/*
 * 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.server.appsearch;

/**
 * An interface which exposes config flags to AppSearch.
 *
 * <p>This interface provides an abstraction for the platform's flag mechanism and implements
 * caching to avoid expensive lookups.
 *
 * <p>Implementations of this interface must be thread-safe.
 *
 * @hide
 */
public interface AppSearchConfig extends AutoCloseable {
    /**
     * Default min time interval between samples in millis if there is no value set for
     * {@link #getCachedMinTimeIntervalBetweenSamplesMillis()} in the flag system.
     */
    long DEFAULT_MIN_TIME_INTERVAL_BETWEEN_SAMPLES_MILLIS = 50;

    /**
     * Default sampling interval if there is no value set for
     * {@link #getCachedSamplingIntervalDefault()} in the flag system.
     */
    int DEFAULT_SAMPLING_INTERVAL = 10;

    int DEFAULT_LIMIT_CONFIG_MAX_DOCUMENT_SIZE_BYTES = 512 * 1024; // 512KiB
    int DEFAULT_LIMIT_CONFIG_MAX_DOCUMENT_COUNT = 20_000;
    int DEFAULT_BYTES_OPTIMIZE_THRESHOLD = 1 * 1024 * 1024; // 1 MiB
    int DEFAULT_TIME_OPTIMIZE_THRESHOLD_MILLIS = Integer.MAX_VALUE;
    int DEFAULT_DOC_COUNT_OPTIMIZE_THRESHOLD = 10_000;

    /** Returns cached value for minTimeIntervalBetweenSamplesMillis. */
    long getCachedMinTimeIntervalBetweenSamplesMillis();

    /**
     * Returns cached value for default sampling interval for all the stats NOT listed in
     * the configuration.
     *
     * <p>For example, sampling_interval=10 means that one out of every 10 stats was logged.
     */
    int getCachedSamplingIntervalDefault();

    /**
     * Returns cached value for sampling interval for batch calls.
     *
     * <p>For example, sampling_interval=10 means that one out of every 10 stats was logged.
     */
    int getCachedSamplingIntervalForBatchCallStats();

    /**
     * Returns cached value for sampling interval for putDocument.
     *
     * <p>For example, sampling_interval=10 means that one out of every 10 stats was logged.
     */
    int getCachedSamplingIntervalForPutDocumentStats();

    /**
     * Returns cached value for sampling interval for initialize.
     *
     * <p>For example, sampling_interval=10 means that one out of every 10 stats was logged.
     */
    int getCachedSamplingIntervalForInitializeStats();

    /**
     * Returns cached value for sampling interval for search.
     *
     * <p>For example, sampling_interval=10 means that one out of every 10 stats was logged.
     */
    int getCachedSamplingIntervalForSearchStats();

    /**
     * Returns cached value for sampling interval for globalSearch.
     *
     * <p>For example, sampling_interval=10 means that one out of every 10 stats was logged.
     */
    int getCachedSamplingIntervalForGlobalSearchStats();

    /**
     * Returns cached value for sampling interval for optimize.
     *
     * <p>For example, sampling_interval=10 means that one out of every 10 stats was logged.
     */
    int getCachedSamplingIntervalForOptimizeStats();

    /** Returns the maximum serialized size an indexed document can be, in bytes. */
    int getCachedLimitConfigMaxDocumentSizeBytes();

    /** Returns the maximum number of active docs allowed per package. */
    int getCachedLimitConfigMaxDocumentCount();

    /**
     * Returns the cached optimize byte size threshold.
     *
     * An AppSearch Optimize job will be triggered if the bytes size of garbage resource exceeds
     * this threshold.
     */
    int getCachedBytesOptimizeThreshold();

    /**
     * Returns the cached optimize time interval threshold.
     *
     * An AppSearch Optimize job will be triggered if the time since last optimize job exceeds
     * this threshold.
     */
    int getCachedTimeOptimizeThresholdMs();

    /**
     * Returns the cached optimize document count threshold threshold.
     *
     * An AppSearch Optimize job will be triggered if the number of document of garbage resource
     * exceeds this threshold.
     */
    int getCachedDocCountOptimizeThreshold();

    /**
     * Closes this {@link AppSearchConfig}.
     *
     * <p>This close() operation does not throw an exception.
     */
    @Override
    void close();
}