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.Iterator;
  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 a 'use' statement
   * 
   * e.g.
   * 
   * <pre>
   * use MyNamespace;
   * use MyNamespace as MyAlias;
   * use MyProject\Sub\Level as MyAlias;
   * use \MyProject\Sub\Level as MyAlias;
   * use \MyProject\Sub\Level as MyAlias, MyNamespace as OtherAlias, MyOtherNamespace;
   * use MyProject\Sub\Level\ { MyAlias, MyNamespace as OtherAlias, MyOtherNamespace, };
   * </pre>
   */
  public class UseStatement extends Statement {
  
  	// none
  	public static final int T_NONE = 0;
  	// 'function' keyword
  	public static final int T_FUNCTION = 1;
  	// 'const' keyword
  	public static final int T_CONST = 2;
  
  	private final ASTNode.NodeList<UseStatementPart> parts = new ASTNode.NodeList<>(PARTS_PROPERTY);
  	private int statementType;
  	private NamespaceName namespace;
  	private EmptyExpression emptyPart;
  
  	/**
  	 * The structural property of this node type.
  	 */
  	public static final ChildListPropertyDescriptor PARTS_PROPERTY = new ChildListPropertyDescriptor(UseStatement.class,
  			"parts", UseStatementPart.class, NO_CYCLE_RISK); //$NON-NLS-1$
  	public static final SimplePropertyDescriptor STATEMENT_TYPE_PROPERTY = new SimplePropertyDescriptor(
  			UseStatement.class, "statementType", Integer.class, NO_CYCLE_RISK); //$NON-NLS-1$
  	public static final ChildPropertyDescriptor NAMESPACE_PROPERTY = new ChildPropertyDescriptor(UseStatement.class,
  			"namespace", NamespaceName.class, OPTIONAL, //$NON-NLS-1$
  			CYCLE_RISK);
  	public static final ChildPropertyDescriptor EMPTY_PART_PROPERTY = new ChildPropertyDescriptor(UseStatement.class,
  			"emptyPart", EmptyExpression.class, OPTIONAL, //$NON-NLS-1$
  			NO_CYCLE_RISK);
  
  	/**
  	 * 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(PARTS_PROPERTY);
  		properyList.add(STATEMENT_TYPE_PROPERTY);
  		properyList.add(NAMESPACE_PROPERTY);
  		properyList.add(EMPTY_PART_PROPERTY);
  		PROPERTY_DESCRIPTORS = Collections.unmodifiableList(properyList);
  	}
  
  	public UseStatement(AST ast) {
  		super(ast);
  	}
  
  	public UseStatement(int start, int end, AST ast, List<UseStatementPart> parts) {
  		this(start, end, ast, parts, T_NONE);
  	}
  
  	public UseStatement(int start, int end, AST ast, List<UseStatementPart> parts, int statementType) {
  		this(start, end, ast, null, parts, null, statementType);
  	}
  
  	public UseStatement(int start, int end, AST ast, NamespaceName namespace, List<UseStatementPart> parts) {
  		this(start, end, ast, namespace, parts, null, T_NONE);
  	}
  
  	public UseStatement(int start, int end, AST ast, NamespaceName namespace, List<UseStatementPart> parts,
  			EmptyExpression emptyPart) {
  		this(start, end, ast, namespace, parts, emptyPart, T_NONE);
  	}
  
  	public UseStatement(int start, int end, AST ast, NamespaceName namespace, List<UseStatementPart> parts,
  			EmptyExpression emptyPart, int statementType) {
  		super(start, end, ast);
  
  		if (parts == null || parts.size() == 0) {
  			throw new IllegalArgumentException();
  		}
  		setNamespace(namespace);
  		Iterator<UseStatementPart> it = parts.iterator();
  		while (it.hasNext()) {
  			this.parts.add(it.next());
  		}
  		setEmptyPart(emptyPart);
  		setStatementType(statementType);
  	}
  
  	public UseStatement(int start, int end, AST ast, UseStatementPart[] parts, int statementType) {
  		super(start, end, ast);
  
  		if (parts == null || parts.length == 0) {
  			throw new IllegalArgumentException();
  		}
  
  		for (UseStatementPart part : parts) {
  			this.parts.add(part);
  		}
  		setStatementType(statementType);
  	}
  
  	public UseStatement(int start, int end, AST ast, UseStatementPart[] parts) {
  		this(start, end, ast, parts, T_NONE);
  	}
  
  	@Override
  	public void accept0(Visitor visitor) {
  		final boolean visit = visitor.visit(this);
  		if (visit) {
  			childrenAccept(visitor);
  		}
  		visitor.endVisit(this);
  	}
  
  	@Override
  	public void childrenAccept(Visitor visitor) {
  		if (getNamespace() != null) {
  			getNamespace().accept(visitor);
  		}
  		for (ASTNode node : this.parts) {
  			node.accept(visitor);
  		}
  		if (getEmptyPart() != null) {
  			getEmptyPart().accept(visitor);
  		}
  	}
  
  	@Override
  	public void traverseTopDown(Visitor visitor) {
  		accept(visitor);
  		if (getNamespace() != null) {
  			getNamespace().traverseTopDown(visitor);
  		}
  		for (ASTNode node : this.parts) {
  			node.traverseTopDown(visitor);
  		}
  		if (getEmptyPart() != null) {
  			getEmptyPart().traverseTopDown(visitor);
  		}
  	}
  
