v -> handleRegister());
    this.callMeCountDownView.setOnClickListener(v -> handlePhoneCallRequest());

    skipButton.setOnClickListener(v -> handleCancel());
    restoreSkipButton.setOnClickListener(v -> displayInitialView(true));

    if (getIntent().getBooleanExtra(RE_REGISTRATION_EXTRA, false)) {
      skipButton.setVisibility(View.VISIBLE);
    } else {
      skipButton.setVisibility(View.INVISIBLE);
    }

    this.keyboard.setOnKeyPressListener(key -> {
      if (key >= 0) verificationCodeView.append(key);
      else          verificationCodeView.delete();
    });

    this.verificationCodeView.setOnCompleteListener(this);
    EventBus.getDefault().register(this);
  }

  private void onDebugClick(View view) {
    debugTapCounter++;

    if (debugTapCounter >= DEBUG_TAP_TARGET) {
      startActivity(new Intent(this, LogSubmitActivity.class));
    } else if (debugTapCounter >= DEBUG_TAP_ANNOUNCE) {
      int remaining = DEBUG_TAP_TARGET - debugTapCounter;
      Toast.makeText(this, getResources().getQuantityString(R.plurals.RegistrationActivity_debug_log_hint, remaining, remaining), Toast.LENGTH_SHORT).show();
    }
  }

  @SuppressLint("ClickableViewAccessibility")
  private void initializeSpinner() {
    this.countrySpinnerAdapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item);
    this.countrySpinnerAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    setCountryDisplay(getString(R.string.RegistrationActivity_select_your_country));

    this.countrySpinner.setAdapter(this.countrySpinnerAdapter);
    this.countrySpinner.setOnTouchListener((v, event) -> {
      if (event.getAction() == MotionEvent.ACTION_UP) {
        Intent intent = new Intent(RegistrationActivity.this, CountrySelectionActivity.class);
        startActivityForResult(intent, PICK_COUNTRY);
      }
      return true;
    });
    this.countrySpinner.setOnKeyListener((v, keyCode, event) -> {
      if (keyCode == KeyEvent.KEYCODE_DPAD_CENTER && event.getAction() == KeyEvent.ACTION_UP) {
        Intent intent = new Intent(RegistrationActivity.this, CountrySelectionActivity.class);
        startActivityForResult(intent, PICK_COUNTRY);
        return true;
      }
      return false;
    });
  }

  private void initializeNumber() {
  }

  @SuppressLint("StaticFieldLeak")
  private void initializeBackupDetection() {
    if (!Permissions.hasAll(this, Manifest.permission.READ_EXTERNAL_STORAGE)) {
      Log.i(TAG, "Skipping backup detection. We don't have the permission.");
      return;
    }

    if (getIntent().getBooleanExtra(RE_REGISTRATION_EXTRA, false)) return;

    new AsyncTask<Void, Void, BackupUtil.BackupInfo>() {
      @Override
      protected @Nullable BackupUtil.BackupInfo doInBackground(Void... voids) {
        try {
          return BackupUtil.getLatestBackup(RegistrationActivity.this);
        } catch (NoExternalStorageException e) {
          Log.w(TAG, e);
          return null;
        }
      }

      @Override
      protected void onPostExecute(@Nullable BackupUtil.BackupInfo backup) {
        if (backup != null) displayRestoreView(backup);
      }
    }.execute();
  }

  private void setCountryDisplay(String value) {
    this.countrySpinnerAdapter.clear();
    this.countrySpinnerAdapter.add(value);
  }

  private String getConfiguredE164Number() {
    return PhoneNumberFormatter.formatE164(countryCode.getText().toString(),
                                           number.getText().toString());
  }

