/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

package org.mozilla.goanna.fxa.authenticator;

import java.io.UnsupportedEncodingException;
import java.net.URISyntaxException;
import java.security.GeneralSecurityException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.Semaphore;

import org.mozilla.goanna.AppConstants;
import org.mozilla.goanna.background.common.GlobalConstants;
import org.mozilla.goanna.background.common.log.Logger;
import org.mozilla.goanna.background.fxa.FxAccountUtils;
import org.mozilla.goanna.db.BrowserContract;
import org.mozilla.goanna.fxa.FirefoxAccounts;
import org.mozilla.goanna.fxa.FxAccountConstants;
import org.mozilla.goanna.fxa.login.State;
import org.mozilla.goanna.fxa.login.State.StateLabel;
import org.mozilla.goanna.fxa.login.StateFactory;
import org.mozilla.goanna.sync.ExtendedJSONObject;
import org.mozilla.goanna.sync.Utils;
import org.mozilla.goanna.sync.setup.Constants;

import android.accounts.Account;
import android.accounts.AccountManager;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.util.Log;

/**
 * A Firefox Account that stores its details and state as user data attached to
 * an Android Account instance.
 * <p>
 * Account user data is accessible only to the Android App(s) that own the
 * Account type. Account user data is not removed when the App's private data is
 * cleared.
 */
public class AndroidFxAccount {
  protected static final String LOG_TAG = AndroidFxAccount.class.getSimpleName();

  public static final int CURRENT_SYNC_PREFS_VERSION = 1;
  public static final int CURRENT_RL_PREFS_VERSION = 1;

  // When updating the account, do not forget to update AccountPickler.
  public static final int CURRENT_ACCOUNT_VERSION = 3;
  public static final String ACCOUNT_KEY_ACCOUNT_VERSION = "version";
  public static final String ACCOUNT_KEY_PROFILE = "profile";
  public static final String ACCOUNT_KEY_IDP_SERVER = "idpServerURI";

  public static final String ACCOUNT_KEY_TOKEN_SERVER = "tokenServerURI";       // Sync-specific.
  public static final String ACCOUNT_KEY_DESCRIPTOR = "descriptor";

  public static final int CURRENT_BUNDLE_VERSION = 2;
  public static final String BUNDLE_KEY_BUNDLE_VERSION = "version";
  public static final String BUNDLE_KEY_STATE_LABEL = "stateLabel";
  public static final String BUNDLE_KEY_STATE = "state";

  public static final Map<String, Boolean> DEFAULT_AUTHORITIES_TO_SYNC_AUTOMATICALLY_MAP;
  static {
    final HashMap<String, Boolean> m = new HashMap<String, Boolean>();
    // By default, Firefox Sync is enabled.
    m.put(BrowserContract.AUTHORITY, true);
    DEFAULT_AUTHORITIES_TO_SYNC_AUTOMATICALLY_MAP = Collections.unmodifiableMap(m);
  }

  private static final String PREF_KEY_LAST_SYNCED_TIMESTAMP = "lastSyncedTimestamp";

  protected final Context context;
  protected final AccountManager accountManager;
  protected final Account account;

  /**
   * A cache associating Account name (email address) to a representation of the
   * account's internal bundle.
   * <p>
   * The cache is invalidated entirely when <it>any</it> new Account is added,
   * because there is no reliable way to know that an Account has been removed
   * and then re-added.
   */
  protected static final ConcurrentHashMap<String, ExtendedJSONObject> perAccountBundleCache =
      new ConcurrentHashMap<>();

  public static void invalidateCaches() {
    perAccountBundleCache.clear();
  }

  /**
   * Create an Android Firefox Account instance backed by an Android Account
   * instance.
   * <p>
   * We expect a long-lived application context to avoid life-cycle issues that
   * might arise if the internally cached AccountManager instance surfaces UI.
   * <p>
   * We take care to not install any listeners or observers that might outlive
   * the AccountManager; and Android ensures the AccountManager doesn't outlive
   * the associated context.
   *
   * @param applicationContext
   *          to use as long-lived ambient Android context.
   * @param account
   *          Android account to use for storage.
   */
  public AndroidFxAccount(Context applicationContext, Account account) {
    this.context = applicationContext;
    this.account = account;
    this.accountManager = AccountManager.get(this.context);
  }

