org.eclipse.osbp.xtext.oxtype/src/org/eclipse/osbp/xtext/oxtype/scoping/jvmtype/KnownTypesScope.java

package org.eclipse.osbp.xtext.oxtype.scoping.jvmtype;

import java.util.List;

import org.eclipse.emf.ecore.util.EcoreUtil;
import org.eclipse.xtext.common.types.JvmType;
import org.eclipse.xtext.naming.QualifiedName;
import org.eclipse.xtext.resource.EObjectDescription;
import org.eclipse.xtext.resource.IEObjectDescription;
import org.eclipse.xtext.util.Strings;

public class KnownTypesScope extends AbstractKnownTypesScope {

	private final List<? extends JvmType> types;

	public KnownTypesScope(List<? extends JvmType> types,
			AbstractOXTypeTypeScope parent) {
		super(parent);
		this.types = types;
	}

	@Override
	protected void doGetElements(JvmType type, List<IEObjectDescription> result) {
		for (int i = 0; i < types.size(); i++) {
			JvmType knownType = types.get(i);
			if (EcoreUtil.isAncestor(knownType, type)) {
				doGetDescriptions(type, knownType, i, result);
			}
		}
		super.doGetElements(type, result);
	}

	@Override
	protected IEObjectDescription doGetSingleElement(QualifiedName name,
			String firstSegment, int dollarIndex) {
		int index = -1;
		JvmType result = null;
		for (int i = 0; i < types.size(); i++) {
			JvmType type = types.get(i);
			JvmType exactMatch = getExactMatch(type, index, name);
			if (exactMatch != null)
				return EObjectDescription.create(name, exactMatch);
			if (isMatch(i, type, firstSegment, name)) {
				JvmType resolved = getUnambiguousResult(result, index, type, i,
						name);
				if (resolved == null) {
					return null;
				}
				if (resolved != result) {
					result = resolved;
					index = i;
				}
			}
		}
		return toDescription(name, result, dollarIndex, index);
	}

	@Override
	protected IEObjectDescription toDescription(QualifiedName name,
			JvmType result, int dollarIndex, int index) {
		if (result != null) {
			JvmType actualResult = dollarIndex > 0
					|| name.getSegmentCount() > 0 ? findNestedType(result,
					index, name) : result;
			if (actualResult != null) {
				return EObjectDescription.create(name, actualResult);
			}
		}
		return null;
	}

	/*
	 * If we know java.util.Map$Entry exists and we query for the FQN, we assume
	 * things are valid.
	 */
	protected JvmType getExactMatch(JvmType type, int index, QualifiedName name) {
		QualifiedName typeName = QualifiedName.create(Strings.split(
				type.getQualifiedName(), '.'));
		if (name.equals(typeName)) {
			return type;
		}
		if (name.startsWith(typeName)) {
			JvmType result = findNestedType(type, index,
					name.skipFirst(typeName.getSegmentCount() - 1));
			return result;
		}
		if (name.getSegmentCount() > typeName.getSegmentCount()) {
			if (typeName.skipLast(1).equals(name.skipLast(1))) {
				if (typeName.getLastSegment().equals(
						name.skipFirst(typeName.getSegmentCount() - 1)
								.toString("$"))) {
					return type;
				}
			}
		}
		return null;
	}

	protected boolean isMatch(int index, JvmType type, String simpleName,
			QualifiedName relativeName) {
		return simpleName.equals(type.getSimpleName());
	}

	@Override
	protected void doGetDescriptions(JvmType type, JvmType knownType,
			int index, List<IEObjectDescription> result) {
		if (type == knownType) {
			result.add(EObjectDescription.create(
					QualifiedName.create(type.getSimpleName()), type));
		} else if (type.eContainer() == knownType) {
			result.add(EObjectDescription.create(
					QualifiedName.create(knownType.getSimpleName(),
							type.getSimpleName()), type));
			result.add(EObjectDescription.create(
					QualifiedName.create(knownType.getSimpleName() + '$'
							+ type.getSimpleName()), type));
		} else {
			String knownTypeName = knownType.getQualifiedName();
			String withDollar = type.getQualifiedName('$');
			String withDot = type.getQualifiedName('.');
			result.add(EObjectDescription.create(
					QualifiedName.create(Strings.split(
							withDot.substring(knownTypeName.length()), '.')),
					type));
			result.add(EObjectDescription.create(QualifiedName
					.create(withDollar.substring(knownTypeName.length())), type));
		}
	}

}