  	@Override
  	public void traverseBottomUp(Visitor visitor) {
  		if (getNamespace() != null) {
  			getNamespace().traverseBottomUp(visitor);
  		}
  		for (ASTNode node : this.parts) {
  			node.traverseBottomUp(visitor);
  		}
  		if (getEmptyPart() != null) {
  			getEmptyPart().traverseBottomUp(visitor);
  		}
  		accept(visitor);
  	}
  
  	@Override
  	public void toString(StringBuilder buffer, String tab) {
  		buffer.append(tab).append("<UseStatement"); //$NON-NLS-1$
  		appendInterval(buffer);
  		if (getStatementType() != T_NONE) {
  			buffer.append(" statementType='").append(getStatementType()) //$NON-NLS-1$
  					.append("'"); //$NON-NLS-1$
  		}
  		buffer.append(">\n"); //$NON-NLS-1$
  		if (getNamespace() != null) {
  			getNamespace().toString(buffer, TAB + tab);
  			buffer.append("\n"); //$NON-NLS-1$
  		}
  		for (UseStatementPart part : this.parts) {
  			part.toString(buffer, TAB + tab);
  			buffer.append("\n"); //$NON-NLS-1$
  		}
  		if (getEmptyPart() != null) {
  			getEmptyPart().toString(buffer, TAB + tab);
  			buffer.append("\n"); //$NON-NLS-1$
  		}
  		buffer.append(tab).append("</UseStatement>"); //$NON-NLS-1$
  	}
  
  	@Override
  	public int getType() {
  		return ASTNode.USE_STATEMENT;
  	}
  
  	/**
  	 * The list of single parts of this 'use' statement
  	 * 
  	 * @return List of this statement parts
  	 */
  	public List<UseStatementPart> parts() {
  		return this.parts;
  	}
  
  	/**
  	 * <b>WARNING:</b> to get "full" use statement type, use
  	 * UseStatementPart#getStatementType().
  	 * 
  	 * @see UseStatementPart#getStatementType()
  	 */
  	public int getStatementType() {
  		return statementType;
  	}
  
  	public void setStatementType(int statementType) {
  		preValueChange(STATEMENT_TYPE_PROPERTY);
  		this.statementType = statementType;
  		postValueChange(STATEMENT_TYPE_PROPERTY);
  	}
  
  	public NamespaceName getNamespace() {
  		return namespace;
  	}
  
  	public void setNamespace(NamespaceName namespace) {
  		ASTNode oldChild = this.namespace;
  		preReplaceChild(oldChild, namespace, NAMESPACE_PROPERTY);
  		this.namespace = namespace;
  		postReplaceChild(oldChild, namespace, NAMESPACE_PROPERTY);
  	}
  
  	/**
  	 * Returns empty node after trailing comma (if existing). <b>Since the new
  	 * PHP 7.2 trailing comma feature, the last element of a group use statement
  	 * can be an EmptyExpression object (whose length is 0). This element is
  	 * stored separately from other regular UseStatementPart parts() elements
  	 * and can be retrieved using this method.</b>
  	 * 
  	 * @return empty node after trailing comma, null otherwise
  	 */
  	public EmptyExpression getEmptyPart() {
  		return emptyPart;
  	}
  
  	public void setEmptyPart(EmptyExpression emptyPart) {
  		ASTNode oldChild = this.emptyPart;
  		preReplaceChild(oldChild, emptyPart, EMPTY_PART_PROPERTY);
  		this.emptyPart = emptyPart;
  		postReplaceChild(oldChild, emptyPart, EMPTY_PART_PROPERTY);
  	}
  
  	@Override
  	final List<? extends ASTNode> internalGetChildListProperty(ChildListPropertyDescriptor property) {
  		if (property == PARTS_PROPERTY) {
  			return parts();
  		}
  		// allow default implementation to flag the error
  		return super.internalGetChildListProperty(property);
  	}
  
  	@Override
  	final ASTNode internalGetSetChildProperty(ChildPropertyDescriptor property, boolean get, ASTNode child) {
  		if (property == NAMESPACE_PROPERTY) {
  			if (get) {
  				return getNamespace();
  			} else {
  				setNamespace((NamespaceName) child);
  				return null;
  			}
  		}
  		if (property == EMPTY_PART_PROPERTY) {
  			if (get) {
  				return getEmptyPart();
  			} else {
  				setEmptyPart((EmptyExpression) child);
  				return null;
  			}
  		}
  		// allow default implementation to flag the error
  		return super.internalGetSetChildProperty(property, get, child);
  	}
  
  	@Override
  	int internalGetSetIntProperty(SimplePropertyDescriptor property, boolean get, int value) {
  		if (property == STATEMENT_TYPE_PROPERTY) {
  			if (get) {
  				return getStatementType();
  			} else {
  				setStatementType(value);
  				return 0;
  			}
  		}
  		return super.internalGetSetIntProperty(property, get, value);
  	}
  
  	/*
  	 * 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 List<UseStatementPart> parts = ASTNode.copySubtrees(target, parts());
  		final NamespaceName namespace = ASTNode.copySubtree(target, getNamespace());
  		return new UseStatement(getStart(), getEnd(), target, namespace, parts, getEmptyPart(), getStatementType());
  	}
  
  	@Override
  	List<StructuralPropertyDescriptor> internalStructuralPropertiesForType(PHPVersion apiLevel) {
  		return PROPERTY_DESCRIPTORS;
  	}
  }
  