path: root/dozentenmodulserver/src/main/java/org/openslx/bwlp/sat/web/WebServer.java

package org.openslx.bwlp.sat.web;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.sql.SQLException;

import org.apache.commons.io.output.ByteArrayOutputStream;
import org.apache.log4j.Logger;
import org.openslx.bwlp.sat.database.mappers.DbLecture;
import org.openslx.bwlp.sat.fileserv.FileServer;
import org.openslx.bwlp.thrift.iface.TNotFoundException;
import org.openslx.util.GenericDataCache;
import org.openslx.util.Json;
import org.openslx.util.vm.VmMetaData;
import org.simpleframework.xml.Serializer;
import org.simpleframework.xml.core.Persister;

import fi.iki.elonen.NanoHTTPD;

public class WebServer extends NanoHTTPD {

	private static final Logger LOGGER = Logger.getLogger(WebServer.class);

	private static final GenericDataCache<byte[]> lectureListCache = new GenericDataCache<byte[]>(15000) {
		Serializer serializer = new Persister();

		@Override
		protected byte[] update() throws Exception {
			VmChooserListXml listXml = DbLecture.getUsableListXml(false);
			ByteArrayOutputStream baos = new ByteArrayOutputStream();
			serializer.write(listXml, baos);
			return baos.toByteArray();
		}
	};

	public WebServer(int port) {
		super("127.0.0.1", port);
		maxRequestSize = 65535;
	}

	@Override
	public Response serve(IHTTPSession session) {
		String uri = session.getUri();

		if (uri == null || uri.length() == 0) {
			return internalServerError();
		}

		// Our special stuff
		if (uri.startsWith("/vmchooser/list")) {
			return serveVmChooserList();
		}
		if (uri.startsWith("/vmchooser/lecture/")) {
			return serveLectureStart(uri.substring(19));
		}
		if (uri.startsWith("/status/fileserver")) {
			return serveStatus();
		}
		if (session.getMethod() == Method.POST && uri.startsWith("/do/")) {
			try {
				session.parseBody(null);
			} catch (IOException | ResponseException e) {
				LOGGER.debug("could not parse request body", e);
				return internalServerError();
			}
			return WebRpc.handle(uri.substring(4), session.getParms());
		}

		return notFound();
	}

	private Response serveStatus() {
		return new NanoHTTPD.Response(NanoHTTPD.Response.Status.OK, "application/json; charset=utf-8",
				Json.serialize(FileServer.instance().getStatus()));
	}

	/**
	 * Return meta data (eg. *.vmx) required to start the given lecture.
	 * 
	 * @param lectureId
	 * @return
	 */
	private Response serveLectureStart(String lectureId) {
		VmMetaData meta;
		try {
			meta = DbLecture.getClientLaunchData(lectureId);
		} catch (TNotFoundException e) {
			return notFound();
		} catch (SQLException e) {
			return internalServerError();
		}
		return new NanoHTTPD.Response(NanoHTTPD.Response.Status.OK, "text/plain; charset=utf-8",
				new ByteArrayInputStream(meta.getFilteredDefinitionArray()));
	}

	private Response serveVmChooserList() {
		return new NanoHTTPD.Response(NanoHTTPD.Response.Status.OK, "text/xml; charset=utf-8",
				new ByteArrayInputStream(lectureListCache.get()));
	}

	public static Response internalServerError() {
		return new NanoHTTPD.Response(NanoHTTPD.Response.Status.INTERNAL_ERROR, "text/plain",
				"Internal Server Error");
	}

	public static Response notFound() {
		return new NanoHTTPD.Response(NanoHTTPD.Response.Status.NOT_FOUND, "text/plain", "Nicht gefunden!");
	}

	public static Response badRequest(String message) {
		if (message == null) {
			message = "Schlechte Anfrage!";
		}
		return new NanoHTTPD.Response(NanoHTTPD.Response.Status.BAD_REQUEST, "text/plain", message);
	}

}