package org.lucares.pdbui;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.SocketAddress;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.Callable;
import java.util.concurrent.TimeoutException;
import java.util.zip.GZIPInputStream;

import org.lucares.pdbui.CsvReaderSettings.ColumnDefinitions;
import org.lucares.performance.db.Entries;

public final class IngestionHandler implements Callable<Void> {

    final Socket clientSocket;
    private final ArrayBlockingQueue<Entries> queue;

    public IngestionHandler(final Socket clientSocket, final ArrayBlockingQueue<Entries> queue) {
        this.clientSocket = clientSocket;
        this.queue = queue;
    }

    @Override
    public Void call() throws Exception {
        final SocketAddress clientAddress = clientSocket.getRemoteSocketAddress();
        Thread.currentThread().setName("worker-" + clientAddress);
        TcpIngestor.LOGGER.debug("opening streams to client");
        try (PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);
                InputStream in = new BufferedInputStream(clientSocket.getInputStream());) {

            TcpIngestor.LOGGER.debug("reading from stream");
            handleInputStream(in);

            TcpIngestor.LOGGER.debug("connection closed: " + clientAddress);
        } catch (final Throwable e) {
            TcpIngestor.LOGGER.warn("Stream handling failed", e);
            throw e;
        }

        return null;
    }

    private void handleInputStream(final InputStream in) throws IOException, InterruptedException, TimeoutException {
        in.mark(1);
        final byte firstByte = (byte) in.read();
        if (isGZIP(firstByte)) {
            in.reset();
            final GZIPInputStream gzip = new GZIPInputStream(in);

            handleInputStream(gzip);
        } else {
            in.reset();
            final CsvToEntryTransformer csvTransformer = new CsvToEntryTransformer(queue,
                    CsvReaderSettings.create("@timestamp", "duration", ",", new ColumnDefinitions()));
            csvTransformer.readCSV(in);
        }
    }

    private boolean isGZIP(final byte firstByte) {
        // GZIP starts with 0x1f, 0x8b, see https://www.ietf.org/rfc/rfc1952.txt section
        // 2.3.1
        // I am cheap and only check the first byte
        return firstByte == 0x1f;
    }
}