package foundation.server;

import javax.servlet.ServletContext;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import foundation.route.RouteTable;
import foundation.server.config.Configer;
import foundation.server.config.ConfigerLoader;
import foundation.server.config.ServerAssembleLoader;
import foundation.server.config.ServerStatus;


public class ServerInstance {

	private static Logger logger;
	private static ServerInstance instance;
	private ServletContext servletContext;
	private String version;

	static {
		logger = LogManager.getLogger(ServerInstance.class);
	}
	
	public ServerInstance(ServletContext servletContext) {
		this.servletContext = servletContext;
		version = "2.0";
	}

	public static void startService(ServletContext servletContext) {
		try {
			instance = new ServerInstance(servletContext);
			instance.start();
		} 
		catch (Exception e) {
			logger.error(e);
			e.printStackTrace();
		}
	}

	public static void stopService() {
		try {
			if(instance != null) {
				instance.stop();
			}
			
		} catch (Exception e) {
			logger.error(e);
			e.printStackTrace();
		}
	}

	public void start() throws Exception {
		try {
			logger.info("server is startting...");
			logger.debug("server root path is " + Configer.getPath_Application());
			ServerStatus.setStarting(true);

			//1. 
			String contextPath = servletContext.getContextPath();
			RouteTable.createInstance(contextPath);
			
			//2. load parameter and assemble configure file
			ConfigerLoader.staticLoad();
			ServerAssembleLoader.staticLoad();

			//3. run initializers
			InitializerContainer initializerContainer = InitializerContainer.getInstance();

			for (Initializer initializer : initializerContainer) {
				initializer.onServerStart();
			}
		} 
		catch (Exception e) {
			e.printStackTrace();
		}
		finally {
			ServerStatus.init();
			ServerStatus.setStarting(false);
			printStartUpMessage();
		}
	}

	public void stop() {
		logger.info("internal server is stopping...");

		InitializerContainer initializerContainer = InitializerContainer.getInstance();

		for (Initializer initializer : initializerContainer) {
			initializer.onServerStop();
		}

		logger.info("internal server has been stopped");
	}

	public void restart() throws Exception {
		stop();
		start();
	}
	
	private static String echoString(String word, int count) {
		StringBuilder result = new StringBuilder();

		for (int i = 1; i <= count; i++) {
			result.append(word);
		}

		return result.toString();
	}

	private void printStartUpMessage() {
		int length_total = 40;

		long total = Math.round((Runtime.getRuntime().totalMemory()) / (1024.0 * 1024));
		long max = Math.round((Runtime.getRuntime().maxMemory()) / (1024.0 * 1024));

		String envirenment = Configer.getString("EnvironmentName");
		System.out.println("--->>> " + envirenment + " --->>>");

		System.out.println(echoString("*", length_total + 2));
		printMessage("Total Memory:" + total + "M", length_total);
		printMessage("Max Memory:" + max + "M", length_total);
		printMessage(version, length_total);
		System.out.println(echoString("*", length_total + 2));
	}

	private void printMessage(String message, int totalLength) {
		MessagePos messagePos = new MessagePos(totalLength, message);
		System.out.println("*" + echoString(" ", messagePos.length_begin) + message + echoString(" ", messagePos.length_end) + "*");
	}

	private class MessagePos {
		private int length_begin;
		private int length_end;
		private int length_message;

		public MessagePos(int totalLength, String message) {
			length_message = message.length();
			length_begin = (totalLength - length_message) / 2;
			length_end = totalLength - length_begin - length_message;
		}
	}

	public static ServerInstance getInstance() {
		return instance;
	}
}