package org.apidesign.deadlock.startuplock;

import java.io.DataOutputStream;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.net.ServerSocket;

public final class CLIHandler {

    // BEGIN: cli.vision

    public static int start(File lockFile) throws IOException {

        if (lockFile.exists ()) {

            // read the port number and connect to it

            int alive = readPortNumber(lockFile);

            if (alive != -1) {

                // exit

                return alive;

            }

        }

        // otherwise try to create the file yourself

        lockFile.createNewFile();

        DataOutputStream os = new DataOutputStream(new FileOutputStream(lockFile));

        ServerSocket server = new ServerSocket();

        int p = server.getLocalPort();

        os.writeInt(p);

        return p;

    }

    // END: cli.vision

    private static int readPortNumber(File lockFile) throws IOException {

        return -1;

    }

}