**** 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 java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.jruby.Ruby;
import org.jruby.RubyObject;
import org.jruby.embed.internal.BiVariableMap;
import org.jruby.embed.LocalVariableBehavior;
import org.jruby.runtime.builtin.IRubyObject;
import org.jruby.runtime.scope.ManyVarsDynamicScope;

This class is responsible to local variable behavior dependent processing.
Author:
Yoko Harada /**
 * This class is responsible to local variable behavior dependent processing.
 *
 * @author Yoko Harada <yokolet@gmail.com>
 */
public class VariableInterceptor {
    //private LocalVariableBehavior behavior;

    /**
     * Constructs an instance with a given local variable behavior.
     *
     * @param behavior local variable behavior
     */
    //public VariableInterceptor(LocalVariableBehavior behavior) {
    //    this.behavior = behavior;
    //}

    //public LocalVariableBehavior getLocalVariableBehavior() {
    //    return behavior;
    //}

    
Returns an appropriate type of a variable instance to the specified local
variable behavior.
Params:
runtime – Ruby runtime
name – variable name
value – variable value
Returns:
an appropriate type of the variable instance./**
     * Returns an appropriate type of a variable instance to the specified local
     * variable behavior.
     *
     * @param runtime Ruby runtime
     * @param name variable name
     * @param value variable value
     * @return an appropriate type of the variable instance.
     */
    public static BiVariable getVariableInstance(LocalVariableBehavior behavior, RubyObject receiver, String name, Object... value) {
        if (value == null || value.length < 1) {
            return null;
        }
        if ("ARGV".equals(name)) {
            return Argv.getInstance(receiver, name, value);
        }
        switch (behavior) {
            case GLOBAL:
                return LocalGlobalVariable.getInstance(receiver, name, value);
            case BSF:
                BiVariable[] bEntries = {
                    PersistentLocalVariable.getInstance(receiver, name, value),
                    GlobalVariable.getInstance(receiver, name, value)
                };
                return resolve(bEntries);
            case PERSISTENT:
                BiVariable[] pEntries = {
                    GlobalVariable.getInstance(receiver, name, value),
                    InstanceVariable.getInstance(receiver, name, value),
                    ClassVariable.getInstance(receiver, name, value),
                    Constant.getInstance(receiver, name, value),
                    PersistentLocalVariable.getInstance(receiver, name, value)
                };
                return resolve(pEntries);
            default:
                BiVariable[] tEntries = {
                    GlobalVariable.getInstance(receiver, name, value),
                    InstanceVariable.getInstance(receiver, name, value),
                    ClassVariable.getInstance(receiver, name, value),
                    Constant.getInstance(receiver, name, value),
                    TransientLocalVariable.getInstance(receiver, name, value)
                };
                return resolve(tEntries);
        }
    }

    private static BiVariable resolve(BiVariable[] entries) {
        for (BiVariable e : entries) {
            if (e != null) {
                return e;
            }
        }
        return null;
    }

    
Injects variable values from Java to Ruby just before an evaluation or
method invocation.
Params:
map – a variable map that has name-value pairs to be injected
runtime – Ruby runtime
scope – scope to inject local variable values
depth – depth of a frame to inject local variable values
receiver – a receiver when the script has been evaluated once/**
     * Injects variable values from Java to Ruby just before an evaluation or
     * method invocation.
     *
     * @param map a variable map that has name-value pairs to be injected
     * @param runtime Ruby runtime
     * @param scope scope to inject local variable values
     * @param depth depth of a frame to inject local variable values
     * @param receiver a receiver when the script has been evaluated once
     */
    public static void inject(BiVariableMap map, Ruby runtime, ManyVarsDynamicScope scope, int depth, IRubyObject receiver) {
        // lvar might not be given while parsing but be given when evaluating.
        // to avoid ArrayIndexOutOfBoundsException, checks the length of scope.getValues()
        if (scope != null && scope.getValues().length > 0) {
            IRubyObject[] values4Injection = map.getLocalVarValues();
            if (values4Injection != null && values4Injection.length > 0) {
                for (int i = 0; i < values4Injection.length; i++) {
                    scope.setValue(i, values4Injection[i], depth);
                }
            }
        }
        Collection<BiVariable> variables = map.getVariables();
        for ( final BiVariable var : variables ) var.inject();
    }

    
Retrieves variable/constant names and values after the evaluation or method
invocation.
Params:
map – variable map that holds retrieved name-value pairs.
runtime – Ruby runtime
receiver – a receiver when the script has been evaluated once/**
     * Retrieves variable/constant names and values after the evaluation or method
     * invocation.
     *
     * @param map variable map that holds retrieved name-value pairs.
     * @param runtime Ruby runtime
     * @param receiver a receiver when the script has been evaluated once
     */
    public static void retrieve(LocalVariableBehavior behavior, BiVariableMap map, RubyObject receiver) {
        Argv.retrieve(receiver, map);
        switch (behavior) {
            case GLOBAL:
                LocalGlobalVariable.retrieve(receiver, map);
                break;
            case BSF:
                PersistentLocalVariable.retrieve(receiver, map);
                break;
            case PERSISTENT:
                PersistentLocalVariable.retrieve(receiver, map);
            // continues to the default case
            default:
                InstanceVariable.retrieve(receiver, map);
                GlobalVariable.retrieve(receiver, map);
                ClassVariable.retrieve(receiver, map);
                Constant.retrieve(receiver, map);
        }
    }

