/**
 * License Agreement.
 *
 * Rich Faces - Natural Ajax for Java Server Faces (JSF)
 *
 * Copyright (C) 2007 Exadel, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License version 2.1 as published by the Free Software Foundation.
 *
 * This library 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 library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
 */

package org.ajax4jsf.resource;

import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

import javax.faces.context.FacesContext;

import org.ajax4jsf.Messages;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Base class for all Html page resources - images, scripts, styles etc. Realise
 * as "brige" pattern - different subclasses for different resource source
 * (static,jar,soft generator ) and customaized with differernt renderers for
 * image, script, style ( linked ir inline ). must operate with different
 * sources - application context, classpath, software generator.
 * 
 * @author shura (latest modification by $Author: nick_belaevski $)
 * @version $Revision: 1.1.2.2 $ $Date: 2007/01/11 16:52:15 $
 * 
 */
public abstract class InternetResourceBase implements InternetResource {

	private static final Log log = LogFactory
			.getLog(InternetResourceBase.class);

	static final int BUFFER_SIZE = 1024;

	// Hours

	private int contentLength = -1;

	private Date lastModified = new Date(System.currentTimeMillis());

	private Date expired;

	private boolean cacheable = true;

	private boolean sessionAware = true;

	private ResourceRenderer renderer = null;

	private Map<Object,Object> customProperties = new HashMap<Object, Object>();

	private String key;

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.ajax4jsf.chameleon.resource.InternetResource#getContentLength()
	 */
	public int getContentLength(ResourceContext resourceContext) {
		return contentLength;
	}

	/**
	 * @param contentLength
	 *            The contentLength to set.
	 */
	protected void setContentLength(int contentLength) {
		this.contentLength = contentLength;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.ajax4jsf.chameleon.resource.InternetResource#getExpired()
	 */
	public Date getExpired(ResourceContext resourceContext) {
		return expired;
	}

	/**
	 * @param expired
	 *            The expired to set.
	 */
	public void setExpired(Date expired) {
		this.expired = expired;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.ajax4jsf.chameleon.resource.InternetResource#getLastModified()
	 */
	public Date getLastModified(ResourceContext resourceContext) {

		if (null != lastModified) {
			return lastModified;
		} else {
			return new Date(System.currentTimeMillis());
		}
	}

	/**
	 * @param lastModified
	 *            The lastModified to set.
	 */
	public void setLastModified(Date lastModified) {
		this.lastModified = lastModified;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.ajax4jsf.chameleon.resource.InternetResource#isCacheable()
	 */
	public boolean isCacheable(ResourceContext resourceContext) {
		return cacheable;
	}

	/**
	 * @param cacheable
	 *            The cacheable to set.
	 */
	public void setCacheable(boolean cacheable) {
		this.cacheable = cacheable;
	}

	/**
	 * @return Returns the sessionAware.
	 */
	public boolean isSessionAware() {
		return requireFacesContext();
	}

	/**
	 * @param sessionAware
	 *            The sessionAware to set.
	 */
	public void setSessionAware(boolean sessionAware) {
		this.sessionAware = sessionAware;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.ajax4jsf.chameleon.resource.InternetResource#getContentType()
	 */
	public String getContentType(ResourceContext resourceContext) {
		return getRenderer(resourceContext).getContentType();
	}

	/**
	 * @return Returns the renderer.
	 */
	public ResourceRenderer getRenderer(ResourceContext resourceContext) {
		return renderer;
	}

	/**
	 * @param renderer
	 *            The renderer to set.
	 */
	public void setRenderer(ResourceRenderer renderer) {
		this.renderer = renderer;
	}

	/**
	 * Key for wich resource registered in resource builder.
	 * 
	 * @return Returns the key.
	 */
	public String getKey() {
		return key;
	}

	/**
	 * Set registration key ( by {@link InternetResourceBuilder} for this
	 * resource.
	 * 
	 * @param key
	 *            The key to set.
	 */
	public void setKey(String key) {
		this.key = key;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.ajax4jsf.resource.InternetResource#getUri(javax.faces.context.FacesContext,
	 *      java.lang.Object)
	 */
	public String getUri(final FacesContext context, Object data) {
		return InternetResourceBuilder.getInstance().getUri(this, context,
				getDataToStore(context, data));
	}

	/**
	 * Template method to construct resource-specific data ( to store in
	 * resource URI ). If resource must store any data in session or other
	 * cache, it must be done here. Since lightweight realisation, information
	 * for restore such data muct be returned by this method.
	 * 
	 * @param context -
	 *            current faces context.
	 * @param data -
	 *            data for build information, usually current
	 *            {@link javax.faces.component.UIComponent}
	 * @return - any {@link java.io.Serializable} object, or null.
	 */
	protected Object getDataToStore(FacesContext context, Object data) {
		return getRenderer(new FacesResourceContext(context)).getData(this, context, data);
	}

	/**
	 * Restore data object from resource URI request parameter ( same object as
	 * returned in getDataToStore method )
	 * 
	 * @param context
	 * @return restored data, or null.
	 */
	protected Object restoreData(ResourceContext context) {

		Object data = context.getResourceData();
		if (data instanceof byte[]) {
			byte[] objectArray = (byte[]) data;
			data = deserializeData(objectArray);
		}
		return data;

