/* -*- Mode: java; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License.  You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * The Original Code is the Grendel mail/news client.
 *
 * The Initial Developer of the Original Code is Netscape Communications
 * Corporation.  Portions created by Netscape are Copyright (C) 1997
 * Netscape Communications Corporation.  All Rights Reserved.
 */


package grendel.storage;

import calypso.util.NetworkDate;

import calypso.util.Assert;
import calypso.util.ByteBuf;

import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.text.DateFormat;
import java.util.Date;
import java.util.Enumeration;
import java.util.NoSuchElementException;
import java.util.Vector;

import javax.activation.DataHandler;
import javax.mail.Address;
import javax.mail.Flags;
import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.MethodNotSupportedException;
import javax.mail.Multipart;
import javax.mail.event.MessageChangedEvent;
import javax.mail.IllegalWriteException;
import javax.mail.Part;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.InternetHeaders;


abstract class MessageBase extends MessageReadOnly implements MessageExtra {

  /* **********************************************************
     Class variables
     **********************************************************
   */


  /* Don't confuse these flags with the values used in X-Mozilla-Status
     headers: they occupy a different space, and range.  There is a
     difference between the in-memory format, and the storage format.
     This is partially because there are potentially in-memory flags
     that don't get saved to disk.

     Parsing of the X-Mozilla-Status header (and conversion to this form)
     happens in the BerkeleyMessage class.

     There can be up to 64 flag-bits (the in-memory flags.)
     There can only be up to 16 X-Mozilla-Status flags (the persistent flags.)
   */
  public static final long FLAG_READ              = 0x00000001;
  public static final long FLAG_REPLIED           = 0x00000002;
  public static final long FLAG_FORWARDED         = 0x00000004;
  public static final long FLAG_MARKED            = 0x00000008;
  public static final long FLAG_DELETED           = 0x00000010;
  public static final long FLAG_HAS_RE            = 0x00000020;  // Subject
  public static final long FLAG_SIGNED            = 0x00000040;  // S/MIME
  public static final long FLAG_ENCRYPTED         = 0x00000080;  // S/MIME
  public static final long FLAG_SMTP_AUTH         = 0x00000100;  // Gag
  public static final long FLAG_PARTIAL           = 0x00000200;  // POP3
  public static final long FLAG_QUEUED            = 0x00000400;  // Offline


  // The mapping between our internal flag bits and javamail's flag strings.
  // The editable entry defines whether this flag can be changed from the
  // outside.

  static class FlagMap {
    long flag;
    Flags.Flag builtin;
    String non_builtin;
    boolean editable;
    FlagMap(long f, String n, boolean e) {
      flag = f;
      non_builtin = n;
      editable = e;
    }
    FlagMap(long f, Flags.Flag n, boolean e) {
      flag = f;
      builtin = n;
      editable = e;
    }
  };
  static FlagMap[] FLAGDEFS = new FlagMap[11];
  static {
    int i = 0;
    FLAGDEFS[i++] = new FlagMap(FLAG_READ,       Flags.Flag.SEEN,     true);
    FLAGDEFS[i++] = new FlagMap(FLAG_REPLIED,    Flags.Flag.ANSWERED, true);
    FLAGDEFS[i++] = new FlagMap(FLAG_FORWARDED,  "Forwarded",         true);
    FLAGDEFS[i++] = new FlagMap(FLAG_MARKED,     "Marked",            true);
    FLAGDEFS[i++] = new FlagMap(FLAG_DELETED,    Flags.Flag.DELETED,  true);
    FLAGDEFS[i++] = new FlagMap(FLAG_HAS_RE,     "HasRe",             false);
    FLAGDEFS[i++] = new FlagMap(FLAG_SIGNED,     "Signed",            false);
    FLAGDEFS[i++] = new FlagMap(FLAG_ENCRYPTED,  "Encrypted",         false);
    FLAGDEFS[i++] = new FlagMap(FLAG_SMTP_AUTH,  "SmtpAuth",          false);
    FLAGDEFS[i++] = new FlagMap(FLAG_PARTIAL,    "Partial",           false);
    FLAGDEFS[i++] = new FlagMap(FLAG_QUEUED,     "Queued",            false);
    Assert.Assertion(i == FLAGDEFS.length);
  };

