package de.spieleck.servlets;

import java.io.*;
import java.net.URL;
import java.util.*;
import java.text.*;
import java.lang.Comparable;

import javax.servlet.*;
import javax.servlet.http.*;

/**
 * Simple Hack for a voting servlet service.
 */
public class VotingServlet 
    extends HttpServlet
{
    /** Request parameter: */
    public static final String ACTION = "a";

    /** Request parameter (and ACTION value) */
    public static final String VOTE = "v";

    /** Request parameter ACTION value */
    public static final String SHOW = "s";

    /** User setting: */
    public static final String LEGEND = "legend";
    /** User setting: */
    public static final String FORWARD = "forward";
    /** User setting: */
    public static final String TITLE = "title";
    /** User setting: */
    public static final String BGCOLOR = "bgcolor";
    /** User setting: */
    public static final String FGCOLOR = "fgcolor";
    /** User setting: */
    public static final String SIZE = "size";
    /** User setting: */
    public static final String FACE = "face";
    /** User setting: */
    public static final String ANSWER = "answer";
    /** User setting: */
    public static final String VOTECOLOR = "votecolor";
    /** User setting: */
    public static final String COLUMN = "column";
    /** User setting: */
    public static final String COOKIETIME = "cookieTime";
    /** User setting: */
    public static final String COOKIEMODE = "cookieMode";
    /** User setting: */
    public static final String COUNTSORT = "countsort";
    /** User setting: */
    public static final String LOCKED = "locked";

    /** The name of the thing */
    public static final String SERVLET = "VotingServlet";
    public static final String VOTESERVLET = "FSN "+SERVLET;

    protected static NumberFormat df = new DecimalFormat("#0.0");

    public static Hashtable configs;

    protected String basePath = null;
    protected String configExt = null;

    protected final static Properties defaultProps = new Properties();
    static
    {
        defaultProps.put(BGCOLOR, "#FFFFFF");
        defaultProps.put(FGCOLOR, "#000000");
        defaultProps.put(COLUMN , "1");
        defaultProps.put(COOKIETIME, ""+(31*24*60*60) );
        defaultProps.put(TITLE  , VOTESERVLET);
        defaultProps.put(VOTECOLOR, "#FF0000");
        defaultProps.put(COUNTSORT, "1");
        defaultProps.put(COOKIEMODE, "0");
    }

    public VotingServlet() { }

    public void init()
        throws ServletException
    {
        configs = new Hashtable();
        basePath = getServletConfig().getInitParameter("basePath");
        configExt = getServletConfig().getInitParameter("configExt");
        log("Start: "+VOTESERVLET
                +" basePath="+basePath
                +" configExt="+configExt);
        if ( configExt == null )
            configExt = "vote.conf";
        if ( basePath == null )
            basePath = "WEB-INF/votedata/";
    }

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


    public void doGet(HttpServletRequest req, HttpServletResponse res)
        throws ServletException, IOException
    {
        String confName = req.getPathInfo();
        if ( confName == null )
            confName = "";
        else
            confName = confName.substring(1);
        //
        Config config = getConfig(confName);
        if(config == null)
        {
            res.sendError(res.SC_EXPECTATION_FAILED, 
                                "Could not find config " + confName);
            return;
        }
        String vote = req.getParameter(VOTE);
        if ( config.getCfg(LOCKED) != null )
            showStanding(config, res);
        else if( vote != null )
            takeVote(config, vote, req, res);
        else if( SHOW.equals(req.getParameter(ACTION)) )
            showStanding(config, res);
        else
        {
            if( !config.getAnswers().hasMoreElements() )
                res.sendError(res.SC_EXPECTATION_FAILED, 
                                "No "+ANSWER+".x in config "+confName);
            else
                showForm(config, req, res);
        }
    }

    protected Config getConfig(String cname)
    {
        Config config = (Config) configs.get(cname);
        if( config != null )
        {
            if ( ! config.isRecent() )
            {
                configs.remove(cname);
                config = null;
            }
        }
        if ( config == null )
        try
        {
            config = new Config(
                    getServletContext().getRealPath(basePath+cname+configExt));
            configs.put(cname, config);
        }
        catch ( IOException io )
        {
            io.printStackTrace();
            return null;
        }
        return config;
    }

    /**
        HTML Help: put optional Attribute
    */
    protected static String optionalAttr(String name, String value)
    {
        if ( value != null )
            return fixedAttr(name, value);
        return "";
    }

    /**
        HTML Help: put mandatory Attribute
    */
    protected static String fixedAttr(String name, String value)
    {
        StringBuffer sb = new StringBuffer(30);
        sb.append(' ').append(name).append("='").append(value).append('\'');
        return sb.toString();
    }