  @SuppressLint("StaticFieldLeak")
  private void handleRestore(BackupUtil.BackupInfo backup) {
    View     view   = LayoutInflater.from(this).inflate(R.layout.enter_backup_passphrase_dialog, null);
    EditText prompt = view.findViewById(R.id.restore_passphrase_input);

    new AlertDialog.Builder(this)
        .setTitle(R.string.RegistrationActivity_enter_backup_passphrase)
        .setView(view)
        .setPositiveButton(getString(R.string.RegistrationActivity_restore), (dialog, which) -> {
          InputMethodManager inputMethodManager = (InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
          inputMethodManager.hideSoftInputFromWindow(prompt.getWindowToken(), 0);

          restoreButton.setIndeterminateProgressMode(true);
          restoreButton.setProgress(50);

          final String passphrase = prompt.getText().toString();

          new AsyncTask<Void, Void, BackupImportResult>() {
            @Override
            protected BackupImportResult doInBackground(Void... voids) {
              try {
                Context        context  = RegistrationActivity.this;
                SQLiteDatabase database = DatabaseFactory.getBackupDatabase(context);

                FullBackupImporter.importFile(context,
                                              AttachmentSecretProvider.getInstance(context).getOrCreateAttachmentSecret(),
                                              database, backup.getFile(), passphrase);

                DatabaseFactory.upgradeRestored(context, database);
                NotificationChannels.restoreContactNotificationChannels(context);

                TextSecurePreferences.setBackupEnabled(context, true);
                TextSecurePreferences.setBackupPassphrase(context, passphrase);
                return BackupImportResult.SUCCESS;
              } catch (FullBackupImporter.DatabaseDowngradeException e) {
                Log.w(TAG, "Failed due to the backup being from a newer version of Signal.", e);
                return BackupImportResult.FAILURE_VERSION_DOWNGRADE;
              } catch (IOException e) {
                Log.w(TAG, e);
                return BackupImportResult.FAILURE_UNKNOWN;
              }
            }

            @Override
            protected void onPostExecute(@NonNull BackupImportResult result) {
              restoreButton.setIndeterminateProgressMode(false);
              restoreButton.setProgress(0);
              restoreBackupProgress.setText("");

              switch (result) {
                case SUCCESS:
                  displayInitialView(true);
                  break;
                case FAILURE_VERSION_DOWNGRADE:
                  Toast.makeText(RegistrationActivity.this, R.string.RegistrationActivity_backup_failure_downgrade, Toast.LENGTH_LONG).show();
                  break;
                case FAILURE_UNKNOWN:
                  Toast.makeText(RegistrationActivity.this, R.string.RegistrationActivity_incorrect_backup_passphrase, Toast.LENGTH_LONG).show();
                  break;
              }
            }
          }.execute();

        })
        .setNegativeButton(android.R.string.cancel, null)
        .show();
  }

  private void handleRegister() {
    if (TextUtils.isEmpty(countryCode.getText())) {
      Toast.makeText(this, getString(R.string.RegistrationActivity_you_must_specify_your_country_code), Toast.LENGTH_LONG).show();
      return;
    }

    if (TextUtils.isEmpty(number.getText())) {
      Toast.makeText(this, getString(R.string.RegistrationActivity_you_must_specify_your_phone_number), Toast.LENGTH_LONG).show();
      return;
    }

    final String e164number = getConfiguredE164Number();

    if (!PhoneNumberFormatter.isValidNumber(e164number, countryCode.getText().toString())) {
      Dialogs.showAlertDialog(this,
                              getString(R.string.RegistrationActivity_invalid_number),
                              String.format(getString(R.string.RegistrationActivity_the_number_you_specified_s_is_invalid), e164number));
    }
  }

  private void handleRequestVerification(@NonNull String e164number, boolean gcmSupported) {
    createButton.setIndeterminateProgressMode(true);
    createButton.setProgress(50);

      requestVerificationCode(e164number, false, false);
  }

  @SuppressLint("StaticFieldLeak")
  private void requestVerificationCode(@NonNull String e164number, boolean gcmSupported, boolean smsRetrieverSupported) {
    new AsyncTask<Void, Void, VerificationRequestResult> () {
      @Override
      protected @NonNull VerificationRequestResult doInBackground(Void... voids) {
        try {
          markAsVerifying(true);

          String password = Util.getSecret(18);

