/*
 * 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.tv.recommendation;

import static androidx.test.InstrumentationRegistry.getContext;
import static com.google.common.truth.Truth.assertThat;

import androidx.test.filters.SmallTest;
import androidx.test.runner.AndroidJUnit4;
import com.android.tv.testing.utils.Utils;
import java.util.Random;
import java.util.concurrent.TimeUnit;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;

/** Unit tests for {@link ChannelRecord}. */
@SmallTest
@RunWith(AndroidJUnit4.class)
public class ChannelRecordTest {
    private static final int CHANNEL_RECORD_MAX_HISTORY_SIZE = ChannelRecord.MAX_HISTORY_SIZE;

    private Random mRandom;
    private ChannelRecord mChannelRecord;
    private long mLatestWatchEndTimeMs;

    @Before
    public void setUp() {
        mLatestWatchEndTimeMs = System.currentTimeMillis() - TimeUnit.DAYS.toMillis(1);
        mChannelRecord = new ChannelRecord(getContext(), null, false);
        mRandom = Utils.createTestRandom();
    }

    @Test
    public void testGetLastWatchEndTime_noHistory() {
    assertThat(mChannelRecord.getLastWatchEndTimeMs()).isEqualTo(0);
    }

    @Test
    public void testGetLastWatchEndTime_oneHistory() {
        addWatchLog();

    assertThat(mChannelRecord.getLastWatchEndTimeMs()).isEqualTo(mLatestWatchEndTimeMs);
    }

    @Test
    public void testGetLastWatchEndTime_maxHistories() {
        for (int i = 0; i < CHANNEL_RECORD_MAX_HISTORY_SIZE; ++i) {
            addWatchLog();
        }

    assertThat(mChannelRecord.getLastWatchEndTimeMs()).isEqualTo(mLatestWatchEndTimeMs);
    }

    @Test
    public void testGetLastWatchEndTime_moreThanMaxHistories() {
        for (int i = 0; i < CHANNEL_RECORD_MAX_HISTORY_SIZE + 1; ++i) {
            addWatchLog();
        }

    assertThat(mChannelRecord.getLastWatchEndTimeMs()).isEqualTo(mLatestWatchEndTimeMs);
    }

    @Test
    public void testGetTotalWatchDuration_noHistory() {
    assertThat(mChannelRecord.getTotalWatchDurationMs()).isEqualTo(0);
    }

    @Test
    public void testGetTotalWatchDuration_oneHistory() {
        long durationMs = addWatchLog();

    assertThat(mChannelRecord.getTotalWatchDurationMs()).isEqualTo(durationMs);
    }

    @Test
    public void testGetTotalWatchDuration_maxHistories() {
        long totalWatchTimeMs = 0;
        for (int i = 0; i < CHANNEL_RECORD_MAX_HISTORY_SIZE; ++i) {
            long durationMs = addWatchLog();
            totalWatchTimeMs += durationMs;
        }

    assertThat(mChannelRecord.getTotalWatchDurationMs()).isEqualTo(totalWatchTimeMs);
    }

    @Test
    public void testGetTotalWatchDuration_moreThanMaxHistories() {
        long totalWatchTimeMs = 0;
        long firstDurationMs = 0;
        for (int i = 0; i < CHANNEL_RECORD_MAX_HISTORY_SIZE + 1; ++i) {
            long durationMs = addWatchLog();
            totalWatchTimeMs += durationMs;
            if (i == 0) {
                firstDurationMs = durationMs;
            }
        }

    // Only latest CHANNEL_RECORD_MAX_HISTORY_SIZE logs are remained.
    assertThat(mChannelRecord.getTotalWatchDurationMs())
        .isEqualTo(totalWatchTimeMs - firstDurationMs);
    }

    /**
     * Add new log history to channelRecord which its duration is lower than 1 minute.
     *
     * @return New watch log's duration time in milliseconds.
     */
    private long addWatchLog() {
        // Time hopping with random seconds.
        mLatestWatchEndTimeMs += TimeUnit.SECONDS.toMillis(mRandom.nextInt(60) + 1);

        long durationMs = TimeUnit.SECONDS.toMillis(mRandom.nextInt(60) + 1);
        mChannelRecord.logWatchHistory(
                new WatchedProgram(
                        null, mLatestWatchEndTimeMs, mLatestWatchEndTimeMs + durationMs));
        mLatestWatchEndTimeMs += durationMs;

        return durationMs;
    }
}