  // This bit, when set, means that some change has been made to the flags
  // which should be written out to the X-Mozilla-Status header in the
  // folder's disk file.  This is done so that we can lazily update the
  // file, rather than writing it every time the flags change.
  public static final long FLAG_DIRTY             = 0x00000800;


  /* Some string-constants in bytebuf form that we use for interrogating
     headers during parsing.
   */
  protected static final ByteBuf FROM             = new ByteBuf("from");
  protected static final ByteBuf TO               = new ByteBuf("to");
  protected static final ByteBuf CC               = new ByteBuf("cc");
  protected static final ByteBuf NEWSGROUPS       = new ByteBuf("newsgroups");
  protected static final ByteBuf DATE             = new ByteBuf("date");
  protected static final ByteBuf SUBJECT          = new ByteBuf("subject");
  protected static final ByteBuf MESSAGE_ID       = new ByteBuf("message-id");
  protected static final ByteBuf REFERENCES       = new ByteBuf("references");
  protected static final ByteBuf IN_REPLY_TO      = new ByteBuf("in-reply-to");

  /* For simplifiedDate() */
  private static Date       scratch_date          = new Date();
  private static DateFormat date_format           = null;


  /* ***********************************************************
     Instance variables -- add them sparingly, memory is scarce.
     ***********************************************************
   */
  long   flags;        // see `FLAG_READ', etc, above.
  long   sentDate;     // milliseconds since the Epoch.

  // These slots are ints but really represent ByteStrings: they are indexes
  // into a ByteStringTable.  It's quite likely that we could live with these
  // being of type `short' instead of `int'.  Should memory usage be a problem,
  // we should consider that.
  //
  int author_name;     // name (not address) of the From or Sender.
  int recipient_name;  // name of first To, or CC, or newsgroup.
  int subject;         // subject minus "Re:" (see `FLAG_HAS_RE').

  // These slots are as above, but represent MessageID objects instead of
  // ByteString objects.  These also could stand to be of type `short'.
  //
  int message_id;      // will never be -1 (meaning null).
  int references[];    // may be null; else length > 0.


  /* **********************************************************
     Methods
     **********************************************************
   */

  MessageBase(FolderBase f) {
    super();
    this.folder = f;
  }

  MessageBase(FolderBase f, InternetHeaders h) {
    this(f);
    initialize(f, h);
  }

  MessageBase(FolderBase f,
              long date,
              long flags,
              ByteBuf author,
              ByteBuf recipient,
              ByteBuf subj,
              ByteBuf id,
              ByteBuf refs[]) {
    this(f);
    ByteStringTable string_table = f.getStringTable();
    MessageIDTable id_table = f.getMessageIDTable();

    if (id == null || id.length() == 0) {
      // #### In previous versions, we did this by getting the MD5 hash
      // #### of the whole header block.  We should do that here too...
      if (id == null) id = new ByteBuf();
      id.append(grendel.util.MessageIDGenerator.generate("missing-id"));
    }

    this.folder = f;
    this.flags = flags;
    this.sentDate = date;
    this.author_name = string_table.intern(author);
    this.recipient_name = string_table.intern(recipient);
    this.subject = string_table.intern(subj);
    this.message_id = id_table.intern(id);

    if (refs == null || refs.length == 0)
      this.references = null;
    else {
      int L = refs.length;
      references = new int[L];
      for (int i = 0; i < L; i++)
        references[i] = id_table.intern(refs[i]);
    }
  }

