org.eclipse.osbp.vaaclipse.addons.app/src/org/eclipse/osbp/vaaclipse/addons/app/resources/StaticResources.java

/**
 * Copyright (c) 2011, 2014 - Lunifera GmbH (Gross Enzersdorf)
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors: 
 * 		Florian Pirchner - Initial implementation
 */
package org.eclipse.osbp.vaaclipse.addons.app.resources;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.util.Map;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.eclipse.osbp.vaaclipse.api.ResourceInfoProvider;
import org.eclipse.osbp.vaaclipse.publicapi.theme.Theme;
import org.eclipse.osbp.vaaclipse.publicapi.theme.ThemeContribution;
import org.eclipse.osbp.vaaclipse.publicapi.theme.ThemeEngine;
import org.osgi.framework.BundleContext;
import org.osgi.service.component.annotations.Activate;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.component.annotations.Deactivate;
import org.osgi.service.component.annotations.Reference;
import org.osgi.service.component.annotations.ReferenceCardinality;
import org.osgi.service.http.HttpService;

/**
 * This class runs as an OSGi component and serves the themes and widgetsets
 * directly from the core Vaadin bundle.
 * <p/>
 * 
 * To add your own theme or widget set create a fragment which contains your
 * theme/widgetset files and export those as packages. The
 * <code>Fragment-Host</code> should be set to the Vaadin core bundle. The
 * fragment containing your theme/widgetset resources will be added to the core
 * Vaadin bundle dynamically.
 * <p/>
 * 
 * Of course static resources should really be deployed separately to a web
 * server that proxies servlet requests on to the container.
 * 
 * @author brindy
 */
@SuppressWarnings("serial")
@Component(immediate = true, enabled = true, property = { "http.alias=/VAADIN" })
public class StaticResources extends HttpServlet {

	/** The http service. */
	private HttpService httpService;

	/** The resource info provider. */
	private ResourceInfoProvider resourceInfoProvider;

	/** The theme engine. */
	private ThemeEngine themeEngine;

	/** The alias. */
	private String alias;

	/**
	 * Instantiates a new static resources.
	 */
	public StaticResources() {

	}

	/**
	 * Bind.
	 *
	 * @param httpService
	 *            the http service
	 */
	@Reference(name = "bindHttpService", service = HttpService.class, target = "(org.eclipse.osbp.ecview.jetty.serviceType=application)", cardinality = ReferenceCardinality.MANDATORY)
	public void bind(HttpService httpService) {
		this.httpService = httpService;
	}

	/**
	 * Unbind.
	 *
	 * @param httpService
	 *            the http service
	 */
	public void unbind(HttpService httpService) {
		this.httpService = null;
	}

	/**
	 * Bind resource info provider.
	 *
	 * @param provider
	 *            the provider
	 */
	@Reference(name = "bindResourceInfoProvider", service = ResourceInfoProvider.class, cardinality = ReferenceCardinality.MANDATORY)
	public void bindResourceInfoProvider(ResourceInfoProvider provider) {
		this.resourceInfoProvider = provider;
	}

	/**
	 * Unbind resource info provider.
	 *
	 * @param provider
	 *            the provider
	 */
	public void unbindResourceInfoProvider(ResourceInfoProvider provider) {
		this.resourceInfoProvider = null;
	}

	/**
	 * Bind theme engine.
	 *
	 * @param themeEngine
	 *            the theme engine
	 */
	@Reference(name = "bindThemeEngine", service = ThemeEngine.class, cardinality = ReferenceCardinality.MANDATORY)
	public void bindThemeEngine(ThemeEngine themeEngine) {
		this.themeEngine = themeEngine;
	}

	/**
	 * Unbind theme engine.
	 *
	 * @param themeEngine
	 *            the theme engine
	 */
	public void unbindThemeEngine(ThemeEngine themeEngine) {
		this.themeEngine = null;
	}

	/**
	 * Start.
	 *
	 * @param ctx
	 *            the ctx
	 * @param properties
	 *            the properties
	 * @throws Exception
	 *             the exception
	 */
	@Activate
	public void start(BundleContext ctx, Map<String, String> properties)
			throws Exception {
		alias = properties.get("http.alias");
		httpService.registerServlet(alias, this, null, null);
	}

	/**
	 * Stop.
	 */
	@Deactivate
	public void stop() {
		httpService.unregister(alias);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * javax.servlet.http.HttpServlet#doGet(javax.servlet.http.HttpServletRequest
	 * , javax.servlet.http.HttpServletResponse)
	 */
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {

		if (this.resourceInfoProvider == null)
			resp.sendError(HttpServletResponse.SC_CONFLICT);

		String path = req.getPathInfo();

		if (path.endsWith("css")) {
			resp.setContentType("text/css");
		}

		String resourcePath = alias + path;

