bundles/core/org.eclipse.apogy.core.programs.javascript/src/org/eclipse/apogy/core/programs/javascript/VariableProxy.java

/*******************************************************************************
 * Copyright (c) 2018 Agence spatiale canadienne / Canadian Space Agency 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Mathieu Larose (Savoir-faire Linux) - Initial API and implementation
 *
 * SPDX-License-Identifier: EPL-1.0
 *     
 *******************************************************************************/
package org.eclipse.apogy.core.programs.javascript;

import java.lang.reflect.Method;

import org.eclipse.apogy.common.emf.AbstractFeatureListNode;
import org.eclipse.apogy.common.emf.ApogyCommonEMFFacade;
import org.eclipse.apogy.common.emf.ApogyCommonEMFFactory;
import org.eclipse.apogy.common.emf.ListFeatureNode;
import org.eclipse.apogy.common.emf.ListRootNode;
import org.eclipse.apogy.core.invocator.ApogyCoreInvocatorFactory;
import org.eclipse.apogy.core.invocator.TypeMember;
import org.eclipse.apogy.core.invocator.Variable;
import org.eclipse.apogy.core.invocator.VariableFeatureReference;
import org.eclipse.emf.ecore.EAttribute;
import org.eclipse.emf.ecore.EOperation;
import org.eclipse.emf.ecore.EReference;
import org.eclipse.emf.ecore.EStructuralFeature;
import org.eclipse.emf.ecore.util.EcoreUtil;
import org.mozilla.javascript.Scriptable;
import org.mozilla.javascript.ScriptableObject;

/**
 * Proxy for an Apogy variable.
 *
 */
public class VariableProxy extends ScriptableObject {
	private static final long serialVersionUID = 1L;
	private VariableFeatureReference variableFeatureReference;
	private Variable variable;
	private JavaScriptProgram program;

	public VariableProxy() {
		// Rhino requires an empty constructor
	}

	/**
	 *
	 * @param variable Apogy variable
	 * @param program  JavaScriptProgram being executed
	 * @throws NoSuchMethodException
	 * @throws SecurityException
	 */
	public VariableProxy(Variable variable, JavaScriptProgram program) throws NoSuchMethodException, SecurityException {
		this.variable = variable;
		this.program = program;
		init();
	}

	private void init() throws NoSuchMethodException, SecurityException {
		this.variableFeatureReference = ApogyCoreInvocatorFactory.eINSTANCE.createVariableFeatureReference();
		this.variableFeatureReference.setVariable(this.variable);

		for (EOperation op : ApogyCommonEMFFacade.INSTANCE
				.getAllAvailableEOperations(this.variable.getVariableType().getInterfaceClass())) {
			defineProperty(op.getName(), new OperationCallInvoker(this.program, this.variableFeatureReference, op), 0);
		}

		for (EStructuralFeature structuralFeature : this.variable.getVariableType().getInterfaceClass()
				.getEAllStructuralFeatures()) {
			if (structuralFeature instanceof EReference) {
				ReferenceGetter referenceGetter = new ReferenceGetter(structuralFeature);
				Method getter = ReferenceGetter.class.getDeclaredMethod("get", new Class[] { Scriptable.class });
				defineProperty(structuralFeature.getName(), referenceGetter, getter, null, 0);
			} else if (structuralFeature instanceof EAttribute) {
				AttributeGetter attributeGetter = new AttributeGetter(this.variableFeatureReference, structuralFeature);
				Method getter = AttributeGetter.class.getDeclaredMethod("get", new Class[] { Scriptable.class });
				defineProperty(structuralFeature.getName(), attributeGetter, getter, null, 0);
			}
		}

		for (TypeMember typeMember : this.variable.getVariableType().getMembers()) {
			recursiveInit(typeMember);
		}
	}

	private void recursiveInit(TypeMember typeMember) throws NoSuchMethodException, SecurityException {
		// If the property already exists and is read-only, defineProperty
		// is ignored.
		//
		// Delete the property in case it already exists and is
		// read-only (which is likely the case since we defined read-only
		// properties for all EReferences in the loop above).
		delete(typeMember.getName());

		TypeMemberGetter typeMemberGetter = new TypeMemberGetter(typeMember);
		Method getter = TypeMemberGetter.class.getDeclaredMethod("get", new Class[] { Scriptable.class });
		defineProperty(typeMember.getName(), typeMemberGetter, getter, null, 0);

		for (TypeMember subMember : typeMember.getMemberType().getMembers()) {
			recursiveInit(subMember);
		}
	}

	@Override
	public String getClassName() {
		return "Proxy";
	}

	public String getName() {
		return this.variable.getName();
	}

	/**
	 * Gets a reference of the EObject wrapped by {@link VariableProxy}
	 *
	 */
	private class ReferenceGetter {
		private final EStructuralFeature feature;

		public ReferenceGetter(EStructuralFeature feature) {
			this.feature = feature;
		}

		/**
		 * Returns the reference (represented by this class) of the EObject (represented
		 * by {@VariableProxy})
		 * 
		 * @param self The JavaScript object
		 * @return the attribute
		 */
		@SuppressWarnings("unused")
		public Object get(Scriptable self) throws NoSuchMethodException, SecurityException {
			VariableFeatureReference subVariableFeatureReference = VariableFeatureReferenceUtil
					.clone(VariableProxy.this.variableFeatureReference);

			ListRootNode listRootNode = ApogyCommonEMFFactory.eINSTANCE.createListRootNode();
			listRootNode.setSourceClass(VariableProxy.this.variable.getVariableType().getInterfaceClass());
			subVariableFeatureReference.setFeatureRoot(listRootNode);

			AbstractFeatureListNode leaf = ApogyCommonEMFFacade.INSTANCE
					.getLeaf(subVariableFeatureReference.getFeatureRoot());
			ListFeatureNode node = ApogyCommonEMFFactory.eINSTANCE.createListFeatureNode();
			node.setStructuralFeature(this.feature);
			leaf.setChild(node);

			Scriptable object = new ReferenceProxy(subVariableFeatureReference, VariableProxy.this.program);
			object.setParentScope(VariableProxy.this);
			return object;
		}
	}

	/**
	 * Gets a type member of the EObject wrapped by {@link @VariableProxy}
	 *
	 */
	private class TypeMemberGetter {
		private final TypeMember typeMember;

		public TypeMemberGetter(TypeMember typeMember) {
			this.typeMember = typeMember;
		}

		/**
		 * Returns the type member (represented by this class) of the EObject
		 * (represented by {@VariableProxy})
		 * 
		 * @param self The JavaScript object
		 * @return the attribute
		 */
		@SuppressWarnings("unused")
		public Object get(Scriptable self) throws NoSuchMethodException, SecurityException {
			VariableFeatureReference subVariableFeatureReference = EcoreUtil
					.copy(VariableProxy.this.variableFeatureReference);

			VariableFeatureReferenceUtil util = new VariableFeatureReferenceUtil();
			util.createTypeMemberHierarchy(subVariableFeatureReference, this.typeMember);

			TypeMemberProxy object = new TypeMemberProxy(subVariableFeatureReference, VariableProxy.this.program);

			object.setParentScope(VariableProxy.this);
			return object;
		}

	}
}