content: /*
   * Copyright 2014, The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package android.telecom;
  
  import android.annotation.UnsupportedAppUsage;
  import android.content.Context;
  import android.net.Uri;
  import android.os.Build;
  import android.telecom.Logging.EventManager;
  import android.telecom.Logging.Session;
  import android.telecom.Logging.SessionManager;
  import android.telephony.PhoneNumberUtils;
  import android.text.TextUtils;
  
  import com.android.internal.annotations.VisibleForTesting;
  import com.android.internal.util.IndentingPrintWriter;
  
  import java.util.IllegalFormatException;
  import java.util.Locale;
  
  /**
   * Manages logging for the entire module.
   *
   * @hide
   */
  public class Log {
  
      private static final long EXTENDED_LOGGING_DURATION_MILLIS = 60000 * 30; // 30 minutes
  
      private static final int EVENTS_TO_CACHE = 10;
      private static final int EVENTS_TO_CACHE_DEBUG = 20;
  
      /**
       * When generating a bug report, include the last X dialable digits when logging phone numbers.
       */
      private static final int NUM_DIALABLE_DIGITS_TO_LOG = Build.IS_USER ? 0 : 2;
  
      // Generic tag for all Telecom logging
      @VisibleForTesting
      public static String TAG = "TelecomFramework";
      public static boolean DEBUG = isLoggable(android.util.Log.DEBUG);
      public static boolean INFO = isLoggable(android.util.Log.INFO);
      public static boolean VERBOSE = isLoggable(android.util.Log.VERBOSE);
      public static boolean WARN = isLoggable(android.util.Log.WARN);
      public static boolean ERROR = isLoggable(android.util.Log.ERROR);
  
      private static final boolean FORCE_LOGGING = false; /* STOP SHIP if true */
      private static final boolean USER_BUILD = Build.IS_USER;
  
      // Used to synchronize singleton logging lazy initialization
      private static final Object sSingletonSync = new Object();
      private static EventManager sEventManager;
      private static SessionManager sSessionManager;
  
      /**
       * Tracks whether user-activated extended logging is enabled.
       */
      private static boolean sIsUserExtendedLoggingEnabled = false;
  
      /**
       * The time when user-activated extended logging should be ended.  Used to determine when
       * extended logging should automatically be disabled.
       */
      private static long sUserExtendedLoggingStopTime = 0;
  
      private Log() {
      }
  
      public static void d(String prefix, String format, Object... args) {
          if (sIsUserExtendedLoggingEnabled) {
              maybeDisableLogging();
              android.util.Slog.i(TAG, buildMessage(prefix, format, args));
          } else if (DEBUG) {
              android.util.Slog.d(TAG, buildMessage(prefix, format, args));
          }
      }
  
      public static void d(Object objectPrefix, String format, Object... args) {
          if (sIsUserExtendedLoggingEnabled) {
              maybeDisableLogging();
              android.util.Slog.i(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args));
          } else if (DEBUG) {
              android.util.Slog.d(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args));
          }
      }
  
      @UnsupportedAppUsage
      public static void i(String prefix, String format, Object... args) {
          if (INFO) {
              android.util.Slog.i(TAG, buildMessage(prefix, format, args));
          }
      }
  
      public static void i(Object objectPrefix, String format, Object... args) {
          if (INFO) {
              android.util.Slog.i(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args));
          }
      }
  
      public static void v(String prefix, String format, Object... args) {
          if (sIsUserExtendedLoggingEnabled) {
              maybeDisableLogging();
              android.util.Slog.i(TAG, buildMessage(prefix, format, args));
          } else if (VERBOSE) {
              android.util.Slog.v(TAG, buildMessage(prefix, format, args));
          }
      }
  
      public static void v(Object objectPrefix, String format, Object... args) {
          if (sIsUserExtendedLoggingEnabled) {
              maybeDisableLogging();
              android.util.Slog.i(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args));
          } else if (VERBOSE) {
              android.util.Slog.v(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args));
          }
      }
  