  MessageBase(FolderBase f,
              long date,
              long flags,
              ByteBuf author,
              ByteBuf recipient,
              ByteBuf subj,
              MessageID id,
              MessageID refs[]) {
    this(f);
    ByteStringTable string_table = f.getStringTable();
    MessageIDTable id_table = f.getMessageIDTable();

    if (id != null) {
      this.message_id = id_table.intern(id);
    } else {
      // #### In previous versions, we did this by getting the MD5 hash
      // #### of the whole header block.  We should do that here too...
      ByteBuf b =
        new ByteBuf(grendel.util.MessageIDGenerator.generate("missing-id"));
      this.message_id = id_table.intern(b);
    }

    this.folder = f;
    this.flags = flags;
    this.sentDate = date;
    this.author_name = string_table.intern(author);
    this.recipient_name = string_table.intern(recipient);
    this.subject = string_table.intern(subj);

    if (refs == null || refs.length == 0)
      this.references = null;
    else {
      int L = refs.length;
      references = new int[L];
      for (int i = 0; i < L; i++)
        references[i] = id_table.intern(refs[i]);
    }
  }

  protected void initialize(Folder f, InternetHeaders h) {
    folder = f;
    FolderBase fb = (FolderBase) f;
    ByteStringTable string_table = fb.getStringTable();
    MessageIDTable id_table = fb.getMessageIDTable();
    String hh[];

    hh = h.getHeader("From");
    author_name = (hh == null || hh.length == 0 ? -1 :
                   string_table.intern(hh[0].trim()));

  // #### need an address parser here...
    recipient_name = -1;
/*
    hh = h.getHeader("To");
      // #### deal with multiple to fields
    recipient_name = (hh == null || hh.length == 0 ? -1 :
                     string_table.intern(hh[0].trim()));

    if (recipient == -1) {
      // #### deal with multiple cc fields
      hh = h.getHeader("CC");
      recipient_name = (hh == null || hh.length == 0 ? -1 :
                       string_table.intern(hh[0].trim()));
    }

    if (recipient == -1) {
      hh = h.getHeader("Newsgroups");
      recipient_name = (hh == null || hh.length == 0 ? -1 :
                       string_table.intern(hh[0].trim()));
    }
 */

    hh = h.getHeader("Subject");
    if (hh != null && hh.length != 0) {
      // Much of this code is duplicated in MessageExtraFactory.  Sigh. ###
      ByteBuf value = new ByteBuf(hh[0]);
      if (value.length() > 2 &&
          (value.byteAt(0) == 'r' || value.byteAt(0) == 'R') &&
          (value.byteAt(1) == 'e' || value.byteAt(1) == 'E')) {
        byte c = value.byteAt(2);
        if (c == ':') {
          value.remove(0, 3);   // Skip over "Re:"
          value.trim();         // Remove any whitespace after colon
          flags |= FLAG_HAS_RE; // yes, we found it.
        } else if (c == '[' || c == '(') {
          int i = 3;    // skip over "Re[" or "Re("

          // Skip forward over digits after the "[" or "(".
          int length = value.length();
          while (i < length &&
                 value.byteAt(i) >= '0' &&
                 value.byteAt(i) <= '9') {
            i++;
          }
          // Now ensure that the following thing is "]:" or "):"
          // Only if it is do we treat this all as a "Re"-ish thing.
          if (i < (length-1) &&
              (value.byteAt(i) == ']' ||
               value.byteAt(i) == ')') &&
              value.byteAt(i+1) == ':') {
            value.remove(0, i+2); // Skip the whole thing.
            value.trim();         // Remove any whitespace after colon
            flags |= FLAG_HAS_RE; // yes, we found it.
          }
        }
      }
      subject = string_table.intern(value);
    }

    hh = h.getHeader("Date");
    if (hh != null && hh.length != 0)
      sentDate = NetworkDate.parseLong(new ByteBuf(hh[0]), true);

    hh = h.getHeader("Message-ID");
    if (hh != null && hh.length != 0) {
      ByteBuf value = new ByteBuf(hh[0]);
      value.trim();
      int length = value.length();
      if (length > 0 &&
          value.byteAt(0) == '<' &&
          value.byteAt(length-1) == '>') {
        value.remove(length-1, length);
        value.remove(0, 1);
      }
      message_id = id_table.intern(value.trim());
    }

