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.event.*;
import javax.swing.*;
import java.util.concurrent.atomic.*;
import java.util.concurrent.*;
import java.util.regex.*;
import java.util.List;
import java.util.zip.*;
import java.util.*;


public class main {
  static List<String> rules = litlist(
    " on \"hello\", say \"hello you too\" "
  );
  
  public static void main(String[] args) throws Exception {
    readLocally("rules");
    answerQuestionsOnPortAndConsole(new StringFunc() {
public String get(String s) {
try { return 
      fallback(s, answer(s))
    ; } catch (Exception _e) {
  throw _e instanceof RuntimeException ? (RuntimeException) _e : new RuntimeException(_e); } }
});
  }
  
  static class Matches {
    String[] m;
  }
  
  static String fallback(String s, String answer) {
    if (answer != null) return answer;
    return "?";
  }
  
  static synchronized String answer(String s) {
    if (match("on * say *", s)) {
      rules.add(0, s); // add rule on top to override others
      saveLocally("rules");
      return "ok";
    }
      
    Matches matches = new Matches();
    for (String rule : rules) {
      if (match("on * say *", rule, matches)) {
        String in = matches.m[0], out = matches.m[1];
        if (match(unquote(in), s))
          return unquote(out);
      }
    }
    return null;
  }
  
  static boolean match(String pat, String s) {
    return match(pat, s, null);
  }
  
  static boolean match(String pat, String s, Matches matches) {
    List<String> tokpat = parse(pat), toks = parse(s);
    String[] m = match2(tokpat, toks);
    //print(structure(tokpat) + " on " + structure(toks) + " => " + structure(m));
    if (m == null)
      return false;
    else {
      if (matches != null) matches.m = m;
      return true;
    }
  }
  
  static List<String> parse(String s) {
    return dropPunctuation(javaTokPlusPeriod(s));
  }



  static abstract class DialogIO {
    abstract boolean isStillConnected();
    abstract String readLineNoBlock();
    abstract boolean waitForLine();
    abstract void sendLine(String line);
    abstract boolean isLocalConnection();
    abstract Socket getSocket();
  }
  
  static abstract class DialogHandler {
    abstract void run(DialogIO io);
  } // Dialog classes

static int answerQuestions_defaultPort = 5000;

static void answerQuestionsOnPort(final StringFunc f) {
  answerQuestionsOnPort(answerQuestions_defaultPort, f);
}

static void answerQuestionsOnPort(int port, final StringFunc f) {
  startDialogServer(port, new DialogHandler() {
public void run(final DialogIO io) {

    String dialogID = randomID(8);
    
    io.sendLine("Your ID: " + dialogID);
    
    while (io.isStillConnected()) {
      if (io.waitForLine()) {
        String line = io.readLineNoBlock();
        String s = dialogID + " at " + now() + ": " + quote(line);
        print(s);
        if ("bye".equals(line)) {
          io.sendLine("bye stranger");
          return;
        }
        String answer = answerQuestions_getAnswer(line, f);
        io.sendLine(answer == null ? "null" : answer);
        //appendToLog(logFile, s);
      }
    }
  
}});
}

static String answerQuestions_getAnswer(String line, StringFunc f) {
  String answer;
  try {
    answer = f.get(line);
  } catch (Throwable e) {
    e.printStackTrace();
    answer = e.toString();
  }
  print("> " + answer);
  return answer;
}

static void answerQuestionsOnPortAndConsole(final StringFunc f) {
  answerQuestionsOnPortAndConsole(answerQuestions_defaultPort, f);
}

static void answerQuestionsOnPortAndConsole(int port, final StringFunc f) {
  answerQuestionsOnPort(port, f);
  print("You may also type on this console.");
  String line;
  while ((line = readLine()) != null) {
    if ("bye".equals(line))
      print("! bye stranger");
    else
      answerQuestions_getAnswer(line, f); // prints answer on console too
  }
}


static String programID;

static synchronized void saveLocally(String variableName) {
  File textFile = new File(programDir(programID), variableName + ".text");
  File structureFile = new File(programDir(programID), variableName + ".structure");
  Object x = get(main.class, variableName);
  
  if (x == null) {
    textFile.delete();
    structureFile.delete();
  } else if (x instanceof String) {
    structureFile.delete();
    saveTextFile(textFile, (String) x);
  } else {
    textFile.delete();
    saveTextFile(structureFile, structure(x));
  }
}
static synchronized void readLocally(String variableName) {
  File textFile = new File(programDir(programID), variableName + ".text");
  File structureFile = new File(programDir(programID), variableName + ".structure");
  