      @UnsupportedAppUsage
      public static void w(String prefix, String format, Object... args) {
          if (WARN) {
              android.util.Slog.w(TAG, buildMessage(prefix, format, args));
          }
      }
  
      public static void w(Object objectPrefix, String format, Object... args) {
          if (WARN) {
              android.util.Slog.w(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args));
          }
      }
  
      public static void e(String prefix, Throwable tr, String format, Object... args) {
          if (ERROR) {
              android.util.Slog.e(TAG, buildMessage(prefix, format, args), tr);
          }
      }
  
      public static void e(Object objectPrefix, Throwable tr, String format, Object... args) {
          if (ERROR) {
              android.util.Slog.e(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args),
                      tr);
          }
      }
  
      public static void wtf(String prefix, Throwable tr, String format, Object... args) {
          android.util.Slog.wtf(TAG, buildMessage(prefix, format, args), tr);
      }
  
      public static void wtf(Object objectPrefix, Throwable tr, String format, Object... args) {
          android.util.Slog.wtf(TAG, buildMessage(getPrefixFromObject(objectPrefix), format, args),
                  tr);
      }
  
      public static void wtf(String prefix, String format, Object... args) {
          String msg = buildMessage(prefix, format, args);
          android.util.Slog.wtf(TAG, msg, new IllegalStateException(msg));
      }
  
      public static void wtf(Object objectPrefix, String format, Object... args) {
          String msg = buildMessage(getPrefixFromObject(objectPrefix), format, args);
          android.util.Slog.wtf(TAG, msg, new IllegalStateException(msg));
      }
  
      /**
       * The ease of use methods below only act mostly as proxies to the Session and Event Loggers.
       * They also control the lazy loaders of the singleton instances, which will never be loaded if
       * the proxy methods aren't used.
       *
       * Please see each method's documentation inside of their respective implementations in the
       * loggers.
       */
  
      public static void setSessionContext(Context context) {
          getSessionManager().setContext(context);
      }
  
      public static void startSession(String shortMethodName) {
          getSessionManager().startSession(shortMethodName, null);
      }
  
      public static void startSession(Session.Info info, String shortMethodName) {
          getSessionManager().startSession(info, shortMethodName, null);
      }
  
      public static void startSession(String shortMethodName, String callerIdentification) {
          getSessionManager().startSession(shortMethodName, callerIdentification);
      }
  
      public static void startSession(Session.Info info, String shortMethodName,
              String callerIdentification) {
          getSessionManager().startSession(info, shortMethodName, callerIdentification);
      }
  
      public static Session createSubsession() {
          return getSessionManager().createSubsession();
      }
  
      public static Session.Info getExternalSession() {
          return getSessionManager().getExternalSession();
      }
  
      public static void cancelSubsession(Session subsession) {
          getSessionManager().cancelSubsession(subsession);
      }
  
      public static void continueSession(Session subsession, String shortMethodName) {
          getSessionManager().continueSession(subsession, shortMethodName);
      }
  
      public static void endSession() {
          getSessionManager().endSession();
      }
  
      public static void registerSessionListener(SessionManager.ISessionListener l) {
          getSessionManager().registerSessionListener(l);
      }
  
      public static String getSessionId() {
          // If the Session logger has not been initialized, then there have been no sessions logged.
          // Don't load it now!
          synchronized (sSingletonSync) {
              if (sSessionManager != null) {
                  return getSessionManager().getSessionId();
              } else {
                  return "";
              }
          }
      }
  
      public static void addEvent(EventManager.Loggable recordEntry, String event) {
          getEventManager().event(recordEntry, event, null);
      }
  
      public static void addEvent(EventManager.Loggable recordEntry, String event, Object data) {
          getEventManager().event(recordEntry, event, data);
      }
  
      public static void addEvent(EventManager.Loggable recordEntry, String event, String format,
              Object... args) {
          getEventManager().event(recordEntry, event, format, args);
      }
  
