Copyright (c) 2016 Google, Inc 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:
  Stefan Xenos (Google) - Initial implementation
/*******************************************************************************
 * Copyright (c) 2016 Google, Inc 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:
 *   Stefan Xenos (Google) - Initial implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.core.nd.java;

import java.util.List;

import org.eclipse.jdt.internal.core.nd.Nd;
import org.eclipse.jdt.internal.core.nd.NdStruct;
import org.eclipse.jdt.internal.core.nd.field.FieldByte;
import org.eclipse.jdt.internal.core.nd.field.FieldList;
import org.eclipse.jdt.internal.core.nd.field.FieldString;
import org.eclipse.jdt.internal.core.nd.field.StructDef;
import org.eclipse.jdt.internal.core.util.CharArrayBuffer;

Represents a TypeParameter, as described in Section 4.7.9.1 of the java VM specification, Java SE 8 edititon.
/**
 * Represents a TypeParameter, as described in Section 4.7.9.1 of the java VM specification, Java SE 8 edititon.
 */
public class NdTypeParameter extends NdStruct {
	public static final FieldString IDENTIFIER;
	public static final FieldList<NdTypeBound> BOUNDS;
	public static final FieldByte TYPE_PARAMETER_FLAGS;

	public static final byte FLG_FIRST_BOUND_IS_A_CLASS = 0x01;

	@SuppressWarnings("hiding")
	public static final StructDef<NdTypeParameter> type;

	static {
		type = StructDef.create(NdTypeParameter.class, NdStruct.type);
		IDENTIFIER = type.addString();
		BOUNDS = FieldList.create(type, NdTypeBound.type);
		TYPE_PARAMETER_FLAGS = type.addByte();

		type.done();
	}

	public NdTypeParameter(Nd nd, long address) {
		super(nd, address);
	}

	public void setIdentifier(char[] identifier) {
		IDENTIFIER.put(getNd(), this.address, identifier);
	}

	public char[] getIdentifier() {
		return IDENTIFIER.get(getNd(), this.address).getChars();
	}

	public void setFirstBoundIsClass(boolean isClass) {
		setFlag(FLG_FIRST_BOUND_IS_A_CLASS, isClass);
	}

	public boolean isFirstBoundAClass() {
		return (TYPE_PARAMETER_FLAGS.get(getNd(), this.address) & FLG_FIRST_BOUND_IS_A_CLASS) != 0;
	}

	private void setFlag(byte flag, boolean value) {
		byte oldValue = TYPE_PARAMETER_FLAGS.get(getNd(), this.address);
		byte newValue;
		if (value) {
			newValue = (byte) (oldValue | flag);
		} else {
			newValue = (byte) (oldValue & ~flag);
		}
		TYPE_PARAMETER_FLAGS.put(getNd(), this.address, newValue);
	}

	public List<NdTypeBound> getBounds() {
		return BOUNDS.asList(getNd(), this.address);
	}

	public void getSignature(CharArrayBuffer result) {
		result.append(getIdentifier());

		List<NdTypeBound> bounds = getBounds();

		// If none of the bounds are classes and there is at least one bound, then insert a double-colon
		// in the type signature.
		if (!bounds.isEmpty() && !isFirstBoundAClass()) {
			result.append(':');
		}

		for (NdTypeBound next : bounds) {
			next.getSignature(result);
		}
	}

	public static void getSignature(CharArrayBuffer buffer, List<NdTypeParameter> params) {
		if (!params.isEmpty()) {
			buffer.append('<');
			for (NdTypeParameter next : params) {
				next.getSignature(buffer);
			}
			buffer.append('>');
		}
	}

	public void createBound(NdTypeSignature boundSignature) {
		BOUNDS.append(getNd(), getAddress()).setType(boundSignature);
	}

	public void allocateBounds(int numBounds) {
		BOUNDS.allocate(getNd(), getAddress(), numBounds);
	}
}