          Optional<String> fcmToken = Optional.absent();

          accountManager = AccountManagerFactory.createManager(RegistrationActivity.this, e164number, password);
          accountManager.requestSmsVerificationCode(smsRetrieverSupported, registrationState.captchaToken);

          return new VerificationRequestResult(password, fcmToken, Optional.absent());
        } catch (IOException e) {
          Log.w(TAG, "Error during account registration", e);
          return new VerificationRequestResult(null, Optional.absent(), Optional.of(e));
        }
      }

      protected void onPostExecute(@NonNull VerificationRequestResult result) {
        if (result.exception.isPresent() && result.exception.get() instanceof CaptchaRequiredException) {
          requestCaptcha(true);
        } else if (result.exception.isPresent()) {
          Toast.makeText(RegistrationActivity.this, R.string.RegistrationActivity_unable_to_connect_to_service, Toast.LENGTH_LONG).show();
          createButton.setIndeterminateProgressMode(false);
          createButton.setProgress(0);
        } else {
          registrationState = new RegistrationState(RegistrationState.State.VERIFYING, e164number, result.password, result.fcmToken, Optional.absent());
          displayVerificationView(e164number, 64);
        }
      }
    }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
  }

  private void requestCaptcha(boolean isSms) {
    startActivityForResult(CaptchaActivity.getIntent(this, isSms), CAPTCHA);
  }

  private void handleVerificationCodeReceived(@Nullable String code) {
    List<Integer> parsedCode = convertVerificationCodeToDigits(code);

    for (int i = 0; i < parsedCode.size(); i++) {
      int index = i;
      verificationCodeView.postDelayed(() -> verificationCodeView.append(parsedCode.get(index)), i * 200);
    }
  }

  private List<Integer> convertVerificationCodeToDigits(@Nullable String code) {
    if (code == null || code.length() != 6 || registrationState.state != RegistrationState.State.VERIFYING) {
      return Collections.emptyList();
    }

    List<Integer> result = new LinkedList<>();

    try {
      for (int i = 0; i < code.length(); i++) {
        result.add(Integer.parseInt(Character.toString(code.charAt(i))));
      }
    } catch (NumberFormatException e) {
      Log.w(TAG, "Failed to convert code into digits.",e );
      return Collections.emptyList();
    }

    return result;
  }

  @SuppressLint("StaticFieldLeak")
  @Override
  public void onCodeComplete(@NonNull String code) {
    this.registrationState = new RegistrationState(RegistrationState.State.CHECKING, this.registrationState);
    callMeCountDownView.setVisibility(View.INVISIBLE);
    keyboard.displayProgress();

    new AsyncTask<Void, Void, Pair<Integer, Long>>() {
      @Override
      protected Pair<Integer, Long> doInBackground(Void... voids) {
        try {
          verifyAccount(code, null);
          return new Pair<>(1, -1L);
        } catch (LockedException e) {
          Log.w(TAG, e);
          return new Pair<>(2, e.getTimeRemaining());
        } catch (IOException e) {
          Log.w(TAG, e);
          return new Pair<>(3, -1L);
        }
      }

      @Override
      protected void onPostExecute(Pair<Integer, Long> result) {
        if (result.first == 1) {
          keyboard.displaySuccess().addListener(new AssertedSuccessListener<Boolean>() {
            @Override
            public void onSuccess(Boolean result) {
              handleSuccessfulRegistration();
            }
          });
        } else if (result.first == 2) {
          keyboard.displayLocked().addListener(new AssertedSuccessListener<Boolean>() {
            @Override
            public void onSuccess(Boolean r) {
              registrationState = new RegistrationState(RegistrationState.State.PIN, registrationState);
              displayPinView(code, result.second);
            }
          });
        } else {
          keyboard.displayFailure().addListener(new AssertedSuccessListener<Boolean>() {
            @Override
            public void onSuccess(Boolean result) {
              registrationState = new RegistrationState(RegistrationState.State.VERIFYING, registrationState);
              callMeCountDownView.setVisibility(View.VISIBLE);
              verificationCodeView.clear();
              keyboard.displayKeyboard();
            }
          });
        }
      }
    }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
  }