  String value = loadTextFile(textFile);
  if (value != null)
    set(main.class, variableName, value);
  else {
    value = loadTextFile(structureFile);
    if (value != null)
    set(main.class, variableName, unstructure(value));
  }
}


static <A> ArrayList<A> litlist(A... a) {
  return new ArrayList<A>(Arrays.asList(a));
}

static List<String> dropPunctuation(List<String> tok) {
  tok = new ArrayList<String>(tok);
  for (int i = 1; i < tok.size(); i += 2) {
    String t = tok.get(i);
    if (t.length() == 1 && !Character.isLetter(t.charAt(0)) && !Character.isDigit(t.charAt(0)) && !"*".equals(t)) {
      tok.set(i-1, tok.get(i-1) + tok.get(i+1));
      tok.remove(i);
      tok.remove(i);
      i -= 2;
    }
  }
  return tok;
}

// match2 matches multiple "*" (matches a single token) wildcards and zero or one "..." wildcards (matches multiple tokens)

static String[] match2(List<String> pat, List<String> tok) {
  // standard case (no ...)
  int i = pat.indexOf("...");
  if (i < 0) return match2_match(pat, tok);
  
  
  pat = new ArrayList<String>(pat); // We're modifying it, so copy first
  pat.set(i, "*");
  int expand = 0;
  while (pat.size() < tok.size()) {
    ++expand;
    pat.add(i, "*");
    pat.add(i+1, ""); // doesn't matter
  }
  
  return match2_match(pat, tok);
}

static String[] match2_match(List<String> pat, List<String> tok) {
  List<String> result = new ArrayList<String>();
  if (pat.size() != tok.size()) {
    /*if (debug)
      print("Size mismatch: " + structure(pat) + " vs " + structure(tok));*/
    return null;
  }
  for (int i = 1; i < pat.size(); i += 2) {
    String p = pat.get(i), t = tok.get(i);
    /*if (debug)
      print("Checking " + p + " against " + t);*/
    if ("*".equals(p))
      result.add(t);
    else if (!p.equals(t))
      return null;
  }
  return result.toArray(new String[result.size()]);
}


// javaTok extended with "..." token.

static List<String> javaTokPlusPeriod(String s) {
  List<String> tok = new ArrayList<String>();
  int l = s.length();
  
  int i = 0;
  while (i < l) {
    int j = i;
    char c; String cc;
    
    // scan for whitespace
    while (j < l) {
      c = s.charAt(j);
      cc = s.substring(j, Math.min(j+2, l));
      if (c == ' ' || c == '\t' || c == '\r' || c == '\n')
        ++j;
      else if (cc.equals("/*")) {
        do ++j; while (j < l && !s.substring(j, Math.min(j+2, l)).equals("*/"));
        j = Math.min(j+2, l);
      } else if (cc.equals("//")) {
        do ++j; while (j < l && "\r\n".indexOf(s.charAt(j)) < 0);
      } else
        break;
    }
    
    tok.add(s.substring(i, j));
    i = j;
    if (i >= l) break;
    c = s.charAt(i); // cc is not needed in rest of loop body
    cc = s.substring(i, Math.min(i+2, l));

    // scan for non-whitespace
    if (c == '\'' || c == '"') {
      char opener = c;
      ++j;
      while (j < l) {
        if (s.charAt(j) == opener) {
          ++j;
          break;
        } else if (s.charAt(j) == '\\' && j+1 < l)
          j += 2;
        else
          ++j;
      }
    } else if (Character.isJavaIdentifierStart(c))
      do ++j; while (j < l && Character.isJavaIdentifierPart(s.charAt(j)));
    else if (Character.isDigit(c))
      do ++j; while (j < l && Character.isDigit(s.charAt(j)));
    else if (cc.equals("[[")) {
      do ++j; while (j+1 < l && !s.substring(j, j+2).equals("]]"));
      j = Math.min(j+2, l);
    } else if (s.substring(j, Math.min(j+3, l)).equals("..."))
      j += 3;
    else
      ++j;

