"DELETE FROM chat WHERE msgid=%d;\n"
    "INSERT INTO chat(mtime, xfrom, mdel)"
    " VALUES(julianday('now'), %Q, %d);\n"
    "COMMIT;",
    mdel, g.zLogin, mdel
  );
}

/*
** WEBPAGE: chat-backup hidden
**
** Download an SQLite database containing all chat content with a
** message-id larger than the "msgid" query parameter.  Setup
** privilege is required to use this URL.
*/
void chat_backup_webpage(void){
  int msgid;
  unsigned char *pDb = 0;
  sqlite3_int64 szDb = 0;
  Blob chatDb;
  login_check_credentials();
  if( !g.perm.Setup ) return;
  msgid = atoi(PD("msgid","0"));
  db_multi_exec(
    "ATTACH ':memory:' AS mem1;\n"
    "PRAGMA mem1.page_size=512;\n"
    "CREATE TABLE mem1.chat AS SELECT * FROM repository.chat WHERE msgid>%d;\n",
    msgid
  );
  pDb = sqlite3_serialize(g.db, "mem1", &szDb, 0);
  if( pDb==0 ){
    fossil_fatal("Out of memory");
  }
  blob_init(&chatDb, (const char*)pDb, (int)szDb);
  cgi_set_content_type("application/x-sqlite3");
  cgi_set_content(&chatDb);
}

/*
** COMMAND: chat
**
** Usage: %fossil chat [SUBCOMMAND] [--remote URL] [ARGS...]
**
** This command performs actions associated with the /chat instance

**
**      When there is no SUBCOMMAND (when this command is simply "fossil chat")
**      the response is to bring up a web-browser window to the chatroom
**      on the default system web-browser.  You can accomplish the same by
**      typing the appropriate URL into the web-browser yourself.  This
**      command is merely a convenience for command-line oriented people.
**
** > fossil chat backup
**
**      Copy chat content from the server down into the local clone,
**      as a backup.  Setup privilege is required on the server.
**
**        --all                  Download all chat content. Normally only
**                               previously undownloaded content is retrieved.
**        --debug                Additional debugging output.
**        --out DATABASE         Store CHAT table in separate database file
**                               DATABASE rather that adding to local clone
**        --unsafe               Allow the use of unencrypted http://
**
** > fossil chat send [ARGUMENTS]
**
**      This command sends a new message to the chatroom.  The message
**      to be sent is determined by arguments as follows:
**
**        -f|--file FILENAME     File to attach to the message
**        --as FILENAME2         Causes --file FILENAME to be sent with

        fossil_print("ERROR: username and/or password is incorrect\n");
      }else{
        fossil_print("ERROR: %s\n", blob_str(&down));
      }
      fossil_fatal("unable to send the chat message");
    }
    blob_reset(&down);
  }else if( strcmp(g.argv[2],"backup")==0 ){
    /* Pull the CHAT table from the default server down into the repository
    ** here on the local side */
    int allowUnsafe = find_option("unsafe",0,0)!=0;
    int bDebug = find_option("debug",0,0)!=0;
    const char *zOut = find_option("out",0,1);
    int bAll = find_option("all",0,0)!=0;
    int mFlags = HTTP_GENERIC | HTTP_QUIET | HTTP_NOCOMPRESS;
    int msgid;
    Blob reqUri;    /* The REQUEST_URI:  .../chat-backup?msgid=... */
    char *zObs;
    const char *zPw;
    Blob up, down;
    int nChat;
    int rc;
    verify_all_options();
    chat_create_tables();
    msgid = bAll ? 0 : db_int(0,"SELECT max(msgid) FROM chat");
    if( !g.url.isHttps && !allowUnsafe ){
      fossil_fatal("URL \"%s\" is unencrypted. Use https:// instead", zUrl);
    }
    blob_init(&reqUri, g.url.path, -1);
    blob_appendf(&reqUri, "/chat-backup?msgid=%d", msgid);
    if( g.url.user && g.url.user[0] ){
      zObs = obscure(g.url.user);
      blob_appendf(&reqUri, "&resid=%t", zObs);
      fossil_free(zObs);
    }
    zPw = g.url.passwd;
    if( zPw==0 && isDefaultUrl ) zPw = unobscure(db_get("last-sync-pw", 0));
    if( zPw && zPw[0] ){
      zObs = obscure(zPw);
      blob_appendf(&reqUri, "&token=%t", zObs);
      fossil_free(zObs);
    }
    g.url.path = blob_str(&reqUri);
    if( bDebug ){
      fossil_print("REQUEST_URI: %s\n", g.url.path);
      mFlags &= ~HTTP_QUIET;
      mFlags |= HTTP_VERBOSE;
    }
    blob_init(&up, 0, 0);
    blob_init(&down, 0, 0);
    http_exchange(&up, &down, mFlags, 4, 0);
    if( zOut ){
      blob_write_to_file(&down, zOut);
      fossil_print("Chat database at %s is %d bytes\n", zOut, blob_size(&down));
    }else{
      db_multi_exec("ATTACH ':memory:' AS chatbu;");
      if( g.fSqlTrace ){
        fossil_trace("-- deserialize(\"chatbu\", pData, %d);\n",
                     blob_size(&down));
      }
      rc = sqlite3_deserialize(g.db, "chatbu",
                            (unsigned char*)blob_buffer(&down),
                             blob_size(&down), blob_size(&down), 0);
      if( rc ){
        fossil_fatal("cannot open patch database: %s", sqlite3_errmsg(g.db));
      }
      nChat = db_int(0, "SELECT count(*) FROM chatbu.chat");
      fossil_print("Got %d new records, %d bytes\n", nChat, blob_size(&down));
      db_multi_exec(
        "REPLACE INTO repository.chat SELECT * FROM chatbu.chat;"
      );
    }
  }else if( strcmp(g.argv[2],"url")==0 ){
    /* Show the URL to access chat. */
    fossil_print("%s/chat\n", zUrl);
  }else{
    fossil_fatal("no such subcommand \"%s\".  Use --help for help", g.argv[2]);
  }
}