// 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.ibex.io.*;
import org.ibex.net.*;
import org.ibex.crypto.*;
import org.ibex.mail.*;
import org.ibex.util.*;
import org.ibex.mail.target.*;
import java.util.*;
import java.net.*;
import java.text.*;
import java.io.*;
 
// FEATURE: IDLE extension for blackberries

// FIXME: this is valid    LSUB "" asdfdas%*%*%*%*SFEFGWEF
// FIXME: be very careful about where/when we quotify stuff
// FIXME: 'UID FOO 100:*' must match at least one message even if all UIDs less than 100
// FIXME: LIST should return INBOX if applicable

// Relevant RFC's:
//   RFC 2060: IMAPv4
//   RFC 3501: IMAPv4 with clarifications
//   RFC 3691: UNSELECT
//   RFC 2971: ID

// to review
//   RFC 4466
//   RFC 4469

// FEATURE: make sure we're being case-insensitive enough; probably want to upcase atom()
// FEATURE: MIME-queries and BODYSTRUCTURE
// FEATURE: READ-WRITE / READ-ONLY status on SELECT
// FEATURE: pipelining
// FEATURE: support [charset]
// FEATURE: \Noselect
// FEATURE: subscriptions
// FEATURE: tune for efficiency
// FEATURE: STARTTLS
// FEATURE: asynchronous client notifications (need to re-read RFC)

public class IMAP {

    public IMAP() { }
    public static final float version = (float)0.2;

    // API Class //////////////////////////////////////////////////////////////////////////////

    public static interface Client {
        public void expunge(int uid);
        public void list(char separator, String mailbox, boolean lsub, boolean phantom);
        public void fetchResponse(int num, int flags, int size, Message m, int muid);  // m may be null or incomplete
    }

    public static interface Server {
        public void      setClient(IMAP.Client client);
        public String[]  capability();
        public Hashtable id(Hashtable clientId);
        public void      copy(Query q, String to);
        public void      logout();
        public void      unselect();
        public void      delete(String m);
        public void      create(String m);
        public void      append(String m, int flags, Date arrival, String body);
        public void      check();
        public void      noop();
        public void      close();
        public void      subscribe(String mailbox);
        public void      unsubscribe(String mailbox);
        public int       unseen(String mailbox);
        public int       recent(String mailbox);
        public int       count(String mailbox);
        public int       count();
        public int       maxuid();
        public int       uidNext(String mailbox);
        public int       uidValidity(String mailbox);
        public int[]     search(Query q, boolean uid);
        public void      rename(String from, String to);
        public void      select(String mailbox, boolean examineOnly);
        public void      setFlags(Query q, int flags, boolean uid, boolean silent);
        public void      removeFlags(Query q, int flags, boolean uid, boolean silent);
        public void      addFlags(Query q, int flags, boolean uid, boolean silent);
        public void      expunge();
        public void      fetch(Query q, int spec, String[] headers, int start, int end, boolean uid);
        public void      lsub(String start, String ref);
        public void      list(String start, String ref);
        public static class Exn extends MailException { public Exn(String s) { super(s); } }
        public static class Bad extends Exn { public Bad(String s) { super(s); } }
        public static class No extends Exn { public No(String s) { super(s); } }
    }


    // MailboxWrapper //////////////////////////////////////////////////////////////////////////////

    /** wraps an IMAP.Server interface around a Mailbox */
    public static class MailboxWrapper implements Server {

        public static final char sep = '.';

        Mailbox inbox = null;
        Mailbox selected = null;
        MailTree root = null;
        Mailbox selected() { if (selected == null) throw new Bad("no mailbox selected"); return selected; }
        final Login auth;
        final Client client;

        public MailboxWrapper(Login auth, Client c) { this.auth=auth; this.client=c;}
        public void setClient(IMAP.Client client) { }

        private String dirname(String name) { return name.substring(0, name.lastIndexOf(sep)); }
        private String basename(String name) { return name.substring(name.lastIndexOf(sep)+1); }
        private Mailbox mailbox(String name, boolean create) { return mailbox(name, create, true); }
        private Mailbox mailbox(String name, boolean create, boolean throwexn) {
            if (name.equalsIgnoreCase("inbox")) return inbox;
            if (name.equalsIgnoreCase("trash")) name = "trash";
            MailTree mt =  mailboxTree(name, create, throwexn);
            Mailbox ret = mt==null ? null : mt.getMailbox();
            if (ret==null && throwexn) throw new Server.No("no such mailbox " + name);
            return ret;
        }
        private MailTree mailboxTree(String name, boolean create) { return mailboxTree(name, create, true); }
        private MailTree mailboxTree(String name, boolean create, boolean throwexn) {
            MailTree m = root;
            for(StringTokenizer st = new StringTokenizer(name, sep + ""); st.hasMoreTokens();)
                if ((m = m.slash(st.nextToken(), create)) == null) {
                    if (throwexn) throw new Server.No("no such mailbox " + name);
                    return null;
                }
            return m;
        }

        // FEATURE: not accurate when a wildcard and subsequent non-wildcards both match a single component
        public void lsub(String start, String ref) { list(start, ref, true); }
        public void list(String start, String ref) { list(start, ref, false); }
        public void list(String start, String ref, boolean lsub) {