    tok.add(s.substring(i, j));
    i = j;
  }
  
  if ((tok.size() % 2) == 0) tok.add("");
  return tok;
}


  public static String unquote(String s) {
    if (s.startsWith("[")) {
      int i = 1;
      while (i < s.length() && s.charAt(i) == '=') ++i;
      if (i < s.length() && s.charAt(i) == '[') {
        String m = s.substring(1, i);
        if (s.endsWith("]" + m + "]"))
          return s.substring(i+1, s.length()-i-1);
      }
    }
    
    if (s.startsWith("\"") && s.endsWith("\"") && s.length() > 1) {
      String st = s.substring(1, s.length()-1);
      StringBuilder sb = new StringBuilder(st.length());
  
      for (int i = 0; i < st.length(); i++) {
        char ch = st.charAt(i);
        if (ch == '\\') {
          char nextChar = (i == st.length() - 1) ? '\\' : st
                  .charAt(i + 1);
          // Octal escape?
          if (nextChar >= '0' && nextChar <= '7') {
              String code = "" + nextChar;
              i++;
              if ((i < st.length() - 1) && st.charAt(i + 1) >= '0'
                      && st.charAt(i + 1) <= '7') {
                  code += st.charAt(i + 1);
                  i++;
                  if ((i < st.length() - 1) && st.charAt(i + 1) >= '0'
                          && st.charAt(i + 1) <= '7') {
                      code += st.charAt(i + 1);
                      i++;
                  }
              }
              sb.append((char) Integer.parseInt(code, 8));
              continue;
          }
          switch (nextChar) {
          case '\\':
              ch = '\\';
              break;
          case 'b':
              ch = '\b';
              break;
          case 'f':
              ch = '\f';
              break;
          case 'n':
              ch = '\n';
              break;
          case 'r':
              ch = '\r';
              break;
          case 't':
              ch = '\t';
              break;
          case '\"':
              ch = '\"';
              break;
          case '\'':
              ch = '\'';
              break;
          // Hex Unicode: u????
          case 'u':
              if (i >= st.length() - 5) {
                  ch = 'u';
                  break;
              }
              int code = Integer.parseInt(
                      "" + st.charAt(i + 2) + st.charAt(i + 3)
                              + st.charAt(i + 4) + st.charAt(i + 5), 16);
              sb.append(Character.toChars(code));
              i += 5;
              continue;
          }
          i++;
        }
        sb.append(ch);
      }
      return sb.toString();      
    } else
      return s; // return original
  }

static BufferedReader readLine_reader;

static String readLine() { try {
 
  if (readLine_reader == null)
    readLine_reader = new BufferedReader(new InputStreamReader(System.in, "UTF-8"));
  String s = readLine_reader.readLine();
  if (s != null)
    print(s);
  return s;

} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}

  static AtomicInteger dialogServer_clients = new AtomicInteger();
  
  static void startDialogServer(int port, DialogHandler handler) {
    if (!startDialogServerIfPortAvailable(port, handler))
      fail("Can't start dialog server on port " + port);
  }
  
  // true on server set up, false on port not available
  // now uses "thread" and not "daemon" (keeps VM alive!)
  static boolean startDialogServerIfPortAvailable(int port, final DialogHandler handler) {
    ServerSocket serverSocket = null;
    try {
      serverSocket = new ServerSocket(port);
    } catch (IOException e) {
      // probably the port number is used - let's assume there already is a chat server.
      return false;
    }
    final ServerSocket _serverSocket = serverSocket;

    Thread _t_0 = new Thread() {
public void run() {
try {

      while (true) {
        try {
          final Socket s = _serverSocket.accept();
          print("connect - clients: " + dialogServer_clients.incrementAndGet());
          Thread _t_1 = new Thread() {
public void run() {
try {

            try {
              final Writer w = new OutputStreamWriter(s.getOutputStream(), "UTF-8");
              final BufferedReader in = new BufferedReader(
                new InputStreamReader(s.getInputStream(), "UTF-8"));
              DialogIO io = new DialogIO() {
                String line;
                boolean buff;
                
