/*
 * Copyright (C) 2011 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.app.calllog;

import android.content.Context;
import android.database.Cursor;
import android.provider.CallLog.Calls;
import android.support.annotation.Nullable;
import android.support.annotation.VisibleForTesting;
import android.telephony.PhoneNumberUtils;
import android.text.TextUtils;
import com.android.contacts.common.util.DateUtils;
import com.android.dialer.calllogutils.CallbackActionHelper;
import com.android.dialer.calllogutils.CallbackActionHelper.CallbackAction;
import com.android.dialer.compat.telephony.TelephonyManagerCompat;
import com.android.dialer.inject.ApplicationContext;
import com.android.dialer.phonenumbercache.CallLogQuery;
import com.android.dialer.phonenumberutil.PhoneNumberHelper;

import java.time.ZoneId;
import java.util.Objects;

/**
 * Groups together calls in the call log. The primary grouping attempts to group together calls to
 * and from the same number into a single row on the call log. A secondary grouping assigns calls,
 * grouped via the primary grouping, to "day groups". The day groups provide a means of identifying
 * the calls which occurred "Today", "Yesterday", "Last week", or "Other".
 *
 * <p>This class is meant to be used in conjunction with {@link GroupingListAdapter}.
 */
public class CallLogGroupBuilder {

  /**
   * Day grouping for call log entries used to represent no associated day group. Used primarily
   * when retrieving the previous day group, but there is no previous day group (i.e. we are at the
   * start of the list).
   */
  public static final int DAY_GROUP_NONE = -1;
  /** Day grouping for calls which occurred today. */
  public static final int DAY_GROUP_TODAY = 0;
  /** Day grouping for calls which occurred yesterday. */
  public static final int DAY_GROUP_YESTERDAY = 1;
  /** Day grouping for calls which occurred before last week. */
  public static final int DAY_GROUP_OTHER = 2;
  /** Instance of the time object used for time calculations. */
  private static final ZoneId TIME_ZONE = ZoneId.systemDefault();

  private final Context appContext;
  /** The object on which the groups are created. */
  private final GroupCreator groupCreator;

  public CallLogGroupBuilder(@ApplicationContext Context appContext, GroupCreator groupCreator) {
    this.appContext = appContext;
    this.groupCreator = groupCreator;
  }

  /**
   * Finds all groups of adjacent entries in the call log which should be grouped together and calls
   * {@link GroupCreator#addGroup(int, int)} on {@link #groupCreator} for each of them.
   *
   * <p>For entries that are not grouped with others, we do not need to create a group of size one.
   *
   * <p>It assumes that the cursor will not change during its execution.
   *
   * @see GroupingListAdapter#addGroups(Cursor)
   */
  public void addGroups(Cursor cursor) {
    final int count = cursor.getCount();
    if (count == 0) {
      return;
    }

    // Clear any previous day grouping information.
    groupCreator.clearDayGroups();

    // Get current system time, used for calculating which day group calls belong to.
    long currentTime = System.currentTimeMillis();
    cursor.moveToFirst();

    // Determine the day group for the first call in the cursor.
    final long firstDate = cursor.getLong(CallLogQuery.DATE);
    final long firstRowId = cursor.getLong(CallLogQuery.ID);
    int groupDayGroup = getDayGroup(firstDate, currentTime);
    groupCreator.setDayGroup(firstRowId, groupDayGroup);

    // Determine the callback action for the first call in the cursor.
    String groupNumber = cursor.getString(CallLogQuery.NUMBER);
    String groupAccountComponentName = cursor.getString(CallLogQuery.ACCOUNT_COMPONENT_NAME);
    int groupFeatures = cursor.getInt(CallLogQuery.FEATURES);
    int groupCallbackAction =
        CallbackActionHelper.getCallbackAction(
            appContext, groupNumber, groupFeatures, groupAccountComponentName);
    groupCreator.setCallbackAction(firstRowId, groupCallbackAction);