            // FIXME this might be wrong
            if (ref.equalsIgnoreCase("inbox")) { client.list(sep,"inbox",lsub,false); return; }

            if (ref.length() == 0) { client.list(sep, start, lsub, false); return; }
            while (start.endsWith(""+sep)) start = start.substring(0, start.length() - 1);
            if (ref.endsWith("%")) ref = ref + sep;
            String[] children = (start.length() == 0 ? root : mailboxTree(start, false)).children();
            for(int i=0; i<children.length; i++) {
                String s = children[i], pre = ref, kid = start + (start.length() > 0 ? sep+"" : "") + s;                
                if (mailbox(kid, false) == null) continue;
                MailTree phant = mailboxTree(kid, false, false);
                if (phant != null) {
                    boolean phantom = phant.getMailbox()==null;
                    while(true) {
                        if (pre.length() == 0) {
                            if (s.length() == 0)       client.list(sep, kid, lsub, phantom);
                        } else switch(pre.charAt(0)) {
                            case sep:        if (s.length() == 0) list(kid, pre.substring(1), lsub);                    break;
                            case '%':        client.list(sep,kid,lsub,phantom);pre=pre.substring(1); s = "";            continue;
                            case '*':        client.list(sep,kid,lsub,phantom);list(kid,pre,lsub);pre=pre.substring(1); break;
                            default:         if (s.length()==0)                                                         break;
                                if (s.charAt(0) != pre.charAt(0))                                          break;
                                s = s.substring(1); pre = pre.substring(1);                                continue;
                        }
                        break;
                    }
                }
            }
        }

        public String[] capability() { return new String[] { "IMAP4rev1" , "UNSELECT" /*, "ID"*/ }; }
        public Hashtable id(Hashtable clientId) {
            Hashtable response = new Hashtable();
            response.put("name", IMAP.class.getName());
            response.put("version", version + "");
            response.put("os", System.getProperty("os.name", null));
            response.put("os-version", System.getProperty("os.version", null));
            response.put("vendor", "none");
            response.put("support-url", "http://mail.ibex.org/");
            return response;
        }   

        public void copy(Query q, String to) { copy(q, mailbox(to, false)); }
        /*  */ void copy(Query q, Mailbox to) {
            for(Mailbox.Iterator it=selected().iterator(q);it.next();) to.insert(it.cur(), it.getFlags() | Mailbox.Flag.RECENT); }

        public void unselect() { selected = null; }

        public void delete(String m0) { mailboxTree(dirname(m0),false).rmdir(basename(m0)); }

        public void rename(String from0, String to) {
            Mailbox from = mailbox(from0, false);
            if (from.equals(inbox))                { from.copy(Query.all(), mailbox(to, true)); }
            else if (to.equalsIgnoreCase("inbox")) { from.copy(Query.all(), mailbox(to, true)); delete(from0); }
            else mailboxTree(dirname(from0), false)
                     .rename(dirname(from0),
                             mailboxTree(dirname(to),
                                         true /* required by IMAP */),
                             basename(to));
        }

        public void create(String m) { mailbox(m, true, false); }
        public void append(String m,int f,Date a,String b) { try {
            // FIXME: more efficient streaming here?
            mailbox(m,false).insert(Message.newMessage(new Fountain.StringFountain(b)), f | Mailbox.Flag.RECENT);
        } catch (Message.Malformed e) { throw new No(e.getMessage()); } }
        public void check() { }
        public void noop() { }
        public void logout() { }
        public void close() {
            for(Mailbox.Iterator it=selected().iterator(Query.deleted()); it.next();) {
                Log.error("imap", "deleting a message due to close(): " + it.cur().summary());
                it.delete();
            }
        }
        public void expunge() { for(Mailbox.Iterator it = selected().iterator(Query.deleted());it.next();) expunge(it); }
        public void expunge(Mailbox.Iterator it) {
            client.expunge(it.uid());
            Log.error("imap", "deleting a message due to expunge(): " + it.cur().summary());
            it.delete();
        }
        public void subscribe(String mailbox) { }
        public void unsubscribe(String mailbox) { }
        public int maxuid() {
            int ret = 0;
            Mailbox mb = selected();
            if (mb == null) return 0;
            return mb.maxuid();
        }
        public int unseen(String mailbox)      { return mailbox(mailbox, false).count(Query.not(Query.seen())); }
        public int recent(String mailbox)      { return mailbox(mailbox, false).count(Query.recent()); }
        public int count(String mailbox)       { return mailbox(mailbox, false).count(Query.all()); }
        public int count()                     { return selected().count(Query.all()); }
        public int uidNext(String mailbox)     { return mailbox(mailbox, false).uidNext(); }
        public int uidValidity(String mailbox) { return Math.abs(mailbox(mailbox, false).uidValidity()); }
        public void select(String mailbox, boolean examineOnly) { selected = mailbox(mailbox, false); }

        public int[] search(Query q, boolean uid) {
            Vec.Int vec = new Vec.Int();
            for(Mailbox.Iterator it = selected().iterator(q); it.next();) {
                vec.addElement(uid ? it.uid() : it.imapNumber());
                if ((it.getFlags() & Mailbox.Flag.RECENT) != 0)
                    it.setFlags(it.getFlags() & ~Mailbox.Flag.RECENT);
            }
            return vec.dump();
        }

        public void setFlags(Query q, int f, boolean uid, boolean silent)    { doFlags(q, f, uid, 0, silent); }
        public void addFlags(Query q, int f, boolean uid, boolean silent)    { doFlags(q, f, uid, 1, silent); }
        public void removeFlags(Query q, int f, boolean uid, boolean silent) { doFlags(q, f, uid, -1, silent); }
        private void doFlags(Query q, int flags, boolean uid, int style, boolean silent) {
            for(Mailbox.Iterator it = selected().iterator(q);it.next();) {
                // FIXME: what's going on here with the recent flag?
                //boolean recent = it.getFlag(Mailbox.Flag.RECENT);
                //try { throw new Exception("flags " + flags); } catch (Exception e) { Log.error(this, e); }
                if (style == -1)     it.setFlags(it.getFlags() & ~flags);
                else if (style == 0) it.setFlags(flags);
                else if (style == 1) it.setFlags(it.getFlags() | flags);
                //it.setFlag(Mailbox.Flag.RECENT, recent);
                if (!silent) client.fetchResponse(it.imapNumber(), it.getFlags(), -1, null, it.uid());
            }
        }

        public void fetch(Query q, int spec, String[] headers, int start, int end, boolean uid) {
            for(Mailbox.Iterator it = selected().iterator(q); it.next(); ) {
                // FIXME it would be great if we could avoid instantiating the entire message just because RFC822SIZE was requested
                Message message =
                    ((spec & (BODYSTRUCTURE | RFC822 | RFC822TEXT | RFC822SIZE)) != 0)
                    ? it.cur()
                    : ((spec & (ENVELOPE | INTERNALDATE | FIELDS | FIELDSNOT | RFC822SIZE | HEADERNOT | HEADER)) != 0)
                    ? Message.newMessage(Fountain.Util.concat(it.head(), Fountain.Util.create("\r\n\r\n")))
                    : null;
                if (message != null) Log.warn("spec", spec);
                long size = message == null ? 0 : message.getLength();
                client.fetchResponse(it.imapNumber(), it.getFlags(), (int)size, message,it.uid());
                it.setFlags(it.getFlags() & ~Mailbox.Flag.RECENT);
            }
        }
    }

