/*******************************************************************************
 * Copyright (c) 2011 Luaj.org. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 ******************************************************************************/
package org.luaj.vm2.libs.jse;

import java.lang.reflect.Array;
import org.luaj.vm2.Varargs;
import org.luaj.vm2.libs.VarArgFunction;
import org.luaj.vm2.libs.jse.CoerceLuaToJava.Coercion;

/**
 * Java method or constructor.
 * <p>
 * Primarily handles argument coercion for parameter lists including scoring of compatibility and
 * java varargs handling.
 * <p>
 * This class is not used directly.
 * It is an abstract base class for {@link JavaConstructor} and {@link JavaMethod}.
 * @see JavaConstructor
 * @see JavaMethod
 * @see CoerceJavaToLua
 * @see CoerceLuaToJava
 */
abstract
class JavaMember extends VarArgFunction {

	static final int METHOD_MODIFIERS_VARARGS = 0x80;

	final Coercion[] fixedargs;
	final Coercion varargs;

	protected JavaMember(Class[] params, int modifiers) {
		boolean isvarargs = ((modifiers & METHOD_MODIFIERS_VARARGS) != 0);
		fixedargs = new CoerceLuaToJava.Coercion[isvarargs? params.length-1: params.length];
		for ( int i=0; i<fixedargs.length; i++ )
			fixedargs[i] = CoerceLuaToJava.getCoercion( params[i] );
		varargs = isvarargs? CoerceLuaToJava.getCoercion( params[params.length-1].getComponentType() ): null;
	}

	int score(Varargs args) {
		int n = args.narg();
		int s = n>fixedargs.length? CoerceLuaToJava.SCORE_WRONG_TYPE * (n-fixedargs.length): 0;
		for ( int j=0; j<fixedargs.length; j++ )
			s += fixedargs[j].score( args.arg(j+1) );
		if ( varargs != null )
			for ( int k=fixedargs.length; k<n; k++ )
				s += varargs.score( args.arg(k+1) );
		return s;
	}

	protected Object[] convertArgs(Varargs args) {
		Object[] a;
		if ( varargs == null ) {
			a = new Object[fixedargs.length];
			for ( int i=0; i<a.length; i++ )
				a[i] = fixedargs[i].coerce( args.arg(i+1) );
		} else {
			// should be the fixed arguments, followed by an array with the varargs
			a = new Object[fixedargs.length+1];
			int nvar = Math.max(0, args.narg()-fixedargs.length);
			Object[] vararray = new Object[nvar];
			for ( int i=0; i<fixedargs.length; i++ )
				a[i] = fixedargs[i].coerce( args.arg(i+1) );
			a[a.length-1] = vararray;
			for ( int i=0; i<nvar; i++ )
				vararray[i] = varargs.coerce( args.arg(fixedargs.length+i+1) );
		}
		return a;
	}
}