    // There must be a message ID on every message.
    if (message_id == -1) {
      // #### In previous versions, we did this by getting the MD5 hash
      // #### of the whole header block.  We should do that here too...
      String id = grendel.util.MessageIDGenerator.generate("missing-id");
      message_id = id_table.intern(new ByteBuf(id));
    }

    hh = h.getHeader("References");
    if (hh != null && hh.length != 0) {
      ByteBuf value = new ByteBuf(hh[0]);
      references = internReferences(id_table, value.trim());
    }

    // Only examine the In-Reply-To header if there is no References header.
    if (references == null) {

      hh = h.getHeader("In-Reply-To");
      if (hh != null && hh.length != 0) {
        ByteBuf value = new ByteBuf(hh[0]);
        references = internReferences(id_table, value.trim());
      }
    }
  }


  // Ported from akbar's "msg_intern_references", mailsum.c.
  protected int[] internReferences(MessageIDTable id_table, ByteBuf refs) {
    byte data[] = refs.toBytes();
    int length = refs.length();
    int s;
    int n_refs = 0;
    for (s=0 ; s<length ; s++) {
      if (data[s] == '>') {
        n_refs++;
      }
    }

    if (n_refs == 0)
      return null;

    int result[] = new int[n_refs];
    int start = 0;
    int cur = 0;

    s = 0;
    while (s < length) {

      // The old way was to skip over whitespace, then skip an optional "<".
      // The new way is to skip over everything up to and including "<".
      // This lets us deal better with In-Reply-To headers, in addition to
      // References headers: we can cope with
      //
      //     In-Reply-To: NAME's message of TIME <ID@HOST>
      //     In-Reply-To: article <ID@HOST> of TIME
      //     In-Reply-To: <ID@HOST>, from NAME <USER@HOST>
      //
      // In the latter case, we're going to fuck up and think that both
      // of them are IDs, but headers like appear to be extremely rare.
      // In a survey of 22,950 mail messages with In-Reply-To headers:
      //
      //     18,396  had at least one occurence of <>-bracketed text.
      //      4,554  had no <>-bracketed text at all (just names and dates.)
      //        714  contained one <>-bracketed addr-spec and no message IDs.
      //          4  contained multiple message IDs.
      //          1  contained one message ID and one <>-bracketed addr-spec.
      //
      // The most common forms of In-Reply-To seem to be
      //
      //        31%  NAME's message of TIME <ID@HOST>
      //        22%  <ID@HOST>
      //         9%  <ID@HOST> from NAME at "TIME"
      //         8%  USER's message of TIME <ID@HOST>
      //         7%  USER's message of TIME
      //         6%  Your message of "TIME"
      //        17%  hundreds of other variants (average 0.4% each?)
      //
      // jwz, 17 Sep 1997.
      //
      while (start < length && data[start] != '<')
        start++;

      // skip over consecutive "<" -- I've seen "<<ID@HOST>>".
      while (start < length && data[start] == '<')
        start++;

      s = start;
      while (s < length && data[s] != '>')
        s++;

      if (s > start &&
          s < length &&
          data[s] == '>') {
        result[cur++] = id_table.intern(data, start, s - start);
        start = s + 1;