    // Single Session Handler //////////////////////////////////////////////////////////////////////////////

    /** takes an IMAP.Server and exposes it to the world as an IMAP server on a TCP socket */
    public static class Listener implements Client {
        String selectedName = null;
        Mailbox inbox = null;
        MailTree root = null;
        Server api;
        Parser parser = null;
        Connection conn = null;
        Login auth;
        public Listener(Login auth) { api = new IMAP.MailboxWrapper(this.auth = auth, this); }
        Parser.Token token() { return parser.token(); }
        Parser.Token token(boolean freak) { return parser.token(freak); }
        void println(String s) {
            conn.println(s);
            //Log.info("", s);
        }
        void newline() { parser.newline(); }
        Query query(int max) { return parser.query(max, maxn(true)); }

        public void login(String u, String p) {
            Object ret;
            if ((ret = auth.login(u,p,IMAP.class)) == null) throw new Server.No("Login failed.");
            if (ret instanceof IMAP.Server) {
                api = (IMAP.Server)ret;
                api.setClient(this);
            } else {
                Account account = (Account)ret;
                ((MailboxWrapper)api).root = root = account.getMailbox(IMAP.class);
                MailTree ibt = root.slash("inbox", false);
                Mailbox ib = ibt==null ? null : ibt.getMailbox();
                ((MailboxWrapper)api).inbox = inbox = ib;
            }
        }

        private int maxn(boolean uid) { return uid ? api.maxuid() : api.count(); }

        public void handleRequest(Connection conn) {
            this.conn = conn;
            parser = new Parser(conn);
            conn.setTimeout(30 * 60 * 1000);
            println("* OK " + conn.vhost + " " + IMAP.class.getName() + " IMAP4rev1 [RFC3501] v" + version + " server ready");
            for(String tag = null;;) try {
                conn.flush();
                boolean uid = false;
                tag = null; Parser.Token tok = token(); if (tok == null) return; tag = tok.astring();
                String command = token().atom();
                if (command.equalsIgnoreCase("UID")) { uid = true; command = token().atom(); }
                int commandKey = ((Integer)commands.get(command.toUpperCase())).intValue();
                switch(commandKey) {
                    case LOGIN:        login(token().astring(), token().astring()); break;
                    case CAPABILITY:   println("* CAPABILITY " + Printer.join(" ", api.capability())); break;
                    case AUTHENTICATE: throw new Server.No("AUTHENTICATE not supported");
                    case LOGOUT:       api.logout(); println("* BYE"); conn.close(); return;
                    case LIST:         api.list(token().q(), token().astring()); break; /*astring is a hack for EUDORA*/
                    case LSUB:         api.lsub(token().q(), token().q()); break;
                    case SUBSCRIBE:    api.subscribe(token().astring()); break;
                    case UNSUBSCRIBE:  api.unsubscribe(token().astring()); break;
                    case RENAME:       api.rename(token().astring(), token().astring()); break;
                    case DELETE:       api.delete(token().atom()); break;
                    case CHECK:        selected(); api.check(); break;
                    case NOOP:         api.noop(); break;
                    case CLOSE:        selected(); api.close(); break;
                    case EXPUNGE:      selected(); api.expunge(); break;
                    case UNSELECT:     selected(); api.unselect(); selected = false; break;
                    case CREATE:       api.create(token().astring()); break;
                    case FETCH:        selected(); lastuid = uid; _fetch((uid
                                                                          ? Query.uid(token().set(maxn(uid)))
                                                                          : Query.imapNumber(token().set(maxn(uid)))),
                                                                         lastfetch=token().lx(), 0, 0, 0, uid, 0); break;
                    case COPY:         selected(); api.copy(uid
                                                            ? Query.uid(token().set(maxn(uid)))
                                                            : Query.imapNumber(token().set(maxn(uid))), token().astring()); break;
                    case SEARCH: {
                        selected();
                        int[] result = api.search(query(maxn(uid)), uid);
                        /*if (result.length > 0)*/ println("* SEARCH " + Printer.join(result));
                        break;
                    }
                    case EXAMINE:
                    case SELECT: {
                        String mailbox = token().astring();
                        api.select(mailbox, commandKey==EXAMINE);
                        println("* FLAGS (\\Answered \\Flagged \\Deleted \\Seen \\Draft)");
                        println("* " + api.count(mailbox)  + " EXISTS");
                        println("* " + api.recent(mailbox) + " RECENT");
                        println("* OK [UNSEEN " + api.unseen(mailbox) + "]");
                        println("* OK [UIDVALIDITY " + api.uidValidity(mailbox) + "] UIDs valid");
                        println("* OK [UIDNEXT " + api.uidNext(mailbox) + "]");
                        println("* OK [PERMANENTFLAGS (\\Answered \\Flagged \\Deleted \\Seen \\Draft)]");
                        selected = true;
                        break; }
                    case STATUS: {
                        String mailbox = token().astring();  // hack for GNUS buggy client
                        Parser.Token[] list = token().l();
                        String response = "";
                        for(int i=0; i<list.length; i++) {
                            String s = list[i].atom().toUpperCase();
                            if (i>0) response += " ";
                            if (s.equals("MESSAGES"))    response += "MESSAGES "    + api.count(mailbox);
                            if (s.equals("RECENT"))      response += "RECENT "      + api.recent(mailbox);
                            if (s.equals("UIDNEXT"))     response += "UIDNEXT "     + api.uidNext(mailbox);
                            if (s.equals("UIDVALIDITY")) response += "UIDVALIDITY " + api.uidValidity(mailbox);
                            if (s.equals("UNSEEN"))      response += "UNSEEN "      + api.unseen(mailbox);
                        }
                        println("* STATUS " + mailbox + " (" + response + ")");
                        break;
                    }
                    case APPEND: { 
                        String m = token().astring();
                        int flags = 0;
                        Date arrival = new Date();
                        Parser.Token t = token();
                        if (t.type == t.LIST)   { flags = t.flags();      t = token(); }
                        Parser.Token t2 = token(false);
                        if (t2 != null) { arrival = t.datetime(); t = t2; }
                        api.append(m, flags, arrival, t.q());
                        break; }
                    case STORE: {
                        selected();
                        Query q = uid ? Query.uid(token().set(maxn(uid))) : Query.imapNumber(token().set(maxn(uid)));
                        String s = token().atom().toUpperCase();
                        int flags = token().flags();
                        if (s.equals("FLAGS"))              api.setFlags(q,    flags, uid, false);
                        else if (s.equals("+FLAGS"))        api.addFlags(q,    flags, uid, false);
                        else if (s.equals("-FLAGS"))        api.removeFlags(q, flags, uid, false);
                        else if (s.equals("FLAGS.SILENT"))  api.setFlags(q,    flags, uid, true);
                        else if (s.equals("+FLAGS.SILENT")) api.addFlags(q,    flags, uid, true);
                        else if (s.equals("-FLAGS.SILENT")) api.removeFlags(q, flags, uid, true);
                        else throw new Server.Bad("unknown STORE specifier " + s);
                        break; }
                    default: throw new Server.Bad("unrecognized command \"" + command + "\"");
                }
                println(tag+" OK "+command+" Completed. " +
                        (commandKey == LOGIN ? ("[CAPABILITY "+Printer.join(" ", api.capability())+"]") : ""));
                try {
                    newline();
                } catch (Stream.EOF e) {
                    Log.info(this, "connection closed");
                    return;
                }
            } catch (Server.Bad b) { println(tag==null ? "* BAD Invalid tag":(tag + " Bad " + b.toString())); Log.warn(this,b);
            } catch (Server.No n)  { println(tag==null?"* BAD Invalid tag":(tag+" No "  + n.toString())); Log.warn(this,n);
            }
        }