  /**
   * Persist the Firefox account to disk as a JSON object. Note that this is a wrapper around
   * {@link AccountPickler#pickle}, and is identical to calling it directly.
   * <p>
   * Note that pickling is different from bundling, which involves operations on a
   * {@link android.os.Bundle Bundle} object of miscellaneous data associated with the account.
   * See {@link #persistBundle} and {@link #unbundle} for more.
   */
  public void pickle(final String filename) {
    AccountPickler.pickle(this, filename);
  }

  public Account getAndroidAccount() {
    return this.account;
  }

  protected int getAccountVersion() {
    String v = accountManager.getUserData(account, ACCOUNT_KEY_ACCOUNT_VERSION);
    if (v == null) {
      return 0;         // Implicit.
    }

    try {
      return Integer.parseInt(v, 10);
    } catch (NumberFormatException ex) {
      return 0;
    }
  }

  /**
   * Saves the given data as the internal bundle associated with this account.
   * @param bundle to write to account.
   */
  protected synchronized void persistBundle(ExtendedJSONObject bundle) {
    perAccountBundleCache.put(account.name, bundle);
    accountManager.setUserData(account, ACCOUNT_KEY_DESCRIPTOR, bundle.toJSONString());
  }

  protected ExtendedJSONObject unbundle() {
    return unbundle(true);
  }

  /**
   * Retrieve the internal bundle associated with this account.
   * @return bundle associated with account.
   */
  protected synchronized ExtendedJSONObject unbundle(boolean allowCachedBundle) {
    if (allowCachedBundle) {
      final ExtendedJSONObject cachedBundle = perAccountBundleCache.get(account.name);
      if (cachedBundle != null) {
        Logger.debug(LOG_TAG, "Returning cached account bundle.");
        return cachedBundle;
      }
    }

    final int version = getAccountVersion();
    if (version < CURRENT_ACCOUNT_VERSION) {
      // Needs upgrade. For now, do nothing. We'd like to just put your account
      // into the Separated state here and have you update your credentials.
      return null;
    }

    if (version > CURRENT_ACCOUNT_VERSION) {
      // Oh dear.
      return null;
    }

    String bundleString = accountManager.getUserData(account, ACCOUNT_KEY_DESCRIPTOR);
    if (bundleString == null) {
      return null;
    }
    final ExtendedJSONObject bundle = unbundleAccountV2(bundleString);
    perAccountBundleCache.put(account.name, bundle);
    Logger.info(LOG_TAG, "Account bundle persisted to cache.");
    return bundle;
  }

  protected String getBundleData(String key) {
    ExtendedJSONObject o = unbundle();
    if (o == null) {
      return null;
    }
    return o.getString(key);
  }

  protected boolean getBundleDataBoolean(String key, boolean def) {
    ExtendedJSONObject o = unbundle();
    if (o == null) {
      return def;
    }
    Boolean b = o.getBoolean(key);
    if (b == null) {
      return def;
    }
    return b;
  }

  protected byte[] getBundleDataBytes(String key) {
    ExtendedJSONObject o = unbundle();
    if (o == null) {
      return null;
    }
    return o.getByteArrayHex(key);
  }

  protected void updateBundleValues(String key, String value, String... more) {
    if (more.length % 2 != 0) {
      throw new IllegalArgumentException("more must be a list of key, value pairs");
    }
    ExtendedJSONObject descriptor = unbundle();
    if (descriptor == null) {
      return;
    }
    descriptor.put(key, value);
    for (int i = 0; i + 1 < more.length; i += 2) {
      descriptor.put(more[i], more[i+1]);
    }
    persistBundle(descriptor);
  }

  private ExtendedJSONObject unbundleAccountV1(String bundle) {
    ExtendedJSONObject o;
    try {
      o = new ExtendedJSONObject(bundle);
    } catch (Exception e) {
      return null;
    }
    if (CURRENT_BUNDLE_VERSION == o.getIntegerSafely(BUNDLE_KEY_BUNDLE_VERSION)) {
      return o;
    }
    return null;
  }

  private ExtendedJSONObject unbundleAccountV2(String bundle) {
    return unbundleAccountV1(bundle);
  }

