// Copyright 2000-2005 the Contributors, as shown in the revision logs.
// Licensed under the Apache Public Source License 2.0 ("the License").
// You may not use this file except in compliance with the License.

package org.ibex.mail;
import org.prevayler.*;
import org.ibex.mail.*;
import org.ibex.util.*;
import org.ibex.js.*;
import org.ibex.io.*;
import org.ibex.io.Fountain;
import java.io.*;
import java.nio.*;
import java.nio.channels.*;
import java.net.*;
import java.util.*;
import java.text.*;
import javax.servlet.*;
import javax.servlet.http.*;

/** An exceptionally crude implementation of Mailbox relying on POSIXy filesystem semantics */
public class FileBasedMailbox extends Mailbox.Default implements MailTree {

    public static final long MAGIC_DATE =  0;
    private static final char slash = File.separatorChar;

    // FIXME: ideally this should be weak, but we end up getting duplicates of SqliteMailboxes
    private static final HashMap<String,MailTree> instances = new HashMap<String,MailTree>();

    public String toString() { return "[FileBasedMailbox " + path.getAbsolutePath() + "]"; }

    public MailTree slash(String name, boolean create) { return getFileBasedMailbox(path.getAbsolutePath()+slash+name, create); }

    public void         rmdir(String subdir) { throw new RuntimeException("FIXME not implemented"); }
    public void         rename(String subdir, MailTree newParent, String newName) { throw new RuntimeException("FIXME not implemented"); }
    public Mailbox      getMailbox() { return this; }

    // FIXME: should be a File()
    public static synchronized MailTree getFileBasedMailbox(String path, boolean create) {
        if (path.endsWith(".sqlite")) path = path.substring(0, path.length()-".sqlite".length());
	path = new File(path).getAbsolutePath().toString();
        try {
            MailTree ret = instances.get(path);
            if (ret == null) {
                Log.error("n", "no match for " + path + " in " + instances.hashCode());
                if (new File(path+".sqlite").exists()) ret = new SqliteMailbox(path+".sqlite");
                else if (new File(path).exists()) ret = new FileBasedMailbox(new File(path));
                else if (create) ret = new SqliteMailbox(path+".sqlite");
                else return null;
                instances.put(path, (MailTree)ret);
                Log.error("n", "filling " + path + " with " + instances.get(path));
            }
            return ret;
        } catch (Exception e) {
            Log.error(FileBasedMailbox.class, e);
            return null;
        }
    }

    // Instance //////////////////////////////////////////////////////////////////////////////

    private File path;
    private FileLock lock;
    private int uidNext;
    private int uidValidity;

    // Helpers //////////////////////////////////////////////////////////////////////////////

    private static void rmDashRf(File f) throws IOException {
        if (!f.isDirectory()) { f.delete(); return; }
        String[] children = f.list();
        for(int i=0; i<children.length; i++) rmDashRf(new File(f.getAbsolutePath() + slash + children[i]));
        f.delete();
    }

    private FileBasedMailbox(File path) throws MailException, IOException, ClassNotFoundException {
        this.path = path;
        path.mkdirs();

        // acquire lock
        File lockfile = new File(this.path.getAbsolutePath() + slash + ".lock");
        lock = new RandomAccessFile(lockfile, "rw").getChannel().tryLock();
        // FIXME!!!
        /*
        if (lock == null) {
            Log.warn(this, "warning: blocking waiting for a lock on " + path);
            lock = new RandomAccessFile(lockfile, "rw").getChannel().lock();
            if (lock == null) throw new IOException("unable to lock FileBasedMailbox: " + path);
        }
        lockfile.deleteOnExit();
        */

        uidValidity = (int)(lockfile.lastModified() & 0xffffffff);
        uidNext = 0;
        String[] files = path.list();
        for(int i=0; i<files.length; i++) {
            try {
                if (files[i].indexOf('.') <= 0) continue;
                files[i] = files[i].substring(0, files[i].indexOf('.'));
                try {
                    int n = Integer.parseInt(files[i]);
                    if (n>=uidNext) uidNext = n;
                } catch (NumberFormatException nfe) { continue; }
            } catch(Exception e) { Log.error(this, e); }
        }
    }

    public String[] sort(String[] s) {
        Arrays.sort(s);
        return s;
    }

    public String[] files() {
        String[] s = path.list(filter);
        Arrays.sort(s, comparator);
        return s;
    }
    
