package org.frameworkset.web.socket.container;

import java.io.IOException;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Map;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.websocket.Endpoint;
import javax.websocket.Extension;

import org.apache.tomcat.websocket.server.WsServerContainer;
import org.frameworkset.http.ServerHttpRequest;
import org.frameworkset.http.ServerHttpResponse;
import org.frameworkset.web.socket.endpoint.ServerEndpointRegistration;
import org.frameworkset.web.socket.handler.HandshakeFailureException;

/**
 * A WebSocket {@code RequestUpgradeStrategy} for Apache Tomcat. Compatible with
 * all versions of Tomcat that support JSR-356, i.e. Tomcat 7.0.47+ and higher.
 *
 * <p>To modify properties of the underlying {@link javax.websocket.server.ServerContainer}
 * you can use {@link ServletServerContainerFactoryBean} in XML configuration or,
 * when using Java configuration, access the container instance through the
 * "javax.websocket.server.ServerContainer" ServletContext attribute.
 *
 * @author Rossen Stoyanchev
 * @since 4.0
 */
public class TomcatRequestUpgradeStrategy extends AbstractStandardUpgradeStrategy {

	@Override
	public String[] getSupportedVersions() {
		return new String[] {"13"};
	}

	@Override
	public void upgradeInternal(ServerHttpRequest request, ServerHttpResponse response,
			String selectedProtocol, List<Extension> selectedExtensions, Endpoint endpoint)
			throws HandshakeFailureException {

		HttpServletRequest servletRequest = getHttpServletRequest(request);
		HttpServletResponse servletResponse = getHttpServletResponse(response);

		StringBuffer requestUrl = servletRequest.getRequestURL();
		String path = servletRequest.getRequestURI();  // shouldn't matter
		Map<String, String> pathParams = Collections.emptyMap();

		ServerEndpointRegistration endpointConfig = new ServerEndpointRegistration(path, endpoint);
		endpointConfig.setSubprotocols(Arrays.asList(selectedProtocol));
		endpointConfig.setExtensions(selectedExtensions);

		try {
			getContainer(servletRequest).doUpgrade(servletRequest, servletResponse, endpointConfig, pathParams);
		}
		catch (ServletException ex) {
			throw new HandshakeFailureException(
					"Servlet request failed to upgrade to WebSocket: " + requestUrl, ex);
		}
		catch (IOException ex) {
			throw new HandshakeFailureException(
					"Response update failed during upgrade to WebSocket: " + requestUrl, ex);
		}
	}

	public WsServerContainer getContainer(HttpServletRequest request) {
		return (WsServerContainer) super.getContainer(request);
	}

}