  @SuppressLint("StaticFieldLeak")
  private void handleVerifyWithPinClicked(@NonNull String code, @Nullable String pin) {
    if (TextUtils.isEmpty(pin) || TextUtils.isEmpty(pin.replace(" ", ""))) {
      Toast.makeText(this, R.string.RegistrationActivity_you_must_enter_your_registration_lock_PIN, Toast.LENGTH_LONG).show();
      return;
    }

    pinButton.setIndeterminateProgressMode(true);
    pinButton.setProgress(50);

    new AsyncTask<Void, Void, Integer>() {
      @Override
      protected Integer doInBackground(Void... voids) {
        try {
          verifyAccount(code, pin);
          return 1;
        } catch (LockedException e) {
          Log.w(TAG, e);
          return 2;
        } catch (RateLimitException e) {
          Log.w(TAG, e);
          return 3;
        } catch (IOException e) {
          Log.w(TAG, e);
          return 4;
        }
      }

      @Override
      protected void onPostExecute(Integer result) {
        pinButton.setIndeterminateProgressMode(false);
        pinButton.setProgress(0);

        if (result == 1) {
          TextSecurePreferences.setRegistrationLockPin(RegistrationActivity.this, pin);
          TextSecurePreferences.setRegistrationtLockEnabled(RegistrationActivity.this, true);
          TextSecurePreferences.setRegistrationLockLastReminderTime(RegistrationActivity.this, System.currentTimeMillis());
          TextSecurePreferences.setRegistrationLockNextReminderInterval(RegistrationActivity.this, RegistrationLockReminders.INITIAL_INTERVAL);

          handleSuccessfulRegistration();
        } else if (result == 2) {
          RegistrationActivity.this.pin.setText("");
          Toast.makeText(RegistrationActivity.this, R.string.RegistrationActivity_incorrect_registration_lock_pin, Toast.LENGTH_LONG).show();
        } else if (result == 3) {
          new AlertDialog.Builder(RegistrationActivity.this)
                         .setTitle(R.string.RegistrationActivity_too_many_attempts)
                         .setMessage(R.string.RegistrationActivity_you_have_made_too_many_incorrect_registration_lock_pin_attempts_please_try_again_in_a_day)
                         .setPositiveButton(android.R.string.ok, null)
                         .show();
        } else if (result == 4) {
          Toast.makeText(RegistrationActivity.this, R.string.RegistrationActivity_error_connecting_to_service, Toast.LENGTH_LONG).show();
        }
      }
    }.execute();
  }

  private void handleForgottenPin(long timeRemaining) {
    new AlertDialog.Builder(RegistrationActivity.this)
        .setTitle(R.string.RegistrationActivity_oh_no)
        .setMessage(getString(R.string.RegistrationActivity_registration_of_this_phone_number_will_be_possible_without_your_registration_lock_pin_after_seven_days_have_passed, (TimeUnit.MILLISECONDS.toDays(timeRemaining) + 1)))
        .setPositiveButton(android.R.string.ok, null)
        .show();
  }

  @SuppressLint("StaticFieldLeak")
  private void handlePhoneCallRequest() {
    if (registrationState.state == RegistrationState.State.VERIFYING) {
      callMeCountDownView.startCountDown(300);

      new AsyncTask<Void, Void, Void>() {
        @Override
        protected Void doInBackground(Void... voids) {
          try {
            accountManager.requestVoiceVerificationCode(Locale.getDefault(), registrationState.captchaToken);
          } catch (CaptchaRequiredException e) {
            requestCaptcha(false);
          } catch (IOException e) {
            Log.w(TAG, e);
          }

          return null;
        }
      }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
    }
  }

  private void verifyAccount(@NonNull String code, @Nullable String pin) throws IOException {
    int     registrationId              = KeyHelper.generateRegistrationId(false);
    byte[]  unidentifiedAccessKey       = UnidentifiedAccessUtil.getSelfUnidentifiedAccessKey(RegistrationActivity.this);
    boolean universalUnidentifiedAccess = TextSecurePreferences.isUniversalUnidentifiedAccess(RegistrationActivity.this);

