/*******************************************************************************
 * Copyright (c) 2015 Jeff Martin.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser General Public
 * License v3.0 which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/lgpl.html
 * <p>
 * Contributors:
 * Jeff Martin - initial API and implementation
 ******************************************************************************/
package cuchaz.enigma.bytecode;

import java.util.ArrayList;
import java.util.List;

import cuchaz.enigma.mapping.*;
import javassist.CtBehavior;
import javassist.CtClass;
import javassist.bytecode.CodeAttribute;
import javassist.bytecode.LocalVariableAttribute;

public class MethodParameterWriter {

    private Translator translator;

    public MethodParameterWriter(Translator translator) {
        this.translator = translator;
    }

    public void writeMethodArguments(CtClass c) {

        // Procyon will read method arguments from the "MethodParameters" attribute, so write those
        for (CtBehavior behavior : c.getDeclaredBehaviors()) {

            // if there's a local variable table here, don't write a MethodParameters attribute
            // let the local variable writer deal with it instead
            // procyon starts doing really weird things if we give it both attributes
            CodeAttribute codeAttribute = behavior.getMethodInfo().getCodeAttribute();
            if (codeAttribute != null && codeAttribute.getAttribute(LocalVariableAttribute.tag) != null) {
                continue;
            }

            BehaviorEntry behaviorEntry = EntryFactory.getBehaviorEntry(behavior);

            // get the number of arguments
            Signature signature = behaviorEntry.getSignature();
            if (signature == null) {
                // static initializers have no signatures, or arguments
                continue;
            }
            int numParams = signature.getArgumentTypes().size();
            if (numParams <= 0) {
                continue;
            }

            // get the list of argument names
            List<String> names = new ArrayList<>(numParams);
            for (int i = 0; i < numParams; i++) {
                names.add(this.translator.translate(new ArgumentEntry(behaviorEntry, i, "")));
            }

            // save the mappings to the class
            MethodParametersAttribute.updateClass(behavior.getMethodInfo(), names);
        }
    }
}