Copyright (c) 2000, 2017 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2000, 2017 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.core.util;

import java.util.ArrayList;

import org.eclipse.jdt.core.IAnnotatable;
import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IMethod;
import org.eclipse.jdt.core.IOpenable;
import org.eclipse.jdt.core.IPackageFragment;
import org.eclipse.jdt.core.IType;
import org.eclipse.jdt.core.ITypeRoot;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.core.Signature;
import org.eclipse.jdt.core.WorkingCopyOwner;
import org.eclipse.jdt.core.compiler.CharOperation;
import org.eclipse.jdt.internal.compiler.util.SuffixConstants;
import org.eclipse.jdt.internal.core.*;

@SuppressWarnings({"rawtypes", "unchecked"})
public class JavaElementFinder extends BindingKeyParser {

	private JavaProject project;
	private WorkingCopyOwner owner;
	public IJavaElement element;
	public JavaModelException exception;
	private ArrayList types = new ArrayList();

	public JavaElementFinder(String key, JavaProject project, WorkingCopyOwner owner) {
		super(key);
		this.project = project;
		this.owner = owner;
	}

	private JavaElementFinder(BindingKeyParser parser, JavaProject project, WorkingCopyOwner owner) {
		super(parser);
		this.project = project;
		this.owner = owner;
	}

	@Override
	public void consumeAnnotation() {
		if (!(this.element instanceof IAnnotatable)) return;
		int size = this.types.size();
		if (size == 0) return;
		IJavaElement annotationType = ((JavaElementFinder) this.types.get(size-1)).element;
		this.element = ((IAnnotatable) this.element).getAnnotation(annotationType.getElementName());
	}

	@Override
	public void consumeField(char[] fieldName) {
		if (!(this.element instanceof IType)) return;
		this.element = ((IType) this.element).getField(new String(fieldName));
	}

	@Override
	public void consumeFullyQualifiedName(char[] fullyQualifiedName) {
		try {
			this.element = this.project.findType(new String(CharOperation.replaceOnCopy(fullyQualifiedName, '/', '.')), this.owner);
		} catch (JavaModelException e) {
			this.exception = e;
		}
	}

	@Override
	public void consumeLocalType(char[] uniqueKey) {
		if (this.element == null) return;
		if (this.element instanceof BinaryType) {
			int lastSlash = CharOperation.lastIndexOf('/', uniqueKey);
			int end = CharOperation.indexOf(';', uniqueKey, lastSlash+1);
			char[] localName = CharOperation.subarray(uniqueKey, lastSlash+1, end);
			IPackageFragment pkg = (IPackageFragment) this.element.getAncestor(IJavaElement.PACKAGE_FRAGMENT);
			this.element = pkg.getClassFile(new String(localName) + SuffixConstants.SUFFIX_STRING_class);
		} else {
			int firstDollar = CharOperation.indexOf('$', uniqueKey);
			int end = CharOperation.indexOf('$', uniqueKey, firstDollar+1);
			if (end == -1)
				end = CharOperation.indexOf(';', uniqueKey, firstDollar+1);
			char[] sourceStart = CharOperation.subarray(uniqueKey, firstDollar+1, end);
			int position = Integer.parseInt(new String(sourceStart));
			try {
				this.element = ((ITypeRoot) this.element.getOpenable()).getElementAt(position);
			} catch (JavaModelException e) {
				this.exception = e;
			}
		}
	}

	@Override
	public void consumeMemberType(char[] simpleTypeName) {
		if (!(this.element instanceof IType)) return;
		this.element = ((IType) this.element).getType(new String(simpleTypeName));
	}

	@Override
	public void consumeMethod(char[] selector, char[] signature) {
		if (!(this.element instanceof IType)) return;
		String[] parameterTypes = Signature.getParameterTypes(new String(signature));
		IType type = (IType) this.element;
		IMethod method = type.getMethod(new String(selector), parameterTypes);
		IMethod[] methods = type.findMethods(method);
		if (methods.length > 0)
			this.element = methods[0];
	}

	@Override
	public void consumePackage(char[] pkgName) {
		pkgName = CharOperation.replaceOnCopy(pkgName, '/', '.');
		try {
			this.element = this.project.findPackageFragment(new String(pkgName));
		} catch (JavaModelException e) {
			this.exception = e;
		}
	}

	@Override
	public void consumeParser(BindingKeyParser parser) {
		this.types.add(parser);
	}

	@Override
	public void consumeSecondaryType(char[] simpleTypeName) {
		if (this.element == null) return;
		IOpenable openable = this.element.getOpenable();
		if (!(openable instanceof ICompilationUnit)) return;
		this.element = ((ICompilationUnit) openable).getType(new String(simpleTypeName));
	}

	@Override
	public void consumeTypeVariable(char[] position, char[] typeVariableName) {
		if (this.element == null) return;
		switch (this.element.getElementType()) {
		case IJavaElement.TYPE:
			this.element = ((IType) this.element).getTypeParameter(new String(typeVariableName));
			break;
		case IJavaElement.METHOD:
			this.element = ((IMethod) this.element).getTypeParameter(new String(typeVariableName));
			break;
		}
	}

	@Override
	public void consumeModule(char[] moduleName) {
		try {
			this.element = this.project.findModule(new String(moduleName), null);
		} catch (JavaModelException e) {
			this.exception = e;
		}
	}

	@Override
	public BindingKeyParser newParser() {
		return new JavaElementFinder(this, this.project, this.owner);
	}

}