/*=============================================================================#
 # Copyright (c) 2008, 2020 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.r.core.model;

import java.util.Comparator;
import java.util.List;

import org.eclipse.statet.jcommons.collections.ImList;
import org.eclipse.statet.jcommons.lang.NonNull;
import org.eclipse.statet.jcommons.lang.NonNullByDefault;
import org.eclipse.statet.jcommons.lang.Nullable;

import org.eclipse.statet.r.core.rsource.ast.RAstNode;


/**
 * Access of a variable of class in source code
 * 
 * Is created by code analysis, not indent to implement by clients.
 */
@NonNullByDefault
public abstract class RElementAccess extends RElementName {
	
	
	public static final Comparator<RElementAccess> NAME_POSITION_COMPARATOR=
		new Comparator<RElementAccess>() {
			private int comparePosition(final @Nullable RAstNode node1, final @Nullable RAstNode node2) {
				if (node1 == node2) {
					return 0;
				}
				if (node1 == null) {
					return -1;
				}
				if (node2 == null) {
					return 1;
				}
				return Integer.compare(node1.getStartOffset(), node2.getStartOffset());
			}
			@Override
			public int compare(final RElementAccess o1, final RElementAccess o2) {
				if (o1 == o2) {
					return 0;
				}
				RElementAccess segment1= o1;
				RElementAccess segment2= o2;
				int offset;
				while ((offset= comparePosition(segment1.getNameNode(), segment2.getNameNode())) == 0) {
					segment1= o1.getNextSegment();
					segment2= o2.getNextSegment();
					if (segment1 == segment2) {
						return 0;
					}
					if (segment1 == null) {
						return -1;
					}
					if (segment2 == null) {
						return 1;
					}
				}
				return offset;
			}
	};
	
	public static @Nullable RElementAccess getMainElementAccessOfNameNode(final RAstNode nameNode) {
		RAstNode node= nameNode;
		while (node != null) {
			final List<Object> attachments= node.getAttachments();
			for (final Object attachment : attachments) {
				if (attachment instanceof RElementAccess) {
					RElementAccess access= (RElementAccess)attachment;
					do {
						if (access.isMaster() && access.getNameNode() == nameNode) {
							return (RElementAccess)attachment;
						}
						access= access.getNextSegment();
					} while (access != null);
				}
			}
			node= node.getRParent();
		}
		return null;
	}
	
	public static @Nullable RElementAccess getElementAccessOfNameNode(final RAstNode nameNode) {
		RAstNode node= nameNode;
		while (node != null) {
			final List<Object> attachments= node.getAttachments();
			for (final Object attachment : attachments) {
				if (attachment instanceof RElementAccess) {
					RElementAccess access= (RElementAccess)attachment;
					do {
						if (access.isMaster() && access.getNameNode() == nameNode) {
							return access;
						}
						access= access.getNextSegment();
					} while (access != null);
				}
			}
			node= node.getRParent();
		}
		return null;
	}
	
	
	public abstract RFrame getFrame();
	
	public abstract boolean isWriteAccess();
	public abstract boolean isFunctionAccess();
	public abstract boolean isCallAccess();
	
	
	public boolean isMaster() {
		return true;
	}
	
	public boolean isSlave() {
		return false;
	}
	
	public RElementAccess getMaster() {
		return this;
	}
	
	
	public abstract RAstNode getNode();
	
	public abstract @Nullable RAstNode getNameNode();
	
	@Override
	public abstract @Nullable RElementAccess getNextSegment();
	
	@Override
	public RElementAccess getLastSegment() {
		@NonNull RElementAccess lastSegment;
		RElementAccess nextSegment= this;
		do {
			lastSegment= nextSegment;
		} while ((nextSegment= nextSegment.getNextSegment()) != null);
		return lastSegment;
	}
	
	public abstract ImList<? extends RElementAccess> getAllInUnit(final boolean includeSlaves);
	
}