package net.sourceforge.fenixedu._development;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.HashSet;
import java.util.Set;

import pt.utl.ist.fenix.tools.util.FileUtils;

public class Custodian {

    private static Set<Integer> pids = new HashSet<Integer>();

    public static void registerPID() {
	try {
	    final Process process = Runtime.getRuntime().exec("ps");
	    process.waitFor();
	    final String processOutput = readProcessOutput(process);
	    final String[] lines = processOutput.split("\n");
	    for (int i = 0; i < lines.length; i++) {
		final String line = lines[i].trim();
		final String[] psParts = line.split(" ");
		final String pid = psParts[0].trim();

		for (int k = 1; k < psParts.length; k++) {
		    final String command = psParts[k].trim();
		    if (command.startsWith("java") || command.endsWith("/java") || command.endsWith("\\java")) {
			pids.add(Integer.valueOf(pid));

			System.out.println("Adding pid: " + pid + " to custodians register.");
		    }
		}
	    }
	    if (pids.isEmpty()) {
		System.out.println("No java pids where found!?!");
	    }
	} catch (Exception e) {
	    System.out.println("Unable to determine PID: " + e.getMessage());
	}
    }

    public static void dumpThreadTrace() throws IOException, InterruptedException {
	if (!pids.isEmpty()) {
	    final StringBuilder stringBuilder = new StringBuilder();
	    stringBuilder.append("kill -QUIT");
	    for (final Integer pid : pids) {
		stringBuilder.append(" ");
		stringBuilder.append(pid);
	    }
	    System.out.println("Sending kill -QUIT signal to java processes.");
	    final Process process = Runtime.getRuntime().exec(stringBuilder.toString());
	    process.waitFor();
	}
    }

    private static String readProcessOutput(final Process process) throws IOException {
	final ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
	FileUtils.copy(process.getInputStream(), byteArrayOutputStream);
	return byteArrayOutputStream.toString();
    }

}