/**
 * $Id: $
 * $Date: $
 *
 */

package org.xmlsh.core;

import java.util.Collection;
import java.util.HashSet;
import java.util.Set;
import org.xmlsh.util.NameValueMap;

@SuppressWarnings("serial")
public class Variables {
  private NameValueMap<XVariable> mGlobals;
  private NameValueMap<XVariable> mLocals = new NameValueMap<XVariable>();

  public Variables() {
    mGlobals = new NameValueMap<XVariable>();

  }

  Variables(Variables that) {
    mGlobals = that.mGlobals.clone();
    mGlobals.putAll(that.mLocals.clone());
  }

  private Variables(NameValueMap<XVariable> globals,
      NameValueMap<XVariable> locals) {
    mGlobals = globals;
    mLocals = locals;
  }

  public XVariable get(String name) {
    // First look in locals
    XVariable v = mLocals.get(name);
    if(v == null)
      v = mGlobals.get(name);
    return v;

  }

  public void put(XVariable var) {
    String name = var.getName();
    if(mLocals.containsKey(name) || var.isLocal()) {
      mLocals.put(name, var);
    }
    else
      mGlobals.put(name, var);
  }

  public Collection<String> getVarNames() {
    Set<String> names = new HashSet<String>(mGlobals.size() + mLocals.size());

    names.addAll(mGlobals.keySet());
    names.addAll(mLocals.keySet());
    return names;

  }

  public void unset(String name) throws InvalidArgumentException {
    // Unsetting a local just sets its value to null
    XVariable var = mLocals.get(name);
    if(var != null)
      var.unset();
    else {
      var = mGlobals.get(name);
      if(var != null) {
        var.unset();
        mGlobals.remove(name);
      }
    }

  }

  public boolean containsKey(String name) {
    return mGlobals.containsKey(name) || mLocals.containsKey(name);
  }

  /*
   * Create a copy of the Variables where the globals are identical but the
   * locals are cloned
   * 
   */
  public Variables pushLocals(NameValueMap<XVariable> contextLocals) {

    NameValueMap<XVariable> locals = mLocals.clone();
    if(contextLocals != null) {
      locals.putAll(contextLocals);

    }
    return new Variables(mGlobals, locals);
  }

  // Returns a direct reference to the local variables
  public NameValueMap<XVariable> getLocalVars() {
    return mLocals;
  }

}

//
//
// Copyright (C) 2008-2014 David A. Lee.
//
// The contents of this file are subject to the "Simplified BSD License" (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.opensource.org/licenses/bsd-license.php
//
// 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.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is David A. Lee
//
// Portions created by (your name) are Copyright (C) (your legal entity). All
// Rights Reserved.
//
// Contributor(s): none.
//