    // Instantiate other group values to those of the first call in the cursor.
    String groupAccountId = cursor.getString(CallLogQuery.ACCOUNT_ID);
    String groupPostDialDigits = cursor.getString(CallLogQuery.POST_DIAL_DIGITS);
    String groupViaNumbers = cursor.getString(CallLogQuery.VIA_NUMBER);
    int groupCallType = cursor.getInt(CallLogQuery.CALL_TYPE);
    int groupSize = 1;

    String number;
    String numberPostDialDigits;
    String numberViaNumbers;
    int callType;
    int callFeatures;
    String accountComponentName;
    String accountId;
    int callbackAction;

    while (cursor.moveToNext()) {
      // Obtain the values for the current call to group.
      number = cursor.getString(CallLogQuery.NUMBER);
      numberPostDialDigits = cursor.getString(CallLogQuery.POST_DIAL_DIGITS);
      numberViaNumbers = cursor.getString(CallLogQuery.VIA_NUMBER);
      callType = cursor.getInt(CallLogQuery.CALL_TYPE);
      callFeatures = cursor.getInt(CallLogQuery.FEATURES);
      accountComponentName = cursor.getString(CallLogQuery.ACCOUNT_COMPONENT_NAME);
      accountId = cursor.getString(CallLogQuery.ACCOUNT_ID);
      callbackAction =
          CallbackActionHelper.getCallbackAction(
              appContext, number, callFeatures, accountComponentName);

      final boolean isSameNumber = equalNumbers(groupNumber, number);
      final boolean isSamePostDialDigits = groupPostDialDigits.equals(numberPostDialDigits);
      final boolean isSameViaNumbers = groupViaNumbers.equals(numberViaNumbers);
      final boolean isSameAccount =
          isSameAccount(groupAccountComponentName, accountComponentName, groupAccountId, accountId);
      final boolean isSameCallbackAction = (groupCallbackAction == callbackAction);

      // Group calls with the following criteria:
      // (1) Calls with the same number, account, and callback action should be in the same group;
      // (2) Never group voice mails; and
      // (3) Only group blocked calls with other blocked calls.
      // (4) Only group calls that were assisted dialed with other calls that were assisted dialed.
      if (isSameNumber
          && isSameAccount
          && isSamePostDialDigits
          && isSameViaNumbers
          && isSameCallbackAction
          && areBothNotVoicemail(callType, groupCallType)
          && (areBothNotBlocked(callType, groupCallType) || areBothBlocked(callType, groupCallType))
          && meetsAssistedDialingGroupingCriteria(groupFeatures, callFeatures)) {
        // Increment the size of the group to include the current call, but do not create
        // the group until finding a call that does not match.
        groupSize++;
      } else {
        // The call group has changed. Determine the day group for the new call group.
        final long date = cursor.getLong(CallLogQuery.DATE);
        groupDayGroup = getDayGroup(date, currentTime);

        // Create a group for the previous group of calls, which does not include the
        // current call.
        groupCreator.addGroup(cursor.getPosition() - groupSize, groupSize);

        // Start a new group; it will include at least the current call.
        groupSize = 1;

        // Update the group values to those of the current call.
        groupNumber = number;
        groupPostDialDigits = numberPostDialDigits;
        groupViaNumbers = numberViaNumbers;
        groupCallType = callType;
        groupAccountComponentName = accountComponentName;
        groupAccountId = accountId;
        groupCallbackAction = callbackAction;
        groupFeatures = callFeatures;
      }

      // Save the callback action and the day group associated with the current call.
      final long currentCallId = cursor.getLong(CallLogQuery.ID);
      groupCreator.setCallbackAction(currentCallId, groupCallbackAction);
      groupCreator.setDayGroup(currentCallId, groupDayGroup);
    }

    // Create a group for the last set of calls.
    groupCreator.addGroup(count - groupSize, groupSize);
  }

  /**
   * Returns true when the two input numbers can be considered identical enough for caller ID
   * purposes and put in a call log group.
   */
  @VisibleForTesting
  boolean equalNumbers(@Nullable String number1, @Nullable String number2) {
    if (PhoneNumberHelper.isUriNumber(number1) || PhoneNumberHelper.isUriNumber(number2)) {
      return compareSipAddresses(number1, number2);
    }