  /**
   * Note that if the user clears data, an account will be left pointing to a
   * deleted profile. Such is life.
   */
  public String getProfile() {
    return accountManager.getUserData(account, ACCOUNT_KEY_PROFILE);
  }

  public String getAccountServerURI() {
    return accountManager.getUserData(account, ACCOUNT_KEY_IDP_SERVER);
  }

  public String getTokenServerURI() {
    return accountManager.getUserData(account, ACCOUNT_KEY_TOKEN_SERVER);
  }

  private String constructPrefsPath(String product, long version, String extra) throws GeneralSecurityException, UnsupportedEncodingException {
    String profile = getProfile();
    String username = account.name;

    if (profile == null) {
      throw new IllegalStateException("Missing profile. Cannot fetch prefs.");
    }

    if (username == null) {
      throw new IllegalStateException("Missing username. Cannot fetch prefs.");
    }

    final String fxaServerURI = getAccountServerURI();
    if (fxaServerURI == null) {
      throw new IllegalStateException("No account server URI. Cannot fetch prefs.");
    }

    // This is unique for each syncing 'view' of the account.
    final String serverURLThing = fxaServerURI + "!" + extra;
    return Utils.getPrefsPath(product, username, serverURLThing, profile, version);
  }

  /**
   * This needs to return a string because of the tortured prefs access in GlobalSession.
   */
  public String getSyncPrefsPath() throws GeneralSecurityException, UnsupportedEncodingException {
    final String tokenServerURI = getTokenServerURI();
    if (tokenServerURI == null) {
      throw new IllegalStateException("No token server URI. Cannot fetch prefs.");
    }

    final String product = GlobalConstants.BROWSER_INTENT_PACKAGE + ".fxa";
    final long version = CURRENT_SYNC_PREFS_VERSION;
    return constructPrefsPath(product, version, tokenServerURI);
  }

  public String getReadingListPrefsPath() throws GeneralSecurityException, UnsupportedEncodingException {
    final String product = GlobalConstants.BROWSER_INTENT_PACKAGE + ".reading";
    final long version = CURRENT_RL_PREFS_VERSION;
    return constructPrefsPath(product, version, "");
  }

  public SharedPreferences getSyncPrefs() throws UnsupportedEncodingException, GeneralSecurityException {
    return context.getSharedPreferences(getSyncPrefsPath(), Utils.SHARED_PREFERENCES_MODE);
  }

  public SharedPreferences getReadingListPrefs() throws UnsupportedEncodingException, GeneralSecurityException {
    return context.getSharedPreferences(getReadingListPrefsPath(), Utils.SHARED_PREFERENCES_MODE);
  }

  /**
   * Extract a JSON dictionary of the string values associated to this account.
   * <p>
   * <b>For debugging use only!</b> The contents of this JSON object completely
   * determine the user's Firefox Account status and yield access to whatever
   * user data the device has access to.
   *
   * @return JSON-object of Strings.
   */
  public ExtendedJSONObject toJSONObject() {
    ExtendedJSONObject o = unbundle();
    o.put("email", account.name);
    try {
      o.put("emailUTF8", Utils.byte2Hex(account.name.getBytes("UTF-8")));
    } catch (UnsupportedEncodingException e) {
      // Ignore.
    }
    return o;
  }

  public static AndroidFxAccount addAndroidAccount(
      Context context,
      String email,
      String profile,
      String idpServerURI,
      String tokenServerURI,
      State state,
      final Map<String, Boolean> authoritiesToSyncAutomaticallyMap)
          throws UnsupportedEncodingException, GeneralSecurityException, URISyntaxException {
    return addAndroidAccount(context, email, profile, idpServerURI, tokenServerURI, state,
        authoritiesToSyncAutomaticallyMap,
        CURRENT_ACCOUNT_VERSION, false, null);
  }

  public static AndroidFxAccount addAndroidAccount(
      Context context,
      String email,
      String profile,
      String idpServerURI,
      String tokenServerURI,
      State state,
      final Map<String, Boolean> authoritiesToSyncAutomaticallyMap,
      final int accountVersion,
      final boolean fromPickle,
      ExtendedJSONObject bundle)
          throws UnsupportedEncodingException, GeneralSecurityException, URISyntaxException {
    if (email == null) {
      throw new IllegalArgumentException("email must not be null");
    }
    if (profile == null) {
      throw new IllegalArgumentException("profile must not be null");
    }
    if (idpServerURI == null) {
      throw new IllegalArgumentException("idpServerURI must not be null");
    }
    if (tokenServerURI == null) {
      throw new IllegalArgumentException("tokenServerURI must not be null");
    }
    if (state == null) {
      throw new IllegalArgumentException("state must not be null");
    }

    // TODO: Add migration code.
    if (accountVersion != CURRENT_ACCOUNT_VERSION) {
      throw new IllegalStateException("Could not create account of version " + accountVersion +
          ". Current version is " + CURRENT_ACCOUNT_VERSION + ".");
    }