        // skip over consecutive ">" -- I've seen "<<ID@HOST>>".
        while (start < length && data[start] == '>')
          start++;
      } else {
        s++;
      }
    }

    if (cur != n_refs) {
      // Whoops!  Something's funny about this line, and the number of
      // ">" characters didn't equal the number of IDs we extracted.
      // This will be an extremely rare situation, so when it happens,
      // just make a new array.
      if (cur == 0)
        result = null;
      else {
        int r2[] = new int[cur];
        System.arraycopy(result, 0, r2, 0, cur);
        result = r2;
      }
    }

    return result;
  }



  public Object getMessageID() {
    MessageIDTable id_table = ((FolderBase)folder).getMessageIDTable();
    return (MessageID) id_table.getObject(message_id);
  }

  public String getSubject() {
    String result = simplifiedSubject();
    if (subjectIsReply()) result = "Re: "  + result;
    return result;
  }

  public String getAuthor() {
    ByteStringTable string_table = ((FolderBase)folder).getStringTable();
    ByteString a = (ByteString)
      string_table.getObject(author_name);
    if (a == null) return "";
    else return a.toString();
  }

  public String getRecipient() {
    ByteStringTable string_table = ((FolderBase)folder).getStringTable();
    ByteString r = (ByteString) string_table.getObject(recipient_name);
    if (r == null) return "";
    else return r.toString();
  }

  public Object[] messageThreadReferences() {
    if (references == null) return null;
    int count = references.length;
    if (count == 0) return null;

    // Note: this conses.
    MessageIDTable id_table = ((FolderBase)folder).getMessageIDTable();
    Object result[] = new Object[count];
    for (int i = 0; i < result.length; i++)
      result[i] = id_table.getObject(references[i]);

    return result;
  }

  public long getSentDateAsLong() {
    return sentDate;
  }

  public Date getSentDate() {
    return new Date(sentDate);
  }

  public Date getReceivedDate() {
    // ### We don't currently remember this info.  Should we?
    return getSentDate();
  }


  public Folder getFolder() {
    return folder;
  }


  // #### Warning, this is untested -- the "javax.mail.Flags" class changed
  // around a bunch since the last time we tried to use this code, and I had
  // to beat on this.

  public Flags getFlags() {
    Flags result = new Flags();
    for (int i=0 ; i<FLAGDEFS.length ; i++) {
      if ((flags & FLAGDEFS[i].flag) != 0) {
        if (FLAGDEFS[i].builtin != null) {
          result.add(FLAGDEFS[i].builtin);
        } else {
          result.add(FLAGDEFS[i].non_builtin);
        }
      }
    }
    return result;
  }

  public boolean isSet(Flags.Flag flag) {
    for (int i=0; i < FLAGDEFS.length ; i++) {
      if (flag.equals(FLAGDEFS[i].builtin)) {
        return (flags & FLAGDEFS[i].flag) != 0;
      }
    }
    return false;
  }

  public boolean isSet(String flag) {
    for (int i=0; i < FLAGDEFS.length ; i++) {
      if (flag.equals(FLAGDEFS[i].non_builtin)) {
        return (flags & FLAGDEFS[i].flag) != 0;
      }
    }
    return false;
  }

  public void setFlags(Flags flag, boolean set) throws MessagingException {

    Flags.Flag[]  builtin_flags = flag.getSystemFlags();
    String [] non_builtin_flags = flag.getUserFlags();

   NEXT_BUILTIN:
    for (int i = 0; i < builtin_flags.length ; i++) {
      Flags.Flag name = builtin_flags[i];
      for (int j=0 ; j<FLAGDEFS.length ; j++) {
        if (FLAGDEFS[j].editable && name.equals(FLAGDEFS[j].builtin)) {
          setFlagBit(FLAGDEFS[j].flag, set);
          continue NEXT_BUILTIN;
        }
      }
      throw new IllegalWriteException("Can't change flag " + name +
                                      " on message " + this);
    }