        private Parser.Token[] lastfetch = null; // hack
        private boolean lastuid = false;  // hack
        private boolean selected = false;
        private void selected() { if (!selected) throw new Server.Bad("no mailbox selected"); }

        // Callbacks //////////////////////////////////////////////////////////////////////////////

        public void expunge(int uid) { println("* " + uid + " EXPUNGE"); }
        public void fetchResponse(int n, int f, int size, Message m, int muid) { _fetch(m, lastfetch, n, f, size, lastuid, muid); }
        public void list(char sep, String mb, boolean sub, boolean p) {
            println("* " + (sub?"LSUB":"LIST")+" ("+(p?"\\Noselect":"")+") \""+sep+"\" \""+mb+"\"");}

        /**
         *   Parse a fetch request <i>or</i> emit a fetch reply.
         *
         *   To avoid duplicating tedious parsing logic, this function
         *   performs both of the following tasks:
         *      - parse the fetch request in Token[] t and return a fetch spec
         *      - emit a fetch reply for the parsed spec with respect to message m
         */
        private void _fetch(Object o, Parser.Token[] t, int num, int flags, int size, boolean uid, int muid) {
            Query q   = o == null ? null : o instanceof Query ? (Query)o : null;
            Message m = o == null ? null : o instanceof Message ? (Message)o : null;
            boolean e = q == null;

            // asynchronous flags update
            if (size == -1) {
                println("* " + num + " FETCH (FLAGS " + Printer.flags(flags) + (uid?(" UID "+muid):"") + ")");
                return;
            }

