/*

 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package jdk.nashorn.internal.ir;

import static jdk.nashorn.internal.codegen.CompilerConstants.__DIR__;

import static jdk.nashorn.internal.codegen.CompilerConstants.__FILE__;

import static jdk.nashorn.internal.codegen.CompilerConstants.__LINE__;

import jdk.nashorn.internal.codegen.types.Type;

import jdk.nashorn.internal.ir.annotations.Immutable;

import jdk.nashorn.internal.ir.visitor.NodeVisitor;

/**

 * IR representation for an identifier.

 */

@Immutable

public final class IdentNode extends Expression implements PropertyKey, FunctionCall {

    private static final int PROPERTY_NAME     = 1 << 0;

    private static final int INITIALIZED_HERE  = 1 << 1;

    private static final int FUNCTION          = 1 << 2;

    private static final int FUTURESTRICT_NAME = 1 << 3;

    /** Identifier. */

    private final String name;

    /** Type for a callsite, e.g. X in a get()X or a set(X)V */

    private final Type callSiteType;

    private final int flags;

    /**

     * Constructor

     *

     * @param token   token

     * @param finish  finish position

     * @param name    name of identifier

     */

    public IdentNode(final long token, final int finish, final String name) {

        super(token, finish);

        this.name = name.intern();

        this.callSiteType = null;

        this.flags = 0;

    }

    private IdentNode(final IdentNode identNode, final String name, final Type callSiteType, final int flags) {

        super(identNode);

        this.name = name;

        this.callSiteType = callSiteType;

        this.flags = flags;

    }

    /**

     * Copy constructor - create a new IdentNode for the same location

     *

     * @param identNode  identNode

     */

    public IdentNode(final IdentNode identNode) {

        super(identNode);

        this.name         = identNode.getName();

        this.callSiteType = null;

        this.flags        = identNode.flags;

    }

    @Override

    public Type getType() {

        return callSiteType == null ? super.getType() : callSiteType;

    }

    @Override

    public boolean isAtom() {

        return true;

    }

    private boolean hasCallSiteType() {

        //this is an identity that's part of a getter or setter

        return callSiteType != null;

    }

    /**

     * Assist in IR navigation.

     *

     * @param visitor IR navigating visitor.

     */

    @Override

    public Node accept(final NodeVisitor<? extends LexicalContext> visitor) {

        if (visitor.enterIdentNode(this)) {

            return visitor.leaveIdentNode(this);

        }

        return this;

    }

    @Override

    public void toString(final StringBuilder sb) {

        if (hasCallSiteType()) {

            sb.append('{');

            final String desc = getType().getDescriptor();

            sb.append(desc.charAt(desc.length() - 1) == ';' ? 'O' : getType().getDescriptor());

            sb.append('}');

        }

        sb.append(name);

    }

    /**

     * Get the name of the identifier

     * @return  IdentNode name

     */

    public String getName() {

        return name;

    }

    @Override

    public String getPropertyName() {

        return getName();

    }

    /**

     * Check if this IdentNode is a property name

     * @return true if this is a property name

     */

    public boolean isPropertyName() {

        return (flags & PROPERTY_NAME) != 0;

    }

    /**

     * Flag this IdentNode as a property name

     * @return a node equivalent to this one except for the requested change.

     */

    public IdentNode setIsPropertyName() {

        if (isPropertyName()) {

            return this;

        }

        return new IdentNode(this, name, callSiteType, flags | PROPERTY_NAME);

    }

    /**

     * Check if this IdentNode is a future strict name

     * @return true if this is a future strict name

     */

    public boolean isFutureStrictName() {

        return (flags & FUTURESTRICT_NAME) != 0;

    }

    /**

     * Flag this IdentNode as a future strict name

     * @return a node equivalent to this one except for the requested change.

     */

    public IdentNode setIsFutureStrictName() {

        if (isFutureStrictName()) {

            return this;

        }

        return new IdentNode(this, name, callSiteType, flags | FUTURESTRICT_NAME);

    }

    /**

     * Helper function for local def analysis.

     * @return true if IdentNode is initialized on creation

     */

    public boolean isInitializedHere() {

        return (flags & INITIALIZED_HERE) != 0;

    }

    /**

     * Flag IdentNode to be initialized on creation

     * @return a node equivalent to this one except for the requested change.

     */

    public IdentNode setIsInitializedHere() {

        if (isInitializedHere()) {

            return this;

        }

        return new IdentNode(this, name, callSiteType, flags | INITIALIZED_HERE);

    }

    /**

     * Check if this IdentNode is a special identity, currently __DIR__, __FILE__

     * or __LINE__

     *

     * @return true if this IdentNode is special

     */

    public boolean isSpecialIdentity() {

        return name.equals(__DIR__.symbolName()) || name.equals(__FILE__.symbolName()) || name.equals(__LINE__.symbolName());

    }

    @Override

    public boolean isFunction() {

        return (flags & FUNCTION) != 0;

    }

    /**

     * Mark this node as being the callee operand of a {@link CallNode}.

     * @return an ident node identical to this one in all aspects except with its function flag set.

     */

    public IdentNode setIsFunction() {

        if (isFunction()) {

            return this;

        }

        return new IdentNode(this, name, callSiteType, flags | FUNCTION);

    }

}