    TextSecurePreferences.setLocalRegistrationId(RegistrationActivity.this, registrationId);
    SessionUtil.archiveAllSessions(RegistrationActivity.this);

    accountManager.verifyAccountWithCode(code, null, registrationId, !registrationState.gcmToken.isPresent(), pin,
                                         unidentifiedAccessKey, universalUnidentifiedAccess);

    IdentityKeyPair    identityKey  = IdentityKeyUtil.getIdentityKeyPair(RegistrationActivity.this);
    List<PreKeyRecord> records      = PreKeyUtil.generatePreKeyRecords(RegistrationActivity.this);
    SignedPreKeyRecord signedPreKey = PreKeyUtil.generateSignedPreKey(RegistrationActivity.this, identityKey, true);

    accountManager.setPreKeys(identityKey.getPublicKey(), signedPreKey, records);

    if (registrationState.gcmToken.isPresent()) {
      accountManager.setGcmId(registrationState.gcmToken);
    }

    TextSecurePreferences.setFcmToken(RegistrationActivity.this, registrationState.gcmToken.orNull());
    TextSecurePreferences.setFcmDisabled(RegistrationActivity.this, !registrationState.gcmToken.isPresent());
    TextSecurePreferences.setWebsocketRegistered(RegistrationActivity.this, true);

    DatabaseFactory.getIdentityDatabase(RegistrationActivity.this)
                   .saveIdentity(Address.fromSerialized(registrationState.e164number),
                                 identityKey.getPublicKey(), IdentityDatabase.VerifiedStatus.VERIFIED,
                                 true, System.currentTimeMillis(), true);

    TextSecurePreferences.setVerifying(RegistrationActivity.this, false);
    TextSecurePreferences.setPushRegistered(RegistrationActivity.this, true);
    TextSecurePreferences.setLocalNumber(RegistrationActivity.this, registrationState.e164number);
    TextSecurePreferences.setPushServerPassword(RegistrationActivity.this, registrationState.password);
    TextSecurePreferences.setSignedPreKeyRegistered(RegistrationActivity.this, true);
    TextSecurePreferences.setPromptedPushRegistration(RegistrationActivity.this, true);
    TextSecurePreferences.setUnauthorizedReceived(RegistrationActivity.this, false);
  }

  private void handleSuccessfulRegistration() {
    ApplicationContext.getInstance(RegistrationActivity.this).getJobManager().add(new RotateCertificateJob(RegistrationActivity.this));

    RotateSignedPreKeyListener.schedule(RegistrationActivity.this);

    Intent nextIntent = getIntent().getParcelableExtra("next_intent");

    if (nextIntent == null) {
      nextIntent = new Intent(RegistrationActivity.this, ConversationListActivity.class);
    }

    startActivity(nextIntent);
    finish();
  }

  private void displayRestoreView(@NonNull BackupUtil.BackupInfo backup) {
    title.animate().translationX(title.getWidth()).setDuration(SCENE_TRANSITION_DURATION).setListener(new AnimationCompleteListener() {
      @Override
      public void onAnimationEnd(Animator animation) {
        title.setText(R.string.RegistrationActivity_restore_from_backup);
        title.clearAnimation();
        title.setTranslationX(-1 * title.getWidth());
        title.animate().translationX(0).setListener(null).setInterpolator(new OvershootInterpolator()).setDuration(SCENE_TRANSITION_DURATION).start();
      }
    }).start();

    subtitle.animate().translationX(subtitle.getWidth()).setDuration(SCENE_TRANSITION_DURATION).setListener(new AnimationCompleteListener() {
      @Override
      public void onAnimationEnd(Animator animation) {
        subtitle.setText(R.string.RegistrationActivity_restore_your_messages_and_media_from_a_local_backup);
        subtitle.clearAnimation();
        subtitle.setTranslationX(-1 * subtitle.getWidth());
        subtitle.animate().translationX(0).setListener(null).setInterpolator(new OvershootInterpolator()).setDuration(SCENE_TRANSITION_DURATION).start();
      }
    }).start();

