package com.power.pipeengine;

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.util.*;

public class LPServlet extends HttpServlet{//extends HttpServlet{
    public boolean isWait = false;
    public String _str = "";

    public LPServlet() {
        super();
        initialize();
    }
    /**
     * Process incoming HTTP GET requests
     *
     * @param request Object that encapsulates the request to the servlet
     * @param response Object that encapsulates the response from the servlet
     */
    public void doGet(
        javax.servlet.http.HttpServletRequest request,
        javax.servlet.http.HttpServletResponse response)
        throws ServletException, IOException {
        doPost(request,response);
		System.out.println("Nothing to do when GET method.");
    }
    /**
     * Process incoming HTTP POST requests
     *
     * @param request Object that encapsulates the request to the servlet
     * @param response Object that encapsulates the response from the servlet
     */
    public void doPost(
        javax.servlet.http.HttpServletRequest request,
        javax.servlet.http.HttpServletResponse response)
        throws ServletException, IOException {

        /**** Initialize Writer ****/
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        response.setStatus(HttpServletResponse.SC_OK);

        /**** get Running Parameters ****/
        _str = "<<<<Start ENGINE Running>>>>\n";
        System.out.println();
        System.out.println(_str);
        out.println(_str);
        String _exePath = request.getParameter("exePath");
        String _outPath = request.getParameter("outPath");
        String _paraPath = request.getParameter("paraPath");
        String _testPath = request.getParameter("testPath");
        String _workPath = request.getParameter("workPath");
        String _logPath = request.getParameter("logPath");

        if (_exePath == null || _outPath == null || _paraPath == null ||
            _testPath == null || _workPath == null || _logPath == null) {
            _str = "**Error: Missing parameters.\n";
            out.println(_str);
            System.out.println(_str);
            return;
        }

        /**** DELETE .out & .log file before Running ***/
        try {
            File bbb = new File(_outPath);
            _str = "CLEAR file --> '"+_outPath+"' "+(bbb.delete()?"OK.":"not exists.")+"\n";
            out.println(_str);
            System.out.println(_str);

            bbb = new File(_logPath);
            _str = "CLEAR file --> '"+_logPath+"' "+(bbb.delete()?"OK.":"not exists."+"\n");
            out.println(_str);
            System.out.println(_str);
        }
        catch (Exception e) {}

        /**** WAITING .mps file before Running  ****/
        if (!waitFile(_testPath, 5, "Waiting INTERMEDIATE file", "1", out)) return;

        /**** EXECUTE Engine COMMAND ****/
        try {
			Runtime r = Runtime.getRuntime();
            Process p = null;
			String cmd[] = {_exePath,_paraPath};
            _str = "EXECUTE engine --> "+cmd[0]+" "+cmd[1]+"\n";
            out.println(_str);
            System.out.println(_str);
			p=r.exec(cmd, null, new File(_workPath));
            //r.runFinalization();
            //r.gc();
		} catch (Exception e) {
            _str = "**Error: Engine running failed --> "+e.toString()+"\n";
            out.println(_str);
            System.out.println(_str);
            return;
        }
        finally {
			System.gc();
        }
        /**** WAITING .out file when Running  ****/
//        if (!waitFile(_outPath, 10, "Waiting RESULT file", "2", out)) return;

        /**** WAITING .log file after Running ****/
//        if (!waitFile(_logPath, 2, "Waiting TEMPORARY file", "3", out)) return;

        /**** DELETE .log file before Running ***/
/*        try {
            File bbb = new File(_logPath);
            _str = "Delete Temporary file --> '"+_logPath+"' "+(bbb.delete()?"OK.":"**Failed.")+"\n";
            out.println(_str);
            System.out.println(_str);
        }
        catch (Exception e) {}
*/
        _str = "<<<<End ENGINE Running>>>>\n";
        out.println(_str);
        System.out.println(_str);
        System.out.println();
    }
    /**
     * Returns the servlet info string.
     */
    public String getServletInfo() {
        return super.getServletInfo();
    }
    /**
     * Called whenever the part throws an exception.
     * @param exception java.lang.Throwable
     */
    private void handleException(java.lang.Throwable exception) {
        System.out.println("--------- UNCAUGHT EXCEPTION ---------");
        exception.printStackTrace(System.out);
    }
    /**
     * Initializes the servlet.
     */
    public void init(ServletConfig config) throws ServletException {
        // insert code to initialize the servlet here
        super.init(config);
    }
    /**
     * Initialize the class.
     */
    /* WARNING: THIS METHOD WILL BE REGENERATED. */
    private void initialize() {
        try {
        } catch (java.lang.Throwable ivjExc) {
            handleException(ivjExc);
        }
    }

    /**
     * Process incoming requests for information
     *
     * @param request Object that encapsulates the request to the servlet
     * @param response Object that encapsulates the response from the servlet
     */
    public void performTask(
        javax.servlet.http.HttpServletRequest request,
        javax.servlet.http.HttpServletResponse response) {
        //System.out.println("performTask() method is called.");
    }
    /**
     * service method comment.
     */
    public void service(HttpServletRequest request, HttpServletResponse response)
        throws javax.servlet.ServletException, java.io.IOException {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();

        String sMethod;
        sMethod = request.getMethod();
        if (sMethod.equals("GET"))
            doGet(request, response);
        else
            doPost(request, response);
    }

    public boolean waitFile(String _FileName, int _interval,
                            String _MsgStr, String _ErrorCode,PrintWriter out )
    {
        try {
            _str = _MsgStr + " --> "+_FileName + "\n";
            System.out.println(_str);
            out.println(_str);
            int count = 1;
            RandomAccessFile ccc = null;
            int interval = _interval;
            while (true) {
                try {
                    ccc = new RandomAccessFile(_FileName,"r");
                    if (ccc.length() < 1)
                        throw new FileNotFoundException("");
                    else
                        break;
                }
                catch (FileNotFoundException ex) {
                        if (ccc != null ) ccc.close();
                        _str = "waiting..."+interval*count++ + " secs.\n";
                        out.println(_str);
                        System.out.println(_str);
                        isWait = true;
                        waitThread wT = new waitThread(interval);
                        wT.start();
                        while (isWait) {};
                        if (interval*count >= 3600) {
                            _str =  "**ERROR " + _ErrorCode + ": " +
                                    "ENGINE running timeout, has been canceled.\n";
                            out.println(_str);
                            System.out.println(_str);
                            return false;
                        }
                }
                finally {
                    if (ccc != null ) ccc.close();
                }
            }
        }
        catch(Exception e) {
            _str = "**Error"+_ErrorCode+":"+e.toString()+"\n";
            out.println(_str);
            System.out.println(_str);
            return false;
        }

        return true;
    }

    public class waitThread extends Thread {
        int interval = 0;
        public waitThread(int secs) { this.interval = secs; }
        public void run()
        {
            try {
                waitThread.sleep(interval*1000);
                isWait = false;
            }
            catch(Exception e){}
        }
    }

}