            lastfetch = t;
            int spec = 0;                              // spec; see constants for flags
            int start = 0, len = 0;
            String[] headers = null;
            StringBuffer r = new StringBuffer();
            if (e) { r.append(num); r.append(" FETCH ("); }
            int initlen = r.length();
            if (uid) {
                boolean good = false;
                for(int i=0; i<t.length; i++)
                    if ((t[i].type == Parser.Token.QUOTED || t[i].type == Parser.Token.ATOM) &&
                        t[i].astring().equalsIgnoreCase("UID")) good = true;
                if (!good) {
                    Parser.Token[] t2 = new Parser.Token[t.length + 1];
                    System.arraycopy(t, 0, t2, 0, t.length);
                    t2[t2.length - 1] = parser.token("UID");
                    lastfetch = (t = t2);
                }
            }
            if (t.length == 0 && (t[0].type == Parser.Token.QUOTED || t[0].type == Parser.Token.ATOM)) {
                if (t[0].astring().equalsIgnoreCase("ALL"))
                    t = new Parser.Token[] { parser.token("FLAGS"), parser.token("INTERNALDATE"),
                                      parser.token("ENVELOPE"), parser.token("RFC822.SIZE") };
                else if (t[0].astring().equalsIgnoreCase("FULL"))
                    t = new Parser.Token[] { parser.token("FLAGS"), parser.token("INTERNALDATE"), parser.token("BODY"), 
                                      parser.token("ENVELOPE"), parser.token("RFC822.SIZE") };
                else if (t[0].astring().equalsIgnoreCase("FAST"))
                    t = new Parser.Token[] { parser.token("FLAGS"), parser.token("INTERNALDATE"),
                                      parser.token("RFC822.SIZE") };
            }
            boolean looked_at_body = false;
            for(int i=0; i<t.length; i++) {
                if (r.length() > initlen) r.append(" ");
                if (t[i] == null || t[i].s == null) continue;
                String s = t[i].s.toUpperCase();
                r.append(s.equalsIgnoreCase("BODY.PEEK")?"BODY":s);
                if (s.equals("BODYSTRUCTURE")) {       spec|=BODYSTRUCTURE;if(e){r.append(" ");r.append(Printer.bodystructure(m));}
                } else if (s.equals("ENVELOPE")) {     spec|=ENVELOPE;     if(e){r.append(" ");r.append(Printer.envelope(m));}
                } else if (s.equals("FLAGS")) {        spec|=FLAGS;        if(e){r.append(" ");r.append(Printer.flags(flags));}
                } else if (s.equals("INTERNALDATE")) { spec|=INTERNALDATE; if(e){r.append(" ");r.append(Printer.date(m.arrival));}
                } else if (s.equals("RFC822")) {       spec|=RFC822;       if(e){r.append(" ");r.append(Printer.message(m));}
                } else if (s.equals("RFC822.TEXT")) {  spec|=RFC822TEXT;   if(e){r.append(" ");r.append(Printer.qq(m.getStream()));}
                } else if (s.equals("RFC822.HEADER")){ spec|=HEADER;       if(e){r.append(" ");r.append(Printer.qq(m.headers.getStream().append("\r\n")));}
                } else if (s.equals("RFC822.SIZE")) {  spec|=RFC822SIZE;   if(e){r.append(" ");r.append(m.getLength());}
                } else if (s.equals("UID")) {          spec|=UID;          if(e){r.append(" ");r.append(muid); }
                } else if (!(s.equals("BODY.PEEK") || s.equals("BODY"))) { throw new Server.No("unknown fetch argument: " + s);
                } else {
                    if (s.equalsIgnoreCase("BODY.PEEK"))   spec |= PEEK;
                    looked_at_body = true;
                    if (i >= t.length - 1 || t[i+1].type != Parser.Token.LIST) {
                        // not sure why this was uncommented....
			//spec |= BODYSTRUCTURE;
			if (e) { r.append(" "); r.append(Printer.bodystructure(m)); } continue;
			//if (e) { r.append(" "); r.append(Printer.qq(m.getBody().getStream())); } continue;
		    }
                    Fountain payload = Fountain.Util.create("");
                    r.append("[");
                    Parser.Token[] list = t[++i].l();
                    s = list.length == 0 ? "" : list[0].s.toUpperCase();
                    r.append(s);
                    if (list.length == 0)                   { spec |= RFC822TEXT;   if(e) payload = m; }
                    else if (s.equals("") || s.equals("1")) { spec |= RFC822TEXT;   if(e) payload = m; }
                    else if (s.equals("TEXT"))              { spec |= RFC822TEXT;   if(e) payload = m.getBody(); }
                    else if (s.equals("HEADER"))            { spec |= HEADER;       if(e) payload = Fountain.Util.concat(m.headers, Fountain.Util.create("\r\n")); }
                    else if (s.equals("HEADER.FIELDS"))     { spec |= FIELDS;       payload=Fountain.Util.create(headers(r,t[i].l()[1].sl(),false,m,e)); }
                    else if (s.equals("HEADER.FIELDS.NOT")) { spec |= FIELDSNOT;    payload=Fountain.Util.create(headers(r,t[i].l()[1].sl(),true,m,e)); }
                    else if (s.equals("MIME")) {              throw new Server.Bad("MIME not supported"); }
                    else                                      throw new Server.Bad("unknown section type " + s);

                    if (i<t.length - 1 && (t[i+1].s != null && t[i+1].s.startsWith("<"))) {
                        i++;
                        s = t[i].s.substring(1, t[i].s.indexOf('>'));
                        int dot = s.indexOf('.');
                        start = dot == -1 ? Integer.parseInt(s) : Integer.parseInt(s.substring(0, s.indexOf('.')));
                        len   = dot == -1 ? -1 : Integer.parseInt(s.substring(s.indexOf('.') + 1));
                        if (e) {
                            if (start == 0 && len == -1) {
                            } else if (len == -1) {
                                payload = Fountain.Util.subFountain(payload, start);
                            } else {
                                len = (int)Math.min(len, payload.getLength()-start);
                                payload = Fountain.Util.subFountain(payload, start, len);
                            }
                            r.append("]");
                            r.append("<"+start+"> ");
                        }
                    } else {
                        if (e) r.append("] ");
                    }
                    if (e) r.append(Printer.qq(payload.getStream()));
                }
            }
            if ((spec & PEEK) == 0 && looked_at_body && e)
                api.addFlags(Query.imapNumber(new int[] { num, num }), Mailbox.Flag.SEEN, false, false);
            if (e) {
		r.append(")");
		println("* " + r.toString());
	    } else {
		api.fetch(q, spec, headers, start, (len==-1?0:len), uid);
	    }
        }

        private String headers(StringBuffer r, String[] headers, boolean negate, Message m, boolean e) {
            String payload = "";
            if (e) r.append(" (");
            if (!negate) {
                if(e) for(int j=0; j<headers.length; j++) {
                    r.append(headers[j] + (j<headers.length-1?" ":""));
                    if (m.headers.get(headers[j]) != null) payload += headers[j]+": "+m.headers.get(headers[j])+"\r\n";
                }
            } else {
 		throw new Server.No("HEADERS.NOT temporarily disaled");
		/*
                if (e) for(int j=0; j<headers.length; j++) r.append(headers[j] + (j<headers.length-1?" ":""));
                if(e) { OUTER: for(Enumeration x=m.headers.keys(); x.hasMoreElements();) {
                    String key = (String)x.nextElement();
                    for(int j=0; j<headers.length; j++) if (key.equalsIgnoreCase(headers[j])) continue OUTER;
                    payload += key + ": " + m.headers.get(key)+"\r\n";
                } }
		*/
            }
            if (e) r.append(")");
            return payload + "\r\n";
        }

