/*
 * 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.streampipes.dataexplorer.v4.query;

import org.apache.streampipes.dataexplorer.v4.query.elements.QueryElement;
import org.influxdb.dto.Query;

import java.util.List;
import java.util.StringJoiner;

public class QueryBuilder {

    private final StringJoiner queryParts;
    private final String databaseName;

    public static QueryBuilder create(String databaseName) {
        return new QueryBuilder(databaseName);
    }

    private QueryBuilder(String databaseName) {
        this.queryParts = new StringJoiner(" ");
        this.databaseName = databaseName;
    }

    public Query build(List<QueryElement<?>> queryElements, Boolean onlyCountResults) {
        for (QueryElement<?> queryPart : queryElements) {
            this.queryParts.add(queryPart.getStatement());
        }
        if (onlyCountResults) {
            return toCountResultsQuery();
        } else {
            return toQuery();
        }
    }

    public Query toQuery() {
        return new Query(this.queryParts.toString(), this.databaseName);
    }

    public Query toCountResultsQuery() {
        String q = "SELECT COUNT(*) FROM (" + this.queryParts.toString() + ")";
        return new Query(q, this.databaseName);
    }
}



