/*
 * Copyright (c) "Neo4j"
 * Neo4j Sweden AB [http://neo4j.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.neo4j.server.http.cypher;

import java.net.URI;
import java.util.List;
import java.util.Map;
import java.util.function.Consumer;
import java.util.function.Function;
import org.neo4j.graphdb.ExecutionPlanDescription;
import org.neo4j.graphdb.Notification;
import org.neo4j.graphdb.QueryExecutionType;
import org.neo4j.graphdb.QueryStatistics;
import org.neo4j.kernel.api.exceptions.Status;
import org.neo4j.server.http.cypher.format.api.FailureEvent;
import org.neo4j.server.http.cypher.format.api.OutputEvent;
import org.neo4j.server.http.cypher.format.api.OutputEventSource;
import org.neo4j.server.http.cypher.format.api.RecordEvent;
import org.neo4j.server.http.cypher.format.api.Statement;
import org.neo4j.server.http.cypher.format.api.StatementEndEvent;
import org.neo4j.server.http.cypher.format.api.StatementStartEvent;
import org.neo4j.server.http.cypher.format.api.TransactionInfoEvent;
import org.neo4j.server.http.cypher.format.api.TransactionNotificationState;
import org.neo4j.server.http.cypher.format.api.TransactionUriScheme;

class OutputEventStreamImpl implements OutputEventSource, OutputEventStream {

    private final Consumer<OutputEventStream> startListener;
    private final Map<String, Object> parameters;
    private final TransactionUriScheme uriInfo;
    private Consumer<OutputEvent> eventListener;

    OutputEventStreamImpl(
            Map<String, Object> parameters, TransactionUriScheme uriInfo, Consumer<OutputEventStream> startListener) {
        this.parameters = parameters;
        this.startListener = startListener;
        this.uriInfo = uriInfo;
    }

    @Override
    public void produceEvents(Consumer<OutputEvent> eventListener) {
        this.eventListener = eventListener;
        startListener.accept(this);
    }

    @Override
    public Map<String, Object> getParameters() {
        return parameters;
    }

    @Override
    public void writeStatementStart(Statement statement, List<String> columns) {
        notifyListener(new StatementStartEvent(statement, columns));
    }

    @Override
    public void writeStatementEnd(
            QueryExecutionType queryExecutionType,
            QueryStatistics queryStatistics,
            ExecutionPlanDescription executionPlanDescription,
            Iterable<Notification> notifications) {
        notifyListener(
                new StatementEndEvent(queryExecutionType, queryStatistics, executionPlanDescription, notifications));
    }

    @Override
    public void writeRecord(List<String> columns, Function<String, Object> valueSupplier) {
        notifyListener(new RecordEvent(columns, valueSupplier));
    }

    @Override
    public void writeTransactionInfo(
            TransactionNotificationState notification, URI commitUri, long expirationTimestamp, String bookmark) {
        notifyListener(new TransactionInfoEvent(notification, commitUri, expirationTimestamp, bookmark));
    }

    @Override
    public void writeFailure(Status status, String message) {
        notifyListener(new FailureEvent(status, message));
    }

    private void notifyListener(OutputEvent event) {
        eventListener.accept(event);
    }

    @Override
    public TransactionUriScheme getUriInfo() {
        return uriInfo;
    }
}