    // Android has internal restrictions that require all values in this
    // bundle to be strings. *sigh*
    Bundle userdata = new Bundle();
    userdata.putString(ACCOUNT_KEY_ACCOUNT_VERSION, "" + CURRENT_ACCOUNT_VERSION);
    userdata.putString(ACCOUNT_KEY_IDP_SERVER, idpServerURI);
    userdata.putString(ACCOUNT_KEY_TOKEN_SERVER, tokenServerURI);
    userdata.putString(ACCOUNT_KEY_PROFILE, profile);

    if (bundle == null) {
      bundle = new ExtendedJSONObject();
      // TODO: How to upgrade?
      bundle.put(BUNDLE_KEY_BUNDLE_VERSION, CURRENT_BUNDLE_VERSION);
    }
    bundle.put(BUNDLE_KEY_STATE_LABEL, state.getStateLabel().name());
    bundle.put(BUNDLE_KEY_STATE, state.toJSONObject().toJSONString());

    userdata.putString(ACCOUNT_KEY_DESCRIPTOR, bundle.toJSONString());

    Account account = new Account(email, FxAccountConstants.ACCOUNT_TYPE);
    AccountManager accountManager = AccountManager.get(context);
    // We don't set an Android password, because we don't want to persist the
    // password (or anything else as powerful as the password). Instead, we
    // internally manage a sessionToken with a remotely owned lifecycle.
    boolean added = accountManager.addAccountExplicitly(account, null, userdata);
    if (!added) {
      return null;
    }

    // Try to work around an intermittent issue described at
    // http://stackoverflow.com/a/11698139.  What happens is that tests that
    // delete and re-create the same account frequently will find the account
    // missing all or some of the userdata bundle, possibly due to an Android
    // AccountManager caching bug.
    for (String key : userdata.keySet()) {
      accountManager.setUserData(account, key, userdata.getString(key));
    }

    AndroidFxAccount fxAccount = new AndroidFxAccount(context, account);

    if (!fromPickle) {
      fxAccount.clearSyncPrefs();
    }

    fxAccount.setAuthoritiesToSyncAutomaticallyMap(authoritiesToSyncAutomaticallyMap);

    return fxAccount;
  }

  public void clearSyncPrefs() throws UnsupportedEncodingException, GeneralSecurityException {
    getSyncPrefs().edit().clear().commit();
  }

  public void setAuthoritiesToSyncAutomaticallyMap(Map<String, Boolean> authoritiesToSyncAutomaticallyMap) {
    if (authoritiesToSyncAutomaticallyMap == null) {
      throw new IllegalArgumentException("authoritiesToSyncAutomaticallyMap must not be null");
    }

    for (String authority : DEFAULT_AUTHORITIES_TO_SYNC_AUTOMATICALLY_MAP.keySet()) {
      boolean authorityEnabled = DEFAULT_AUTHORITIES_TO_SYNC_AUTOMATICALLY_MAP.get(authority);
      final Boolean enabled = authoritiesToSyncAutomaticallyMap.get(authority);
      if (enabled != null) {
        authorityEnabled = enabled.booleanValue();
      }
      // Accounts are always capable of being synced ...
      ContentResolver.setIsSyncable(account, authority, 1);
      // ... but not always automatically synced.
      ContentResolver.setSyncAutomatically(account, authority, authorityEnabled);
    }
  }

  public Map<String, Boolean> getAuthoritiesToSyncAutomaticallyMap() {
    final Map<String, Boolean> authoritiesToSync = new HashMap<>();
    for (String authority : DEFAULT_AUTHORITIES_TO_SYNC_AUTOMATICALLY_MAP.keySet()) {
      final boolean enabled = ContentResolver.getSyncAutomatically(account, authority);
      authoritiesToSync.put(authority, enabled);
    }
    return authoritiesToSync;
  }

  /**
   * Is a sync currently in progress?
   *
   * @return true if Android is currently syncing the underlying Android Account.
   */
  public boolean isCurrentlySyncing() {
    boolean active = false;
    for (String authority : AndroidFxAccount.DEFAULT_AUTHORITIES_TO_SYNC_AUTOMATICALLY_MAP.keySet()) {
      active |= ContentResolver.isSyncActive(account, authority);
    }
    return active;
  }

  /**
   * Request a sync.  See {@link FirefoxAccounts#requestSync(Account, EnumSet, String[], String[])}.
   */
  public void requestSync() {
    requestSync(FirefoxAccounts.SOON, null, null);
  }