   NEXT_NON_BUILTIN:
    for (int i = 0; i < non_builtin_flags.length ; i++) {
      String name = non_builtin_flags[i];
      for (int j=0 ; j<FLAGDEFS.length ; j++) {
        if (FLAGDEFS[j].editable && name.equals(FLAGDEFS[j].non_builtin)) {
          setFlagBit(FLAGDEFS[j].flag, set);
          continue NEXT_NON_BUILTIN;
        }
      }
      throw new IllegalWriteException("Can't change flag " + name +
                                      " on message " + this);
    }
  }

  protected synchronized void setFlagBit(long flag, boolean value) {
    long newflags = flags;
    if (value) {
      newflags |= flag;
    } else {
      newflags &= ~flag;
    }
    if (flags != newflags) {
      flags = newflags;
      ((FolderBase)folder).doNotifyMessageChangedListeners
        (MessageChangedEvent.FLAGS_CHANGED, this);
    }
  }


  // #### are these still part of the JavaMail spec? I don't see them in
  // http://www.javasoft.com/products/javamail/javadocs/javax/mail/Message.html

  public boolean isRead() {
    return ((flags & FLAG_READ) != 0);
  }
  public void setIsRead(boolean value) {
    setFlagBit(FLAG_READ, value);
  }

  public boolean isReplied() {
    return ((flags & FLAG_REPLIED) != 0);
  }
  public void setReplied(boolean value) {
    setFlagBit(FLAG_REPLIED, value);
  }

  public boolean isForwarded() {
    return ((flags & FLAG_FORWARDED) != 0);
  }
  public void setForwarded(boolean value) {
    setFlagBit(FLAG_FORWARDED, value);
  }

  public boolean isFlagged() {
    return ((flags & FLAG_MARKED) != 0);
  }
  public void setFlagged(boolean value) {
    setFlagBit(FLAG_MARKED, value);
  }

  public boolean isDeleted() {
    return ((flags & FLAG_DELETED) != 0);
  }
  public void setDeleted(boolean value) {
    setFlagBit(FLAG_DELETED, value);
  }

  public boolean isSigned() {
    return ((flags & FLAG_SIGNED) != 0);
  }
  public boolean isEncrypted() {
    return ((flags & FLAG_ENCRYPTED) != 0);
  }


  public boolean flagsAreDirty() {
    return ((flags & FLAG_DIRTY) != 0);
  }
  public void setFlagsDirty(boolean value) {
    setFlagBit(FLAG_DIRTY, value);
  }

  public void saveChanges() {
    // ### Should this actually do something?
  }

  public InputStream getRawText() throws IOException {
    return null;
  }

  public String simplifiedSubject() {
    ByteStringTable string_table = ((FolderBase)folder).getStringTable();
    ByteString s = (ByteString) string_table.getObject(subject);
    if (s == null) return "";
    else return s.toString();  // #### fix me
  }

  public boolean subjectIsReply() {
    return ((flags & FLAG_HAS_RE) != 0);
  }

  public String simplifiedDate() {
    return SimplifyADate(sentDate);
  }

  static String SimplifyADate(long ldate) {
    if (ldate <= 0) return "";

    synchronized(scratch_date) {
      if (date_format == null) {
        date_format = DateFormat.getDateTimeInstance();
      }
      scratch_date.setTime(ldate);

      /* #### This needs to be more clever.  I guess we should make our
         own subclass of DateFormat and put the cleverness there. */
      return date_format.format(scratch_date);
    }
  }

  public void putByteStream(OutputStream out) throws MessagingException {
    throw new MethodNotSupportedException("MessageBase.putByteStream");
  }


  public DataHandler getDataHandler() {
    return null;
  }

  public Object getContent() {
    return null;
  }


  /** Get the InternetHeaders object.  Someday, maybe we'll keep this around
    in a weak link or something.  But for now, we always recreate it.
    Subclasses might want to redefine just this, or they might want to
    redefine all the routines below that use this. */
  protected InternetHeaders getHeadersObj() throws MessagingException {
    return new InternetHeaders(getInputStreamWithHeaders());
  }

}