    registrationContainer.animate().translationX(registrationContainer.getWidth()).setDuration(SCENE_TRANSITION_DURATION).setListener(new AnimationCompleteListener() {
      @Override
      public void onAnimationEnd(Animator animation) {
        registrationContainer.clearAnimation();
        registrationContainer.setVisibility(View.INVISIBLE);
        registrationContainer.setTranslationX(0);

        restoreContainer.setTranslationX(-1 * registrationContainer.getWidth());
        restoreContainer.setVisibility(View.VISIBLE);
        restoreButton.setProgress(0);
        restoreButton.setIndeterminateProgressMode(false);
        restoreButton.setOnClickListener(v -> handleRestore(backup));
        restoreBackupSize.setText(getString(R.string.RegistrationActivity_backup_size_s, Util.getPrettyFileSize(backup.getSize())));
        restoreBackupTime.setText(getString(R.string.RegistrationActivity_backup_timestamp_s, DateUtils.getExtendedRelativeTimeSpanString(RegistrationActivity.this, Locale.US, backup.getTimestamp())));
        restoreBackupProgress.setText("");
        restoreContainer.animate().translationX(0).setDuration(SCENE_TRANSITION_DURATION).setListener(null).setInterpolator(new OvershootInterpolator()).start();
      }
    }).start();
  }

  private void displayInitialView(boolean forwards) {
    int startDirectionMultiplier = forwards ? -1 : 1;
    int endDirectionMultiplier   = forwards ? 1 : -1;

    title.animate().translationX(startDirectionMultiplier * title.getWidth()).setDuration(SCENE_TRANSITION_DURATION).setListener(new AnimationCompleteListener() {
      @Override
      public void onAnimationEnd(Animator animation) {
        title.setText(R.string.registration_activity__verify_your_number);
        title.clearAnimation();
        title.setTranslationX(endDirectionMultiplier * title.getWidth());
        title.animate().translationX(0).setListener(null).setInterpolator(new OvershootInterpolator()).setDuration(SCENE_TRANSITION_DURATION).start();
      }
    }).start();

    subtitle.animate().translationX(startDirectionMultiplier * subtitle.getWidth()).setDuration(SCENE_TRANSITION_DURATION).setListener(new AnimationCompleteListener() {
      @Override
      public void onAnimationEnd(Animator animation) {
        subtitle.setText(R.string.registration_activity__please_enter_your_mobile_number_to_receive_a_verification_code_carrier_rates_may_apply);
        subtitle.clearAnimation();
        subtitle.setTranslationX(endDirectionMultiplier * subtitle.getWidth());
        subtitle.animate().translationX(0).setListener(null).setInterpolator(new OvershootInterpolator()).setDuration(SCENE_TRANSITION_DURATION).start();
      }
    }).start();

    View container;

    if (verificationContainer.getVisibility() == View.VISIBLE) container = verificationContainer;
    else                                                       container = restoreContainer;

    container.animate().translationX(startDirectionMultiplier * container.getWidth()).setDuration(SCENE_TRANSITION_DURATION).setListener(new AnimationCompleteListener() {
      @Override
      public void onAnimationEnd(Animator animation) {
        container.clearAnimation();
        container.setVisibility(View.INVISIBLE);
        container.setTranslationX(0);

        registrationContainer.setTranslationX(endDirectionMultiplier * registrationContainer.getWidth());
        registrationContainer.setVisibility(View.VISIBLE);
        createButton.setProgress(0);
        createButton.setIndeterminateProgressMode(false);
        registrationContainer.animate().translationX(0).setDuration(SCENE_TRANSITION_DURATION).setListener(null).setInterpolator(new OvershootInterpolator()).start();
      }
    }).start();
  }

  private void displayVerificationView(@NonNull String e164number, int callCountdown) {
    ServiceUtil.getInputMethodManager(this)
               .hideSoftInputFromWindow(countryCode.getWindowToken(), 0);

