Copyright (c) 2000, 2015 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, 2015 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.text.edits;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;

A move target edit denotes the target of a move operation. Move
target edits are only valid inside an edit tree if they have a
corresponding source edit. Furthermore a target edit can't
can't be a direct or indirect child of its associated source edit.
Violating one of two requirements will result in a 
MalformedTreeException when executing the edit tree.

Move target edits can't be used as a parent for other edits.
Trying to add an edit to a move target edit results in a 
MalformedTreeException as well.
See Also:
MoveSourceEdit
CopyTargetEdit
Since:
3.0/**
 * A move target edit denotes the target of a move operation. Move
 * target edits are only valid inside an edit tree if they have a
 * corresponding source edit. Furthermore a target edit can't
 * can't be a direct or indirect child of its associated source edit.
 * Violating one of two requirements will result in a <code>
 * MalformedTreeException</code> when executing the edit tree.
 * <p>
 * Move target edits can't be used as a parent for other edits.
 * Trying to add an edit to a move target edit results in a <code>
 * MalformedTreeException</code> as well.
 *
 * @see org.eclipse.text.edits.MoveSourceEdit
 * @see org.eclipse.text.edits.CopyTargetEdit
 *
 * @since 3.0
 */
public final class MoveTargetEdit extends TextEdit {

	private MoveSourceEdit fSource;

	
Constructs a new move target edit
Params:
offset – the edit's offset/**
	 * Constructs a new move target edit
	 *
	 * @param offset the edit's offset
	 */
	public MoveTargetEdit(int offset) {
		super(offset, 0);
	}

	
Constructs an new move target edit
Params:
offset – the edit's offset
source – the corresponding source edit/**
	 * Constructs an new move target edit
	 *
	 * @param offset the edit's offset
	 * @param source the corresponding source edit
	 */
	public MoveTargetEdit(int offset, MoveSourceEdit source) {
		this(offset);
		setSourceEdit(source);
	}

	/*
	 * Copy constructor
	 */
	private MoveTargetEdit(MoveTargetEdit other) {
		super(other);
	}

	
Returns the associated source edit or null
if no source edit is associated yet.
Returns:
the source edit or null/**
	 * Returns the associated source edit or <code>null</code>
	 * if no source edit is associated yet.
	 *
	 * @return the source edit or <code>null</code>
	 */
	public MoveSourceEdit getSourceEdit() {
		return fSource;
	}

	
Sets the source edit.
Params:
edit – the source edit
Throws:
MalformedTreeException – is thrown if the target edit
 is a direct or indirect child of the source edit/**
	 * Sets the source edit.
	 *
	 * @param edit the source edit
	 *
	 * @exception MalformedTreeException is thrown if the target edit
	 *  is a direct or indirect child of the source edit
	 */
	public void setSourceEdit(MoveSourceEdit edit) {
		if (fSource != edit) {
			fSource= edit;
			fSource.setTargetEdit(this);
			TextEdit parent= getParent();
			while (parent != null) {
				if (parent == fSource)
					throw new MalformedTreeException(parent, this, TextEditMessages.getString("MoveTargetEdit.wrong_parent")); //$NON-NLS-1$
				parent= parent.getParent();
			}
		}
	}

	@Override
	protected TextEdit doCopy() {
		return new MoveTargetEdit(this);
	}

	@Override
	protected void postProcessCopy(TextEditCopier copier) {
		if (fSource != null) {
			MoveTargetEdit target= (MoveTargetEdit)copier.getCopy(this);
			MoveSourceEdit source= (MoveSourceEdit)copier.getCopy(fSource);
			if (target != null && source != null)
				target.setSourceEdit(source);
		}
	}

	@Override
	protected void accept0(TextEditVisitor visitor) {
		boolean visitChildren= visitor.visit(this);
		if (visitChildren) {
			acceptChildren(visitor);
		}
	}

	//---- consistency check ----------------------------------------------------------

	@Override
	int traverseConsistencyCheck(TextEditProcessor processor, IDocument document, List<List<TextEdit>> sourceEdits) {
		return super.traverseConsistencyCheck(processor, document, sourceEdits) + 1;
	}

	@Override
	void performConsistencyCheck(TextEditProcessor processor, IDocument document) throws MalformedTreeException {
		if (fSource == null)
			throw new MalformedTreeException(getParent(), this, TextEditMessages.getString("MoveTargetEdit.no_source")); //$NON-NLS-1$
		if (fSource.getTargetEdit() != this)
			throw new MalformedTreeException(getParent(), this, TextEditMessages.getString("MoveTargetEdit.different_target")); //$NON-NLS-1$
	}

	//---- document updating ----------------------------------------------------------------

	/*
	 * @see TextEdit#performDocumentUpdating
	 */
	@Override
	int performDocumentUpdating(IDocument document) throws BadLocationException {
		String source= fSource.getContent();
		document.replace(getOffset(), getLength(), source);
		fDelta= source.length() - getLength();

		MultiTextEdit sourceRoot= fSource.getSourceRoot();
		if (sourceRoot != null) {
			sourceRoot.internalMoveTree(getOffset());
			TextEdit[] sourceChildren= sourceRoot.removeChildren();
			List<TextEdit> children= new ArrayList<>(sourceChildren.length);
			for (TextEdit child : sourceChildren) {
				child.internalSetParent(this);
				children.add(child);
			}
			internalSetChildren(children);
		}
		fSource.clearContent();
		return fDelta;
	}

	//---- region updating --------------------------------------------------------------

	@Override
	int traverseRegionUpdating(TextEditProcessor processor, IDocument document, int accumulatedDelta, boolean delete) {
		// the children got already updated / normalized while they got removed
		// from the source edit. So we only have to adjust the offset computed to
		// far.
		if (delete) {
			deleteTree();
		} else {
			internalMoveTree(accumulatedDelta);
		}
		return accumulatedDelta + fDelta;
	}

	@Override
	boolean deleteChildren() {
		return false;
	}
}