      public static void registerEventListener(EventManager.EventListener e) {
          getEventManager().registerEventListener(e);
      }
  
      public static void addRequestResponsePair(EventManager.TimedEventPair p) {
          getEventManager().addRequestResponsePair(p);
      }
  
      public static void dumpEvents(IndentingPrintWriter pw) {
          // If the Events logger has not been initialized, then there have been no events logged.
          // Don't load it now!
          synchronized (sSingletonSync) {
              if (sEventManager != null) {
                  getEventManager().dumpEvents(pw);
              } else {
                  pw.println("No Historical Events Logged.");
              }
          }
      }
  
      /**
       * Dumps the events in a timeline format.
       * @param pw The {@link IndentingPrintWriter} to write to.
       * @hide
       */
      public static void dumpEventsTimeline(IndentingPrintWriter pw) {
          // If the Events logger has not been initialized, then there have been no events logged.
          // Don't load it now!
          synchronized (sSingletonSync) {
              if (sEventManager != null) {
                  getEventManager().dumpEventsTimeline(pw);
              } else {
                  pw.println("No Historical Events Logged.");
              }
          }
      }
  
      /**
       * Enable or disable extended telecom logging.
       *
       * @param isExtendedLoggingEnabled {@code true} if extended logging should be enabled,
       *          {@code false} if it should be disabled.
       */
      public static void setIsExtendedLoggingEnabled(boolean isExtendedLoggingEnabled) {
          // If the state hasn't changed, bail early.
          if (sIsUserExtendedLoggingEnabled == isExtendedLoggingEnabled) {
              return;
          }
  
          if (sEventManager != null) {
              sEventManager.changeEventCacheSize(isExtendedLoggingEnabled ?
                      EVENTS_TO_CACHE_DEBUG : EVENTS_TO_CACHE);
          }
  
          sIsUserExtendedLoggingEnabled = isExtendedLoggingEnabled;
          if (sIsUserExtendedLoggingEnabled) {
              sUserExtendedLoggingStopTime = System.currentTimeMillis()
                      + EXTENDED_LOGGING_DURATION_MILLIS;
          } else {
              sUserExtendedLoggingStopTime = 0;
          }
      }
  
      private static EventManager getEventManager() {
          // Checking for null again outside of synchronization because we only need to synchronize
          // during the lazy loading of the events logger. We don't need to synchronize elsewhere.
          if (sEventManager == null) {
              synchronized (sSingletonSync) {
                  if (sEventManager == null) {
                      sEventManager = new EventManager(Log::getSessionId);
                      return sEventManager;
                  }
              }
          }
          return sEventManager;
      }
  
      @VisibleForTesting
      public static SessionManager getSessionManager() {
          // Checking for null again outside of synchronization because we only need to synchronize
          // during the lazy loading of the session logger. We don't need to synchronize elsewhere.
          if (sSessionManager == null) {
              synchronized (sSingletonSync) {
                  if (sSessionManager == null) {
                      sSessionManager = new SessionManager();
                      return sSessionManager;
                  }
              }
          }
          return sSessionManager;
      }
  
      public static void setTag(String tag) {
          TAG = tag;
          DEBUG = isLoggable(android.util.Log.DEBUG);
          INFO = isLoggable(android.util.Log.INFO);
          VERBOSE = isLoggable(android.util.Log.VERBOSE);
          WARN = isLoggable(android.util.Log.WARN);
          ERROR = isLoggable(android.util.Log.ERROR);
      }
  
      /**
       * If user enabled extended logging is enabled and the time limit has passed, disables the
       * extended logging.
       */
      private static void maybeDisableLogging() {
          if (!sIsUserExtendedLoggingEnabled) {
              return;
          }
  
          if (sUserExtendedLoggingStopTime < System.currentTimeMillis()) {
              sUserExtendedLoggingStopTime = 0;
              sIsUserExtendedLoggingEnabled = false;
          }
      }
  
      public static boolean isLoggable(int level) {
          return FORCE_LOGGING || android.util.Log.isLoggable(TAG, level);
      }
  