        private static final Hashtable commands = new Hashtable();
        private static final int UID = 0;          static { commands.put("UID", new Integer(UID)); }
        private static final int AUTHENTICATE = 1; static { commands.put("AUTHENTICATE", new Integer(AUTHENTICATE)); }
        private static final int LIST = 2;         static { commands.put("LIST", new Integer(LIST)); }
        private static final int LSUB = 3;         static { commands.put("LSUB", new Integer(LSUB)); }
        private static final int SUBSCRIBE = 4;    static { commands.put("SUBSCRIBE", new Integer(SUBSCRIBE)); }
        private static final int UNSUBSCRIBE = 5;  static { commands.put("UNSUBSCRIBE", new Integer(UNSUBSCRIBE)); }
        private static final int CAPABILITY = 6;   static { commands.put("CAPABILITY", new Integer(CAPABILITY)); }
        private static final int ID = 7;           static { commands.put("ID", new Integer(ID)); }
        private static final int LOGIN = 8;        static { commands.put("LOGIN", new Integer(LOGIN)); }
        private static final int LOGOUT = 9;       static { commands.put("LOGOUT", new Integer(LOGOUT)); }
        private static final int RENAME = 10;      static { commands.put("RENAME", new Integer(RENAME)); }
        private static final int EXAMINE = 11;     static { commands.put("EXAMINE", new Integer(EXAMINE)); }
        private static final int SELECT = 12;      static { commands.put("SELECT", new Integer(SELECT)); }
        private static final int COPY = 13;        static { commands.put("COPY", new Integer(COPY)); }
        private static final int DELETE = 14;      static { commands.put("DELETE", new Integer(DELETE)); }
        private static final int CHECK = 15;       static { commands.put("CHECK", new Integer(CHECK)); }
        private static final int NOOP = 16;        static { commands.put("NOOP", new Integer(NOOP)); }
        private static final int CLOSE = 17;       static { commands.put("CLOSE", new Integer(CLOSE)); }
        private static final int EXPUNGE = 18;     static { commands.put("EXPUNGE", new Integer(EXPUNGE)); }
        private static final int UNSELECT = 19;    static { commands.put("UNSELECT", new Integer(UNSELECT)); }
        private static final int CREATE = 20;      static { commands.put("CREATE", new Integer(CREATE)); }
        private static final int STATUS = 21;      static { commands.put("STATUS", new Integer(STATUS)); }
        private static final int FETCH = 22;       static { commands.put("FETCH", new Integer(FETCH)); }
        private static final int APPEND = 23;      static { commands.put("APPEND", new Integer(APPEND)); }
        private static final int STORE = 24;       static { commands.put("STORE", new Integer(STORE)); }
        private static final int SEARCH = 25;      static { commands.put("SEARCH", new Integer(SEARCH)); }
    }

    public static class Parser {
        private Stream stream;
        public Parser(Stream from) { this.stream = from; }
        public Token token(String s) { return new Token(s); }
        protected Query query(int max, int maxuid) {
            String s = null;
            boolean not = false;
            Query q = null;
            Query ret = null;
            while(true) {
                Parser.Token t = token(false);
                if (t == null) break;
                if (t.type == t.LIST) throw new Server.No("nested queries not yet supported FIXME");
                else if (t.type == t.SET) return Query.imapNumber(t.set(max));
                s = t.atom().toUpperCase();
                if (s.equals("NOT"))   return Query.not(query(max, maxuid));
                if (s.equals("OR"))    return Query.or(query(max, maxuid), query(max, maxuid));    // FIXME parse rest of list
                if (s.equals("AND"))   return Query.and(query(max, maxuid), query(max, maxuid));

                if (s.startsWith("UN"))        { not = true; s = s.substring(2); }
                if (s.equals("ANSWERED"))        q = Query.answered();
                else if (s.equals("DELETED"))    q = Query.deleted();
                else if (s.equals("ALL"))        q = Query.all();
                else if (s.equals("DRAFT"))      q = Query.draft();
                else if (s.equals("FLAGGED"))    q = Query.flagged();
                else if (s.equals("RECENT"))     q = Query.recent();
                else if (s.equals("SEEN"))       q = Query.seen();
                else if (s.equals("OLD"))      { not = true; q = Query.recent(); }
                else if (s.equals("NEW"))        q = Query.and(Query.recent(), Query.not(Query.seen()));
                else if (s.equals("KEYWORD"))    q = Query.header("keyword", token().flag());
                else if (s.equals("HEADER"))     q = Query.header(token().astring(), token().astring());
                else if (s.equals("BCC"))        q = Query.header("bcc", token().astring());
                else if (s.equals("CC"))         q = Query.header("cc", token().astring());
                else if (s.equals("FROM"))       q = Query.header("from", token().astring());
                else if (s.equals("TO"))         q = Query.header("to", token().astring());
                else if (s.equals("SUBJECT"))    q = Query.header("subject", token().astring());
                else if (s.equals("LARGER"))     q = Query.size(token().n(), Integer.MAX_VALUE);
                else if (s.equals("SMALLER"))    q = Query.size(Integer.MIN_VALUE, token().n());
                else if (s.equals("BODY"))       q = Query.body(token().astring());
                else if (s.equals("TEXT"))       q = Query.full(token().astring());
                else if (s.equals("BEFORE"))     q = Query.arrival(new Date(0), token().date());
                else if (s.equals("SINCE"))      q = Query.arrival(token().date(), new Date(Long.MAX_VALUE));
                else if (s.equals("ON"))       { Date d = token().date(); q = Query.arrival(d, new Date(d.getTime() + 24 * 60 * 60)); }
                else if (s.equals("SENTBEFORE")) q = Query.sent(new Date(0), token().date());
                else if (s.equals("SENTSINCE"))  q = Query.sent(token().date(), new Date(Long.MAX_VALUE));
                else if (s.equals("SENTON"))   { Date d = token().date(); q = Query.sent(d, new Date(d.getTime() + 24 * 60 * 60)); }
                else if (s.equals("UID"))        q = Query.uid(token().set(max));
                q = not ? Query.not(q) : q;
                ret = ret == null ? q : Query.and(ret, q);
            }
            return ret;
        }

