/***** BEGIN LICENSE BLOCK *****
 * Version: CPL 1.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Common Public
 * License Version 1.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.eclipse.org/legal/cpl-v10.html
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * Copyright (C) 2001 Alan Moore <alan_moore@gmx.net>
 * Copyright (C) 2001-2002 Jan Arne Petersen <jpetersen@uni-bonn.de>
 * Copyright (C) 2002-2004 Anders Bengtsson <ndrsbngtssn@yahoo.se>
 * Copyright (C) 2004 Thomas E Enebo <enebo@acm.org>
 * Copyright (C) 2004 Stefan Matthias Aust <sma@3plus4.de>
 * 
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the CPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the CPL, the GPL or the LGPL.
 ***** END LICENSE BLOCK *****/
package org.jruby.ast.util;

import org.jruby.Ruby;
import org.jruby.RubyArray;
import org.jruby.runtime.builtin.IRubyObject;
import org.jruby.runtime.MethodIndex;

/**
 *
 * @author  jpetersen
 */
public final class ArgsUtil {
    
    public static IRubyObject[] convertToJavaArray(IRubyObject value) {
        if (value == null) {
        	return IRubyObject.NULL_ARRAY;
        }
        
        if (value instanceof RubyArray) {
            return ((RubyArray)value).toJavaArrayMaybeUnsafe();
        }
        
        return new IRubyObject[] { value };
    }

    /**
     * This name may be a bit misleading, since this also attempts to coerce
     * array behavior using to_ary.
     * 
     * @param runtime The JRuby runtime
     * @param value The value to convert
     * @param coerce Whether to coerce using to_ary or just wrap with an array
     */
    public static RubyArray convertToRubyArray(Ruby runtime, IRubyObject value, boolean coerce) {
        if (value == null) {
            return RubyArray.newArrayLight(runtime, 0);
        }
        
        if (!coerce) {
            // don't attempt to coerce to array, just wrap and return
            return RubyArray.newArrayNoCopyLight(runtime, new IRubyObject[] {value});
        }
        
        IRubyObject newValue = value.convertToType(runtime.getArray(), MethodIndex.TO_ARY, "to_ary", false);

        if (newValue.isNil()) {
            return RubyArray.newArrayNoCopyLight(runtime, new IRubyObject[] {value});
        }
        
        // empirically it appears that to_ary coersions always return array or nil, so this
        // should always be an array by now.
        return (RubyArray)newValue;
    }
    
    /**
     * Remove first element from array
     * 
     * @param array to have first element "popped" off
     * @return all but first element of the supplied array
     */
    public static IRubyObject[] popArray(IRubyObject[] array) {
    	if (array == null || array.length == 0) {
    		return IRubyObject.NULL_ARRAY;
    	}
    	
    	IRubyObject[] newArray = new IRubyObject[array.length - 1];
    	System.arraycopy(array, 1, newArray, 0, array.length - 1);
    	
    	return newArray;
    }
}