/*
 * Copyright (C) 2015 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.contacts.common.compat;

import android.telephony.PhoneNumberUtils;
import android.text.Spannable;
import android.text.TextUtils;
import android.text.style.TtsSpan;
import com.android.dialer.compat.CompatUtils;
import com.google.i18n.phonenumbers.NumberParseException;
import com.google.i18n.phonenumbers.PhoneNumberUtil;
import com.google.i18n.phonenumbers.Phonenumber.PhoneNumber;

/**
 * This class contains static utility methods extracted from PhoneNumberUtils, and the methods were
 * added in API level 23. In this way, we could enable the corresponding functionality for pre-M
 * devices. We need maintain this class and keep it synced with PhoneNumberUtils. Another thing to
 * keep in mind is that we use com.google.i18n rather than com.android.i18n in here, so we need make
 * sure the application behavior is preserved.
 */
public class PhoneNumberUtilsCompat {

  /** Not instantiable. */
  private PhoneNumberUtilsCompat() {}

  public static String normalizeNumber(String phoneNumber) {
    if (CompatUtils.isLollipopCompatible()) {
      return PhoneNumberUtils.normalizeNumber(phoneNumber);
    } else {
      return normalizeNumberInternal(phoneNumber);
    }
  }

  /** Implementation copied from {@link PhoneNumberUtils#normalizeNumber} */
  private static String normalizeNumberInternal(String phoneNumber) {
    if (TextUtils.isEmpty(phoneNumber)) {
      return "";
    }
    StringBuilder sb = new StringBuilder();
    int len = phoneNumber.length();
    for (int i = 0; i < len; i++) {
      char c = phoneNumber.charAt(i);
      // Character.digit() supports ASCII and Unicode digits (fullwidth, Arabic-Indic, etc.)
      int digit = Character.digit(c, 10);
      if (digit != -1) {
        sb.append(digit);
      } else if (sb.length() == 0 && c == '+') {
        sb.append(c);
      } else if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) {
        return normalizeNumber(PhoneNumberUtils.convertKeypadLettersToDigits(phoneNumber));
      }
    }
    return sb.toString();
  }

  public static String formatNumber(
      String phoneNumber, String phoneNumberE164, String defaultCountryIso) {
    if (CompatUtils.isLollipopCompatible()) {
      return PhoneNumberUtils.formatNumber(phoneNumber, phoneNumberE164, defaultCountryIso);
    } else {
      // This method was deprecated in API level 21, so it's only used on pre-L SDKs.
      return PhoneNumberUtils.formatNumber(phoneNumber);
    }
  }

  public static CharSequence createTtsSpannable(CharSequence phoneNumber) {
    if (CompatUtils.isMarshmallowCompatible()) {
      return PhoneNumberUtils.createTtsSpannable(phoneNumber);
    } else {
      return createTtsSpannableInternal(phoneNumber);
    }
  }

  public static TtsSpan createTtsSpan(String phoneNumber) {
    if (CompatUtils.isMarshmallowCompatible()) {
      return PhoneNumberUtils.createTtsSpan(phoneNumber);
    } else if (CompatUtils.isLollipopCompatible()) {
      return createTtsSpanLollipop(phoneNumber);
    } else {
      return null;
    }
  }

  /** Copied from {@link PhoneNumberUtils#createTtsSpannable} */
  private static CharSequence createTtsSpannableInternal(CharSequence phoneNumber) {
    if (phoneNumber == null) {
      return null;
    }
    Spannable spannable = Spannable.Factory.getInstance().newSpannable(phoneNumber);
    addTtsSpanInternal(spannable, 0, spannable.length());
    return spannable;
  }

  /** Compat method for addTtsSpan, see {@link PhoneNumberUtils#addTtsSpan} */
  public static void addTtsSpan(Spannable s, int start, int endExclusive) {
    if (CompatUtils.isMarshmallowCompatible()) {
      PhoneNumberUtils.addTtsSpan(s, start, endExclusive);
    } else {
      addTtsSpanInternal(s, start, endExclusive);
    }
  }

  /** Copied from {@link PhoneNumberUtils#addTtsSpan} */
  private static void addTtsSpanInternal(Spannable s, int start, int endExclusive) {
    s.setSpan(
        createTtsSpan(s.subSequence(start, endExclusive).toString()),
        start,
        endExclusive,
        Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
  }

  /** Copied from {@link PhoneNumberUtils#createTtsSpan} */
  private static TtsSpan createTtsSpanLollipop(String phoneNumberString) {
    if (phoneNumberString == null) {
      return null;
    }

    // Parse the phone number
    final PhoneNumberUtil phoneNumberUtil = PhoneNumberUtil.getInstance();
    PhoneNumber phoneNumber = null;
    try {
      // Don't supply a defaultRegion so this fails for non-international numbers because
      // we don't want to TalkBalk to read a country code (e.g. +1) if it is not already
      // present
      phoneNumber = phoneNumberUtil.parse(phoneNumberString, /* defaultRegion */ null);
    } catch (NumberParseException ignored) {
    }

    // Build a telephone tts span
    final TtsSpan.TelephoneBuilder builder = new TtsSpan.TelephoneBuilder();
    if (phoneNumber == null) {
      // Strip separators otherwise TalkBack will be silent
      // (this behavior was observed with TalkBalk 4.0.2 from their alpha channel)
      builder.setNumberParts(splitAtNonNumerics(phoneNumberString));
    } else {
      if (phoneNumber.hasCountryCode()) {
        builder.setCountryCode(Integer.toString(phoneNumber.getCountryCode()));
      }
      builder.setNumberParts(Long.toString(phoneNumber.getNationalNumber()));
    }
    return builder.build();
  }

  /**
   * Split a phone number using spaces, ignoring anything that is not a digit
   *
   * @param number A {@code CharSequence} before splitting, e.g., "+20(123)-456#"
   * @return A {@code String} after splitting, e.g., "20 123 456".
   */
  private static String splitAtNonNumerics(CharSequence number) {
    StringBuilder sb = new StringBuilder(number.length());
    for (int i = 0; i < number.length(); i++) {
      sb.append(PhoneNumberUtils.isISODigit(number.charAt(i)) ? number.charAt(i) : " ");
    }
    // It is very important to remove extra spaces. At time of writing, any leading or trailing
    // spaces, or any sequence of more than one space, will confuse TalkBack and cause the TTS
    // span to be non-functional!
    return sb.toString().replaceAll(" +", " ").trim();
  }
}