                Socket getSocket() { return s; }
                
                // local means localhost - todo: test
                boolean isLocalConnection() {
                  return s.getInetAddress().isLoopbackAddress();
                }
                
                boolean isStillConnected() {
                  return !(buff || s.isClosed());
                }
                
                String readLineNoBlock() {
                  String l = line;
                  line = null;
                  return l;
                }
                
                boolean waitForLine() { try {
 
                  if (line != null) return true;
                  //print("Readline");
                  line = in.readLine();
                  //print("Readline done: " + line);
                  if (line == null) buff = true;
                  return line != null;
                
} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
                
                void sendLine(String line) { try {
 
                  w.write(line + "\n");
                  w.flush();
                
} catch (Throwable __e) { throw __e instanceof RuntimeException ? (RuntimeException) __e : new RuntimeException(__e); }}
              };
              
              try {
                handler.run(io);
              } finally {
                s.close();
              }
            } finally {
              print("client disconnect - " + dialogServer_clients.decrementAndGet() + " remaining");
            }
          } catch (Exception _e) {
  throw _e instanceof RuntimeException ? (RuntimeException) _e : new RuntimeException(_e); } }
};
_t_1.start();
        } catch (SocketTimeoutException e) {
        }
      }   
    } catch (Exception _e) {
  throw _e instanceof RuntimeException ? (RuntimeException) _e : new RuntimeException(_e); } }
};
_t_0.start();
   
    print("Dialog server on port " + port + " started."); 
    return true;
  }

// actually it's now almost the same as jsonDecode :)
static Object unstructure(String text) {
  final List<String> tok = javaTok(text);
  
  class X {
    int i = 1;

    Object parse() {
      String t = tok.get(i);
      if (t.startsWith("\"")) {
        String s = unquote(tok.get(i));
        i += 2;
        return s;
      }
      if (t.equals("{"))
        return parseMap();
      if (t.equals("["))
        return parseList();
      if (t.equals("null")) {
        i += 2; return null;
      }
      if (t.equals("false")) {
        i += 2; return false;
      }
      if (t.equals("true")) {
        i += 2; return true;
      }
      if (isInteger(t)) {
        i += 2; return Integer.parseInt(t);
      }
      throw new RuntimeException("Unknown token " + (i+1) + ": " + t);
    }
    
    Object parseList() {
      consume("[");
      List list = new ArrayList();
      while (!tok.get(i).equals("]")) {
        list.add(parse());
        if (tok.get(i).equals(",")) i += 2;
      }
      consume("]");
      return list;
    }
    
    Object parseMap() {
      consume("{");
      Map map = new TreeMap();
      while (!tok.get(i).equals("}")) {
        String key = unquote(tok.get(i));
        i += 2;
        consume(":");
        Object value = parse();
        map.put(key, value);
        if (tok.get(i).equals(",")) i += 2;
      }
      consume("}");
      return map;
    }
    
    void consume(String s) {
      if (!tok.get(i).equals(s)) {
        String prevToken = i-2 >= 0 ? tok.get(i-2) : "";
        String nextTokens = join(tok.subList(i, Math.min(i+4, tok.size())));
        fail(quote(s) + " expected: " + prevToken + " " + nextTokens + " (" + i + "/" + tok.size() + ")");
      }
      i += 2;
    }
  }
  
  return new X().parse();
}

static File programDir(String snippetID) {
  return new File(userHome(), "JavaX-Data/" + formatSnippetID(snippetID));
}


static String randomID(int length) {
  return makeRandomID(length);
}

static long now_virtualTime;
static long now() {
  return now_virtualTime != 0 ? now_virtualTime : System.currentTimeMillis();
}


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

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

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

  /** 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";
    if (contents != null) {
      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 (contents != null)
      if (!new File(tempFileName).renameTo(file))
        throw new IOException("Can't rename " + tempFileName + " to " + fileName);
  }
  
  public static void saveTextFile(File fileName, String contents) {
    try {
      saveTextFile(fileName.getPath(), contents);
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }


  public static String loadTextFile(String fileName) {
    try {
      return loadTextFile(fileName, null);
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }
  
