/*
 * 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.dialer.telecom;

import android.content.Context;
import android.net.Uri;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.annotation.WorkerThread;
import android.telecom.Call;
import android.telecom.PhoneAccountHandle;
import android.telephony.PhoneNumberUtils;
import android.telephony.SubscriptionInfo;
import android.text.TextUtils;
import com.android.dialer.common.Assert;
import com.android.dialer.common.LogUtil;
import com.google.common.base.Optional;
import java.util.Locale;

/**
 * Class to provide a standard interface for obtaining information from the underlying
 * android.telecom.Call. Much of this should be obtained through the incall.Call, but on occasion we
 * need to interact with the telecom.Call directly (eg. call blocking, before the incall.Call has
 * been created).
 */
public class TelecomCallUtil {

  /** Returns Whether the call handle is an emergency number. */
  public static boolean isEmergencyCall(@NonNull Call call) {
    Assert.isNotNull(call);
    Uri handle = call.getDetails().getHandle();
    return PhoneNumberUtils.isEmergencyNumber(handle == null ? "" : handle.getSchemeSpecificPart());
  }

  /**
   * Returns The phone number which the {@code Call} is currently connected, or {@code null} if the
   * number is not available.
   */
  @Nullable
  public static String getNumber(@Nullable Call call) {
    if (call == null) {
      return null;
    }
    if (call.getDetails().getGatewayInfo() != null) {
      return call.getDetails().getGatewayInfo().getOriginalAddress().getSchemeSpecificPart();
    }
    Uri handle = getHandle(call);
    return handle == null ? null : handle.getSchemeSpecificPart();
  }

  /**
   * Returns The handle (e.g., phone number) to which the {@code Call} is currently connected, or
   * {@code null} if the number is not available.
   */
  @Nullable
  public static Uri getHandle(@Nullable Call call) {
    return call == null ? null : call.getDetails().getHandle();
  }

  /**
   * Normalizes the number of the {@code call} to E.164. The country of the SIM associated with the
   * call is used to determine the country.
   *
   * <p>If the number cannot be formatted (because for example the country cannot be determined),
   * returns the number with non-dialable digits removed.
   */
  @WorkerThread
  public static Optional<String> getNormalizedNumber(Context appContext, Call call) {
    Assert.isWorkerThread();

    Optional<String> e164 = getE164Number(appContext, call);
    if (e164.isPresent()) {
      return e164;
    }
    String rawNumber = getNumber(call);
    if (TextUtils.isEmpty(rawNumber)) {
      return Optional.absent();
    }
    return Optional.of(PhoneNumberUtils.normalizeNumber(rawNumber));
  }

  /**
   * Formats the number of the {@code call} to E.164. The country of the SIM associated with the
   * call is used to determine the country.
   *
   * <p>If the number cannot be formatted (because for example the country cannot be determined),
   * returns {@link Optional#absent()}.
   */
  @WorkerThread
  public static Optional<String> getE164Number(Context appContext, Call call) {
    Assert.isWorkerThread();
    PhoneAccountHandle phoneAccountHandle = call.getDetails().getAccountHandle();
    Optional<SubscriptionInfo> subscriptionInfo =
        TelecomUtil.getSubscriptionInfo(appContext, phoneAccountHandle);
    String rawNumber = getNumber(call);
    if (TextUtils.isEmpty(rawNumber)) {
      return Optional.absent();
    }
    String countryCode =
        subscriptionInfo.isPresent() ? subscriptionInfo.get().getCountryIso() : null;
    if (countryCode == null) {
      LogUtil.w("TelecomCallUtil.getE164Number", "couldn't find a country code for call");
      return Optional.absent();
    }
    return Optional.fromNullable(
        PhoneNumberUtils.formatNumberToE164(rawNumber, countryCode.toUpperCase(Locale.US)));
  }
}