package org.jbpm.pvm.internal.script;

import javax.script.*;
import java.util.List;
import java.util.Arrays;

public class BshScriptEngineFactory implements
	javax.script.ScriptEngineFactory
{
	// Begin impl ScriptEnginInfo
	
	final List<String> extensions = Arrays.asList( "bsh", "java" );

	final List<String> mimeTypes = Arrays.asList(
		"application/x-beanshell", 
		"application/x-bsh",
		"application/x-java-source" 
	);

	final List<String> names = Arrays.asList( "beanshell", "bsh", "java" );

    public String getEngineName() {
		return "BeanShell Engine";
	}

    public String getEngineVersion() {
		return "1.0";
	}

    public List<String> getExtensions() {
		return extensions;
	}

    public List<String> getMimeTypes() {
		return mimeTypes;
	}

    public List<String> getNames() {
		return names;
	}

    public String getLanguageName() {
		return "BeanShell";
	}

    public String getLanguageVersion() {
		return bsh.Interpreter.VERSION + "";
	}

    public Object getParameter( String param ) {
	    if ( param.equals( ScriptEngine.ENGINE ) )
			return getEngineName();
		if ( param.equals( ScriptEngine.ENGINE_VERSION ) )
			return getEngineVersion();
		if ( param.equals( ScriptEngine.NAME ) )
			return getEngineName();
		if ( param.equals( ScriptEngine.LANGUAGE ) )
			return getLanguageName();
		if ( param.equals( ScriptEngine.LANGUAGE_VERSION ) )
			return getLanguageVersion();
		if ( param.equals( "THREADING" ) )
			return "MULTITHREADED";

		return null;
	}

    public String getMethodCallSyntax( 
		String objectName, String methodName, String ... args ) 
	{
		// Note: this is very close to the bsh.StringUtil.methodString()
		// method, which constructs a method signature from arg *types*.  Maybe
		// combine these later.

        StringBuilder sb = new StringBuilder();
		if ( objectName != null )
			sb.append( objectName + "." );
		sb.append( methodName + "(" );
        if ( args.length > 0 )
			sb.append(" ");
        for( int i=0; i<args.length; i++ )
            sb.append( ( (args[i] == null) ? "null" : args[i] ) 
				+ ( i < (args.length-1) ? ", " : " " ) );
        sb.append(")");
        return sb.toString();
	}

    public String getOutputStatement( String message ) {
		return "print( \"" + message + "\" );";
	}

    public String getProgram( String ... statements )
	{
		StringBuilder sb = new StringBuilder();
		for( int i=0; i< statements.length; i++ )
		{
			sb.append( statements[i] );
			if ( !statements[i].endsWith(";") )
				sb.append( ";" );
			sb.append("\n");
		}
		return sb.toString();
	}

	// End impl ScriptEngineInfo

	// Begin impl ScriptEngineFactory

	public ScriptEngine getScriptEngine() 
	{
		return new BshScriptEngine();
	}
		
	// End impl ScriptEngineFactory
}