      /**
       * Generates an obfuscated string for a calling handle in {@link Uri} format, or a raw phone
       * phone number in {@link String} format.
       * @param pii The information to obfuscate.
       * @return The obfuscated string.
       */
      public static String piiHandle(Object pii) {
          if (pii == null || VERBOSE) {
              return String.valueOf(pii);
          }
  
          StringBuilder sb = new StringBuilder();
          if (pii instanceof Uri) {
              Uri uri = (Uri) pii;
              String scheme = uri.getScheme();
  
              if (!TextUtils.isEmpty(scheme)) {
                  sb.append(scheme).append(":");
              }
  
              String textToObfuscate = uri.getSchemeSpecificPart();
              if (PhoneAccount.SCHEME_TEL.equals(scheme)) {
                  obfuscatePhoneNumber(sb, textToObfuscate);
              } else if (PhoneAccount.SCHEME_SIP.equals(scheme)) {
                  for (int i = 0; i < textToObfuscate.length(); i++) {
                      char c = textToObfuscate.charAt(i);
                      if (c != '@' && c != '.') {
                          c = '*';
                      }
                      sb.append(c);
                  }
              } else {
                  sb.append(pii(pii));
              }
          } else if (pii instanceof String) {
              String number = (String) pii;
              obfuscatePhoneNumber(sb, number);
          }
  
          return sb.toString();
      }
  
      /**
       * Obfuscates a phone number, allowing NUM_DIALABLE_DIGITS_TO_LOG digits to be exposed for the
       * phone number.
       * @param sb String buffer to write obfuscated number to.
       * @param phoneNumber The number to obfuscate.
       */
      private static void obfuscatePhoneNumber(StringBuilder sb, String phoneNumber) {
          int numDigitsToObfuscate = getDialableCount(phoneNumber)
                  - NUM_DIALABLE_DIGITS_TO_LOG;
          for (int i = 0; i < phoneNumber.length(); i++) {
              char c = phoneNumber.charAt(i);
              boolean isDialable = PhoneNumberUtils.isDialable(c);
              if (isDialable) {
                  numDigitsToObfuscate--;
              }
              sb.append(isDialable && numDigitsToObfuscate >= 0 ? "*" : c);
          }
      }
  
      /**
       * Determines the number of dialable characters in a string.
       * @param toCount The string to count dialable characters in.
       * @return The count of dialable characters.
       */
      private static int getDialableCount(String toCount) {
          int numDialable = 0;
          for (char c : toCount.toCharArray()) {
              if (PhoneNumberUtils.isDialable(c)) {
                  numDialable++;
              }
          }
          return numDialable;
      }
  
      /**
       * Redact personally identifiable information for production users.
       * If we are running in verbose mode, return the original string,
       * and return "***" otherwise.
       */
      public static String pii(Object pii) {
          if (pii == null || VERBOSE) {
              return String.valueOf(pii);
          }
          return "***";
      }
  
      private static String getPrefixFromObject(Object obj) {
          return obj == null ? "<null>" : obj.getClass().getSimpleName();
      }
  
      private static String buildMessage(String prefix, String format, Object... args) {
          // Incorporate thread ID and calling method into prefix
          String sessionName = getSessionId();
          String sessionPostfix = TextUtils.isEmpty(sessionName) ? "" : ": " + sessionName;
  
          String msg;
          try {
              msg = (args == null || args.length == 0) ? format
                      : String.format(Locale.US, format, args);
          } catch (IllegalFormatException ife) {
              e(TAG, ife, "Log: IllegalFormatException: formatString='%s' numArgs=%d", format,
                      args.length);
              msg = format + " (An error occurred while formatting the message.)";
          }
          return String.format(Locale.US, "%s: %s%s", prefix, msg, sessionPostfix);
      }
  }
  