/*
 * Copyright (C) 2017 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 com.android.dialer.phonenumberproto;

import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.annotation.WorkerThread;
import android.telephony.PhoneNumberUtils;
import android.text.TextUtils;
import com.android.dialer.DialerPhoneNumber;
import com.android.dialer.common.Assert;
import com.android.dialer.common.LogUtil;
import com.google.i18n.phonenumbers.NumberParseException;
import com.google.i18n.phonenumbers.PhoneNumberUtil;
import com.google.i18n.phonenumbers.PhoneNumberUtil.MatchType;
import com.google.i18n.phonenumbers.PhoneNumberUtil.PhoneNumberFormat;
import com.google.i18n.phonenumbers.Phonenumber.PhoneNumber;
import com.google.i18n.phonenumbers.ShortNumberInfo;

/**
 * Wrapper for selected methods in {@link PhoneNumberUtil} which uses the {@link DialerPhoneNumber}
 * lite proto instead of the {@link com.google.i18n.phonenumbers.Phonenumber.PhoneNumber} POJO.
 *
 * <p>All methods should be called on a worker thread.
 */
public class DialerPhoneNumberUtil {
  private final PhoneNumberUtil phoneNumberUtil;
  private final ShortNumberInfo shortNumberInfo;

  @WorkerThread
  public DialerPhoneNumberUtil() {
    Assert.isWorkerThread();
    this.phoneNumberUtil = PhoneNumberUtil.getInstance();
    this.shortNumberInfo = ShortNumberInfo.getInstance();
  }

  /**
   * Parses the provided raw phone number into a {@link DialerPhoneNumber}.
   *
   * @see PhoneNumberUtil#parse(CharSequence, String)
   */
  @WorkerThread
  public DialerPhoneNumber parse(@Nullable String numberToParse, @Nullable String defaultRegion) {
    Assert.isWorkerThread();

    DialerPhoneNumber.Builder dialerPhoneNumber = DialerPhoneNumber.newBuilder();

    if (defaultRegion != null) {
      dialerPhoneNumber.setCountryIso(defaultRegion);
    }

    // Numbers can be null or empty for incoming "unknown" calls.
    if (numberToParse == null) {
      return dialerPhoneNumber.build();
    }

    // If the number is a service number, just store the raw number and don't bother trying to parse
    // it. PhoneNumberUtil#parse ignores these characters which can lead to confusing behavior, such
    // as the numbers "#123" and "123" being considered the same. The "#" can appear in the middle
    // of a service number and the "*" can appear at the beginning (see a bug).
    if (isServiceNumber(numberToParse)) {
      return dialerPhoneNumber.setNormalizedNumber(numberToParse).build();
    }

    String postDialPortion = PhoneNumberUtils.extractPostDialPortion(numberToParse);
    if (!postDialPortion.isEmpty()) {
      dialerPhoneNumber.setPostDialPortion(postDialPortion);
    }

    String networkPortion = PhoneNumberUtils.extractNetworkPortion(numberToParse);

    try {
      PhoneNumber phoneNumber = phoneNumberUtil.parse(networkPortion, defaultRegion);
      if (phoneNumberUtil.isValidNumber(phoneNumber)) {
        String validNumber = phoneNumberUtil.format(phoneNumber, PhoneNumberFormat.E164);
        if (TextUtils.isEmpty(validNumber)) {
          throw new IllegalStateException(
              "e164 number should not be empty: " + LogUtil.sanitizePii(numberToParse));
        }
        // The E164 representation doesn't contain post-dial digits, but we need to preserve them.
        if (!postDialPortion.isEmpty()) {
          validNumber += postDialPortion;
        }
        return dialerPhoneNumber.setNormalizedNumber(validNumber).setIsValid(true).build();
      }
    } catch (NumberParseException e) {
      // fall through
    }
    return dialerPhoneNumber.setNormalizedNumber(networkPortion + postDialPortion).build();
  }

  /**
   * Returns true if the two numbers:
   *
   * <ul>
   *   <li>were parseable by libphonenumber (see {@link #parse(String, String)}),
   *   <li>are a {@link MatchType#SHORT_NSN_MATCH}, {@link MatchType#NSN_MATCH}, or {@link
   *       MatchType#EXACT_MATCH}, and
   *   <li>have the same post-dial digits.
   * </ul>
   *
   * <p>If either number is not parseable, returns true if their raw inputs have the same network
   * and post-dial portions.
   *
   * <p>An empty number is never considered to match another number.
   *
   * @see PhoneNumberUtil#isNumberMatch(PhoneNumber, PhoneNumber)
   */
  @WorkerThread
  public boolean isMatch(
      @NonNull DialerPhoneNumber firstNumberIn, @NonNull DialerPhoneNumber secondNumberIn) {
    Assert.isWorkerThread();

    // An empty number should not be combined with any other number.
    if (firstNumberIn.getNormalizedNumber().isEmpty()
        || secondNumberIn.getNormalizedNumber().isEmpty()) {
      return false;
    }

    // Two numbers with different countries should not match.
    if (!firstNumberIn.getCountryIso().equals(secondNumberIn.getCountryIso())) {
      return false;
    }

    PhoneNumber phoneNumber1 = null;
    try {
      phoneNumber1 =
          phoneNumberUtil.parse(firstNumberIn.getNormalizedNumber(), firstNumberIn.getCountryIso());
    } catch (NumberParseException e) {
      // fall through
    }

    PhoneNumber phoneNumber2 = null;
    try {
      phoneNumber2 =
          phoneNumberUtil.parse(
              secondNumberIn.getNormalizedNumber(), secondNumberIn.getCountryIso());
    } catch (NumberParseException e) {
      // fall through
    }

    // If either number is a service number or either number can't be parsed by libphonenumber, just
    // fallback to basic textual matching.
    if (isServiceNumber(firstNumberIn.getNormalizedNumber())
        || isServiceNumber(secondNumberIn.getNormalizedNumber())
        || phoneNumber1 == null
        || phoneNumber2 == null) {
      return firstNumberIn.getNormalizedNumber().equals(secondNumberIn.getNormalizedNumber());
    }

    // Both numbers are parseable, first check for short codes to so that a number like "5555"
    // doesn't match "55555" (due to those being a SHORT_NSN_MATCH below).
    if (shortNumberInfo.isPossibleShortNumber(phoneNumber1)
        || shortNumberInfo.isPossibleShortNumber(phoneNumber2)) {
      return firstNumberIn.getNormalizedNumber().equals(secondNumberIn.getNormalizedNumber());
    }

    // Both numbers are parseable, use more sophisticated libphonenumber matching.
    MatchType matchType = phoneNumberUtil.isNumberMatch(phoneNumber1, phoneNumber2);

    return (matchType == MatchType.SHORT_NSN_MATCH
            || matchType == MatchType.NSN_MATCH
            || matchType == MatchType.EXACT_MATCH)
        && firstNumberIn.getPostDialPortion().equals(secondNumberIn.getPostDialPortion());
  }

  private boolean isServiceNumber(@NonNull String rawNumber) {
    return rawNumber.contains("#") || rawNumber.startsWith("*");
  }
}