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/*
 * Copyright (c) 2019, 2023 Oracle and/or its affiliates.
 *
 * 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 io.helidon.dbclient;

import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.List;
import java.util.Map;
import java.util.concurrent.CompletableFuture;
import java.util.function.BiFunction;
import java.util.stream.Stream;

import static io.helidon.dbclient.DbStatementParameters.UNDEFINED;

/**
 * Base {@link DbStatement} implementation.
 *
 * @param  type of subclass
 */
public abstract class DbStatementBase> implements DbStatement {

    private final DbExecuteContext context;
    private DbStatementParameters parameters;

    /**
     * Create a new instance.
     *
     * @param context context
     */
    protected DbStatementBase(DbExecuteContext context) {
        this.context = context;
    }

    /**
     * Get the execution context.
     *
     * @return execution context
     */
    public DbExecuteContext context() {
        return context;
    }

    /**
     * Returns execution context cast to it's extending class.
     *
     * @param cls {@link DbExecuteContext} extending class
     * @return extended execution context
     * @param  execution context extending type
     */
    protected  C context(Class cls) {
        return cls.cast(context);
    }

    /**
     * Get the statement parameters.
     *
     * @return statement parameters
     */
    public DbStatementParameters parameters() {
        return parameters != null ? parameters : UNDEFINED;
    }

    /**
     * Get the statement type.
     *
     * @return statement type
     */
    public abstract DbStatementType statementType();

    /**
     * Execute the statement with interception.
     *
     * @param function function used to compute the query result
     * @param       query result type
     * @return query result
     */
    protected  T doExecute(BiFunction, DbClientServiceContext, T> function) {
        CompletableFuture stmtFuture = new CompletableFuture<>();
        CompletableFuture queryFuture = new CompletableFuture<>();
        queryFuture.whenComplete((r, ex) -> stmtFuture.complete(null));
        DbClientServiceContext serviceContext =
                new DbClientServiceContextImpl(context, statementType(), stmtFuture, queryFuture, parameters);
        context().clientServices().forEach(service -> service.statement(serviceContext));
        return function.apply(queryFuture, serviceContext);
    }

    /**
     * Decorate the given stream to invoke {@link Stream#close()} on terminal operations.
     *
     * @param stream stream to decorate
     * @param     the type of the stream elements
     * @return decorated stream
     */
    protected static  Stream autoClose(Stream stream) {
        return AutoClosingStream.decorate(stream);
    }

    @Override
    public S namedParam(Object parameters) {
        @SuppressWarnings("unchecked")
        Class