/*
 * Copyright (C) 2021 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.car.telemetry.publisher.statsconverters;

import static com.android.car.telemetry.publisher.Constants.STATS_BUNDLE_KEY_ELAPSED_TIMESTAMP;

import android.annotation.NonNull;
import android.os.PersistableBundle;

import com.android.car.telemetry.AtomsProto;
import com.android.car.telemetry.StatsLogProto;

import java.util.ArrayList;
import java.util.List;

/**
 * Class for converting event metric data to {@link PersistableBundle} compatible format.
 */
public class EventMetricDataConverter {
    /**
     * Converts a list of {@link StatsLogProto.EventMetricData} to {@link PersistableBundle} format
     * such that along with the elapsed time array each field of the atom has an associated array
     * containing the field's data in order received, matching the elapsed time array order.
     *
     * <p>Example: { elapsed_timestamp_nanos: [32948395739, 45623453646, ...] uid: [1000, 1100, ...]
     * ... }
     *
     * @param eventDataList the list of {@link StatsLogProto.EventMetricData} to be converted.
     * @return {@link PersistableBundle} that holds the converted values.
     * @throws StatsConversionException if atom field mismatch or can't convert dimension value.
     */
    @NonNull
    static PersistableBundle convertEventDataList(
            @NonNull List<StatsLogProto.EventMetricData> eventDataList)
            throws StatsConversionException {
        List<Long> elapsedTimes = new ArrayList<>(eventDataList.size());
        List<AtomsProto.Atom> atoms = new ArrayList<>(eventDataList.size());
        for (StatsLogProto.EventMetricData eventData : eventDataList) {
            if (eventData.hasAggregatedAtomInfo()) {
                StatsLogProto.AggregatedAtomInfo aggregate = eventData.getAggregatedAtomInfo();
                AtomsProto.Atom atom = aggregate.getAtom();
                for (long elapsedTime : aggregate.getElapsedTimestampNanosList()) {
                    elapsedTimes.add(elapsedTime);
                    atoms.add(atom);
                }
            } else {
                elapsedTimes.add(eventData.getElapsedTimestampNanos());
                atoms.add(eventData.getAtom());
            }
        }
        PersistableBundle bundle = AtomListConverter.convert(atoms, null, null, null);
        long[] elapsedTimesArray = new long[elapsedTimes.size()];
        for (int i = 0; i < elapsedTimes.size(); ++i) {
            elapsedTimesArray[i] = elapsedTimes.get(i);
        }
        bundle.putLongArray(STATS_BUNDLE_KEY_ELAPSED_TIMESTAMP, elapsedTimesArray);
        return bundle;
    }
}