content: /*******************************************************************************
   * Copyright (c) 2009 IBM Corporation 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/
   *
   * SPDX-License-Identifier: EPL-2.0
   * 
   * Contributors:
   *     IBM Corporation - initial API and implementation
   *     Zend Technologies
   *******************************************************************************/
  package org.eclipse.php.core.ast.nodes;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  
  import org.eclipse.php.core.PHPVersion;
  import org.eclipse.php.core.ast.match.ASTMatcher;
  import org.eclipse.php.core.ast.visitor.Visitor;
  
  /**
   * Represents an assignment statement.
   * 
   * <pre>
   * e.g.
   * 
   * $a = 5, $a += 5, $a .= $b,
   * </pre>
   */
  public class Assignment extends Expression implements IOperationNode {
  
  	// '='
  	public static final int OP_EQUAL = 0;
  	// '+='
  	public static final int OP_PLUS_EQUAL = 1;
  	// '-='
  	public static final int OP_MINUS_EQUAL = 2;
  	// '*='
  	public static final int OP_MUL_EQUAL = 3;
  	// '/='
  	public static final int OP_DIV_EQUAL = 4;
  	// '.='
  	public static final int OP_CONCAT_EQUAL = 5;
  	// '%='
  	public static final int OP_MOD_EQUAL = 6;
  	// '&='
  	public static final int OP_AND_EQUAL = 7;
  	// '|='
  	public static final int OP_OR_EQUAL = 8;
  	// '^='
  	public static final int OP_XOR_EQUAL = 9;
  	// '<<='
  	public static final int OP_SL_EQUAL = 10;
  	// '>>='
  	public static final int OP_SR_EQUAL = 11;
  	// '**='
  	public static final int OP_POW_EQUAL = 12;
  	// '??='
  	public static final int OP_COALESCE_EQUAL = 13;
  
  	private VariableBase leftHandSide;
  	private int operator;
  	private Expression rightHandSide;
  
  	/**
  	 * The structural property of this node type.
  	 */
  	public static final ChildPropertyDescriptor LEFT_HAND_SIDE_PROPERTY = new ChildPropertyDescriptor(Assignment.class,
  			"variable", VariableBase.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$
  	public static final SimplePropertyDescriptor OPERATOR_PROPERTY = new SimplePropertyDescriptor(Assignment.class,
  			"operator", Integer.class, MANDATORY); //$NON-NLS-1$
  	public static final ChildPropertyDescriptor RIGHT_HAND_SIDE_PROPERTY = new ChildPropertyDescriptor(Assignment.class,
  			"value", Expression.class, MANDATORY, CYCLE_RISK); //$NON-NLS-1$
  
  	/**
  	 * A list of property descriptors (element type:
  	 * {@link StructuralPropertyDescriptor}), or null if uninitialized.
  	 */
  	private static final List<StructuralPropertyDescriptor> PROPERTY_DESCRIPTORS;
  
  	static {
  		List<StructuralPropertyDescriptor> properyList = new ArrayList<>(3);
  		properyList.add(LEFT_HAND_SIDE_PROPERTY);
  		properyList.add(OPERATOR_PROPERTY);
  		properyList.add(RIGHT_HAND_SIDE_PROPERTY);
  		PROPERTY_DESCRIPTORS = Collections.unmodifiableList(properyList);
  	}
  
  	public Assignment(int start, int end, AST ast, VariableBase leftHandSide, int operator, Expression rightHandSide) {
  		super(start, end, ast);
  		if (leftHandSide == null || rightHandSide == null || getOperator(operator) == null) {
  			throw new IllegalArgumentException();
  		}
  
  		setLeftHandSide(leftHandSide);
  		setOperator(operator);
  		setRightHandSide(rightHandSide);
  	}
  
