static class CompilerBot {

  static bool verbose;

  static File compileSnippet(S snippetID) {

    ret compileSnippet(snippetID, "");

  }

  static Pair<File, S> compileSnippet2(S snippetID) {

    ret compileSnippet2(snippetID, "");

  }

  // returns jar path

  static File compileSnippet(S snippetID, S javaTarget) {

    ret compileSnippet2(snippetID, javaTarget).a;

  }

  // returns jar path, Java source

  static Pair<File, S> compileSnippet2(S snippetID, S javaTarget) {

    S transpiledSrc = getServerTranspiled2(snippetID);

    if (transpiledSrc == null) fail("Snippet not found or not public: " + snippetID);

    int i = transpiledSrc.indexOf('\n');

    String libs = transpiledSrc.substring(0, Math.max(0, i));

    if (verbose)

      print("Compiling snippet: " + snippetID + ". Libs: " + libs);

    transpiledSrc = transpiledSrc.substring(i+1);

    return pair(compile(transpiledSrc, libs, javaTarget, snippetID), transpiledSrc);

  }

  static File compile(S src) {

    ret compile(src, "");

  }

  static File compile(S src, S libs) {

    ret compile(src, libs, null);

  }

  static File compile(S src, S dehlibs, S javaTarget) {

    ret compile(src, dehlibs, javaTarget, null);

  }

  static File compile(S src, S dehlibs, S javaTarget, S progID) {

    if (verbose)

      print("Compiling " + l(src) + " chars");

    // Note: This is different from the calculation in x30

    // (might lead to programs being compiled twice)

    S md5 = md5(dehlibs + "\n" + src + "\n" + fsIOpt(progID));

    File jar = getJarFile(md5);

    if (jar == null || jar.length() <= 22) {

      // have to compile

      //print("Have to compile: " + progID + " / " + md5);

      LS tok = javaTok(src);

      LS mainClass = findMainClass(tok);

      bool canRename = mainClass != null && useDummyMainClasses() && isSnippetID(progID) && !tok_classHasModifier(mainClass, "public");

      if (verbose)

        print("useRenaming: " + useDummyMainClasses() + ", canRename: " + canRename + ", progID: " + progID);

      S mainClassName = joinNemptiesWithDot(tok_packageName(tok), or(getClassDeclarationName(mainClass), "main"));

      temp tempSetTL(javaCompileToJar_addMoreFiles, 

        dir -> {

          if (!eq(mainClassName, "main"))

            saveTextFile(newFile(dir, "main-class"), mainClassName);

          saveTextFile(newFile(dir, manifestPathInJar()), manifestTextForMainClass(mainClassName);

        });

      javaCompileToJar_optionalRename(src, dehlibs, jar, canRename ? progID : null, progID);

    } else {

      if (verbose)

        print("Getting classes from cache (" + jar.getAbsolutePath() + ", " + jar.length() + " bytes)");

      touchFile(jar); // so we can find the unused ones easier

    }

    ret jar;

  }

  // look in non-virtual JavaX-Caches first (important for packaged programs)

  // Edit: Huh? This is strange.

  static File getJarFile(S md5) {

    assertTrue(isMD5(md5));

    S fileName = md5 + ".jar";

    File f = newFile(destDir(), fileName);

    ret fileExists(f) ? f : userDir(appendSlash(compilerBotDestDirSubName()) + fileName);

  }

  /*swappable*/ static File destDir() {

    ret compilerBotDestDir();

  }

}