// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you 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.
package com.cloud.consoleproxy;

import java.io.IOException;
import java.io.OutputStream;
import java.util.Map;

import com.cloud.consoleproxy.util.Logger;
import com.sun.net.httpserver.Headers;
import com.sun.net.httpserver.HttpExchange;
import com.sun.net.httpserver.HttpHandler;

public class ConsoleProxyAjaxImageHandler implements HttpHandler {
	private static final Logger s_logger = Logger.getLogger(ConsoleProxyAjaxImageHandler.class);

	public void handle(HttpExchange t) throws IOException {
		try {
	        if(s_logger.isDebugEnabled())
	        	s_logger.debug("AjaxImageHandler " + t.getRequestURI());
	        
	        long startTick = System.currentTimeMillis();
	        
	        doHandle(t);
	        
	        if(s_logger.isDebugEnabled())
	        	s_logger.debug(t.getRequestURI() + "Process time " + (System.currentTimeMillis() - startTick) + " ms");
		} catch (IOException e) {
			throw e;
		} catch (IllegalArgumentException e) {
			s_logger.warn("Exception, ", e);
			t.sendResponseHeaders(400, -1);		// bad request
		} catch(OutOfMemoryError e) {
			s_logger.error("Unrecoverable OutOfMemory Error, exit and let it be re-launched");
			System.exit(1);
		} catch(Throwable e) {
			s_logger.error("Unexpected exception, ", e);
			t.sendResponseHeaders(500, -1);		// server error
		} finally {
			t.close();
		}
	}

	private void doHandle(HttpExchange t) throws Exception, IllegalArgumentException {
		String queries = t.getRequestURI().getQuery();
		Map<String, String> queryMap = ConsoleProxyHttpHandlerHelper.getQueryMap(queries);
		
		String host = queryMap.get("host");
		String portStr = queryMap.get("port");
		String sid = queryMap.get("sid");
		String tag = queryMap.get("tag");
		String ticket = queryMap.get("ticket");
		String keyStr = queryMap.get("key");
		int key = 0;
		
		if(tag == null)
			tag = "";
		
		int port;
		if(host == null || portStr == null || sid == null)
			throw new IllegalArgumentException();
		
		try {
			port = Integer.parseInt(portStr);
		} catch (NumberFormatException e) {
			s_logger.warn("Invalid numeric parameter in query string: " + portStr);
			throw new IllegalArgumentException(e);
		}
		
		try {
			key = Integer.parseInt(keyStr);
		} catch (NumberFormatException e) {
			s_logger.warn("Invalid numeric parameter in query string: " + keyStr);
			throw new IllegalArgumentException(e);
		}

		ConsoleProxyClientParam param = new ConsoleProxyClientParam();
		param.setClientHostAddress(host);
		param.setClientHostPort(port);
		param.setClientHostPassword(sid);
		param.setClientTag(tag);
		param.setTicket(ticket);
		ConsoleProxyClient viewer = ConsoleProxy.getVncViewer(param);
		byte[] img = viewer.getAjaxImageCache().getImage(key);
		if(img != null) {
			Headers hds = t.getResponseHeaders();
			hds.set("Content-Type", "image/jpeg");
			t.sendResponseHeaders(200, img.length);
			
			OutputStream os = t.getResponseBody();
			try {
				os.write(img, 0, img.length);
			} finally {
				os.close();
			}
		} else {
			if(s_logger.isInfoEnabled())
				s_logger.info("Image has already been swept out, key: " + key);
			t.sendResponseHeaders(404, -1);
		}
	}
}