  	public Assignment(AST ast) {
  		super(ast);
  	}
  
  	public static String getOperator(int operator) {
  		switch (operator) {
  		case OP_EQUAL:
  			return "="; //$NON-NLS-1$
  		case OP_PLUS_EQUAL:
  			return "+="; //$NON-NLS-1$
  		case OP_MINUS_EQUAL:
  			return "-="; //$NON-NLS-1$
  		case OP_MUL_EQUAL:
  			return "*="; //$NON-NLS-1$
  		case OP_DIV_EQUAL:
  			return "/="; //$NON-NLS-1$
  		case OP_MOD_EQUAL:
  			return "%="; //$NON-NLS-1$
  		case OP_CONCAT_EQUAL:
  			return ".="; //$NON-NLS-1$
  		case OP_AND_EQUAL:
  			return "&="; //$NON-NLS-1$
  		case OP_OR_EQUAL:
  			return "|="; //$NON-NLS-1$
  		case OP_XOR_EQUAL:
  			return "^="; //$NON-NLS-1$
  		case OP_SL_EQUAL:
  			return "<<="; //$NON-NLS-1$
  		case OP_SR_EQUAL:
  			return ">>="; //$NON-NLS-1$
  		case OP_POW_EQUAL:
  			return "**="; //$NON-NLS-1$
  		case OP_COALESCE_EQUAL:
  			return "??="; //$NON-NLS-1$
  		default:
  			throw new IllegalArgumentException();
  		}
  	}
  
  	@Override
  	public void childrenAccept(Visitor visitor) {
  		leftHandSide.accept(visitor);
  		rightHandSide.accept(visitor);
  	}
  
  	@Override
  	public void traverseTopDown(Visitor visitor) {
  		accept(visitor);
  		leftHandSide.traverseTopDown(visitor);
  		rightHandSide.traverseTopDown(visitor);
  	}
  
  	@Override
  	public void traverseBottomUp(Visitor visitor) {
  		leftHandSide.traverseBottomUp(visitor);
  		rightHandSide.traverseBottomUp(visitor);
  		accept(visitor);
  	}
  
  	@Override
  	public void toString(StringBuilder buffer, String tab) {
  		buffer.append(tab).append("<Assignment"); //$NON-NLS-1$
  		appendInterval(buffer);
  		buffer.append(" operator='").append(getXmlStringValue(getOperator(operator))).append("'>\n"); //$NON-NLS-1$ //$NON-NLS-2$
  		leftHandSide.toString(buffer, TAB + tab);
  		buffer.append("\n").append(TAB).append(tab).append("<Value>\n"); //$NON-NLS-1$ //$NON-NLS-2$
  		rightHandSide.toString(buffer, TAB + TAB + tab);
  		buffer.append("\n").append(TAB).append(tab).append("</Value>\n"); //$NON-NLS-1$ //$NON-NLS-2$
  		buffer.append(tab).append("</Assignment>"); //$NON-NLS-1$
  	}
  
  	@Override
  	public void accept0(Visitor visitor) {
  		final boolean visit = visitor.visit(this);
  		if (visit) {
  			childrenAccept(visitor);
  		}
  		visitor.endVisit(this);
  	}
  
  	@Override
  	public int getType() {
  		return ASTNode.ASSIGNMENT;
  	}
  
  	/**
  	 * Returns the operator of this assignment expression.
  	 * 
  	 * @return the assignment operator
  	 */
  	public int getOperator() {
  		return this.operator;
  	}
  
  	/*
  	 * (non-Javadoc)
  	 * 
  	 * @see
  	 * org.eclipse.php.internal.core.ast.nodes.IOperationNode#getOperationString
  	 * ()
  	 */
  	@Override
  	public String getOperationString() {
  		return getOperator(this.getOperator());
  	}
  
  	/*
  	 * (non-Javadoc)
  	 * 
  	 * @see
  	 * org.eclipse.php.internal.core.ast.nodes.IOperationNode#getOperationString
  	 * (int)
  	 */
  	@Override
  	public String getOperationString(int op) {
  		return getOperator(op);
  	}
  
  	/**
  	 * Sets the operator of this assignment expression.
  	 * 
  	 * @param assignmentOperator
  	 *            the assignment operator
  	 * @exception IllegalArgumentException
  	 *                if the argument is incorrect
  	 */
  	public void setOperator(int assignmentOperator) {
  		if (getOperator(assignmentOperator) == null) {
  			throw new IllegalArgumentException("Invalid operator"); //$NON-NLS-1$
  		}
  		preValueChange(OPERATOR_PROPERTY);
  		this.operator = assignmentOperator;
  		postValueChange(OPERATOR_PROPERTY);
  	}
  