    ServiceUtil.getInputMethodManager(this)
               .hideSoftInputFromWindow(number.getWindowToken(), 0);

    title.animate().translationX(-1 * title.getWidth()).setDuration(SCENE_TRANSITION_DURATION).setListener(new AnimationCompleteListener() {
      @Override
      public void onAnimationEnd(Animator animation) {
        title.setText(getString(R.string.RegistrationActivity_enter_the_code_we_sent_to_s, formatNumber(e164number)));
        title.clearAnimation();
        title.setTranslationX(title.getWidth());
        title.animate().translationX(0).setListener(null).setInterpolator(new OvershootInterpolator()).setDuration(SCENE_TRANSITION_DURATION).start();
      }
    }).start();

    subtitle.setText("");

    registrationContainer.animate().translationX(-1 * registrationContainer.getWidth()).setDuration(SCENE_TRANSITION_DURATION).setListener(new AnimationCompleteListener() {
      @Override
      public void onAnimationEnd(Animator animation) {
        registrationContainer.clearAnimation();
        registrationContainer.setVisibility(View.INVISIBLE);
        registrationContainer.setTranslationX(0);

        verificationContainer.setTranslationX(verificationContainer.getWidth());
        verificationContainer.setVisibility(View.VISIBLE);
        verificationContainer.animate().translationX(0).setListener(null).setInterpolator(new OvershootInterpolator()).setDuration(SCENE_TRANSITION_DURATION).start();
      }
    }).start();

    this.callMeCountDownView.startCountDown(callCountdown);

    this.wrongNumberButton.setOnClickListener(v -> onWrongNumberClicked());
  }

  private void displayPinView(String code, long lockedUntil) {
    title.animate().translationX(-1 * title.getWidth()).setDuration(SCENE_TRANSITION_DURATION).setListener(new AnimationCompleteListener() {
      @Override
      public void onAnimationEnd(Animator animation) {
        title.setText(R.string.RegistrationActivity_registration_lock_pin);
        title.clearAnimation();
        title.setTranslationX(title.getWidth());
        title.animate().translationX(0).setListener(null).setInterpolator(new OvershootInterpolator()).setDuration(SCENE_TRANSITION_DURATION).start();
      }
    }).start();

    subtitle.animate().translationX(-1 * subtitle.getWidth()).setDuration(SCENE_TRANSITION_DURATION).setListener(new AnimationCompleteListener() {
      @Override
      public void onAnimationEnd(Animator animation) {
        subtitle.setText(R.string.RegistrationActivity_this_phone_number_has_registration_lock_enabled_please_enter_the_registration_lock_pin);
        subtitle.clearAnimation();
        subtitle.setTranslationX(subtitle.getWidth());
        subtitle.animate().translationX(0).setListener(null).setInterpolator(new OvershootInterpolator()).setDuration(SCENE_TRANSITION_DURATION).start();
      }
    }).start();

    verificationContainer.animate().translationX(-1 * verificationContainer.getWidth()).setDuration(SCENE_TRANSITION_DURATION).setListener(new AnimationCompleteListener() {
      @Override
      public void onAnimationEnd(Animator animation) {
        verificationContainer.clearAnimation();
        verificationContainer.setVisibility(View.INVISIBLE);
        verificationContainer.setTranslationX(0);

        pinContainer.setTranslationX(pinContainer.getWidth());
        pinContainer.setVisibility(View.VISIBLE);
        pinContainer.animate().translationX(0).setListener(null).setInterpolator(new OvershootInterpolator()).setDuration(SCENE_TRANSITION_DURATION).start();
      }
    }).start();

    pinButton.setOnClickListener(v -> handleVerifyWithPinClicked(code, pin.getText().toString()));
    pinForgotButton.setOnClickListener(v -> handleForgottenPin(lockedUntil));
    pin.addTextChangedListener(new TextWatcher() {
      @Override
      public void beforeTextChanged(CharSequence s, int start, int count, int after) {}
      @Override
      public void onTextChanged(CharSequence s, int start, int before, int count) {}
      @Override
      public void afterTextChanged(Editable s) {
        if       (s != null && code.equals(s.toString()))                   pinClarificationContainer.setVisibility(View.VISIBLE);
        else if (pinClarificationContainer.getVisibility() == View.VISIBLE) pinClarificationContainer.setVisibility(View.GONE);
      }
    });
  }