  /**
   * Request a sync.  See {@link FirefoxAccounts#requestSync(Account, EnumSet, String[], String[])}.
   *
   * @param syncHints to pass to sync.
   */
  public void requestSync(EnumSet<FirefoxAccounts.SyncHint> syncHints) {
    requestSync(syncHints, null, null);
  }

  /**
   * Request a sync.  See {@link FirefoxAccounts#requestSync(Account, EnumSet, String[], String[])}.
   *
   * @param syncHints to pass to sync.
   * @param stagesToSync stage names to sync.
   * @param stagesToSkip stage names to skip.
   */
  public void requestSync(EnumSet<FirefoxAccounts.SyncHint> syncHints, String[] stagesToSync, String[] stagesToSkip) {
    FirefoxAccounts.requestSync(getAndroidAccount(), syncHints, stagesToSync, stagesToSkip);
  }

  public synchronized void setState(State state) {
    if (state == null) {
      throw new IllegalArgumentException("state must not be null");
    }
    Logger.info(LOG_TAG, "Moving account named like " + getObfuscatedEmail() +
        " to state " + state.getStateLabel().toString());
    updateBundleValues(
        BUNDLE_KEY_STATE_LABEL, state.getStateLabel().name(),
        BUNDLE_KEY_STATE, state.toJSONObject().toJSONString());
    broadcastAccountStateChangedIntent();
  }

  protected void broadcastAccountStateChangedIntent() {
    final Intent intent = new Intent(FxAccountConstants.ACCOUNT_STATE_CHANGED_ACTION);
    intent.putExtra(Constants.JSON_KEY_ACCOUNT, account.name);
    context.sendBroadcast(intent, FxAccountConstants.PER_ACCOUNT_TYPE_PERMISSION);
  }

  public synchronized State getState() {
    String stateLabelString = getBundleData(BUNDLE_KEY_STATE_LABEL);
    String stateString = getBundleData(BUNDLE_KEY_STATE);
    if (stateLabelString == null || stateString == null) {
      throw new IllegalStateException("stateLabelString and stateString must not be null, but: " +
          "(stateLabelString == null) = " + (stateLabelString == null) +
          " and (stateString == null) = " + (stateString == null));
    }

    try {
      StateLabel stateLabel = StateLabel.valueOf(stateLabelString);
      Logger.debug(LOG_TAG, "Account is in state " + stateLabel);
      return StateFactory.fromJSONObject(stateLabel, new ExtendedJSONObject(stateString));
    } catch (Exception e) {
      throw new IllegalStateException("could not get state", e);
    }
  }

  /**
   * <b>For debugging only!</b>
   */
  public void dump() {
    if (!FxAccountUtils.LOG_PERSONAL_INFORMATION) {
      return;
    }
    ExtendedJSONObject o = toJSONObject();
    ArrayList<String> list = new ArrayList<String>(o.keySet());
    Collections.sort(list);
    for (String key : list) {
      FxAccountUtils.pii(LOG_TAG, key + ": " + o.get(key));
    }
  }

  /**
   * Return the Firefox Account's local email address.
   * <p>
   * It is important to note that this is the local email address, and not
   * necessarily the normalized remote email address that the server expects.
   *
   * @return local email address.
   */
  public String getEmail() {
    return account.name;
  }

  /**
   * Return the Firefox Account's local email address, obfuscated.
   * <p>
   * Use this when logging.
   *
   * @return local email address, obfuscated.
   */
  public String getObfuscatedEmail() {
    return Utils.obfuscateEmail(account.name);
  }

  /**
   * Create an intent announcing that a Firefox account will be deleted.
   *
   * @param context
   *          Android context.
   * @param account
   *          Android account being removed.
   * @return <code>Intent</code> to broadcast.
   */
  public static Intent makeDeletedAccountIntent(final Context context, final Account account) {
    final Intent intent = new Intent(FxAccountConstants.ACCOUNT_DELETED_ACTION);

    intent.putExtra(FxAccountConstants.ACCOUNT_DELETED_INTENT_VERSION_KEY,
        Long.valueOf(FxAccountConstants.ACCOUNT_DELETED_INTENT_VERSION));
    intent.putExtra(FxAccountConstants.ACCOUNT_DELETED_INTENT_ACCOUNT_KEY, account.name);
    return intent;
  }

  public void setLastSyncedTimestamp(long now) {
    try {
      getSyncPrefs().edit().putLong(PREF_KEY_LAST_SYNCED_TIMESTAMP, now).commit();
    } catch (Exception e) {
      Logger.warn(LOG_TAG, "Got exception setting last synced time; ignoring.", e);
    }
  }

  public long getLastSyncedTimestamp() {
    final long neverSynced = -1L;
    try {
      return getSyncPrefs().getLong(PREF_KEY_LAST_SYNCED_TIMESTAMP, neverSynced);
    } catch (Exception e) {
      Logger.warn(LOG_TAG, "Got exception getting last synced time; ignoring.", e);
      return neverSynced;
    }
  }

