package org.webswing.server;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.util.Map;
import java.util.Properties;
import java.util.UUID;

import jakarta.servlet.ServletContext;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.MultipartConfig;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.webswing.Constants;
import org.webswing.server.api.GlobalUrlHandler;
import org.webswing.server.api.services.sessionpool.SessionPoolHolderService;
import org.webswing.server.api.services.startup.StartupService;
import org.webswing.server.common.service.security.SecurityManagerService;
import org.webswing.server.services.sessionpool.impl.LocalSessionPoolConnector;
import org.webswing.util.GitRepositoryState;

import com.google.inject.Binder;
import com.google.inject.Guice;
import com.google.inject.Injector;
import com.google.inject.Module;

@WebServlet(asyncSupported = true, displayName = "WebswingServlet", urlPatterns = { "/*" })
@MultipartConfig(fileSizeThreshold = 5242880)
public class WebswingServlet extends HttpServlet {
	private static final Logger log = LoggerFactory.getLogger(StartupService.class);

	private static final long serialVersionUID = 1962501775857788874L;

	private StartupService startup;
	private GlobalUrlHandler handler;
	private SecurityManagerService securityManager;
	private LocalSessionPoolConnector sessionPool;

	@Override
	public void init() throws ServletException {
		log.info("Initializing Webswing " + GitRepositoryState.getInstance().getDescribe());
		Module servletModule = new Module() {
			public void configure(Binder binder) {
				binder.bind(ServletContext.class).toInstance(getServletContext());
			}
		};
				
		try {
			Injector injector = Guice.createInjector(servletModule, new WebswingServerModule());
			
			initializeDefaultSystemProperties();
				
			this.startup = injector.getInstance(StartupService.class);
			this.startup.start();
			this.securityManager = injector.getInstance(SecurityManagerService.class);
			this.handler = injector.getInstance(GlobalUrlHandler.class);
			this.handler.init();
			
			// initialize local session pool
			SessionPoolHolderService sessionPoolHolder = injector.getInstance(SessionPoolHolderService.class);
			this.sessionPool= injector.getInstance(LocalSessionPoolConnector.class);
			sessionPoolHolder.registerSessionPool(this.sessionPool);
		} catch (Exception e) {
			log.error("Initialization of Webswing failed. ", e);
			destroy();
			throw new ServletException("Webswing failed to start!", e);
		}
	}
	
	private void initializeDefaultSystemProperties() {
		String propFileUri = System.getProperty(Constants.PROPERTIES_FILE_PATH);
		if (propFileUri != null) {
			try {
				File propFile = new File(URI.create(propFileUri));
				Properties p = new Properties(System.getProperties());
				try (InputStream propFileStream = new FileInputStream(propFile)) {
					p.load(propFileStream);
				}
				
				// set the system properties
				for (Map.Entry<Object, Object> prop : p.entrySet()) {
					if (!System.getProperties().containsKey(prop.getKey())) {
						System.getProperties().put(prop.getKey(), prop.getValue());
					}
				}
			} catch (Exception e) {
				log.error("Exception occurred during initialization of System Properties", e);
				System.exit(-1);
			}
		}
		
		System.setProperty(Constants.WEBSWING_SERVER_ID, UUID.randomUUID().toString());
		
		log.info("Starting webswing server with id [" + System.getProperty(Constants.WEBSWING_SERVER_ID) + "]...");
		
		if (StringUtils.isBlank(System.getProperty(Constants.WEBSWING_CONNECTION_SECRET))) {
			log.error("Missing " + Constants.WEBSWING_CONNECTION_SECRET + " system property!");
			System.exit(-1);
		}
		
		if (StringUtils.equalsIgnoreCase(System.getProperty(Constants.WEBSWING_CONNECTION_SECRET), Constants.WEBSWING_CONNECTION_SECRET_DEFAULT)) {
			String msg = "Please change " + Constants.WEBSWING_CONNECTION_SECRET + " system property to a non-default value in production!";
			log.error(msg, new IllegalStateException(msg));
		}
		
		if (System.getProperty(Constants.SERVER_WEBSOCKET_URL) == null) {
			throw new RuntimeException("Failed to initialized server! Missing " + Constants.SERVER_WEBSOCKET_URL + " property!");
		}
	}
	
	public void handleRequest(HttpServletRequest req, HttpServletResponse res) {
		securityManager.secure(handler, req, res);
	}

	@Override
	public void destroy() {
		if (this.sessionPool!=null){
			this.sessionPool.destroy();
		}
		if (this.handler != null) {
			this.handler.destroy();
		}
		if (this.startup != null) {
			this.startup.stop();
		}
		log.info("Webswing Server Stopped.");
	}

	@Override
	public void doHead(HttpServletRequest req, HttpServletResponse res) throws IOException, ServletException {
		handleRequest(req, res);
	}

	@Override
	public void doOptions(HttpServletRequest req, HttpServletResponse res) throws IOException, ServletException {
		handleRequest(req, res);
	}

	@Override
	public void doTrace(HttpServletRequest req, HttpServletResponse res) throws IOException, ServletException {
		handleRequest(req, res);
	}

	@Override
	public void doDelete(HttpServletRequest req, HttpServletResponse res) throws IOException, ServletException {
		handleRequest(req, res);
	}

	@Override
	public void doPut(HttpServletRequest req, HttpServletResponse res) throws IOException, ServletException {
		handleRequest(req, res);
	}

	@Override
	public void doGet(HttpServletRequest req, HttpServletResponse res) throws IOException, ServletException {
		handleRequest(req, res);
	}

	@Override
	public void doPost(HttpServletRequest req, HttpServletResponse res) throws IOException, ServletException {
		handleRequest(req, res);
	}

	@Override
	protected long getLastModified(HttpServletRequest req) {
		return handler.getLastModified(req);
	}
	
}