/*

  * #%L

  * JavaScriptWithScopeElement.java - mongodb-async-driver - Allanbank Consulting, Inc.

  * %%

  * Copyright (C) 2011 - 2014 Allanbank Consulting, Inc.

  * %%

  * Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0

  * 

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  * #L%

  */

 package com.allanbank.mongodb.bson.element;

 import static com.allanbank.mongodb.util.Assertions.assertNotNull;

 import java.util.Iterator;

 import com.allanbank.mongodb.bson.Document;

 import com.allanbank.mongodb.bson.Element;

 import com.allanbank.mongodb.bson.ElementType;

 import com.allanbank.mongodb.bson.Visitor;

 import com.allanbank.mongodb.bson.builder.BuilderFactory;

 import com.allanbank.mongodb.bson.builder.DocumentBuilder;

 import com.allanbank.mongodb.bson.io.StringEncoder;

 /**

  * A wrapper for a BSON JavaScript with Scope.

  * 

  * @api.yes This class is part of the driver's API. Public and protected members

  *          will be deprecated for at least 1 non-bugfix release (version

  *          numbers are <major>.<minor>.<bugfix>) before being

  *          removed or modified.

  * @copyright 2011-2013, Allanbank Consulting, Inc., All Rights Reserved

  */

 public class JavaScriptWithScopeElement extends JavaScriptElement {

     /** The BSON type for a string. */

     @SuppressWarnings("hiding")

     public static final ElementType TYPE = ElementType.JAVA_SCRIPT_WITH_SCOPE;

     /** Serialization version for the class. */

     private static final long serialVersionUID = -5697976862389984453L;

     /**

      * Computes and returns the number of bytes that are used to encode the

      * element.

      * 

      * @param name

      *            The name for the element.

      * @param javaScript

      *            The BSON JavaScript value.

      * @param scope

      *            The scope for the JavaScript

      * @return The size of the element when encoded in bytes.

      */

     private static long computeSize(final String name, final String javaScript,

             final Document scope) {

         long result = 15; // type (1) + name null byte (1) + length (4)

         // javaScript length (4) and null byte (5)

         result += StringEncoder.utf8Size(name);

         result += StringEncoder.utf8Size(javaScript);

         if (scope != null) {

             result += scope.size();

         }

         return result;

     }

     /** The BSON scope value. */

     private final Document myScope;

     /**

      * Constructs a new {@link JavaScriptWithScopeElement}.

      * 

      * @param name

      *            The name for the BSON string.

      * @param javaScript

      *            The BSON JavaScript value.

      * @param scope

      *            The scope for the JavaScript

      * @throws IllegalArgumentException

      *             If the {@code name}, {@code javaScript}, or {@code scope} is

      *             <code>null</code>.

      */

     public JavaScriptWithScopeElement(final String name,

             final String javaScript, final Document scope) {

         this(name, javaScript, scope, computeSize(name, javaScript, scope));

         assertNotNull(scope, "JavaScript element's scope cannot be null.");

     }

     /**

      * Constructs a new {@link JavaScriptWithScopeElement}.

      * 

      * @param name

      *            The name for the BSON string.

      * @param javaScript

      *            The BSON JavaScript value.

      * @param scope

      *            The scope for the JavaScript

      * @param size

      *            The size of the element when encoded in bytes. If not known

      *            then use the

      *            {@link JavaScriptWithScopeElement#JavaScriptWithScopeElement(String, String, Document)}

      *            constructor instead.

      * @throws IllegalArgumentException

      *             If the {@code name}, {@code javaScript}, or {@code scope} is

      *             <code>null</code>.

      */

     public JavaScriptWithScopeElement(final String name,

             final String javaScript, final Document scope, final long size) {

         super(name, javaScript, size);

         assertNotNull(scope, "JavaScript element's scope cannot be null.");

         myScope = scope;

     }

     /**

      * Accepts the visitor and calls the

      * {@link Visitor#visitJavaScript(String,String,Document)} method.

      * 

      * @see Element#accept(Visitor)

      */

     @Override

     public void accept(final Visitor visitor) {

         visitor.visitJavaScript(getName(), getJavaScript(), getScope());

     }

     /**

      * {@inheritDoc}

      * <p>

      * Overridden to compare the Java Script (as text) if the base class

      * comparison is equals.

      * </p>

      */

     @Override

     public int compareTo(final Element otherElement) {

         int result = super.compareTo(otherElement);

         if (result == 0) {

             final JavaScriptWithScopeElement other = (JavaScriptWithScopeElement) otherElement;

             final Iterator<Element> thisIter = myScope.iterator();

             final Iterator<Element> otherIter = other.myScope.iterator();

             while (thisIter.hasNext() && otherIter.hasNext()) {

                 result = thisIter.next().compareTo(otherIter.next());

                 if (result != 0) {

                     return result;

                 }

             }

             if (thisIter.hasNext()) {

                 return 1;

             }

             else if (otherIter.hasNext()) {

                 return -1;

             }

             else {

                 return 0;

             }

         }

         return result;

     }

     /**

      * Determines if the passed object is of this same type as this object and

      * if so that its fields are equal.

      * 

      * @param object

      *            The object to compare to.

      * 

      * @see java.lang.Object#equals(java.lang.Object)

      */

     @Override

     public boolean equals(final Object object) {

         boolean result = false;

         if (this == object) {

             result = true;

         }

         else if ((object != null) && (getClass() == object.getClass())) {

             final JavaScriptWithScopeElement other = (JavaScriptWithScopeElement) object;

             result = super.equals(object)

                     && nullSafeEquals(myScope, other.myScope);

         }

         return result;

     }

     /**

      * Returns the BSON JavaScript scope.

      * 

      * @return The BSON JavaScript scope.

      */

     public Document getScope() {

         return myScope;

     }

     /**

      * {@inheritDoc}

      */

     @Override

     public ElementType getType() {

         return TYPE;

     }

     /**

      * {@inheritDoc}

      * <p>

      * Returns a document representing the code and scope similar to the strict

      * JSON encoding.

      * </p>

      * <p>

      * <b>Note:</b> This value will not be recreated is a Object-->Element

      * conversion. A more generic sub-document is created instead.

      * </p>

      */

     @Override

     public Document getValueAsObject() {

         final DocumentBuilder b = BuilderFactory.start();

         b.add("$code", getJavaScript());

         b.add("$scope", myScope);

         return b.build();

     }

     /**

      * Computes a reasonable hash code.

      * 

      * @return The hash code value.

      */

     @Override

     public int hashCode() {

         int result = 1;

         result = (31 * result) + super.hashCode();

         result = (31 * result) + ((myScope != null) ? myScope.hashCode() : 3);

         return result;

     }

     /**

      * {@inheritDoc}

      * <p>

      * Returns a new {@link JavaScriptElement}.

      * </p>

      */

     @Override

     public JavaScriptWithScopeElement withName(final String name) {

         if (getName().equals(name)) {

             return this;

         }

         return new JavaScriptWithScopeElement(name, getJavaScript(), myScope);

     }

 }