/*
 * generated by Xtext 2.10.0
 */
package org.etsi.mts.tdl.scoping;

import org.eclipse.emf.common.util.BasicEList;
import org.eclipse.emf.common.util.EList;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.EReference;
import org.eclipse.xtext.scoping.IScope;
import org.eclipse.xtext.scoping.Scopes;
import org.eclipse.xtext.scoping.impl.AbstractDeclarativeScopeProvider;
import org.etsi.mts.tdl.DataInstance;
import org.etsi.mts.tdl.DataInstanceUse;
import org.etsi.mts.tdl.DataType;
import org.etsi.mts.tdl.ElementImport;
import org.etsi.mts.tdl.Package;
import org.etsi.mts.tdl.PackageableElement;
import org.etsi.mts.tdl.structuredobjectives.Entity;
import org.etsi.mts.tdl.structuredobjectives.EntityReference;
import org.etsi.mts.tdl.structuredobjectives.Event;
import org.etsi.mts.tdl.structuredobjectives.EventReference;
import org.etsi.mts.tdl.structuredobjectives.EventSpecificationTemplate;
import org.etsi.mts.tdl.structuredobjectives.LiteralValue;

/**
 * This class contains custom scoping description.
 * 
 * See https://www.eclipse.org/Xtext/documentation/303_runtime_concepts.html#scoping
 * on how and when to use it.
 */
public class TPLan2ScopeProvider extends AbstractDeclarativeScopeProvider {
	
	@Override
	public IScope getScope(EObject context, EReference reference) {
		if (reference.getEType().getInstanceClass() == Event.class) {
			EList<EObject> elements = getScopedElementsOfType(context, Event.class);
			return Scopes.scopeFor(elements);
		} else if (reference.getEType().getInstanceClass() == Entity.class) {
			EList<EObject> elements = getScopedElementsOfType(context, Entity.class);
			return Scopes.scopeFor(elements);
		} else if (reference.getEType().getInstanceClass() == EventSpecificationTemplate.class) {
			EList<EObject> elements = getScopedElementsOfType(context, EventSpecificationTemplate.class);
			return Scopes.scopeFor(elements);
		}
		
		return super.getScope(context, reference);
	}
	
	public IScope scope_ElementImport_importedElement(ElementImport context, EReference ref) {
		EList<EObject> elements = new BasicEList<>();
		Package ip = context.getImportedPackage();
		for (PackageableElement e : ip.getPackagedElement()) {
			elements.add(e);
		}
		IScope scope = Scopes.scopeFor(elements);
		return scope;
	}

	
	public IScope scope_EventReference_event(EventReference context, EReference ref) {
		EList<EObject> elements = getScopedElementsOfType(context, Event.class);
		IScope scope = Scopes.scopeFor(elements);
		return scope;
	}

	public IScope scope_EntityReference_entity(EntityReference context, EReference ref) {
		EList<EObject> elements = getScopedElementsOfType(context, Entity.class);
		IScope scope = Scopes.scopeFor(elements);
		return scope;
	}

	public IScope scope_DataInstanceUse_dataInstance(DataInstanceUse context, EReference ref) {
		EList<EObject> elements = getScopedElementsOfType(context, DataInstance.class);
		IScope scope = Scopes.scopeFor(elements);
		return scope;
	}

	public IScope scope_LiteralValue_dataType(LiteralValue context, EReference ref) {
		EList<EObject> elements = getScopedElementsOfType(context, DataType.class);
		IScope scope = Scopes.scopeFor(elements);
		return scope;
	}

	
	private Package getPackage(EObject e) {
		if (e.eContainer() instanceof Package) {
			return (Package)e.eContainer();
		} else {
			return getPackage(e.eContainer());
		}
	}
	
	private EList<EObject> getScopedElementsOfType(EObject context, Class c) {
		EList<EObject> elements = new BasicEList<>();
		Package p = getPackage(context);
		
		//within same package
		for (PackageableElement e : p.getPackagedElement()) {
			if (c.isInstance(e)) {
				elements.add(e);
			}
		}
		
		//within imported packages
		for (ElementImport i : p.getImport()) {
			Package ip = i.getImportedPackage();
			if (i.getImportedElement().isEmpty()) {
				//import all
				for (PackageableElement e : ip.getPackagedElement()) {
					if (c.isInstance(e)) {
						elements.add(e);
					}
				}
			} else {
				//specific imports
				for (PackageableElement e : i.getImportedElement()) {
					if (c.isInstance(e)) {
						elements.add(e);
					}
				}
			}
		}
		return elements;
	}
}