    private static Comparator<String> comparator = new Comparator<String>() {
        public int compare(String a, String b) {
            if (a.indexOf('.')==-1) return a.compareTo(b);
            if (b.indexOf('.')==-1) return a.compareTo(a);
            int ai = Integer.parseInt(a.substring(0, a.indexOf('.')));
            int bi = Integer.parseInt(b.substring(0, b.indexOf('.')));
            return ai<bi ? -1 : ai>bi ? 1 : 0;
        }
    };

    public Mailbox.Iterator  iterator()           { return new Iterator(); }
    public String[] children() {
        Vec vec = new Vec();
        String[] list = sort(path.list());
        for(int i=0; i<list.length; i++) {
            File f = new File(path.getAbsolutePath() + slash + list[i]);
            if (f.isDirectory() && f.getName().charAt(0) != '.') vec.addElement(list[i]);
            if (!f.isDirectory() && f.getName().endsWith(".sqlite"))
                vec.addElement(list[i].substring(0, list[i].length()-".sqlite".length()));
        }
        return (String[])vec.copyInto(new String[vec.size()]);
    }

    public int uidValidity() { return uidValidity; }

    // UGLY: Apple Mail doesn't like UID=0, so we add one
    public int uidNext() {  return uidNext+1; }

    public synchronized void insert(Message message, int flags) {
        try {
            String name, fullname; File target, f;
            for(int i = uidNext; ; i++) {
                name = i + ".";
                fullname = path.getAbsolutePath() + slash + name;
                target = new File(fullname);
                f = new File(target.getCanonicalPath() + "-");
                if (!f.exists() && !target.exists()) break;
                Log.error(this, "aieeee!!!! target of insert() already exists: " + target.getAbsolutePath());
            }
            Stream stream = new Stream(new FileOutputStream(f));
            message.getStream().transcribe(stream);
            stream.close();
            f.renameTo(new File(fullname));
            uidNext++;
            f = new File(fullname);
            if ((flags & Mailbox.Flag.SEEN) == 0)  f.setLastModified(MAGIC_DATE);
            else if (f.lastModified()==MAGIC_DATE) f.setLastModified(System.currentTimeMillis());
        } catch (IOException e) { throw new MailException.IOException(e); }
        Log.info(this, path + " <= " + message.summary());
    }

    

    private static FilenameFilter filter =
        new FilenameFilter() { public boolean accept(File dir, String name) {
            return name.endsWith(".");
        } };

    private class Iterator extends Mailbox.Default.Iterator {
        int cur = -1;
        String[] files = files();
        private File file() { return new File(path.getAbsolutePath() + slash + files[cur]); }
        public boolean done() { return cur >= files.length; }
        public boolean next() { cur++; return !done(); }
        public boolean recent() { return false; }
        public int nntpNumber() { return cur+1; }  // FIXME: lame
        public int imapNumber() { return cur+1; }  // EUDORA insists that message numbers start at 1, not 0

        // UGLY: Apple Mail doesn't like UID=0, so we add one
        public int uid() { return done() ? -1 : 1+Integer.parseInt(files[cur].substring(0, files[cur].length()-1)); }
        public void delete() { File f = file(); if (f != null && f.exists()) f.delete(); }
        public int  getFlags() { return file().lastModified()==MAGIC_DATE ? 0 : Flag.SEEN; }
        public void setFlags(int flags) {
            File f = file();
            if ((flags & Mailbox.Flag.SEEN) == 0)  f.setLastModified(MAGIC_DATE);
            else if (f.lastModified()==MAGIC_DATE) f.setLastModified(System.currentTimeMillis());
            // FIXME: other flags?
            // FIXME: definitely need DELETED flag in order to do message moves!
        }
        public Headers head() { return done() ? null : new Headers(new Fountain.File(file())); }
        public Message cur() { return Message.newMessage(new Fountain.File(file())); }
    }

