/*
 * eXist Open Source Native XML Database
 * Copyright (C) 2001-2009 The eXist team
 *  http://exist-db.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *  
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *  
 *  $Id$
 */

package org.exist.xquery.functions.response;

import java.util.Date;

import javax.xml.datatype.Duration;

import org.apache.log4j.Logger;
import org.exist.dom.QName;
import org.exist.http.servlets.ResponseWrapper;
import org.exist.xquery.Cardinality;
import org.exist.xquery.Dependency;
import org.exist.xquery.Function;
import org.exist.xquery.FunctionSignature;
import org.exist.xquery.Profiler;
import org.exist.xquery.Variable;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.value.DurationValue;
import org.exist.xquery.value.BooleanValue;
import org.exist.xquery.value.FunctionParameterSequenceType;
import org.exist.xquery.value.Item;
import org.exist.xquery.value.JavaObjectValue;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;

/**
 * Set's a HTTP Cookie on the HTTP Response
 * 
 * @author Adam Retter <adam.retter@devon.gov.uk>
 * 
 * @see org.exist.xquery.Function
 */
public class SetCookie extends Function {
	
	protected static final Logger logger = Logger.getLogger(SetCookie.class);
	protected static final FunctionParameterSequenceType NAME_PARAM = new FunctionParameterSequenceType("name", Type.STRING, Cardinality.EXACTLY_ONE, "The cookie name");
	protected static final FunctionParameterSequenceType VALUE_PARAM = new FunctionParameterSequenceType("value", Type.STRING, Cardinality.EXACTLY_ONE, "The cookie value");
	protected static final FunctionParameterSequenceType MAX_AGE_PARAM = new FunctionParameterSequenceType("max-age", Type.DURATION, Cardinality.EXACTLY_ONE, "The xs:duration of the cookie");
	protected static final FunctionParameterSequenceType SECURE_PARAM = new FunctionParameterSequenceType("name", Type.BOOLEAN, Cardinality.ZERO_OR_ONE, "The flag on whether the cookie is to be secure (eg. only transferred using HTTPS)");

	public final static FunctionSignature signatures[] = {
		new FunctionSignature(
			new QName("set-cookie", ResponseModule.NAMESPACE_URI, ResponseModule.PREFIX),
			"Sets a HTTP Cookie on the HTTP Response.",
			new SequenceType[] { NAME_PARAM, VALUE_PARAM },
			new SequenceType(Type.ITEM, Cardinality.EMPTY)),
		new FunctionSignature(
			new QName("set-cookie", ResponseModule.NAMESPACE_URI, ResponseModule.PREFIX),
			"Sets a HTTP Cookie on the HTTP Response.",
			new SequenceType[] { NAME_PARAM, VALUE_PARAM, MAX_AGE_PARAM, SECURE_PARAM },
			new SequenceType(Type.ITEM, Cardinality.EMPTY)) 
		};
	
	public SetCookie(XQueryContext context, FunctionSignature signature) {
		super(context, signature);
	}
	
	/* (non-Javadoc)
	 * @see org.exist.xquery.Expression#eval(org.exist.dom.DocumentSet, org.exist.xquery.value.Sequence, org.exist.xquery.value.Item)
	 */
	public Sequence eval(Sequence contextSequence, Item contextItem) throws XPathException {
		
		if (context.getProfiler().isEnabled()) {
			context.getProfiler().start(this);       
			context.getProfiler().message(this, Profiler.DEPENDENCIES, "DEPENDENCIES", Dependency.getDependenciesName(this.getDependencies()));
			if (contextSequence != null) {
				context.getProfiler().message(this, Profiler.START_SEQUENCES, "CONTEXT SEQUENCE", contextSequence);
			}
			if (contextItem != null) {
				context.getProfiler().message(this, Profiler.START_SEQUENCES, "CONTEXT ITEM", contextItem.toSequence());	
			}
		}
		
		ResponseModule myModule = (ResponseModule)context.getModule(ResponseModule.NAMESPACE_URI);
		
		// response object is read from global variable $response
		Variable var = myModule.resolveVariable(ResponseModule.RESPONSE_VAR);
		if(var == null || var.getValue() == null) {
			throw new XPathException(this, "Response not set");
		}
		if(var.getValue().getItemType() != Type.JAVA_OBJECT) {
			throw new XPathException(this, "Variable $response is not bound to a Java object.");
		}
		JavaObjectValue response = (JavaObjectValue)var.getValue().itemAt(0);
		
		//get parameters
		String name = getArgument(0).eval(contextSequence, contextItem).getStringValue();
		String value = getArgument(1).eval(contextSequence, contextItem).getStringValue();
        
        Sequence ageSeq = Sequence.EMPTY_SEQUENCE;
        if(getArgumentCount()>2){
            ageSeq = getArgument(2).eval(contextSequence, contextItem);
        }

		//set response header
		if(response.getObject() instanceof ResponseWrapper) {
			if (ageSeq.isEmpty()) {
				((ResponseWrapper) response.getObject()).addCookie(name, value);
			} else {
				Duration duration = ((DurationValue) ageSeq.itemAt(0)).getCanonicalDuration();
				int maxAge = (int) (duration.getTimeInMillis(new Date(System.currentTimeMillis())) / 1000L);
				
				Sequence secureSeq = getArgument(3).eval(contextSequence, contextItem);
				
				if (secureSeq.isEmpty()) {
					((ResponseWrapper) response.getObject()).addCookie(name, value, maxAge);
				} else {
					((ResponseWrapper) response.getObject()).addCookie(name, value, maxAge, ((BooleanValue)secureSeq.itemAt(0)).effectiveBooleanValue() );
				}
			}
		} else {
			throw new XPathException(this, "Type error: variable $response is not bound to a response object");
		}
		return Sequence.EMPTY_SEQUENCE;
	}
}