package org.lcsim.geometry.compact.converter;
   
   import java.io.BufferedInputStream;
   import java.io.BufferedOutputStream;
   import java.io.File;
   import java.io.FileInputStream;
   import java.io.FileOutputStream;
   import java.io.InputStream;
   import java.io.OutputStream;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  import javax.imageio.spi.ServiceRegistry;
  
  /**
   * A main routine which can be used to invoke other main routines.
   * @author tonyj
   */
  public class Main
  {
     private String inFile;
     private String outFile;
     private String format;
     private Converter converter;
     
     String getInputFile()
     {
        return inFile;
     }
     String getOutputFile()
     {
        return outFile;
     }
     String getFormat()
     {
        return format;
     }
     void parseArgs(String[] args) throws InvalidArgumentException
     {
        for (int i=0; i<args.length; i++)
        {
           String arg = args[i];
           if ("-o".equals(arg))
           {
              i++;
              if (i >= args.length) usage();
              format = args[i];
           }
           else if (arg.startsWith("-")) usage();
           else if (inFile == null) inFile = arg;
           else if (outFile == null) outFile = arg;
           else throw new InvalidArgumentException();
        }
        
        if (format != null)
        {
           for (Converter c : getConverters())
           {
              if (c.getOutputFormat().equalsIgnoreCase(format))
              {
                 converter = c;
                 break;
              }
           }
           if (converter == null) throw new InvalidArgumentException("Sorry, could not find converter for format: "+format);
        }
        // If not explicitly set try to guess output type from output file
        else if (outFile != null)
        {
           File out = new File(outFile);
           for (Converter c : getConverters())
           {
              if (c.getFileFilter().accept(out))
              {
                 converter = c;
                 break;
              }
           }
           if (converter == null) throw new InvalidArgumentException("Sorry, could not find converter for output file");
        }
     }
     public static void main(String[] args)
     {
        Main main = new Main();
        try
        {
           main.parseArgs(args);
        }
        catch (InvalidArgumentException x)
        {
           String message = x.getMessage();
           if (message != null) System.err.println(message);
           usage();
        }
        if (main.outFile == null)
        {
           MainGUI.main(args);
        }
        else if (main.converter != null)
       {
           try 
           {
               main.run();
           }
           catch (Exception x)
           {  
               throw new RuntimeException(x);
           }
       }
    }
    private void run() throws Exception
    {
       InputStream in = new BufferedInputStream(new FileInputStream(inFile));
       OutputStream out = new BufferedOutputStream(new FileOutputStream(outFile));
       converter.convert(inFile,in,out);
       in.close();
       out.close();
    }
    
    private static void usage()
    {
       System.out.println("java "+Main.class.getName()+" [-o <format>] [<input> [<output>]]");
       System.exit(0);
    }
    static List<Converter> getConverters()
    {
       Iterator<Converter> iter = getServices(Converter.class);
       List<Converter> result = new ArrayList<Converter>();
       while (iter.hasNext()) result.add(iter.next());
       return result;
    }
    private static <T> Iterator<T> getServices(Class<T> providerClass)
    {
       return ServiceRegistry.lookupProviders(providerClass,Main.class.getClassLoader());
    }
    class InvalidArgumentException extends Exception
    {
       InvalidArgumentException()
       {
          super();
       }
       InvalidArgumentException(String message)
       {
          super(message);
       }
    }
 }