/*******************************************************************************
 * Copyright (c) 2000, 2019 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.jdt.core.dom;

import java.util.List;

/**
 * Abstract base class of all AST node types that declare a single
 * variable.
 * <pre>
 * VariableDeclaration:
 *    SingleVariableDeclaration
 *    VariableDeclarationFragment
 * </pre>
 *
 * @see SingleVariableDeclaration
 * @see VariableDeclarationFragment
 * @since 2.0
 */
public abstract class VariableDeclaration extends ASTNode {

	/**
	 * The variable name; lazily initialized; defaults to an unspecified,
	 * legal Java identifier.
	 */
	SimpleName variableName = null;

	/**
	 * The number of extra array dimensions that appear after the variable;
	 * defaults to 0. Not used in JLS8 and later.
	 *
	 * @since 2.1
	 * @deprecated In JLS8 and later, use {@link #extraDimensions} instead.
	 */
	int extraArrayDimensions = 0;

	/**
	 * List of extra dimensions this node has with optional annotations
	 * (element type: {@link Dimension}).
	 * Null before JLS8. Added in JLS8; defaults to an empty list
	 * (see constructor).
	 * 
	 * @since 3.10
	 */
	ASTNode.NodeList extraDimensions = null;

	/**
	 * The initializer expression, or <code>null</code> if none;
	 * defaults to none.
	 */
	Expression optionalInitializer = null;

	/**
	 * Creates and returns a structural property descriptor for the
	 * "name" property declared on the given concrete node type (child type: {@link SimpleName}).
	 *
	 * @return the property descriptor
	 */
	static final ChildPropertyDescriptor internalNamePropertyFactory(Class nodeClass) {
		return new ChildPropertyDescriptor(nodeClass, "name", SimpleName.class, MANDATORY, NO_CYCLE_RISK); //$NON-NLS-1$
	}

	/**
	 * Creates and returns a structural property descriptor for the
	 * "extraDimensions" property declared on the given concrete node type (type: {@link Integer}).
	 *
	 * @return the property descriptor
	 * @deprecated In JLS8 and later, use {@link #internalExtraDimensions2PropertyFactory(Class)} instead.
	 */
	static final SimplePropertyDescriptor internalExtraDimensionsPropertyFactory(Class nodeClass) {
		return 	new SimplePropertyDescriptor(nodeClass, "extraDimensions", int.class, MANDATORY); //$NON-NLS-1$
	}
	
	/**
	 * Creates and returns a structural property descriptor for the
	 * "extraDimensions2" property declared on the given concrete node type (element type: {@link Dimension}).
	 *
	 * @return the property descriptor
	 */
	static final ChildListPropertyDescriptor internalExtraDimensions2PropertyFactory(Class nodeClass) {
		return 	new ChildListPropertyDescriptor(nodeClass, "extraDimensions2", Dimension.class, CYCLE_RISK); //$NON-NLS-1$
	}
	
	/**
	 * Creates and returns a structural property descriptor for the
	 * "initializer" property declared on the given concrete node type (child type: {@link Expression}).
	 *
	 * @return the property descriptor
	 */
	static final ChildPropertyDescriptor internalInitializerPropertyFactory(Class nodeClass) {
		return 	new ChildPropertyDescriptor(nodeClass, "initializer", Expression.class, OPTIONAL, CYCLE_RISK); //$NON-NLS-1$
	}

	/**
	 * Returns structural property descriptor for the "name" property
	 * of this node (child type: {@link SimpleName}).
	 *
	 * @return the property descriptor
	 * @since 3.1
	 */
	abstract ChildPropertyDescriptor internalNameProperty();

	/**
	 * Returns the structural property descriptor for the "name" property
	 * of this node (child type: {@link SimpleName}).
	 *
	 * @return the property descriptor
	 * @since 3.1
	 */
	public final ChildPropertyDescriptor getNameProperty() {
		return internalNameProperty();
	}

