package perf;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;

class TCPPerfServer {
	public static void main(String argv[]) throws Exception {
		int tcpPort = 36039;
		Long clientNumberOfMegabytes;

		ServerSocket serverSocket = new ServerSocket(tcpPort);

		System.out.println("TCPPerfServer gestartet. Warte auf eingehende Requests...");
		
		while (true) {
			Socket connectionSocket = serverSocket.accept();

			BufferedReader inFromClient = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
			BufferedWriter outToClient = new BufferedWriter(new OutputStreamWriter(connectionSocket.getOutputStream()));

			char[] buffer = new char[1024];
			clientNumberOfMegabytes = new Long(inFromClient.readLine());
		
			if (clientNumberOfMegabytes == 0) {
				connectionSocket.close();
				break;
			}
			
			System.out.println("Request von TCPPerfClient " + connectionSocket.getInetAddress() + ":" + connectionSocket.getPort() + " empfangen. Erzeuge und sende " + clientNumberOfMegabytes + "MB ...");

			for (long mb = 0; mb < clientNumberOfMegabytes; mb++) {
				long megabyteStartTimeMilli = System.currentTimeMillis();
				for (long segment = 1; segment < 1024; segment++) {
					long segmentStartTimeNano = System.nanoTime();
					outToClient.write(buffer);
					if (clientNumberOfMegabytes == 1) {
						double transferDurationSegment = System.nanoTime() - segmentStartTimeNano;
						//System.out.printf("Dauer pro Segment: %.0f ns, Rate: %.0f KByte/s (MB: %d, Segment: %d)\n", transferDurationSegment, (1024 / (transferDurationSegment / 1000000000)), mb, segment);
						// CSV Output Excel
						System.out.println(mb + "," + segment + "," + transferDurationSegment);
					}
				}
				double transferDurationMB = System.currentTimeMillis() - megabyteStartTimeMilli;
				System.out.printf("1 MB (genauer MiB) gesendet in: %.0f ms, Rate: %.0f Bytes/s (MB: %d)\n", transferDurationMB, ((1024 * 1024) / (transferDurationMB / 1000)), mb);
			}
			System.out.print("\n");
			connectionSocket.close();
		}
		serverSocket.close();
	}
}