  private void handleCancel() {
    TextSecurePreferences.setPromptedPushRegistration(RegistrationActivity.this, true);
    Intent nextIntent = getIntent().getParcelableExtra("next_intent");

    if (nextIntent == null) {
      nextIntent = new Intent(RegistrationActivity.this, ConversationListActivity.class);
    }

    startActivity(nextIntent);
    finish();
  }

  private void handlePromptForNoPlayServices(@NonNull String e164number) {
    AlertDialog.Builder dialog = new AlertDialog.Builder(this);
    dialog.setTitle(R.string.RegistrationActivity_missing_google_play_services);
    dialog.setMessage(R.string.RegistrationActivity_this_device_is_missing_google_play_services);
    dialog.setPositiveButton(R.string.RegistrationActivity_i_understand, (dialog1, which) -> handleRequestVerification(e164number, false));
    dialog.setNegativeButton(android.R.string.cancel, null);
    dialog.show();
  }

  private void markAsVerifying(boolean verifying) {
    TextSecurePreferences.setVerifying(this, verifying);

    if (verifying) {
      TextSecurePreferences.setPushRegistered(this, false);
    }
  }

  private String formatNumber(@NonNull String e164Number) {
    return e164Number;
  }

  private void onWrongNumberClicked() {
    displayInitialView(false);
    registrationState = new RegistrationState(RegistrationState.State.INITIAL, null, null, Optional.absent(), Optional.absent());
  }

  @Subscribe(threadMode = ThreadMode.MAIN)
  public void onEvent(FullBackupBase.BackupEvent event) {
    if (event.getCount() == 0) restoreBackupProgress.setText(R.string.RegistrationActivity_checking);
    else                       restoreBackupProgress.setText(getString(R.string.RegistrationActivity_d_messages_so_far, event.getCount()));
  }

  private class CountryCodeChangedListener implements TextWatcher {
    @Override
    public void afterTextChanged(Editable s) {
      if (TextUtils.isEmpty(s) || !TextUtils.isDigitsOnly(s)) {
        setCountryDisplay(getString(R.string.RegistrationActivity_select_your_country));
        return;
      }

      int countryCode   = Integer.parseInt(s.toString());
      setCountryDisplay("N/A");
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
    }

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
    }
  }

  private class NumberChangedListener implements TextWatcher {

    @Override
    public void afterTextChanged(Editable s) {
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
    }

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {

    }
  }

  private static class VerificationRequestResult {
    private final String                password;
    private final Optional<String>      fcmToken;
    private final Optional<IOException> exception;

    private VerificationRequestResult(String password, Optional<String> fcmToken, Optional<IOException> exception) {
      this.password  = password;
      this.fcmToken  = fcmToken;
      this.exception = exception;
    }
  }

  private static class RegistrationState {
    private enum State {
      INITIAL, VERIFYING, CHECKING, PIN
    }

    private final State            state;
    private final String           e164number;
    private final String           password;
    private final Optional<String> gcmToken;
    private final Optional<String> captchaToken;

    RegistrationState(State state, String e164number, String password, Optional<String> gcmToken, Optional<String> captchaToken) {
      this.state        = state;
      this.e164number   = e164number;
      this.password     = password;
      this.gcmToken     = gcmToken;
      this.captchaToken = captchaToken;
    }

    RegistrationState(State state, RegistrationState previous) {
      this.state        = state;
      this.e164number   = previous.e164number;
      this.password     = previous.password;
      this.gcmToken     = previous.gcmToken;
      this.captchaToken = previous.captchaToken;
    }

    RegistrationState(Optional<String> captchaToken, RegistrationState previous) {
      this.state        = previous.state;
      this.e164number   = previous.e164number;
      this.password     = previous.password;
      this.gcmToken     = previous.gcmToken;
      this.captchaToken = captchaToken;
    }
  }

  private enum BackupImportResult {
    SUCCESS, FAILURE_VERSION_DOWNGRADE, FAILURE_UNKNOWN
  }
}