}

/* Definition of repository tables used by chat
*/
static const char zChatSchema1[] =
@ CREATE TABLE repository.chat(
@   msgid INTEGER PRIMARY KEY AUTOINCREMENT,
@   mtime JULIANDAY,       -- Time for this entry - Julianday Zulu
@   xfrom TEXT,            -- Login of the sender
@   xmsg  TEXT,            -- Raw, unformatted text of the message
@   file  BLOB,            -- Text of the uploaded file, or NULL
@   fname TEXT,            -- Filename of the uploaded file, or NULL
@   fmime TEXT,            -- MIMEType of the upload file, or NULL
@   mdel INT               -- msgid of another message to delete
@ );
;


/*
** Make sure the repository data tables used by chat exist.  Create them
** if they do not.
*/
static void chat_create_tables(void){
  if( !db_table_exists("repository","chat") ){
    db_multi_exec(zChatSchema1/*works-like:""*/);
  }else if( !db_table_has_column("repository","chat","mdel") ){
    db_multi_exec("ALTER TABLE chat ADD COLUMN mdel INT");
  }
}

/*
** WEBPAGE: chat-send
**
** This page receives (via XHR) a new chat-message and/or a new file

** |           "mtime": text    // When sent:  YYYY-MM-DD HH:MM:SS UTC
** |           "xfrom": text    // Login name of sender
** |           "uclr":  text    // Color string associated with the user
** |           "xmsg":  text    // HTML text of the message
** |           "fsize": integer // file attachment size in bytes
** |           "fname": text    // Name of file attachment
** |           "fmime": text    // MIME-type of file attachment
** |           "mdel":  integer // message id of prior message to delete
** |        }
** |      ]
** |    }
**
** The "fname" and "fmime" fields are only present if "fsize" is greater
** than zero.  The "xmsg" field may be an empty string if "fsize" is zero.
**
** The "msgid" values will be in increasing order.
**
** The "mdel" will only exist if "xmsg" is an empty string and "fsize" is zero.
*/
void chat_poll_webpage(void){
  Blob json;                  /* The json to be constructed and returned */
  sqlite3_int64 dataVersion;  /* Data version.  Used for polling. */
  sqlite3_int64 newDataVers;
  int iDelay = 1000;          /* Delay until next poll (milliseconds) */
  const char *zSep = "{\"msgs\":[\n";   /* List separator */
  int msgid = atoi(PD("name","0"));
  Stmt q1;
  login_check_credentials();
  if( !g.perm.Chat ) return;
  chat_create_tables();
  cgi_set_content_type("text/json");
  dataVersion = db_int64(0, "PRAGMA data_version");
  db_prepare(&q1,
    "SELECT msgid, datetime(mtime), xfrom, xmsg, length(file),"
    "       fname, fmime, mdel"
    "  FROM chat"
    " WHERE msgid>%d"
    " ORDER BY msgid",
    msgid
  );
  blob_init(&json, 0, 0);
  while(1){
    int cnt = 0;
    while( db_step(&q1)==SQLITE_ROW ){
      int id = db_column_int(&q1, 0);
      const char *zDate = db_column_text(&q1, 1);
      const char *zFrom = db_column_text(&q1, 2);
      const char *zRawMsg = db_column_text(&q1, 3);
      int nByte = db_column_int(&q1, 4);
      const char *zFName = db_column_text(&q1, 5);
      const char *zFMime = db_column_text(&q1, 6);
      int iToDel = db_column_int(&q1, 7);
      char *zMsg;
      cnt++;
      blob_append(&json, zSep, -1);
      zSep = ",\n";
      blob_appendf(&json, "{\"msgid\":%d,\"mtime\":%!j,", id, zDate);
      blob_appendf(&json, "\"xfrom\":%!j,", zFrom);
      blob_appendf(&json, "\"uclr\":%!j,", hash_color(zFrom));

      /* TBD:  Convert the raw message into HTML, perhaps by running it
      ** through a text formatter, or putting markup on @name phrases,
      ** etc. */
      zMsg = mprintf("%h", zRawMsg ? zRawMsg : "");
      blob_appendf(&json, "\"xmsg\":%!j,", zMsg);
      fossil_free(zMsg);

      if( nByte==0 ){
        blob_appendf(&json, "\"fsize\":0");
      }else{
        blob_appendf(&json, "\"fsize\":%d,\"fname\":%!j,\"fmime\":%!j",
               nByte, zFName, zFMime);
      }
      if( iToDel ){
        blob_appendf(&json, ",\"mdel\":%d}", iToDel);
      }else{
        blob_append(&json, "}", 1);
      }
    }
    if( cnt ){
      blob_append(&json, "\n]}", 3);
      cgi_set_content(&json);
      break;
    }
    sqlite3_sleep(iDelay);

  blob_zero(&r);
  zMime = db_text(0, "SELECT fmime FROM chat wHERE msgid=%d", msgid);
  if( zMime==0 ) return;
  db_blob(&r, "SELECT file FROM chat WHERE msgid=%d", msgid);
  cgi_set_content_type(zMime);
  cgi_set_content(&r);
}


/*
** WEBPAGE: chat-delete
**
** Delete the chat entry identified by the name query parameter.
** Invoking fetch("chat-delete/"+msgid) from javascript in the client
** will delete a chat entry from the CHAT table.
**
** This routine both deletes the identified chat entry and also inserts
** a new entry with the current timestamp and with:
**
**   *  xmsg = NULL
**   *  file = NULL
**   *  mdel = The msgid of the row that was deleted
**
** This new entry will then be propagated to all listeners so that they
** will know to delete their copies of the message too.
*/
void chat_delete_webpage(void){
  int mdel;
  char *zOwner;
  login_check_credentials();
  if( !g.perm.Chat ) return;
  chat_create_tables();
  mdel = atoi(PD("name","0"));
  zOwner = db_text(0, "SELECT xfrom FROM chat WHERE msgid=%d", mdel);
  if( zOwner==0 ) return;
  if( fossil_strcmp(zOwner, g.zLogin)!=0 && !g.perm.Admin ) return;
  db_multi_exec(
    "BEGIN;\n"
    "DELETE FROM chat WHERE msgid=%d;\n"
    "INSERT INTO chat(mtime, xfrom, mdel)"
    " VALUES(julianday('now'), %Q, %d);\n"
    "COMMIT;",
    mdel, g.zLogin, mdel
  );
}