**** 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) 2009-2011 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) 2009-2011 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.RubyModule;
import org.jruby.RubyObject;
import org.jruby.javasupport.JavaEmbedUtils;
import org.jruby.parser.StaticScope;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.builtin.IRubyObject;

Author:
Yoko Harada /**
 *
 * @author Yoko Harada <yokolet@gmail.com>
 */
abstract class AbstractVariable implements BiVariable {
    /*
     * receiver a receiver object to inject this var in. When the variable/constant
     * is originated from Java, receiver may be null. During the injection, the
     * receiver must be set.
     */
    protected final IRubyObject receiver;
    protected final String name;
    protected Object javaObject = null;
    protected Class javaType = null;
    protected IRubyObject rubyObject = null;
    protected boolean fromRuby;

    
Constructor used when this variable is originaed from Java.
Params:
runtime – 
name – 
fromRuby – 
values – /**
     * Constructor used when this variable is originaed from Java.
     *
     * @param runtime
     * @param name
     * @param fromRuby
     * @param values
     */
    protected AbstractVariable(IRubyObject receiver, String name, boolean fromRuby) {
        this.receiver = receiver;
        this.name = name.intern();
        this.fromRuby = fromRuby;
    }

    
Constructor when the variable is originated from Ruby.
Params:
receiver – a receiver object that this variable/constant is originally in. When
       the variable/constant is originated from Ruby, receiver may not be null.
name – 
fromRuby – 
rubyObject – /**
     * Constructor when the variable is originated from Ruby.
     *
     * @param receiver a receiver object that this variable/constant is originally in. When
     *        the variable/constant is originated from Ruby, receiver may not be null.
     * @param name
     * @param fromRuby
     * @param rubyObject
     */
    protected AbstractVariable(IRubyObject receiver, String name, boolean fromRuby, IRubyObject rubyObject) {
        this.receiver = receiver;
        this.name = name.intern();
        this.fromRuby = fromRuby;
        this.rubyObject = rubyObject;
    }

    final Ruby getRuntime() { return receiver.getRuntime(); }

    final ThreadContext getCurrentContext() { return getRuntime().getCurrentContext(); }

    final RubyObject getTopSelf() { return getTopSelf(receiver); }

    static RubyObject getTopSelf(final IRubyObject receiver) {
        return (RubyObject) receiver.getRuntime().getTopSelf();
    }

    protected void updateByJavaObject(final Ruby runtime, Object... values) {
        assert values != null;
        javaObject = values[0];
        if (javaObject == null) {
            javaType = null;
        } else if (values.length > 1) {
            javaType = (Class) values[1];
        } else {
            javaType = javaObject.getClass();
        }
        rubyObject = JavaEmbedUtils.javaToRuby(runtime, javaObject);
        fromRuby = false;
    }

    protected void updateRubyObject(final IRubyObject rubyObject) {
        if ( rubyObject == null ) return;
        this.rubyObject = rubyObject;
        this.javaType = null;
        // NOTE: quite weird - but won't pass tests otherwise !?!
        //this.javaObject = null;
        // delays updating javaObject for performance.
    }

    public IRubyObject getReceiver() {
        return receiver;
    }

    
Returns true if a given receiver is identical to the receiver this object has.
Returns:
true if identical otherwise false/**
     * Returns true if a given receiver is identical to the receiver this object has.
     *
     * @return true if identical otherwise false
     */
    public boolean isReceiverIdentical(final RubyObject receiver) {
        return getReceiver() == receiver;
    }

    public String getName() {
        return name;
    }

    public Object getJavaObject() {
        if (rubyObject == null) return javaObject;

        if (javaType != null) { // Java originated variables
            javaObject = javaType.cast( rubyObject.toJava(javaType) );
        }
        else { // Ruby originated variables
            javaObject = rubyObject.toJava(Object.class);
            if (javaObject != null) {
                javaType = javaObject.getClass();
            }
        }
        return javaObject;
    }

    public void setJavaObject(final Ruby runtime, Object javaObject) {
        updateByJavaObject(runtime, javaObject);
    }

    public IRubyObject getRubyObject() {
        return rubyObject;
    }

    public void setRubyObject(final IRubyObject rubyObject) {
        updateRubyObject(rubyObject);
    }

    protected static RubyModule getRubyClass(final Ruby runtime) {
        ThreadContext context = runtime.getCurrentContext();
        StaticScope scope = context.getCurrentStaticScope();
        RubyModule rubyClass = scope.getModule();
        return rubyClass;
    }

    protected static boolean isValidName(String pattern, Object name) {
        if ( ! ( name instanceof String ) ) return false;
        return ( (String) name).matches(pattern);
    }
}