	
	/**
	 * Returns the structural property descriptor for the "extraDimensions" property
	 * of this node (type: {@link Integer}) (below JLS8 only).
	 *
	 * @return the property descriptor
	 * @since 3.1
	 * @deprecated In JLS8 and later, use {@link #internalExtraDimensions2Property()} instead.
	 */
	abstract SimplePropertyDescriptor internalExtraDimensionsProperty();

	/**
	 * Returns the structural property descriptor for the "extraDimensions" property
	 * of this node (type: {@link Integer}) (below JLS8 only).
	 *
	 * @return the property descriptor
	 * @since 3.1
	 * @deprecated In JLS8 and later, use {@link #getExtraDimensions2Property()} instead.
	 */
	public final SimplePropertyDescriptor getExtraDimensionsProperty() {
		return internalExtraDimensionsProperty();
	}

	/**
	 * Returns the structural property descriptor for the "extraDimensions" property
	 * of this node (element type: {@link Dimension}) (added in JLS8 API).
	 *
	 * @return the property descriptor
	 * @since 3.10
	 */
	abstract ChildListPropertyDescriptor internalExtraDimensions2Property();
	
	/**
	 * Returns the structural property descriptor for the "extraDimensions" property
	 * of this node (element type: {@link Dimension}) (added in JLS8 API).
	 *
	 * @return the property descriptor
	 * @since 3.10
	 */
	public final ChildListPropertyDescriptor getExtraDimensions2Property() {
		return internalExtraDimensions2Property();
	}
	
	/**
	 * Returns structural property descriptor for the "initializer" property
	 * of this node (child type: {@link Expression}).
	 *
	 * @return the property descriptor
	 * @since 3.1
	 */
	abstract ChildPropertyDescriptor internalInitializerProperty();

	/**
	 * Returns structural property descriptor for the "initializer" property
	 * of this node (child type: {@link Expression}).
	 *
	 * @return the property descriptor
	 * @since 3.1
	 */
	public final ChildPropertyDescriptor getInitializerProperty() {
		return internalInitializerProperty();
	}

	/**
	 * Creates a new AST node for a variable declaration owned by the given AST.
	 * <p>
	 * N.B. This constructor is package-private.
	 * </p>
	 *
	 * @param ast the AST that is to own this node
	 */
	VariableDeclaration(AST ast) {
		super(ast);
		if (ast.apiLevel >= AST.JLS8_INTERNAL) {
			this.extraDimensions = new ASTNode.NodeList(getExtraDimensions2Property());
		}
	}

	/**
	 * Returns the name of the variable declared in this variable declaration.
	 *
	 * @return the variable name node
	 */
	public SimpleName getName() {
		if (this.variableName == null) {
			// lazy init must be thread-safe for readers
			synchronized (this) {
				if (this.variableName == null) {
					preLazyInit();
					this.variableName = new SimpleName(this.ast);
					postLazyInit(this.variableName, internalNameProperty());
				}
			}
		}
		return this.variableName;
	}

	/**
	 * Sets the name of the variable declared in this variable declaration
	 * to the given name.
	 *
	 * @param variableName the new variable name
	 * @exception IllegalArgumentException if:
	 * <ul>
	 * <li>the node belongs to a different AST</li>
	 * <li>the node already has a parent</li>
	 * </ul>
	 */
	public void setName(SimpleName variableName) {
		if (variableName == null) {
			throw new IllegalArgumentException();
		}
		ChildPropertyDescriptor p = internalNameProperty();
		ASTNode oldChild = this.variableName;
		preReplaceChild(oldChild, variableName, p);
		this.variableName = variableName;
		postReplaceChild(oldChild, variableName, p);
	}