    // there's no reason this has to operate on a FileBasedMailbox -- it could operate on arbitrary mailboxes!
    // use this for file attachments: http://jakarta.apache.org/commons/fileupload/
    public static class Servlet extends HttpServlet {
        public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException { doGet(request, response); }
        private void frames(HttpServletRequest request, HttpServletResponse response, boolean top) throws IOException {
            String basename = request.getRequestURI();
            PrintWriter pw = new PrintWriter(response.getWriter());
            pw.println("<html>");
            if (top) {
                pw.println("  <frameset rows='30%,*'>");
                //pw.println("    <frame src='"+basename+"?frame=banner' marginwidth=0 marginheight=0 name=banner/>");
                //pw.println("    <frame src='"+basename+"?frame=top' marginwidth=0 marginheight=0 name=top/>");
                pw.println("    <frame src='"+basename+"?frame=topright' marginwidth=0 marginheight=0 name=topright/>");
                pw.println("    <frame src='"+basename+"?frame=bottom' marginwidth=0 marginheight=0 name='bottom'/>");
            } else {
                pw.println("  <frameset cols='150,*'>");
                pw.println("    <frame src='"+basename+"?frame=topleft' marginwidth=0 marginheight=0 name=topleft/>");
                pw.println("    <frame src='"+basename+"?frame=topright' marginwidth=0 marginheight=0 name=topright/>");
            }
            pw.println("  </frameset>");
            pw.println("</html>");
            pw.flush();
        }

        public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
            String frame = request.getParameter("frame");
            String basename = request.getRequestURI();

            if (frame == null) { frames(request, response, true); return; }
            if (frame.equals("top")) { frames(request, response, false); return; }
            if (frame.equals("banner")) { banner(request, response); return; }
            if (frame.equals("topleft")) { return; }

            if (request.getServletPath().indexOf("..") != -1) throw new IOException(".. not allowed in image paths");
            ServletContext cx = getServletContext();
            String path = cx.getRealPath(request.getServletPath());
            Mailbox mbox = FileBasedMailbox.getFileBasedMailbox(path, false).getMailbox();
            if (mbox == null) throw new IOException("no such mailbox: " + path);

            Vec msgs = new Vec();
            for(Mailbox.Iterator it = mbox.iterator(); it.next();) {
                String[] s = new String[4];
                Message m = it.cur();
                s[0] = (m.from==null?"":m.from.toString(true));
                s[1] = m.subject;
                s[2] = (m.date + "").trim().replaceAll(" ","&nbsp;");
                s[3] = it.imapNumber() + "";
                msgs.addElement(s);
            }
            String[][] messages;
            msgs.copyInto(messages = new String[msgs.size()][]);

            if ("bottom".equals(frame)) { bottom(request, response, messages, mbox); return; }
            if ("topright".equals(frame)) { topright(request, response, messages); return; }
        }

        private void bottom(HttpServletRequest request, HttpServletResponse response, String[][] messages, Mailbox mbox)
            throws IOException {
            PrintWriter pw = new PrintWriter(response.getWriter());
            pw.println("<html>");
            pw.println("  <head>");
            pw.println("  <style>");
            pw.println("      body { margin: 10px; }");
            pw.println("      pre {");
            pw.println("         font-family: monospace;");
            pw.println("         background-color:  #F0F0E0;");
            pw.println("         color: rgb(0, 0, 0);");
            pw.println("         padding: 5px;");
            pw.println("         margin: 0px;");
            pw.println("         overflow: auto;");
            //pw.println("         width: 80%;");
            //pw.println("         border-style: solid;");
            //pw.println("         border-width: 1px;");
            pw.println("      }");
            pw.println("  </style>");
            pw.println("  </head>");
            pw.println("  <body>");
            if (request.getParameter("msgnum") != null) {
                int target = Integer.parseInt(request.getParameter("msgnum"));
                Mailbox.Iterator it = mbox.iterator();
                while(it.next())
                    if (it.imapNumber() == target)
                        break;
                if (it.cur() != null) {
                    pw.println("    <table width=100% border=0 cellspacing=0 style='border: 1px black solid; background-color:#F0F0E0;'>");
                    pw.println("      <tr style='border: 1px black solid; font-family: monospace'><td style='padding: 5px'>");
                    Headers h = it.cur().headers;
                    pw.println(" Subject: " + it.cur().subject +"<br>");
                    pw.println("    From: " + it.cur().from +"<br>");
                    pw.println("    Date: " + it.cur().date +"<br>");
                        /*
                    for(java.util.Enumeration e = h.names(); e.hasMoreElements();) {
                        String key = (String)e.nextElement();
                        if (key==null || key.length()==0 || key.equals("from") ||
                            key.equals("to") || key.equals("subject") || key.equals("date")) continue;
                        key = Character.toUpperCase(key.charAt(0)) + key.substring(1);
                        String val = h.get(key);
                        for(int i=key.length(); i<15; i++)pw.print(" ");
                        pw.print(key+": ");
                        pw.println(val);
                    }
                        */
                    pw.print("</td></tr><tr><td style='border-top: 1px black; border-top-style: dotted;'><pre>");
                    StringBuffer tgt = new StringBuffer();
                    it.cur().getBody().getStream().transcribe(tgt);
                    pw.println(tgt.toString());
                    pw.println("    </pre></td></tr></table>");
                }
            }
            pw.println("  </body>");
            pw.println("</html>");
            pw.flush();
            pw.close();
        }
        