        private static void bad(String s) { throw new Server.Bad(s); }
        class Token {
            public final byte type;
            private final String s;
            private final Parser.Token[] l;
            private final int n;
            private static final byte NIL = 0, LIST = 1, QUOTED = 2, NUMBER = 3, ATOM = 4, BAREWORD = 5, SET = 6;
            public Token()                         { this.s = null; n = 0;      l = null; type = NIL; }
            public Token(String s)                 { this(s, false); }
            public Token(String s, boolean quoted) { this.s = s;    n = 0;      l = null; type = quoted ? QUOTED : ATOM;  }
            public Token(Parser.Token[] list)      { this.s = null; n = 0;      l = list; type = LIST; }
            public Token(int number)               { this.s = null; n = number; l = null; type = NUMBER; }

            public String toString() {
                // FIXME hack
                switch(type) {
                    case NIL: return "NIL";
                    case LIST: return "(" + Printer.join(", ", l) + ")";
                    case QUOTED: return s;
                    case NUMBER: return n+"";
                    case ATOM: return s;
                    case BAREWORD: return s;
                    case SET: return "<set>";
                }
                return "???";
            }

            public String   flag()    { if (type != ATOM) bad("expected a flag"); return s; }
            public int      n()       { if (type != NUMBER) bad("expected number"); return n; }
            public int      nz()      { int n = n(); if (n == 0) bad("expected nonzero number"); return n; }
            public String   q()       { if (type == NIL) return null; if (type != QUOTED) bad("expected qstring"); return s; }
            public Parser.Token[]  l()       { if (type == NIL) return null; if (type != LIST) bad("expected list"); return l; }
            public Parser.Token[]  lx()      {
		if (type == LIST) return l;
		Vec v = new Vec();
		v.addElement(this);
		while(true) {
		    Parser.Token t = token(false);
		    if (t == null) break;
		    v.addElement(t);
		}
		Parser.Token[] ret = new Parser.Token[v.size()];
		v.copyInto(ret);
		return ret;
	    }
            public String   nstring() { if (type==NIL) return null; if (type!=QUOTED) bad("expected nstring"); return s; }
            public String   astring() {
                if (type != ATOM && type != QUOTED) bad("expected atom or string");
                if (s == null) bad("astring cannot be null");
                return s; }
            public String[] sl() {
                if (type == NIL) return null;
                if (type != LIST) bad("expected list");
                String[] ret = new String[l.length];
                for(int i=0; i<ret.length; i++) ret[i] = l[i].s;
                return ret;
            }
            public int flags() {
                if (type != LIST) bad("expected flag list");
                int ret = 0;
                for(int i=0; i<l.length; i++) {
                    String flag = l[i].s;
                    if (flag.equals("\\Deleted"))       ret |= Mailbox.Flag.DELETED;
                    else if (flag.equals("\\Seen"))     ret |= Mailbox.Flag.SEEN;
                    else if (flag.equals("\\Flagged"))  ret |= Mailbox.Flag.FLAGGED;
                    else if (flag.equals("\\Draft"))    ret |= Mailbox.Flag.DRAFT;
                    else if (flag.equals("\\Answered")) ret |= Mailbox.Flag.ANSWERED;
                    else if (flag.equals("\\Recent"))   ret |= Mailbox.Flag.RECENT;
                    else                                Log.warn(this, "unknown flag: " + flag);
                }
                return ret;
            }
            public int[] set(int largest) {
                if (type != ATOM) bad("expected a messageid set");
                Vec.Int ids = new Vec.Int();
                StringTokenizer st = new StringTokenizer(s, ",");
                while(st.hasMoreTokens()) {
                    String s = st.nextToken();
                    if (s.indexOf(':') == -1) {
                        if (s.equals("*")) {
                            ids.addElement(largest);
                            ids.addElement(largest);
                        } else {
                            ids.addElement(Integer.parseInt(s));
                            ids.addElement(Integer.parseInt(s));
                        }
                        continue; }
                    int start = Integer.parseInt(s.substring(0, s.indexOf(':')));
                    String end_s = s.substring(s.indexOf(':')+1);
                    int end = end_s.equals("*") ? largest : Integer.parseInt(end_s);
                    for(int j=Math.min(start,end); j<=Math.max(start,end); j++) {
                        ids.addElement(j);
                        ids.addElement(j);
                    }
                }
                return ids.dump();
            }
            public Date date() {
                if (type != QUOTED && type != ATOM) bad("Expected quoted or unquoted date");
                try { return new SimpleDateFormat("dd-MMM-yyyy").parse(s);
                } catch (ParseException p) { throw new Server.Bad("invalid date format; " + p); }
            }
            public Date datetime() {
                if (type != QUOTED) bad("Expected quoted datetime");
                try { return new SimpleDateFormat("dd-MMM-yyyy hh:mm:ss zzzz").parse(s.trim());
                } catch (ParseException p) { throw new Server.Bad("invalid datetime format " + s + " : " + p); }
            }
            public String atom() {
                if (type != ATOM) bad("expected atom");
                for(int i=0; i<s.length(); i++) {
                    char c = s.charAt(i);
                    if (c == '(' || c == ')' || c == '{' || c == ' ' || c == '%' || c == '*' || c == '\"' | c == '\\')
                        bad("invalid char in atom: " + c);
                }
                return s;
            }
        }

        public void newline() { stream.readln(); }

        public Token token() { return token(true); }
        public Token token(boolean freak) {
            Vec toks = new Vec();
            StringBuffer sb = new StringBuffer();
            char c = stream.getc(); while (c == ' ') c = stream.getc();
            if (c == '\r' || c == '\n') { if (freak) bad("unexpected end of line"); return null; }
            else if (c == '{') {
                while(stream.peekc() != '}') sb.append(stream.getc());
                stream.getc();
                stream.println("+ Ready when you are...");
                int octets = Integer.parseInt(sb.toString());
                while(stream.peekc() == ' ') stream.getc();   // whitespace
                while(stream.peekc() == '\n' || stream.peekc() == '\r') stream.getc();
                byte[] bytes = new byte[octets];
                int numread = 0;
                while(numread < bytes.length) {
                    int n = stream.read(bytes, numread, bytes.length - numread);
                    if (n == -1) bad("end of stream while reading IMAP qstring");
                    numread += n;
                }
                return new Token(new String(bytes), true);
            } else if (c == '\"') {
                while(true) {
                    c = stream.getc();
                    if (c == '\\') sb.append(stream.getc());
                    else if (c == '\"') break;
                    else sb.append(c);
                }
                return new Token(sb.toString(), true);
                
