package org.apidesign.vm4brwsr;

 import java.io.BufferedWriter;

 import java.io.FileWriter;

 import java.io.IOException;

 import java.io.InputStream;

 import java.io.Writer;

 import java.util.Arrays;

 import java.util.HashSet;

 import java.util.LinkedList;

 import java.util.List;

 import java.util.Set;

 /** Generator of JavaScript from bytecode of classes on classpath of the VM.

  *

  * @author Jaroslav Tulach <jtulach@netbeans.org>

  */

 final class GenJS {

     private GenJS() {}

     public static void main(String... args) throws IOException {

         if (args.length < 2) {

             System.err.println("Usage: java -cp ... -jar ... <file_to_generate_js_code_to> java/lang/Class org/your/App ...");

             return;

         }

         Writer w = new BufferedWriter(new FileWriter(args[0]));

         List<String> classes = Arrays.asList(args).subList(1, args.length);

         compile(w, classes);

         w.close();

     }

     static void compile(Appendable out, String... names) throws IOException {

         compile(out, Arrays.asList(names));

     }

     static void compile(Appendable out, List<String> names) throws IOException {

         Set<String> processed = new HashSet<String>();

         LinkedList<String> toProcess = new LinkedList<String>(names);

         for (;;) {

             toProcess.removeAll(processed);

             if (toProcess.isEmpty()) {

                 break;

             }

             String name = toProcess.getFirst();

             processed.add(name);

             if (name.startsWith("java/") 

                 && !name.equals("java/lang/Object")

                 && !name.equals("java/lang/String")

             ) {

                 continue;

             }

             InputStream is = GenJS.class.getClassLoader().getResourceAsStream(name + ".class");

             if (is == null) {

                 throw new IOException("Can't find class " + name); 

             }

             try {

                 ByteCodeToJavaScript.compile(is, out, toProcess);

             } catch (RuntimeException ex) {

                 if (out instanceof CharSequence) {

                     CharSequence seq = (CharSequence)out;

                     int lastBlock = seq.length();

                     while (lastBlock-- >= 0) {

                         if (seq.charAt(lastBlock) == '{') {

                             break;

                         }

                     }

                     throw new IOException("Error while compiling " + name + "\n" 

                         + seq.subSequence(lastBlock + 1, seq.length()), ex

                     );

                 } else {

                     throw new IOException("Error while compiling " + name + "\n" 

                         + out, ex

                     );

                 }

             }

         }

     }

 }