        private void banner(HttpServletRequest request, HttpServletResponse response) throws IOException {
            String basename = request.getServletPath();
            String realpath = getServletContext().getRealPath(basename);
            /*
            MailingList list = MailingList.getMailingList(realpath);
            list.banner(request, response);
            */
            banner(request, response);
        }

        private void topright(HttpServletRequest request, HttpServletResponse response, String[][] messages) throws IOException {
            PrintWriter pw = new PrintWriter(response.getWriter());
            String basename = request.getRequestURI();
            pw.println("<html>");
            pw.println("  <head>");
            pw.println("    <style>");
            pw.println("      TH, TD, P, LI {");
            pw.println("          font-family: helvetica, verdana, arial, sans-serif;");
            pw.println("          font-size: 12px;  ");
            pw.println("          text-decoration:none; ");
            pw.println("      }");
            pw.println("      body { margin: 10px; }");
            pw.println("      a:link    { color: #000; text-decoration: none; }");
            pw.println("      a:active  { color: #f00; text-decoration: none; }");
            pw.println("      a:visited { color: #777; text-decoration: none; }");
            pw.println("      a:hover   { color: #000; text-decoration: none; }");
            pw.println("      /* a:hover   { color: #00f; text-decoration: none; border-bottom: 1px dotted; } */");
            pw.println("    </style>");
            pw.println("  </head>");
            pw.println("  <body onKeyPress='doKey(event.keyCode)'>");
            pw.println("    <script>");
            pw.println("      var chosen = null;");
            pw.println("      var all = [];");
            pw.println("      function doKey(x) {");
            pw.println("          if (chosen == null) { choose(all[0]); return; }");
            pw.println("          switch(x) {");
            pw.println("              case 112: if (chosen.id > 0) choose(all[chosen.id-1]); break;");
            pw.println("              case 110: if (chosen.id < (all.length-1)) choose(all[1+(1*chosen.id)]); break;");
            pw.println("          }");
            pw.println("      }");
            pw.println("      function choose(who) {");
            pw.println("          who.style.background = '#ffc';");
            pw.println("          if (chosen != null) chosen.style.background = '#ccc';");
            pw.println("          parent.parent.bottom.location='"+basename+"?frame=bottom&msgnum='+who.id;");
            pw.println("          chosen = who;");
            pw.println("      }");
            pw.println("    </script>");
            pw.println("    <div style='border: 1px black solid;'><table width=100% border=0 cellpadding=0 cellspacing=0>");
            pw.println("    <tr><td style='padding: 4px' bgcolor=#eff7ff>");
            pw.flush();
            banner(request, response);
            pw.println("    </td></tr>");
            pw.println("    <tr><td>");
            pw.println("    <table width=100% cellpadding=0 cellspacing=0 style='border-top: 1px black solid; cursor:pointer;'>");
            boolean odd=true;
            for(int i=0; i<messages.length; i++) {
                odd = !odd;
                String[] m = messages[i];
                pw.println("      <tr style='cursor:pointer; background: "+(odd?"#e8eef7":"white")+"' id='"+m[3]+"' "+
                           "onmouseover='this.style.color=\"blue\"' "+
                           "onmouseout='this.style.color=\"black\"' "+
                           "onclick='choose(this);'>");
                pw.println("<td style='cursor:pointer; padding:5px; padding-bottom:2px'>"+m[0]+"</td>");
                pw.println("<td style='cursor:pointer; padding:5px; padding-bottom:2px'>"+m[1]+"</td>");
                pw.println("<td style='cursor:pointer; padding:5px; padding-bottom:2px'>"+m[2]+"</td>");
                pw.println("</tr>");
                pw.println("<script> all["+i+"] = document.getElementById('"+i+"'); </script>");
            }
            pw.println("    </table>");
            pw.println("    </td></tr>");
            pw.println("    </table></div>");
            pw.println("  </body>");
            pw.println("</html>");
            pw.flush();
            pw.close();
        }
    }
}