  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(File fileName) {
    try {
      return loadTextFile(fileName, null);
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }

  public static String loadTextFile(File fileName, String defaultContents) throws IOException {
    try {
      return loadTextFile(fileName.getPath(), defaultContents);
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }
  
  public static String loadTextFile(Reader reader) throws IOException {
    StringBuilder builder = new StringBuilder();
    try {
      char[] buffer = new char[1024];
      int n;
      while (-1 != (n = reader.read(buffer)))
        builder.append(buffer, 0, n);
        
    } finally {
      reader.close();
    }
    return builder.toString();
  }

  public static String quote(String s) {
    if (s == null) return "null";
    return "\"" + s.replace("\\", "\\\\").replace("\"", "\\\"").replace("\r", "\\r").replace("\n", "\\n") + "\"";
  }

  static void set(Class c, String field, Object value) {
    try {
      Field f = set_findStaticField(c, field);
      f.setAccessible(true);
      f.set(null, value);
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }
  
  static Field set_findStaticField(Class<?> c, String field) {
    for (Field f : c.getDeclaredFields())
      if (f.getName().equals(field) && (f.getModifiers() & Modifier.STATIC) != 0)
        return f;
    throw new RuntimeException("Static field '" + field + "' not found in " + c.getName());
  }

static Object get(Object o, String field) {
  if (o instanceof Class) return get((Class) o, field);
  try {
    Field f = get_findField(o.getClass(), field);
    f.setAccessible(true);
    return f.get(o);
  } catch (Exception e) {
    throw new RuntimeException(e);
  }
}

static Object get(Class c, String field) {
  try {
    Field f = get_findStaticField(c, field);
    f.setAccessible(true);
    return f.get(null);
  } catch (Exception e) {
    throw new RuntimeException(e);
  }
}

static Field get_findStaticField(Class<?> c, String field) {
  for (Field f : c.getDeclaredFields())
    if (f.getName().equals(field) && (f.getModifiers() & Modifier.STATIC) != 0)
      return f;
  throw new RuntimeException("Static field '" + field + "' not found in " + c.getName());
}

static Field get_findField(Class<?> c, String field) {
  for (Field f : c.getDeclaredFields())
    if (f.getName().equals(field))
      return f;
  throw new RuntimeException("Field '" + field + "' not found in " + c.getName());
}

static String structure(Object o) {
  return structure(o, 0);
}
  
static String structure(Object o, int stringSizeLimit) {
  if (o == null) return "null";
  String name = o.getClass().getName();
  
  StringBuilder buf = new StringBuilder();
  
  if (o instanceof Collection) {
    for (Object x : (Collection) o) {
      if (buf.length() != 0) buf.append(", ");
      buf.append(structure(x, stringSizeLimit));
    }
    return "[" + buf + "]";
  }
  
  if (o instanceof Map) {
    for (Object e : ((Map) o).entrySet()) {
      if (buf.length() != 0) buf.append(", ");
      buf.append(structure(((Map.Entry) e).getKey(), stringSizeLimit));
      buf.append("=");
      buf.append(structure(((Map.Entry) e).getValue(), stringSizeLimit));
    }
    return "{" + buf + "}";
  }
  
  if (o.getClass().isArray()) {
    int n = Array.getLength(o);
    for (int i = 0; i < n; i++) {
      if (buf.length() != 0) buf.append(", ");
      buf.append(structure(Array.get(o, i), stringSizeLimit));
    }
    return "{" + buf + "}";
  }

  if (o instanceof String)
    return quote(stringSizeLimit != 0 ? shorten((String) o, stringSizeLimit) : (String) o);
  
  // Need more cases? This should cover all library classes...
  if (name.startsWith("java.") || name.startsWith("javax."))
    return String.valueOf(o);
    
  String shortName = o.getClass().getName().replaceAll("^main\\$", "");

  // TODO: go to superclasses too
  Field[] fields = o.getClass().getDeclaredFields();
  int numFields = 0;
  String fieldName = "";
  for (Field field : fields) {
    if ((field.getModifiers() & Modifier.STATIC) != 0)
      continue;
    Object value;
    try {
      value = field.get(o);
    } catch (Exception e) {
      value = "?";
    }
    
    fieldName = field.getName();
    
