/*
 * 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.calldetails;

import android.content.Context;
import android.content.CursorLoader;
import android.database.Cursor;
import com.android.dialer.CoalescedIds;
import com.android.dialer.calldetails.CallDetailsEntries.CallDetailsEntry;
import com.android.dialer.calllog.database.contract.AnnotatedCallLogContract.AnnotatedCallLog;
import com.android.dialer.common.Assert;
import com.android.dialer.duo.DuoComponent;

/**
 * A {@link CursorLoader} that loads call detail entries from {@link AnnotatedCallLog} for {@link
 * CallDetailsActivity}.
 */
public final class CallDetailsCursorLoader extends CursorLoader {

  // Columns in AnnotatedCallLog that are needed to build a CallDetailsEntry proto.
  // Be sure to update (1) constants that store indexes of the elements and (2) method
  // toCallDetailsEntry(Cursor) when updating this array.
  public static final String[] COLUMNS_FOR_CALL_DETAILS =
      new String[] {
        AnnotatedCallLog._ID,
        AnnotatedCallLog.CALL_TYPE,
        AnnotatedCallLog.FEATURES,
        AnnotatedCallLog.TIMESTAMP,
        AnnotatedCallLog.DURATION,
        AnnotatedCallLog.DATA_USAGE,
        AnnotatedCallLog.PHONE_ACCOUNT_COMPONENT_NAME,
        AnnotatedCallLog.CALL_MAPPING_ID
      };

  // Indexes for COLUMNS_FOR_CALL_DETAILS
  private static final int ID = 0;
  private static final int CALL_TYPE = 1;
  private static final int FEATURES = 2;
  private static final int TIMESTAMP = 3;
  private static final int DURATION = 4;
  private static final int DATA_USAGE = 5;
  private static final int PHONE_ACCOUNT_COMPONENT_NAME = 6;
  private static final int CALL_MAPPING_ID = 7;

  CallDetailsCursorLoader(Context context, CoalescedIds coalescedIds) {
    super(
        context,
        AnnotatedCallLog.CONTENT_URI,
        COLUMNS_FOR_CALL_DETAILS,
        annotatedCallLogIdsSelection(coalescedIds),
        annotatedCallLogIdsSelectionArgs(coalescedIds),
        AnnotatedCallLog.TIMESTAMP + " DESC");
  }

  @Override
  public void onContentChanged() {
    // Do nothing here.
    // This is to prevent the loader to reload data when Loader.ForceLoadContentObserver detects a
    // change.
    // Without this, the app will crash when the user deletes call details as the deletion triggers
    // the data loading but no data can be fetched and we want to ensure the data set is not empty
    // when building CallDetailsEntries proto (see toCallDetailsEntries(Cursor)).
    //
    // OldCallDetailsActivity doesn't respond to underlying data changes and we decided to keep it
    // that way in CallDetailsActivity.
  }

  /**
   * Build a string of the form "COLUMN_NAME IN (?, ?, ..., ?)", where COLUMN_NAME is the name of
   * the ID column in {@link AnnotatedCallLog}.
   *
   * <p>This string will be used as the {@code selection} parameter to initialize the loader.
   */
  private static String annotatedCallLogIdsSelection(CoalescedIds coalescedIds) {
    // First, build a string of question marks ('?') separated by commas (',').
    StringBuilder questionMarks = new StringBuilder();
    for (int i = 0; i < coalescedIds.getCoalescedIdCount(); i++) {
      if (i != 0) {
        questionMarks.append(", ");
      }
      questionMarks.append("?");
    }

    return AnnotatedCallLog._ID + " IN (" + questionMarks + ")";
  }

  /**
   * Returns a string that will be used as the {@code selectionArgs} parameter to initialize the
   * loader.
   */
  private static String[] annotatedCallLogIdsSelectionArgs(CoalescedIds coalescedIds) {
    String[] args = new String[coalescedIds.getCoalescedIdCount()];

    for (int i = 0; i < coalescedIds.getCoalescedIdCount(); i++) {
      args[i] = String.valueOf(coalescedIds.getCoalescedId(i));
    }

    return args;
  }

  /**
   * Creates a new {@link CallDetailsEntries} from the entire data set loaded by this loader.
   *
   * @param cursor A cursor pointing to the data set loaded by this loader. The caller must ensure
   *     the cursor is not null and the data set it points to is not empty.
   * @return A {@link CallDetailsEntries} proto.
   */
  static CallDetailsEntries toCallDetailsEntries(Context context, Cursor cursor) {
    Assert.isNotNull(cursor);
    Assert.checkArgument(cursor.moveToFirst());

    CallDetailsEntries.Builder entries = CallDetailsEntries.newBuilder();

    do {
      entries.addEntries(toCallDetailsEntry(context, cursor));
    } while (cursor.moveToNext());

    return entries.build();
  }

  /** Creates a new {@link CallDetailsEntry} from the provided cursor using its current position. */
  private static CallDetailsEntry toCallDetailsEntry(Context context, Cursor cursor) {
    CallDetailsEntry.Builder entry = CallDetailsEntry.newBuilder();
    entry
        .setCallId(cursor.getLong(ID))
        .setCallType(cursor.getInt(CALL_TYPE))
        .setFeatures(cursor.getInt(FEATURES))
        .setDate(cursor.getLong(TIMESTAMP))
        .setDuration(cursor.getLong(DURATION))
        .setDataUsage(cursor.getLong(DATA_USAGE))
        .setCallMappingId(cursor.getString(CALL_MAPPING_ID));

    String phoneAccountComponentName = cursor.getString(PHONE_ACCOUNT_COMPONENT_NAME);
    entry.setIsDuoCall(DuoComponent.get(context).getDuo().isDuoAccount(phoneAccountComponentName));

    return entry.build();
  }
}