    // PhoneNumberUtils.compare(String, String) ignores special characters such as '#'. For example,
    // it thinks "123" and "#123" are identical enough for caller ID purposes.
    // When either input number contains special characters, we put the two in the same group iff
    // their raw numbers are exactly the same.
    if (PhoneNumberHelper.numberHasSpecialChars(number1)
        || PhoneNumberHelper.numberHasSpecialChars(number2)) {
      return PhoneNumberHelper.sameRawNumbers(number1, number2);
    }

    return PhoneNumberUtils.compare(number1, number2);
  }

  private boolean isSameAccount(String name1, String name2, String id1, String id2) {
    return TextUtils.equals(name1, name2) && TextUtils.equals(id1, id2);
  }

  @VisibleForTesting
  boolean compareSipAddresses(@Nullable String number1, @Nullable String number2) {
    if (number1 == null || number2 == null) {
      return Objects.equals(number1, number2);
    }

    int index1 = number1.indexOf('@');
    final String userinfo1;
    final String rest1;
    if (index1 != -1) {
      userinfo1 = number1.substring(0, index1);
      rest1 = number1.substring(index1);
    } else {
      userinfo1 = number1;
      rest1 = "";
    }

    int index2 = number2.indexOf('@');
    final String userinfo2;
    final String rest2;
    if (index2 != -1) {
      userinfo2 = number2.substring(0, index2);
      rest2 = number2.substring(index2);
    } else {
      userinfo2 = number2;
      rest2 = "";
    }

    return userinfo1.equals(userinfo2) && rest1.equalsIgnoreCase(rest2);
  }

  /**
   * Given a call date and the current date, determine which date group the call belongs in.
   *
   * @param date The call date.
   * @param now The current date.
   * @return The date group the call belongs in.
   */
  private int getDayGroup(long date, long now) {
    int days = DateUtils.getDayDifference(TIME_ZONE, date, now);

    if (days == 0) {
      return DAY_GROUP_TODAY;
    } else if (days == 1) {
      return DAY_GROUP_YESTERDAY;
    } else {
      return DAY_GROUP_OTHER;
    }
  }

  private boolean areBothNotVoicemail(int callType, int groupCallType) {
    return callType != Calls.VOICEMAIL_TYPE && groupCallType != Calls.VOICEMAIL_TYPE;
  }

  private boolean areBothNotBlocked(int callType, int groupCallType) {
    return callType != Calls.BLOCKED_TYPE && groupCallType != Calls.BLOCKED_TYPE;
  }

  private boolean areBothBlocked(int callType, int groupCallType) {
    return callType == Calls.BLOCKED_TYPE && groupCallType == Calls.BLOCKED_TYPE;
  }

  private boolean meetsAssistedDialingGroupingCriteria(int groupFeatures, int callFeatures) {
    int groupAssisted = (groupFeatures & TelephonyManagerCompat.FEATURES_ASSISTED_DIALING);
    int callAssisted = (callFeatures & TelephonyManagerCompat.FEATURES_ASSISTED_DIALING);

    return groupAssisted == callAssisted;
  }

  public interface GroupCreator {

    /**
     * Defines the interface for adding a group to the call log. The primary group for a call log
     * groups the calls together based on the number which was dialed.
     *
     * @param cursorPosition The starting position of the group in the cursor.
     * @param size The size of the group.
     */
    void addGroup(int cursorPosition, int size);

    /**
     * Defines the interface for tracking each call's callback action. Calls in a call group are
     * associated with the same callback action as the first call in the group. The value of a
     * callback action should be one of the categories in {@link CallbackAction}.
     *
     * @param rowId The row ID of the current call.
     * @param callbackAction The current call's callback action.
     */
    void setCallbackAction(long rowId, @CallbackAction int callbackAction);

    /**
     * Defines the interface for tracking the day group each call belongs to. Calls in a call group
     * are assigned the same day group as the first call in the group. The day group assigns calls
     * to the buckets: Today, Yesterday, Last week, and Other
     *
     * @param rowId The row ID of the current call.
     * @param dayGroup The day group the call belongs to.
     */
    void setDayGroup(long rowId, int dayGroup);

    /** Defines the interface for clearing the day groupings information on rebind/regroup. */
    void clearDayGroups();
  }
}