		String themeId = null;
		if (path.startsWith("/themes")) {
			themeId = path.split("/")[2];
		}
		if (themeId == null || themeId.isEmpty()) {
			themeId = resourceInfoProvider.getCssTheme();
		}
		InputStream in = getInputStream(resourcePath,
				themeEngine.getTheme(themeId),
				resourceInfoProvider.getApplicationtWidgetset(),
				resourceInfoProvider.getApplicationtWidgetsetName(),
				resourceInfoProvider.getApplicationHeaderIcon());

		if (in == null) {
			resp.sendError(HttpServletResponse.SC_NOT_FOUND);
			return;
		}

		try {
			OutputStream out = resp.getOutputStream();

			byte[] buffer = new byte[1024];
			int read = 0;

			try {
				while (-1 != (read = in.read(buffer))) {
					out.write(buffer, 0, read);
				}
			} finally {
				out.close();
			}
		} catch (Exception e) {
			e.printStackTrace();
			resp.sendError(HttpServletResponse.SC_NOT_FOUND);
		} finally {
			in.close();
		}
	}

	/**
	 * Gets the input stream.
	 *
	 * @param url
	 *            the url
	 * @param theme
	 *            the theme
	 * @param e4WidgetsetUri
	 *            the e4 widgetset uri
	 * @param e4WidgetsetName
	 *            the e4 widgetset name
	 * @param headerIconUri
	 *            the header icon uri
	 * @return the input stream
	 */
	public InputStream getInputStream(String url, Theme theme,
			String e4WidgetsetUri, String e4WidgetsetName, String headerIconUri) {
		String path = null;

		StringBuffer urlString = new StringBuffer(url);
		urlString.trimToSize();
		if (urlString.length() == 0)
			throw new IllegalArgumentException();
		if (urlString.charAt(0) != '/')
			throw new IllegalArgumentException();
		String processedUrl = urlString.substring(1);
		String[] segments = processedUrl.split("/");

		if (segments.length < 2)
			throw new IllegalArgumentException();

		if (!"VAADIN".equals(segments[0]))
			throw new IllegalArgumentException();

		if (segments[1].equals("widgetsets")) {
			// return
			// "platform:/plugin/org.eclipse.osbp.vaaclipse.resources" +
			// url;
			String widgetSetName = segments[2];
			if (e4WidgetsetName.equals(widgetSetName)) {
				String restPath = buildSegments(segments, 3);
				path = e4WidgetsetUri + "/" + restPath;
			} else {
				path = "platform:/plugin/com.vaadin.client-compiled" + url;
			}
		} else if (segments[1].equals("themes")) {
			String themeName = segments[2];

			if (theme.getWebId().equals(themeName)) {
				if ("styles.css".equals(segments[3])) {
					return theme.getCssAsStream();
				} else if ("original_styles.css".equals(segments[3])) {
					path = theme.getCssUri();
				} else {
					if ("plugin".equals(segments[3])) // this is absolute
														// bundle path
					{
						String bundleName = segments[4];
						path = "platform:/plugin/" + bundleName + "/"
								+ buildSegments(segments, 5);
					} else {// this is relative theme path
						if (url.endsWith("css")) {
							String cssFileName = url.substring(url
									.lastIndexOf('/') + 1);
							cssFileName = cssFileName.substring(0,
									cssFileName.lastIndexOf('.'));
							ThemeContribution themeContribution = themeEngine
									.getThemeContributionByWebId(cssFileName);
							if (themeContribution != null)
								path = themeContribution.getCssUri();
							else {
								for (String cssUri : theme.getAllCssURIs()) {
									String relPath = buildSegments(
											segments, 3);
									String cssPath = cssUri.substring(0,
											cssUri.lastIndexOf('/'))
											+ "/"
											+ relPath;
									try {
										URL cssUrl = new URL(cssPath);
										return cssUrl.openStream();
									} catch (Exception e) {
									}
								}
							}
						} else {
							String relPath = buildSegments(segments, 3);
							return theme.getThemeResourceAsStream(relPath);
						}
					}
				}
			} else // any theme
			{
				if ("styles.css".equals(segments[3])) {
					Theme inheritedTheme = themeEngine.getTheme(themeName);
					path = inheritedTheme.getCssUri();
				} else {
					path = "platform:/plugin/com.vaadin.themes" + url;
				}
			}
		} else if ("vaadinBootstrap.js".equals(segments[1])) {
			path = "platform:/plugin/com.vaadin.server" + url;
		} else if ("vaadinPush.debug.js".equals(segments[1])) {
			path = "platform:/plugin/com.vaadin.push" + url;
		} else if ("vaadinPush.js".equals(segments[1])) {
			path = "platform:/plugin/com.vaadin.push" + url;
		} else {
			return null;
		}

		try {
			URL u = new URL(path);
			return u.openStream();
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
	}

	/**
	 * Builds the segments.
	 *
	 * @param segments
	 *            the segments
	 * @param start
	 *            the start
	 * @return the string
	 */
	private static String buildSegments(String[] segments, int start) {
		StringBuffer b = new StringBuffer();
		for (int i = start; i < segments.length; i++) {
			b.append(segments[i]);
			b.append('/');
		}
		if (b.length() > 0)
			return b.substring(0, b.length() - 1);
		else
			return "";
	}
}