    // put special cases here...

    if (value != null) {
      if (buf.length() != 0) buf.append(", ");
      buf.append(fieldName + "=" + structure(value, stringSizeLimit));
    }
    ++numFields;
  }
  String b = buf.toString();
  if (numFields == 1)
    b = b.replaceAll("^" + fieldName + "=", ""); // drop field name if only one
  String s = shortName;
  if (buf.length() != 0)
    s += "(" + b + ")";
  return s;
}

// replacement for class JavaTok
// maybe incomplete, might want to add floating point numbers
// todo also: extended multi-line strings

static List<String> javaTok(String s) {
  List<String> tok = new ArrayList<String>();
  int l = s.length();
  
  int i = 0;
  while (i < l) {
    int j = i;
    char c; String cc;
    
    // scan for whitespace
    while (j < l) {
      c = s.charAt(j);
      cc = s.substring(j, Math.min(j+2, l));
      if (c == ' ' || c == '\t' || c == '\r' || c == '\n')
        ++j;
      else if (cc.equals("/*")) {
        do ++j; while (j < l && !s.substring(j, Math.min(j+2, l)).equals("*/"));
        j = Math.min(j+2, l);
      } else if (cc.equals("//")) {
        do ++j; while (j < l && "\r\n".indexOf(s.charAt(j)) < 0);
      } else
        break;
    }
    
    tok.add(s.substring(i, j));
    i = j;
    if (i >= l) break;
    c = s.charAt(i); // cc is not needed in rest of loop body
    cc = s.substring(i, Math.min(i+2, l));

    // scan for non-whitespace
    if (c == '\'' || c == '"') {
      char opener = c;
      ++j;
      while (j < l) {
        if (s.charAt(j) == opener) {
          ++j;
          break;
        } else if (s.charAt(j) == '\\' && j+1 < l)
          j += 2;
        else
          ++j;
      }
    } else if (Character.isJavaIdentifierStart(c))
      do ++j; while (j < l && Character.isJavaIdentifierPart(s.charAt(j)));
    else if (Character.isDigit(c))
      do ++j; while (j < l && Character.isDigit(s.charAt(j)));
    else if (cc.equals("[[")) {
      do ++j; while (j+1 < l && !s.substring(j, j+2).equals("]]"));
      j = Math.min(j+2, l);
    } else
      ++j;

    tok.add(s.substring(i, j));
    i = j;
  }
  
  if ((tok.size() % 2) == 0) tok.add("");
  return tok;
}


  public static String join(String glue, Iterable<String> strings) {
    StringBuilder buf = new StringBuilder();
    Iterator<String> i = strings.iterator();
    if (i.hasNext()) {
      buf.append(i.next());
      while (i.hasNext())
        buf.append(glue).append(i.next());
    }
    return buf.toString();
  }
  
  public static String join(String glue, String[] strings) {
    return join(glue, Arrays.asList(strings));
  }
  
  public static String join(Iterable<String> strings) {
    return join("", strings);
  }
  
  public static String join(String[] strings) {
    return join("", strings);
  }


  static RuntimeException fail() {
    throw new RuntimeException("fail");
  }
  
  static RuntimeException fail(String msg) {
    throw new RuntimeException(msg);
  }

static boolean isInteger(String s) {
  return Pattern.matches("\\-?\\d+", s);
}

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 String shorten(String s, int max) {
  return s.length() <= max ? s : s.substring(0, Math.min(s.length(), max)) + "...";
}

static String formatSnippetID(String id) {
  return "#" + parseSnippetID(id);
}

static String formatSnippetID(long id) {
  return "#" + id;
}

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

public static long parseSnippetID(String snippetID) {
  return Long.parseLong(shortenSnippetID(snippetID));
}

static String shortenSnippetID(String snippetID) {
  if (snippetID.startsWith("#"))
    snippetID = snippetID.substring(1);
  String httpBlaBla = "http://tinybrain.de/";
  if (snippetID.startsWith(httpBlaBla))
    snippetID = snippetID.substring(httpBlaBla.length());
  return snippetID;
}
}
interface StringFunc {
  String get(String s);
}