                // NOTE: this is technically a violation of the IMAP grammar, since atoms like FOO[BAR should be legal
            } else if (c == ']' || c == ')') { return null;
            } else if (c == '[' || c == '(') {
                Token t;
                do { t = token(); if (t != null) toks.addElement(t); } while (t != null);
                Token[] ret = new Token[toks.size()];
                toks.copyInto(ret);
                return new Token(ret);
                
            } else while(true) {
                sb.append(c);
                c = stream.peekc();
                if (c == ' ' || c == '\"' || c == '(' || c == ')' || c == '[' || c == ']' ||
                    c == '{' || c == '\n' || c == '\r')
                    return new Token(sb.toString(), false);
                stream.getc();
            }
        }
    }
    
    public static class Printer {
            static String quotify(String s){
                return s==null?"NIL":"\""+s.replaceAll("\\\\","\\\\").replaceAll("\"","\\\\\"")+"\"";}
            static String quotify(Date d) {
                return new SimpleDateFormat("dd-MMM-yyyy HH:mm:ss +zzzz").format(d); }
            static String address(Address a) {
                return"("+quotify(a.description)+" NIL "+quotify(a.user)+" "+quotify(a.host)+")"; }
            public static String addressList(Object a) {
                if (a == null) return "NIL";
                if (a instanceof Address) return "("+address((Address)a)+")";
                if (a instanceof String) return "("+address(Address.parse((String)a))+")";
                Address[] aa = (Address[])a;
                StringBuffer ret = new StringBuffer();
                ret.append("(");
                for(int i=0; i<aa.length; i++) { ret.append(aa[i]); if (i < aa.length - 1) ret.append(" "); }
                ret.append(")");
                return ret.toString();
            }
            static String flags(Mailbox.Iterator it) {
                return
                    ((it.getFlags() & Mailbox.Flag.DELETED)!=0  ? "\\Deleted "  : "") +
                    ((it.getFlags() & Mailbox.Flag.SEEN)!=0     ? "\\Seen "     : "") +
                    ((it.getFlags() & Mailbox.Flag.FLAGGED)!=0  ? "\\Flagged "  : "") +
                    ((it.getFlags() & Mailbox.Flag.DRAFT)!=0    ? "\\Draft "    : "") +
                    ((it.getFlags() & Mailbox.Flag.ANSWERED)!=0 ? "\\Answered " : "") +
                    ((it.getFlags() & Mailbox.Flag.RECENT)!=0   ? "\\Recent "   : "");
        }
        static String flags(int flags) {
            String ret = "(" +
                (((flags & Mailbox.Flag.DELETED) == Mailbox.Flag.DELETED) ? "\\Deleted "  : "") +
                (((flags & Mailbox.Flag.SEEN) == Mailbox.Flag.SEEN)    ? "\\Seen "     : "") +
                (((flags & Mailbox.Flag.FLAGGED) == Mailbox.Flag.FLAGGED) ? "\\Flagged "  : "") +
                (((flags & Mailbox.Flag.DRAFT) == Mailbox.Flag.DRAFT)   ? "\\Draft "    : "") +
                (((flags & Mailbox.Flag.ANSWERED) == Mailbox.Flag.ANSWERED)? "\\Answered " : "") +
                (((flags & Mailbox.Flag.RECENT) == Mailbox.Flag.RECENT)  ? "\\Recent "   : "");
            if (ret.endsWith(" ")) ret = ret.substring(0, ret.length() - 1);
            return ret + ")";
        }
        static String bodystructure(Message m) {
            // FIXME
            return "(\"TEXT\" \"PLAIN\" (\"CHARSET\" \"ISO-8859-1\") NIL NIL \"7BIT\" "+m.getLength()+" "+m.getNumLines()+")";
        }
        static String message(Message m) { return m.toString(); }
        static String date(Date d) { return "\""+d.toString()+"\""; }
        static String envelope(Message m) {
            return
                "(" + quotify(m.arrival.toString()) +
                " " + quotify(m.subject) +          
                " " + addressList(m.from) +      
                " " + addressList(m.headers.get("sender")) +
                " " + addressList(m.replyto) + 
                " " + addressList(m.to) + 
                " " + addressList(m.cc) + 
                " " + addressList(m.bcc) + 
                " " + quotify((String)m.headers.get("in-reply-to")) +
                " " + quotify(m.messageid) +
                ")";
        }
        
        // FIXME: ugly
        public static String qq(Stream stream) {
            StringBuffer sb = new StringBuffer();
            stream.transcribe(sb);
            return qq(sb.toString());
        }
        public static String qq(String s) {
            StringBuffer ret = new StringBuffer();
            ret.append('{');
            ret.append(s.getBytes().length);
            ret.append('}');
            ret.append('\r');
            ret.append('\n');
            ret.append(s);
            return ret.toString();
        }
        
        private static String join(int[] nums) {
            StringBuffer ret = new StringBuffer();
            for(int i=0; i<nums.length; i++) {
                ret.append(nums[i]);
                if (i<nums.length-1) ret.append(' ');
            }
            return ret.toString();
        }
        private static String join(String delimit, Object[] stuff) {
            StringBuffer ret = new StringBuffer();
            for(int i=0; i<stuff.length; i++) {
                ret.append(stuff[i]);
                if (i<stuff.length - 1) ret.append(delimit);
            }
            return ret.toString();
        }
        }


    // Main //////////////////////////////////////////////////////////////////////////////

    public static final int
        PEEK=0x1, BODYSTRUCTURE=0x2, ENVELOPE=0x4, FLAGS=0x8, INTERNALDATE=0x10, FIELDS=0x800, FIELDSNOT=0x1000,
        RFC822=0x20, RFC822TEXT=0x40, RFC822SIZE=0x80, HEADERNOT=0x100, UID=0x200, HEADER=0x400;
}