import javax.imageio.*;
import java.awt.image.*;
import java.awt.event.*;
import java.awt.*;
import java.security.NoSuchAlgorithmException;
import java.security.MessageDigest;
import java.lang.reflect.*;
import java.net.*;
import java.io.*;
import javax.swing.text.*;
import javax.swing.*;
import java.util.concurrent.*;
import java.util.regex.*;
import java.util.List;
import java.util.zip.*;
import java.util.*;

public class main {
  public static void main(String[] args) throws Exception {
    print("Your computer ID: " + computerID());
  }

static void print() {
  System.out.println();
}

static void print(Object o) {
  System.out.println(o);
}

static void print(long i) {
  System.out.println(i);
}

static String _computerID;
public static String computerID() throws IOException {
  if (_computerID == null) {
    File file = new File(userHome(), ".tinybrain/computer-id");
    _computerID = loadTextFile(file.getPath(), null);
    if (_computerID == null) {
      _computerID = makeRandomID(12);
      saveTextFile(file.getPath(), _computerID);
    }
  }
  return _computerID;
}

  /** writes safely (to temp file, then rename) */
  public static void saveTextFile(String fileName, String contents) throws IOException {
    File file = new File(fileName);
    File parentFile = file.getParentFile();
    if (parentFile != null)
      parentFile.mkdirs();
    String tempFileName = fileName + "_temp";
    FileOutputStream fileOutputStream = new FileOutputStream(tempFileName);
    OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fileOutputStream, "UTF-8");
    PrintWriter printWriter = new PrintWriter(outputStreamWriter);
    printWriter.print(contents);
    printWriter.close();
    if (file.exists() && !file.delete())
      throw new IOException("Can't delete " + fileName);

    if (!new File(tempFileName).renameTo(file))
      throw new IOException("Can't rename " + tempFileName + " to " + fileName);
  }

  public static String loadTextFile(String fileName, String defaultContents) throws IOException {
    if (!new File(fileName).exists())
      return defaultContents;

    FileInputStream fileInputStream = new FileInputStream(fileName);
    InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream, "UTF-8");
    return loadTextFile(inputStreamReader);
  }

  public static String loadTextFile(Reader reader) throws IOException {
    StringBuilder builder = new StringBuilder();
    try {
      BufferedReader bufferedReader = new BufferedReader(reader);
      String line;
      while ((line = bufferedReader.readLine()) != null)
        builder.append(line).append('\n');
    } finally {
      reader.close();
    }
    return builder.length() == 0 ? "" : builder.substring(0, builder.length()-1);
  }

static String _userHome;
static String userHome() {
  if (_userHome == null) {
    if (isAndroid())
      _userHome = "/storage/sdcard0/";
    else
      _userHome = System.getProperty("user.home");
    //System.out.println("userHome: " + _userHome);
  }
  return _userHome;
}


static String makeRandomID(int length) {
  Random random = new Random();
  char[] id = new char[length];
  for (int i = 0; i< id.length; i++)
    id[i] = (char) ((int) 'a' + random.nextInt(26));
  return new String(id);
}

static boolean isAndroid() { return System.getProperty("java.vendor").toLowerCase().indexOf("android") >= 0; }
}