	}

	/**
	 * Deserialize parameters object from byte array. By default, used Java
	 * de-serialisation from ObjectOutputStream , but implementations can
	 * override this method ( togewer with getDataToStore ) for implement short
	 * version.
	 * 
	 * @param objectArray
	 * @return
	 * @throws IOException
	 * @throws ClassNotFoundException
	 */
	protected Object deserializeData(byte[] objectArray) {
		return objectArray;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.ajax4jsf.chameleon.resource.InternetResource#getResourceAsStream()
	 */
	public InputStream getResourceAsStream(ResourceContext context) {
		throw new UnsupportedOperationException(Messages.getMessage(
				Messages.METHOD_NOT_IMPLEMENTED, "getResourceAsStream"));
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.ajax4jsf.resource.InternetResource#getProperty(java.lang.Object)
	 */
	public Object getProperty(Object key) {
		// TODO Auto-generated method stub
		return customProperties.get(key);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.ajax4jsf.resource.InternetResource#setProperty(java.lang.Object,
	 *      java.lang.Object)
	 */
	public void setProperty(Object key, Object value) {
		customProperties.put(key, value);

	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.ajax4jsf.resource.InternetResource#encode(javax.faces.context.FacesContext,
	 *      javax.faces.component.UIComponent)
	 */
	public void encode(FacesContext context, Object data) throws IOException {
		if (log.isDebugEnabled()) {
			log.debug(Messages.getMessage(Messages.ENCODE_HTML_INFO, getKey()));
		}
		getRenderer(new FacesResourceContext(context)).encode(this, context, data);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.ajax4jsf.resource.InternetResource#encode(javax.faces.context.FacesContext,
	 *      java.lang.Object, java.util.Map)
	 */
	public void encode(FacesContext context, Object data, Map<String, Object> attributes)
			throws IOException {
		if (log.isDebugEnabled()) {
			log.debug(Messages.getMessage(Messages.ENCODE_HTML_INFO_2,
					getKey(), attributes));
		}
		getRenderer(new FacesResourceContext(context)).encodeBegin(this, context, data, attributes);
		getRenderer(new FacesResourceContext(context)).encodeEnd(this, context, data);

	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.ajax4jsf.resource.InternetResource#encodeBegin(javax.faces.context.FacesContext,
	 *      javax.faces.component.UIComponent, java.util.Map)
	 */
	public void encodeBegin(FacesContext context, Object component, Map<String, Object> attrs)
			throws IOException {
		if (log.isDebugEnabled()) {
			log.debug(Messages.getMessage(Messages.ENCODE_BEGIN_HTML_INFO,
					getKey(), attrs));
		}
		getRenderer(new FacesResourceContext(context)).encodeBegin(this, context, component, attrs);

	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.ajax4jsf.resource.InternetResource#encodeEnd(javax.faces.context.FacesContext,
	 *      javax.faces.component.UIComponent, java.util.Map)
	 */
	public void encodeEnd(FacesContext context, Object component)
			throws IOException {
		if (log.isDebugEnabled()) {
			log.debug(Messages.getMessage(Messages.ENCODE_END_HTML_INFO,
					getKey()));
		}
		getRenderer(new FacesResourceContext(context)).encodeEnd(this, context, component);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.ajax4jsf.resource.InternetResource#send(javax.faces.context.FacesContext,
	 *      java.lang.Object)
	 */
	public void send(ResourceContext context) throws IOException {
		if (log.isDebugEnabled()) {
			log
					.debug(Messages.getMessage(Messages.SEND_CONTENT_INFO,
							getKey()));
		}
		int total = getRenderer(context).send(this, context);
		// For cacheable resources, store size.
		if (isCacheable(context)) {
			setContentLength(total);
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.ajax4jsf.chameleon.resource.InternetResource#sendHeaders(javax.servlet.http.HttpServletResponse)
	 */
	public void sendHeaders(ResourceContext context) {
		boolean cached = context.isCacheEnabled() && isCacheable(context);
		if (log.isDebugEnabled()) {
			log.debug(Messages.getMessage(Messages.SET_RESPONSE_HEADERS_INFO,
					getKey()));
		}
		// context.setHeader("Content-Type",getContentType());
		context.setContentType(getContentType(context));
		if (!cached && getContentLength(context) > 0) {
			context.setIntHeader("Content-Length", getContentLength(context));
		} else {
			// context.setHeader("Transfer-Encoding", "chunked");
		}
		Date lastModified = getLastModified(context);
		if (lastModified != null) {
			context.setDateHeader("Last-Modified", lastModified.getTime());
		}
		if (cached) {
			Date expired = getExpired(context);
			if (expired != null) {
				context.setDateHeader("Expires", expired.getTime());
			} else {
				context.setDateHeader("Expires", System.currentTimeMillis()
						+ DEFAULT_EXPIRE);
				context.setHeader("Cache-control", "max-age="
						+ (DEFAULT_EXPIRE / 1000));
			}
		} else {
			context.setHeader("Cache-control", "max-age=0, no-store, no-cache");
			context.setHeader("Pragma", "no-cache");
			context.setIntHeader("Expires", 0);
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.ajax4jsf.resource.InternetResource#requireFacesContext()
	 */
	public boolean requireFacesContext() {
		// by default, send data in ordinary Http request.
		return getRenderer(null).requireFacesContext();
	}

}