    /**
        HTML Help: provide Font Tag
    */
    public String makeFontTag(Config cfg)
    {
        return makeFontTag(cfg, cfg.getCfg(SIZE));
    }

    public String makeFontTag(Config cfg, String size)
    {
        StringBuffer sb = new StringBuffer(50);
        sb.append("<font");
        sb.append(fixedAttr("color", cfg.getCfg(FGCOLOR)));
        sb.append(optionalAttr("face", cfg.getCfg(FACE)));
        sb.append(optionalAttr("size", size));
        sb.append('>');
        return sb.toString();
    }
    
    /**
        HTML Help: start page
    */
    protected void startHtml(PrintWriter pw, Config config)
    {
        String title = config == null ? VOTESERVLET : config.getCfg(TITLE);
        pw.println("<html>");
        pw.println("<head><title>" + title + "</title></head>");
        pw.print("<body ");
        if ( config != null  )
            pw.print(optionalAttr("bgcolor",config.getCfg(BGCOLOR)));
        pw.println(">");
        if ( config != null ) 
            pw.println(makeFontTag(config));
        pw.println("<h2>" + title + "</h2>");
        pw.println("</font>");
    }

    /**
        HTML Help: end page
    */
    protected void endHtml(PrintWriter pw, Config cfg)
    {
        pw.println("<br />");
        if ( cfg != null )
            pw.print(makeFontTag(cfg,"1"));
        pw.println(new Date());
        pw.println("</body></html>");
        pw.close();
    }

    /**
        Page: show results
    */
    protected void showStanding(Config config, HttpServletResponse res)
        throws IOException
    {
        String font = makeFontTag(config);
        Vote[] vs = config.getVotes();
        int i, total = 0, tmax = -1;
        for ( i = 0; i < vs.length; i++ )
        {
            int c = vs[i].getCount();
            total += c;
            if ( c > tmax )
                tmax = c;
        }
        if ( total == 0 )
            total = tmax = 1;
        PrintWriter pw;
        res.setContentType("text/html");
        pw = res.getWriter();
        startHtml(pw, config);
        pw.println("<table border=0 width='99%' cellpadding='0'>");
        if ( "1".equals(config.getCfg(LEGEND)) )
            pw.println("<tr><td width='30%' nowrap>" + font + "<b>Option</b></font></td><td width='69%' colspan='3' nowrap><b>" + font + "Result</b></font></td></tr>");
        for ( i = 0; i < vs.length; i++ )
        {
            int count = vs[i].getCount();
            double qf = 100.0 * count / total;
            int q2 = (int) Math.round(100.0 * count / tmax);
            pw.println("<tr><td nowrap width='30%'>" + font + vs[i].getAnswer() + "</font></td><td nowrap width='10%'>" + font + count + "</font></td><td nowrap widt='10%' ALIGN='RIGHT'>" + font + df.format(qf) + "%</font></td>");
            pw.println("<td nowrap width='49%'><table width='99%' cellspacing='0' cellpadding='0'>");
            pw.println("<tr><td "+optionalAttr("bgcolor",config.getCfg(VOTECOLOR)) + "' width='" + (q2 == 0 ? "1'>" : q2 + "%'>&nbsp;")+"</td><td>&nbsp;</td></tr></table></td></tr>");
        }
        pw.println("</table>");
        endHtml(pw,config);
    }

    /**
        Page: show vote form
    */
    protected void showForm(Config config, 
            HttpServletRequest req, HttpServletResponse res)
        throws IOException
    {
        boolean columnFlag = "1".equals(config.getCfg(COLUMN));
        String row1 = "";
        String row2 = "";
        String font = makeFontTag(config);
        PrintWriter pw;
        res.setContentType("text/html");
        pw = res.getWriter();
        startHtml(pw, config);
        pw.println("<table border='0' width='99%' cellpadding='0'>");
        pw.println("<form method=post action='"+req.getRequestURI()+"'>");
        if(columnFlag)
        {
            row1 = "<tr>";
            row2 = "</tr>";
        }
        else
        {
            pw.println("<tr>");
        }
        Enumeration e = config.getAnswers();
        while(e.hasMoreElements()) 
        {
            String value = (String) e.nextElement();
            pw.println(row1+"<td nowrap>"+font+"<input type='radio' name='" + VOTE + "' value='" + value + "'>" + value + "</font></td>" + row2);
        }

        pw.println(row1+"<td nowrap>"+font+"<input type='submit' value='Vote'></font></td>" + row2);
        if(!columnFlag)
            pw.println("</tr>");
        pw.println("</form></table>");
        endHtml(pw,config);
    }