  // Debug only!  This is dangerous!
  public void unsafeTransitionToDefaultEndpoints() {
    unsafeTransitionToStageEndpoints(
        FxAccountConstants.DEFAULT_AUTH_SERVER_ENDPOINT,
        FxAccountConstants.DEFAULT_TOKEN_SERVER_ENDPOINT);
    }

  // Debug only!  This is dangerous!
  public void unsafeTransitionToStageEndpoints() {
    unsafeTransitionToStageEndpoints(
        FxAccountConstants.STAGE_AUTH_SERVER_ENDPOINT,
        FxAccountConstants.STAGE_TOKEN_SERVER_ENDPOINT);
  }

  protected void unsafeTransitionToStageEndpoints(String authServerEndpoint, String tokenServerEndpoint) {
    try {
      getReadingListPrefs().edit().clear().commit();
    } catch (UnsupportedEncodingException | GeneralSecurityException e) {
      // Ignore.
    }
    try {
      getSyncPrefs().edit().clear().commit();
    } catch (UnsupportedEncodingException | GeneralSecurityException e) {
      // Ignore.
    }
    State state = getState();
    setState(state.makeSeparatedState());
    accountManager.setUserData(account, ACCOUNT_KEY_IDP_SERVER, authServerEndpoint);
    accountManager.setUserData(account, ACCOUNT_KEY_TOKEN_SERVER, tokenServerEndpoint);
    ContentResolver.setIsSyncable(account, BrowserContract.READING_LIST_AUTHORITY, 1);
  }

  /**
   * Take the lock to own updating any Firefox Account's internal state.
   *
   * We use a <code>Semaphore</code> rather than a <code>ReentrantLock</code>
   * because the callback that needs to release the lock may not be invoked on
   * the thread that initially acquired the lock. Be aware!
   */
  protected static final Semaphore sLock = new Semaphore(1, true /* fair */);

  // Which consumer took the lock?
  // Synchronized by this.
  protected String lockTag = null;

  // Are we locked?  (It's not easy to determine who took the lock dynamically,
  // so we maintain this flag internally.)
  // Synchronized by this.
  protected boolean locked = false;

  // Block until we can take the shared state lock.
  public synchronized void acquireSharedAccountStateLock(final String tag) throws InterruptedException {
    final long id = Thread.currentThread().getId();
    this.lockTag = tag;
    Log.d(Logger.DEFAULT_LOG_TAG, "Thread with tag and thread id acquiring lock: " + lockTag + ", " + id + " ...");
    sLock.acquire();
    locked = true;
    Log.d(Logger.DEFAULT_LOG_TAG, "Thread with tag and thread id acquiring lock: " + lockTag + ", " + id + " ... ACQUIRED");
  }

  // If we hold the shared state lock, release it.  Otherwise, ignore the request.
  public synchronized void releaseSharedAccountStateLock() {
    final long id = Thread.currentThread().getId();
    Log.d(Logger.DEFAULT_LOG_TAG, "Thread with tag and thread id releasing lock: " + lockTag + ", " + id + " ...");
    if (locked) {
      sLock.release();
      locked = false;
      Log.d(Logger.DEFAULT_LOG_TAG, "Thread with tag and thread id releasing lock: " + lockTag + ", " + id + " ... RELEASED");
    } else {
      Log.d(Logger.DEFAULT_LOG_TAG, "Thread with tag and thread id releasing lock: " + lockTag + ", " + id + " ... NOT LOCKED");
    }
  }

  @Override
  protected synchronized void finalize() {
    if (locked) {
      // Should never happen, but...
      sLock.release();
      locked = false;
      final long id = Thread.currentThread().getId();
      Log.e(Logger.DEFAULT_LOG_TAG, "Thread with tag and thread id releasing lock: " + lockTag + ", " + id + " ... RELEASED DURING FINALIZE");
    }
  }
}