/*
 * 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.flink.connector.jdbc.databases.mysql.dialect;

import org.apache.flink.annotation.Internal;
import org.apache.flink.connector.jdbc.converter.JdbcRowConverter;
import org.apache.flink.connector.jdbc.dialect.AbstractDialect;
import org.apache.flink.table.types.logical.LogicalTypeRoot;
import org.apache.flink.table.types.logical.RowType;

import java.util.Arrays;
import java.util.EnumSet;
import java.util.Optional;
import java.util.Set;
import java.util.stream.Collectors;

/** JDBC dialect for MySQL. */
@Internal
public class MySqlDialect extends AbstractDialect {

    private static final long serialVersionUID = 1L;

    // Define MAX/MIN precision of TIMESTAMP type according to Mysql docs:
    // https://dev.mysql.com/doc/refman/8.0/en/fractional-seconds.html
    private static final int MAX_TIMESTAMP_PRECISION = 6;
    private static final int MIN_TIMESTAMP_PRECISION = 0;

    // Define MAX/MIN precision of DECIMAL type according to Mysql docs:
    // https://dev.mysql.com/doc/refman/8.0/en/fixed-point-types.html
    private static final int MAX_DECIMAL_PRECISION = 65;
    private static final int MIN_DECIMAL_PRECISION = 1;

    // The JDBC option to enable execute multiple MySQL statements in batch mode:
    // https://dev.mysql.com/doc/connector-j/8.0/en/connector-j-connp-props-performance-extensions.html#cj-conn-prop_rewriteBatchedStatements
    private static final String REWRITE_BATCHED_STATEMENTS = "rewriteBatchedStatements";

    @Override
    public JdbcRowConverter getRowConverter(RowType rowType) {
        return new MySQLRowConverter(rowType);
    }

    @Override
    public String getLimitClause(long limit) {
        return "LIMIT " + limit;
    }

    @Override
    public Optional<String> defaultDriverName() {
        return Optional.of("com.mysql.jdbc.Driver");
    }

    @Override
    public String quoteIdentifier(String identifier) {
        return "`" + identifier + "`";
    }

    /**
     * Mysql upsert query use DUPLICATE KEY UPDATE.
     *
     * <p>NOTE: It requires Mysql's primary key to be consistent with pkFields.
     *
     * <p>We don't use REPLACE INTO, if there are other fields, we can keep their previous values.
     */
    @Override
    public Optional<String> getUpsertStatement(
            String tableName, String[] fieldNames, String[] uniqueKeyFields) {
        String updateClause =
                Arrays.stream(fieldNames)
                        .map(f -> quoteIdentifier(f) + "=VALUES(" + quoteIdentifier(f) + ")")
                        .collect(Collectors.joining(", "));
        return Optional.of(
                getInsertIntoStatement(tableName, fieldNames)
                        + " ON DUPLICATE KEY UPDATE "
                        + updateClause);
    }

    @Override
    public String dialectName() {
        return "MySQL";
    }

    @Override
    public Optional<Range> decimalPrecisionRange() {
        return Optional.of(Range.of(MIN_DECIMAL_PRECISION, MAX_DECIMAL_PRECISION));
    }

    @Override
    public Optional<Range> timestampPrecisionRange() {
        return Optional.of(Range.of(MIN_TIMESTAMP_PRECISION, MAX_TIMESTAMP_PRECISION));
    }

    @Override
    public Set<LogicalTypeRoot> supportedTypes() {
        // The data types used in Mysql are list at:
        // https://dev.mysql.com/doc/refman/8.0/en/data-types.html

        // TODO: We can't convert BINARY data type to
        //  PrimitiveArrayTypeInfo.BYTE_PRIMITIVE_ARRAY_TYPE_INFO in
        // LegacyTypeInfoDataTypeConverter.
        return EnumSet.of(
                LogicalTypeRoot.CHAR,
                LogicalTypeRoot.VARCHAR,
                LogicalTypeRoot.BOOLEAN,
                LogicalTypeRoot.VARBINARY,
                LogicalTypeRoot.DECIMAL,
                LogicalTypeRoot.TINYINT,
                LogicalTypeRoot.SMALLINT,
                LogicalTypeRoot.INTEGER,
                LogicalTypeRoot.BIGINT,
                LogicalTypeRoot.FLOAT,
                LogicalTypeRoot.DOUBLE,
                LogicalTypeRoot.DATE,
                LogicalTypeRoot.TIME_WITHOUT_TIME_ZONE,
                LogicalTypeRoot.TIMESTAMP_WITHOUT_TIME_ZONE);
    }

    @Override
    public String appendDefaultUrlProperties(String url) {
        if (!url.contains(REWRITE_BATCHED_STATEMENTS)) {
            String defaultUrlProperties = REWRITE_BATCHED_STATEMENTS + "=true";
            if (url.contains("?")) {
                return url + "&" + defaultUrlProperties;
            } else {
                return url + "?" + defaultUrlProperties;
            }
        } else {
            return url;
        }
    }
}