**** BEGIN LICENSE BLOCK *****
Version: EPL 2.0/GPL 2.0/LGPL 2.1
The contents of this file are subject to the Eclipse Public
License Version 2.0 (the "License"); you may not use this file
except in compliance with the License. You may obtain a copy of
the License at http://www.eclipse.org/legal/epl-v20.html
Software distributed under the License is distributed on an "AS
IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
implied. See the License for the specific language governing
rights and limitations under the License.
Copyright (C) 2009-2012 Yoko Harada 
Alternatively, the contents of this file may be used under the terms of
either of the GNU General Public License Version 2 or later (the "GPL"),
or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
in which case the provisions of the GPL or the LGPL are applicable instead
of those above. If you wish to allow use of your version of this file only
under the terms of either the GPL or the LGPL, and not to allow others to
use your version of this file under the terms of the EPL, indicate your
decision by deleting the provisions above and replace them with the notice
and other provisions required by the GPL or the LGPL. If you do not delete
the provisions above, a recipient may use your version of this file under
the terms of any one of the EPL, the GPL or the LGPL.
 **** END LICENSE BLOCK *****
/**
 * **** BEGIN LICENSE BLOCK *****
 * Version: EPL 2.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Eclipse Public
 * License Version 2.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.eclipse.org/legal/epl-v20.html
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * Copyright (C) 2009-2012 Yoko Harada <yokolet@gmail.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the EPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the EPL, the GPL or the LGPL.
 * **** END LICENSE BLOCK *****
 */
package org.jruby.embed.variable;

import org.jruby.Ruby;
import org.jruby.RubyObject;
import org.jruby.embed.internal.BiVariableMap;
import org.jruby.internal.runtime.GlobalVariables;
import org.jruby.runtime.builtin.IRubyObject;

An implementation of BiVariable for JSR223 style global variable. The assigned
name is like a local variables in Java, but a global in Ruby.
Author:
Yoko Harada /**
 * An implementation of BiVariable for JSR223 style global variable. The assigned
 * name is like a local variables in Java, but a global in Ruby.
 *
 * @author Yoko Harada <yokolet@gmail.com>
 */
public class LocalGlobalVariable extends GlobalVariable {

    private static final String VALID_NAME = "([a-zA-Z]|(_([a-zA-Z]|_|\\d)))([a-zA-Z]|_|\\d)*";

    
Returns an instance of this class. This factory method is used when a local global type variable is put into BiVariableMap. 
Params:
runtime – Ruby runtime
name – a variable name
javaObject – Java object that should be assigned to.
Returns:
the instance of LocalGlobalVariable/**
     * Returns an instance of this class. This factory method is used when a local
     * global type variable is put into {@link BiVariableMap}.
     *
     * @param runtime Ruby runtime
     * @param name a variable name
     * @param javaObject Java object that should be assigned to.
     * @return the instance of LocalGlobalVariable
     */
    public static BiVariable getInstance(RubyObject receiver, String name, Object... javaObject) {
        if (name.matches(VALID_NAME)) {
            return new LocalGlobalVariable(receiver, name, javaObject);
        }
        return null;
    }

    private LocalGlobalVariable(RubyObject receiver, String name, Object... javaObject) {
        super(receiver, name, javaObject);
    }

    
A constructor used when local global type variables are retrieved from Ruby.
Params:
name – the local global type variable name
irubyObject – Ruby global object/**
     * A constructor used when local global type variables are retrieved from Ruby.
     *
     * @param name the local global type variable name
     * @param irubyObject Ruby global object
     */
    // NOTE: reflectively used by BiVariable
    LocalGlobalVariable(RubyObject receiver, String name, IRubyObject irubyObject) {
        super(receiver, name, irubyObject);
    }

    
Retrieves global variables eagerly from Ruby right after the evaluation. The
variable names to be retrieved must be in a variable map.
Params:
receiver – receiver object returned when a script is evaluated.
vars – map to save retrieved global variables./**
     * Retrieves global variables eagerly from Ruby right after the evaluation. The
     * variable names to be retrieved must be in a variable map.
     *
     * @param receiver receiver object returned when a script is evaluated.
     * @param vars map to save retrieved global variables.
     */
    public static void retrieve(final RubyObject receiver, final BiVariableMap vars) {
        if ( vars.isLazy() ) return;

        final GlobalVariables globalVars = receiver.getRuntime().getGlobalVariables();
        for ( final String name : globalVars.getNames() ) {
            if ( isPredefined(name) ) continue;

            final IRubyObject value = globalVars.get(name);
            String javaName = name.substring(1); // eliminates a preceding character, "$"
            updateLocalGlobal(getTopSelf(receiver), vars, javaName, value);
        }
    }

    private static void updateLocalGlobal(final RubyObject receiver,
        final BiVariableMap vars, final String name, final IRubyObject value) {
        vars.updateVariable(receiver, name, value, LocalGlobalVariable.class);
    }

    
Retrieves a global variable by key from Ruby runtime after the evaluation.
This method is used when eager retrieval is off.
Params:
runtime – Ruby runtime
vars – map to save a retrieved global variable.
name – name of the global variable/**
     * Retrieves a global variable by key from Ruby runtime after the evaluation.
     * This method is used when eager retrieval is off.
     *
     * @param runtime Ruby runtime
     * @param vars map to save a retrieved global variable.
     * @param name name of the global variable
     */
    public static void retrieveByKey(final Ruby runtime,
        final BiVariableMap vars, final String name) {
        final GlobalVariables globalVars = runtime.getGlobalVariables();
        // if the specified key doesn't exist, this method is called before the
        // evaluation. Don't update value in this case.
        final String gName = ("$" + name).intern();
        if ( ! globalVars.getNames().contains(gName) ) return;

        // the specified key is found, so let's update
        final IRubyObject value = globalVars.get(gName);
        updateLocalGlobal((RubyObject) runtime.getTopSelf(), vars, name, value);
    }

    
Returns enum type of this variable defined in BiVariable. 
Returns:
this enum type, BiVariable.Type.GlobalVariable./**
     * Returns enum type of this variable defined in {@link BiVariable}.
     *
     * @return this enum type, BiVariable.Type.GlobalVariable.
     */
    @Override
    public Type getType() {
        return Type.LocalGlobalVariable;
    }

    
Returns true if the given name is a local global type variable. Unless
returns false.
Params:
name – is a name to be checked.
Returns:
true if the given name is of a local global type variable./**
     * Returns true if the given name is a local global type variable. Unless
     * returns false.
     *
     * @param name is a name to be checked.
     * @return true if the given name is of a local global type variable.
     */
    public static boolean isValidName(Object name) {
        return isValidName(VALID_NAME, name);
    }

    
Injects a global value to a parsed Ruby script. This method is
invoked during EvalUnit#run() is executed.
/**
     * Injects a global value to a parsed Ruby script. This method is
     * invoked during EvalUnit#run() is executed.
     */
    @Override
    public void inject() {
        synchronized (getRuntime()) {
            String name = this.name.startsWith("$") ? this.name : '$' + this.name;
            getRuntime().getGlobalVariables().set(name, rubyObject);
        }
    }

    
Removes this object from BiVariableMap. 
Params:
runtime – environment where a variable is removed./**
     * Removes this object from {@link BiVariableMap}.
     *
     * @param runtime environment where a variable is removed.
     */
    @Override
    public void remove() {
        synchronized (getRuntime()) {
            String name = this.name.startsWith("$") ? this.name : '$' + this.name;
            getRuntime().getGlobalVariables().clear(name);
        }
    }
}