  	/**
  	 * Returns the left hand side of this assignment expression.
  	 * 
  	 * @return the left hand side node
  	 */
  	public VariableBase getLeftHandSide() {
  		return this.leftHandSide;
  	}
  
  	/**
  	 * Sets the left hand side of this assignment expression.
  	 * 
  	 * @param expression
  	 *            the left hand side node
  	 * @exception IllegalArgumentException
  	 *                if:
  	 *                <ul>
  	 *                <li>the node belongs to a different AST</li>
  	 *                <li>the node already has a parent</li>
  	 *                <li>a cycle in would be created</li>
  	 *                </ul>
  	 */
  	public void setLeftHandSide(VariableBase leftHandSide) {
  		if (leftHandSide == null) {
  			throw new IllegalArgumentException();
  		}
  		// an Assignment may occur inside a Expression - must check cycles
  		ASTNode oldChild = this.leftHandSide;
  		preReplaceChild(oldChild, leftHandSide, LEFT_HAND_SIDE_PROPERTY);
  		this.leftHandSide = leftHandSide;
  		postReplaceChild(oldChild, leftHandSide, LEFT_HAND_SIDE_PROPERTY);
  	}
  
  	/**
  	 * Returns the right hand side of this assignment expression.
  	 * 
  	 * @return the right hand side node
  	 */
  	public Expression getRightHandSide() {
  		return this.rightHandSide;
  	}
  
  	/**
  	 * Sets the right hand side of this assignment expression.
  	 * 
  	 * @param expression
  	 *            the right hand side node
  	 * @exception IllegalArgumentException
  	 *                if:
  	 *                <ul>
  	 *                <li>the node belongs to a different AST</li>
  	 *                <li>the node already has a parent</li>
  	 *                <li>a cycle in would be created</li>
  	 *                </ul>
  	 */
  	public void setRightHandSide(Expression expression) {
  		if (expression == null) {
  			throw new IllegalArgumentException();
  		}
  		// an Assignment may occur inside a Expression - must check cycles
  		ASTNode oldChild = this.rightHandSide;
  		preReplaceChild(oldChild, expression, RIGHT_HAND_SIDE_PROPERTY);
  		this.rightHandSide = expression;
  		postReplaceChild(oldChild, expression, RIGHT_HAND_SIDE_PROPERTY);
  	}
  
  	/*
  	 * Method declared on ASTNode.
  	 */
  	@Override
  	public boolean subtreeMatch(ASTMatcher matcher, Object other) {
  		// dispatch to correct overloaded match method
  		return matcher.match(this, other);
  	}
  
  	@Override
  	ASTNode clone0(AST target) {
  		final VariableBase left = ASTNode.copySubtree(target, getLeftHandSide());
  		final Expression right = ASTNode.copySubtree(target, getRightHandSide());
  		final Assignment result = new Assignment(this.getStart(), this.getEnd(), target, left, this.getOperator(),
  				right);
  		return result;
  	}
  
  	@Override
  	List<StructuralPropertyDescriptor> internalStructuralPropertiesForType(PHPVersion apiLevel) {
  		return PROPERTY_DESCRIPTORS;
  	}
  
  	@Override
  	final int internalGetSetIntProperty(SimplePropertyDescriptor property, boolean get, int value) {
  		if (property == OPERATOR_PROPERTY) {
  			if (get) {
  				return getOperator();
  			} else {
  				setOperator(value);
  				return 0;
  			}
  		}
  		// allow default implementation to flag the error
  		return super.internalGetSetIntProperty(property, get, value);
  	}
  
  	@Override
  	final ASTNode internalGetSetChildProperty(ChildPropertyDescriptor property, boolean get, ASTNode child) {
  		if (property == LEFT_HAND_SIDE_PROPERTY) {
  			if (get) {
  				return getLeftHandSide();
  			} else {
  				setLeftHandSide((VariableBase) child);
  				return null;
  			}
  		}
  		if (property == RIGHT_HAND_SIDE_PROPERTY) {
  			if (get) {
  				return getRightHandSide();
  			} else {
  				setRightHandSide((Expression) child);
  				return null;
  			}
  		}
  		// allow default implementation to flag the error
  		return super.internalGetSetChildProperty(property, get, child);
  	}
  
  }
  