    
Retrieves specified variable/constant name and value after the evaluation
or method invocation only when it is requested.
Params:
map – variable map that holds retrieved name-value pairs.
runtime – Ruby runtime
receiver – a receiver when the script has been evaluated once
@
/**
     * Retrieves specified variable/constant name and value after the evaluation
     * or method invocation only when it is requested.
     *
     * @param map variable map that holds retrieved name-value pairs.
     * @param runtime Ruby runtime
     * @param receiver a receiver when the script has been evaluated once
     * @
     */
    public static void tryLazyRetrieval(LocalVariableBehavior behavior, BiVariableMap map, IRubyObject receiver, Object key) {
        if (Argv.isValidName(key)) {
            Argv.retrieveByKey((RubyObject)receiver, map, (String)key);
            return;
        }
        switch (behavior) {
            case GLOBAL:
                if (LocalGlobalVariable.isValidName(key)) {
                    LocalGlobalVariable.retrieveByKey(receiver.getRuntime(), map, (String)key);
                }
                break;
            case BSF:
                break;
            case PERSISTENT:
            default:
                if (GlobalVariable.isValidName(key)) {
                    GlobalVariable.retrieveByKey(receiver.getRuntime(), map, (String)key);
                } else if (InstanceVariable.isValidName(key)) {
                    InstanceVariable.retrieveByKey((RubyObject) receiver,map, (String)key);
                } else if (ClassVariable.isValidName(key)) {
                    ClassVariable.retrieveByKey((RubyObject)receiver, map, (String)key);
                } else if (Constant.isValidName(key)) {
                    Constant.retrieveByKey((RubyObject)receiver, map, (String)key);
                }
        }
    }

    
Clears global variable values from Ruby runtime to behave the same as
JSR 223 reference implementation.
Params:
variables – a variable list to be cleared from Ruby runtime
runtime – Ruby runtime/**
     * Clears global variable values from Ruby runtime to behave the same as
     * JSR 223 reference implementation.
     *
     * @param variables a variable list to be cleared from Ruby runtime
     * @param runtime Ruby runtime
     */
    public static void terminateGlobalVariables(LocalVariableBehavior behavior, Collection<BiVariable> variables, Ruby runtime) {
        if (variables == null) return;
        if (LocalVariableBehavior.GLOBAL == behavior) {
            for ( final BiVariable var : variables ) {
                if (BiVariable.Type.LocalGlobalVariable == var.getType()) {
                    String name = var.getName();
                    name = name.startsWith("$") ? name : "$" + name;
                    runtime.getGlobalVariables().set(name, runtime.getNil());
                }
            }
        }
    }

    
Clears local variables form the variable map so that old local variable
name-value pairs are not to be used in successive evaluations.
Params:
varNames – variable name list to be cleared
variables – variable value list to be cleared/**
     * Clears local variables form the variable map so that old local variable
     * name-value pairs are not to be used in successive evaluations.
     *
     * @param varNames variable name list to be cleared
     * @param variables variable value list to be cleared
     */
    public static void terminateLocalVariables(LocalVariableBehavior behavior, List<String> varNames, List<BiVariable> variables) {
        if (variables == null) return;
        if (LocalVariableBehavior.TRANSIENT == behavior) {
            for (int i = 0; i < variables.size(); i++) {
                if (BiVariable.Type.LocalVariable == variables.get(i).getType()) {
                    varNames.remove(i);
                    variables.remove(i);
                }
            }
        }
    }

    
Checks the given name is whether a legal Ruby variable/constant name or not.
Params:
name – a given name to be checked
Returns:
true when the name is a legal Ruby variable/constant name, otherwise false./**
     * Checks the given name is whether a legal Ruby variable/constant name or not.
     *
     * @param name a given name to be checked
     * @return true when the name is a legal Ruby variable/constant name, otherwise false.
     */
    public static boolean isKindOfRubyVariable(LocalVariableBehavior behavior, String name) {
        if ("ARGV".equals(name)) return true;
        switch (behavior) {
            case GLOBAL:
                return LocalGlobalVariable.isValidName(name);
            case BSF:
                if (PersistentLocalVariable.isValidName(name)) return true;
                if (GlobalVariable.isValidName(name)) return true;
                return false;
            case PERSISTENT:
                if (GlobalVariable.isValidName(name)) return true;
                if (PersistentLocalVariable.isValidName(name)) return true;
                if (InstanceVariable.isValidName(name)) return true;
                if (Constant.isValidName(name)) return true;
                if (ClassVariable.isValidName(name)) return true;
                return false;
            default:
                if (GlobalVariable.isValidName(name)) return true;
                if (TransientLocalVariable.isValidName(name)) return true;
                if (InstanceVariable.isValidName(name)) return true;
                if (Constant.isValidName(name)) return true;
                if (ClassVariable.isValidName(name)) return true;
                return false;
        }
    }
}