	/**
	 * Returns the number of extra array dimensions over and above the
	 * explicitly-specified type.
	 * <p>
	 * For example, <code>int x[][]</code> has a type of
	 * <code>int</code> and two extra array dimensions;
	 * <code>int[][] x</code> has a type of <code>int[][]</code>
	 * and zero extra array dimensions. The two constructs have different
	 * ASTs, even though there are really syntactic variants of the same
	 * variable declaration.
	 * </p>
	 * <p>
	 * In the JLS8 API, this method is a convenience method that
	 * counts {@link #extraDimensions()}.
	 * </p>
	 *
	 * @return the number of extra array dimensions
	 * @since 2.1
	 */
	public int getExtraDimensions() {
		// more efficient than checking getAST().API_LEVEL
		if (this.extraDimensions == null) {
			// JLS2,3,4 behavior - bona fide property
			return this.extraArrayDimensions;
		} else {
			return this.extraDimensions.size();
		}
	}

	/**
	 * Sets the number of extra array dimensions over and above the
	 * explicitly-specified type.
	 * <p>
	 * For example, <code>int x[][]</code> has a type of
	 * <code>int</code> and two extra array dimensions;
	 * <code>int[][] x</code> has a type of <code>int[][]</code>
	 * and zero extra array dimensions. The two constructs have different
	 * ASTs, even though there are really syntactic variants of the same
	 * variable declaration.
	 * </p>
	 *
	 * @param dimensions the number of array dimensions
	 * @exception IllegalArgumentException if the number of dimensions is
	 *    negative
	 * @exception UnsupportedOperationException if this operation is used in
	 * a JLS8 or later AST 
	 * @deprecated In the JLS8 API, this method is replaced by
	 * {@link #extraDimensions()} which contains a list of {@link Dimension} nodes.
	 * @since 2.1
	 */
	public void setExtraDimensions(int dimensions) {
		internalSetExtraDimensions(dimensions);
	}

	/**
	 * Internal synonym for deprecated method. Used to avoid
	 * deprecation warnings.
	 * @since 3.10
	 */
	final void internalSetExtraDimensions(int dimensions) {
		// more efficient than just calling supportedOnlyIn2_3_4() to check
		if (this.extraDimensions != null) {
			supportedOnlyIn2_3_4();
		}
		if (dimensions < 0) {
			throw new IllegalArgumentException();
		}
		SimplePropertyDescriptor p = internalExtraDimensionsProperty();
		preValueChange(p);
		this.extraArrayDimensions = dimensions;
		postValueChange(p);
	}

	/**
	 * Returns the live ordered list of extra dimensions with optional annotations (added in JLS8 API).
	 *
	 * @return the live list of extra dimensions with optional annotations (element type: {@link Dimension})
	 * @exception UnsupportedOperationException if this operation is used below JLS8
	 * @since 3.10
	 */
	public List extraDimensions() {
		// more efficient than just calling unsupportedIn2_3_4() to check
		if (this.extraDimensions == null) {
			unsupportedIn2_3_4();
		}
		return this.extraDimensions;
	}

	/**
	 * Returns the initializer of this variable declaration, or
	 * <code>null</code> if there is none.
	 *
	 * @return the initializer expression node, or <code>null</code> if
	 *    there is none
	 */
	public Expression getInitializer() {
		return this.optionalInitializer;
	}

	/**
	 * Sets or clears the initializer of this variable declaration.
	 *
	 * @param initializer the initializer expression node, or <code>null</code>
	 *    if there is none
	 * @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 setInitializer(Expression initializer) {
		ChildPropertyDescriptor p = internalInitializerProperty();
		ASTNode oldChild = this.optionalInitializer;
		preReplaceChild(oldChild, initializer, p);
		this.optionalInitializer = initializer;
		postReplaceChild(oldChild, initializer, p);
	}

	/**
	 * Resolves and returns the binding for the variable declared in this
	 * variable declaration.
	 * <p>
	 * Note that bindings are generally unavailable unless requested when the
	 * AST is being built.
	 * </p>
	 *
	 * @return the binding, or <code>null</code> if the binding cannot be
	 *    resolved
	 */
	public IVariableBinding resolveBinding() {
		return this.ast.getBindingResolver().resolveVariable(this);
	}
}