    /**
        Page: take a vote
    */
    protected void takeVote(Config config, String vote,
                            HttpServletRequest req, HttpServletResponse res)
        throws IOException, ServletException
    {
        boolean cancel = false;
        if(!(config.getCfg(COOKIETIME)).equals("0"))
        {
            String cookieName;
            if ( config.getCfg(COOKIEMODE).equals("0") )
                cookieName = config.getCookie();
            else
                cookieName = config.getCookie()+":"+vote;
            Cookie acookie[] = req.getCookies();
            if(acookie != null)
                for(int i = 0; i < acookie.length; i++)
                    if(cookieName.equals(acookie[i].getName()))
                    {
                        cancel = true;
                        break;
                    }
            Cookie c = new Cookie(cookieName, "*");
            c.setMaxAge(Integer.parseInt(config.getCfg(COOKIETIME)));
            res.addCookie(c);
        }
        if ( !cancel )
            config.vote(req, vote);
        String forward = config.getCfg(FORWARD);
        if(forward == null)
            showStanding(config, res);
        else if(!forward.startsWith("http://"))
        {
            RequestDispatcher requestdispatcher = getServletConfig()
                        .getServletContext().getRequestDispatcher(forward);
            requestdispatcher.forward(req, res);
        }
        else
            res.sendRedirect(res.encodeRedirectURL(forward));
    }

    /**
        subclass to contain configuration data
     */
    protected static class Config
    {
        protected long edited;
        // protected String path;
        protected File configFile;
        protected String cookie;
        // protected String font;

        protected String logName;
        protected String countName;

        protected Properties props;
        protected Properties counts;

        public Config(String path)
            throws IOException
        {
            // this.path = path;
            configFile = new File(path);
            logName = path+".log";
            countName = path+".count";
            readConfig();
            // Mangle name into a cookie
            int i = path.lastIndexOf("/");
            if ( i == -1 )
                i = path.lastIndexOf("\\");
            if ( i == -1 )
                i = 0;
            cookie =  "v."+path.substring(i)+"."+path.hashCode()+".c";
            appendLog("read");
        }

        public boolean isRecent()
        {
            return edited == configFile.lastModified();
        }

        public String getCookie()
        {
            return cookie;
        }

        public String getCfg(String key)
        {
            return props.getProperty(key);
        }

        protected synchronized void readConfig()
            throws IOException
        {
            props = new Properties(defaultProps);
            counts = new Properties();
            // font = null;
            edited = configFile.lastModified();
            props.load(new FileInputStream(configFile));
            File count = new File(countName);
            if ( count.exists() )
            {
                try
                {
                    counts.load(new FileInputStream(countName));
                }
                catch(IOException lost)
                {
                    lost.printStackTrace();
                }
            }
            Enumeration e = getAnswers();
            while(e.hasMoreElements()) 
            {
                String value = (String) e.nextElement();
                if ( counts.getProperty(value) == null )
                    counts.put(value, "0");
            }
        }

        public Enumeration getAnswers()
        {
            return new Enumeration()
                {
                    int nextPos = 1;
                    public boolean hasMoreElements()
                    {
                        return props.getProperty(ANSWER+"."+nextPos) != null;
                    }
                    public Object nextElement()
                    {
                        return props.getProperty(ANSWER+"."+nextPos++);
                    }
                };
        }

        public synchronized Vote[] getVotes()
        {
            Vote[] vs = new Vote[counts.size()];
            int pos = 0;
            Enumeration e = counts.keys();
            while ( e.hasMoreElements() )
            {
                String key = (String) e.nextElement();
                vs[ pos++ ] = new Vote(key, 
                                    safeParseInt(counts.getProperty(key)));
            }
            if ( "1".equals(getCfg(COUNTSORT)) )
                Arrays.sort(vs);
            return vs;
        }

        protected int safeParseInt(String str)
        {
            if ( str == null )
                return 0;
            try
            {
                return Integer.parseInt(str);
            }
            catch ( NumberFormatException e )
            {
                e.printStackTrace();
                return 0;
            }
        }

        public void vote(HttpServletRequest req, String answer)
        {
            String remoteAddr = req.getRemoteAddr();
            try
            {
                synchronized(this) 
                {
                    counts.put(answer, Integer.toString(safeParseInt(
                                            counts.getProperty(answer))+1));
                    OutputStream os = new FileOutputStream(countName);
                    long t0 = appendLog(remoteAddr + " " + answer);
                    counts.save(os,getCfg(TITLE)+" "+t0);
                    os.close();
                }
            }
            catch(IOException e) 
            {
                e.printStackTrace();
            }
        }

        protected synchronized long appendLog(String line)
        {
            long t0 = System.currentTimeMillis();
            try
            {
                FileWriter filewriter = new FileWriter(logName, true);
                PrintWriter pw = new PrintWriter(filewriter);
                pw.println(t0+" "+line);
                pw.close();
            }
            catch ( IOException fail )
            {
                fail.printStackTrace();
            }
            return t0;
        }
    }

    /**
        subclass to hold a single votes statistics
    */
    protected static class Vote
        implements Comparable
    {
        protected String answer;
        protected int count;

        public Vote(String answer, int count)
        {
            this.answer = answer;
            this.count = count;
        }

        public String getAnswer()
        {
            return answer;
        }

        public int getCount()
        {
            return count;
        }

        public int compareTo(Object o)
        {
            if ( o instanceof Vote )
                return ((Vote)o).getCount() - getCount();

            return 1;
        }
    }

}