/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.kafka.streams;

import org.apache.kafka.streams.state.QueryableStoreType;

import java.util.Objects;

/**
 * Represents all the query options that a user can provide to state what kind of stores it is expecting. The options would be whether a user would want to enable/disable stale stores* or whether it knows the list of partitions that it specifically wants to fetch. If this information is not provided the default behavior is to fetch the stores for all the partitions available on that instance* for that particular store name.
 * It contains a partition, which for a point queries can be populated from the  KeyQueryMetadata.
 */
public class StoreQueryParams<T> {

    private Integer partition;
    private boolean includeStaleStores;
    private final String storeName;
    private final QueryableStoreType<T> queryableStoreType;

    public StoreQueryParams(final String storeName, final QueryableStoreType<T>  queryableStoreType) {
        this.storeName = storeName;
        this.queryableStoreType = queryableStoreType;
    }

    public StoreQueryParams withPartition(final Integer partition) {
        this.partition = partition;
        return this;
    }

    public StoreQueryParams withIncludeStaleStores(final boolean includeStaleStores) {
        this.includeStaleStores = includeStaleStores;
        return this;
    }

    /**
     * Get the partition to be used to fetch list of Queryable store from QueryableStoreProvider.
     *
     * @return an Integer partition
     */
    public Integer getPartition() {
        return partition;
    }

    /**
     * Get the flag includeStaleStores. If true, include standbys and recovering stores along with running stores
     *
     * @return boolean includeStaleStores
     */
    public boolean includeStaleStores() {
        return includeStaleStores;
    }

    /**
     * Get the store name for which key is queried by the user.
     *
     * @return String storeName
     */
    public String getStoreName() {
        return storeName;
    }

    /**
     * Get the queryable store type for which key is queried by the user.
     *
     * @return QueryableStoreType queryableStoreType
     */
    public QueryableStoreType<T> getQueryableStoreType() {
        return queryableStoreType;
    }

    /**
     * Get whether the store query params are fetching all partitions or a single partition.
     *
     * @return boolean. True, if all partitions are requests or false if a specific partition is requested
     */
    public boolean getAllLocalPartitions() {
        return partition == null ? true : false;
    }

    @Override
    public boolean equals(final Object obj) {
        if (!(obj instanceof StoreQueryParams)) {
            return false;
        }
        final StoreQueryParams storeQueryParams = (StoreQueryParams) obj;
        return Objects.equals(storeQueryParams.partition, partition)
                && Objects.equals(storeQueryParams.includeStaleStores, includeStaleStores)
                && Objects.equals(storeQueryParams.storeName, storeName)
                && Objects.equals(storeQueryParams.queryableStoreType, queryableStoreType);
    }

    @Override
    public String toString() {
        return "StoreQueryParams {" +
                "partition=" + partition +
                ", includeStaleStores=" + includeStaleStores +
                ", storeName=" + storeName +
                ", queryableStoreType=" + queryableStoreType +
                '}';
    }

    @Override
    public int hashCode() {
        return Objects.hash(partition, includeStaleStores, storeName, queryableStoreType);
    }
}

     /**
     * Get a facade wrapping the local {@link StateStore} instances with the provided {@code storeName} if the Store's
     * type is accepted by the provided {@link QueryableStoreType#accepts(StateStore) queryableStoreType}.
     * The returned object can be used to query the {@link StateStore} instances.
     *
     * Only permits queries on active replicas of the store (no standbys or restoring replicas).
     * See {@link KafkaStreams#store(String, QueryableStoreType, StoreQueryParams)}
     * for the option to set {@code StoreQueryParams.withAllPartitionAndStaleStoresEnabled or StoreQueryParams.withPartitionAndStaleStoresEnabled(final Integer partition)} and trade off consistency in favor of availability.
     *
     * @param storeName           name of the store to find
     * @param queryableStoreType  accept only stores that are accepted by {@link QueryableStoreType#accepts(StateStore)}
     * @param <T>                 return type
     * @return A facade wrapping the local {@link StateStore} instances
     * @throws InvalidStateStoreException if Kafka Streams is (re-)initializing or a store with {@code storeName} and
     * {@code queryableStoreType} doesn't exist
     */
    public <T> T store(final String storeName, final QueryableStoreType<T> queryableStoreType) {
        return store(storeName, queryableStoreType, StoreQueryParams.withAllPartitionAndStaleStoresDisabled());
    }

    /**
     * Get a facade wrapping the local {@link StateStore} instances with the provided {@code storeName} if the Store's
     * type is accepted by the provided {@link QueryableStoreType#accepts(StateStore) queryableStoreType}.
     * The returned object can be used to query the {@link StateStore} instances.
     *
     * @param storeName           name of the store to find
     * @param queryableStoreType  accept only stores that are accepted by {@link QueryableStoreType#accepts(StateStore)}
     * @param storeQueryParams    If StoreQueryParams.withAllPartitionAndStaleStoresDisabled() is used, it only permit queries on the active replicas for all the partitions
     *                            available on the local instance, and only if the
     *                            task for that partition is running. I.e., the state store is not a standby replica,
     *                            and it is not restoring from the changelog.
     *                            If StoreQueryParams.withPartitionAndStaleStoresEnabled(final Integer partition) is used, it only permit queries on the specific provided active replicas
     *                            for the partition provided in the parameter, and only if the
     *                            task for that partition is running. I.e., the state store is not a standby replica,
     *                            and it is not restoring from the changelog.
     *                            If StoreQueryParams.withAllPartitionAndStaleStoresEnabled(), allow queries on standbys and restoring replicas in addition to active ones.
     *                            If StoreQueryParams.withPartitionAndStaleStoresEnabled(final Integer partition), allow queries on the specific partition irrespective if it is a standby
     *                            or a restoring replicas in addition to active ones.
     * @param <T>                 return type
     * @return A facade wrapping the local {@link StateStore} instances
     * @throws InvalidStateStoreException if Kafka Streams is (re-)initializing or a store with {@code storeName} and
     * {@code queryableStoreType} doesn't exist
     */
    public <T> T store(final String storeName,
                       final QueryableStoreType<T> queryableStoreType,
                       final StoreQueryParams storeQueryParams) {
        validateIsRunningOrRebalancing();
        return queryableStoreProvider.getStore(storeName, queryableStoreType, storeQueryParams);
    }