/*
 * 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.hugegraph.backend.store.postgresql;

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

import org.apache.hugegraph.backend.id.Id;
import org.apache.hugegraph.backend.store.BackendStore;
import org.apache.hugegraph.backend.store.BackendStoreProvider;
import org.apache.hugegraph.backend.store.mysql.MysqlSessions;
import org.apache.hugegraph.backend.store.mysql.MysqlStoreProvider;
import org.apache.hugegraph.backend.store.mysql.MysqlTable;
import org.apache.hugegraph.config.HugeConfig;
import org.apache.hugegraph.type.HugeType;
import org.apache.hugegraph.type.define.Directions;
import org.apache.hugegraph.util.Log;
import org.slf4j.Logger;

public class PostgresqlStoreProvider extends MysqlStoreProvider {

    private static final Logger LOG = Log.logger(PostgresqlStoreProvider.class);

    @Override
    protected BackendStore newSchemaStore(HugeConfig config, String store) {
        return new PostgresqlSchemaStore(this, this.database(), store);
    }

    @Override
    protected BackendStore newGraphStore(HugeConfig config, String store) {
        return new PostgresqlGraphStore(this, this.database(), store);
    }

    @Override
    protected BackendStore newSystemStore(HugeConfig config, String store) {
        return new PostgresqlSystemStore(this, this.database(), store);
    }

    @Override
    public String type() {
        return "postgresql";
    }

    @Override
    public String driverVersion() {
        /*
         * Versions history:
         * [1.0] #441: supports PostgreSQL and Cockroach backend
         * [1.1] #270 & #398: support shard-index and vertex + sortkey prefix,
         *                    also split range table to rangeInt, rangeFloat,
         *                    rangeLong and rangeDouble
         * [1.2] #633: support unique index
         * [1.3] #661: reduce the storage of vertex/edge id
         * [1.4] #691: support aggregate property
         * [1.5] #746: support userdata for indexlabel
         * [1.6] #894: asStoredString() encoding is changed to signed B64
         *             instead of sortable B64
         * [1.7] #295: support ttl for vertex and edge
         * [1.8] #1333: support read frequency for property key
         * [1.9] #1506: rename read frequency to write type
         * [1.9] #1533: add meta table in system store
         */
        return "1.9";
    }

    public static class PostgresqlSchemaStore extends PostgresqlStore {

        private final PostgresqlTables.Counters counters;

        public PostgresqlSchemaStore(BackendStoreProvider provider,
                                     String database, String store) {
            super(provider, database, store);

            this.counters = new PostgresqlTables.Counters();

            registerTableManager(HugeType.VERTEX_LABEL,
                                 new PostgresqlTables.VertexLabel());
            registerTableManager(HugeType.EDGE_LABEL,
                                 new PostgresqlTables.EdgeLabel());
            registerTableManager(HugeType.PROPERTY_KEY,
                                 new PostgresqlTables.PropertyKey());
            registerTableManager(HugeType.INDEX_LABEL,
                                 new PostgresqlTables.IndexLabel());
        }

        @Override
        protected Collection<MysqlTable> tables() {
            List<MysqlTable> tables = new ArrayList<>(super.tables());
            tables.add(this.counters);
            return tables;
        }

        @Override
        public void increaseCounter(HugeType type, long increment) {
            this.checkOpened();
            MysqlSessions.Session session = this.session(type);
            this.counters.increaseCounter(session, type, increment);
        }

        @Override
        public long getCounter(HugeType type) {
            this.checkOpened();
            MysqlSessions.Session session = this.session(type);
            return this.counters.getCounter(session, type);
        }

        @Override
        public boolean isSchemaStore() {
            return true;
        }
    }

    public static class PostgresqlGraphStore extends PostgresqlStore {

        public PostgresqlGraphStore(BackendStoreProvider provider,
                                    String database, String store) {
            super(provider, database, store);

            registerTableManager(HugeType.VERTEX,
                                 new PostgresqlTables.Vertex(store));
            registerTableManager(HugeType.EDGE_OUT,
                                 new PostgresqlTables.Edge(store,
                                                           Directions.OUT));
            registerTableManager(HugeType.EDGE_IN,
                                 new PostgresqlTables.Edge(store,
                                                           Directions.IN));
            registerTableManager(HugeType.SECONDARY_INDEX,
                                 new PostgresqlTables.SecondaryIndex(store));
            registerTableManager(HugeType.RANGE_INT_INDEX,
                                 new PostgresqlTables.RangeIntIndex(store));
            registerTableManager(HugeType.RANGE_FLOAT_INDEX,
                                 new PostgresqlTables.RangeFloatIndex(store));
            registerTableManager(HugeType.RANGE_LONG_INDEX,
                                 new PostgresqlTables.RangeLongIndex(store));
            registerTableManager(HugeType.RANGE_DOUBLE_INDEX,
                                 new PostgresqlTables.RangeDoubleIndex(store));
            registerTableManager(HugeType.SEARCH_INDEX,
                                 new PostgresqlTables.SearchIndex(store));
            registerTableManager(HugeType.SHARD_INDEX,
                                 new PostgresqlTables.ShardIndex(store));
            registerTableManager(HugeType.UNIQUE_INDEX,
                                 new PostgresqlTables.UniqueIndex(store));
        }

        @Override
        public boolean isSchemaStore() {
            return false;
        }

        @Override
        public Id nextId(HugeType type) {
            throw new UnsupportedOperationException(
                    "PostgresqlGraphStore.nextId()");
        }

        @Override
        public void increaseCounter(HugeType type, long increment) {
            throw new UnsupportedOperationException(
                    "PostgresqlGraphStore.increaseCounter()");
        }

        @Override
        public long getCounter(HugeType type) {
            throw new UnsupportedOperationException(
                    "PostgresqlGraphStore.getCounter()");
        }
    }

    public static class PostgresqlSystemStore extends PostgresqlGraphStore {

        private final PostgresqlTables.Meta meta;

        public PostgresqlSystemStore(BackendStoreProvider provider,
                                     String database, String store) {
            super(provider, database, store);

            this.meta = new PostgresqlTables.Meta();
        }

        @Override
        public void init() {
            super.init();
            this.checkOpened();
            MysqlSessions.Session session = this.session(HugeType.META);
            String driverVersion = this.provider().driverVersion();
            this.meta.writeVersion(session, driverVersion);
            LOG.info("Write down the backend version: {}", driverVersion);
        }

        @Override
        public String storedVersion() {
            super.init();
            this.checkOpened();
            MysqlSessions.Session session = this.session(HugeType.META);
            return this.meta.readVersion(session);
        }

        @Override
        protected Collection<MysqlTable> tables() {
            List<MysqlTable> tables = new ArrayList<>(super.tables());
            tables.add(this.meta);
            return tables;
        }
    }
}