persistable sclass Gazelle_GrabPostsLoop {
  S server = gazelle_server();
  S _user, _botToken;
  Set<S> fields = litset("_modified", "text");
  long changedAfter;
  double delay = 0.5;
  double errorDelay = 10;
  bool verbose, enabled = true;
  int pollFor = 600; // seconds for each poll
  bool firstGrab = true;
  
  !include #1028121 // setField + change()
  
  run {
    while licensed {
      pcall { if (enabled) grab(); }
      sleepSeconds(delay);
    }
  }
  
  void grab {
    O[] params = litobjectarray(+_user, +_botToken, fields := joinWithSpace(fields),
      +changedAfter, +pollFor);
    print(params := litorderedmap(params));
    Map _result = cast postJSONPage(server + "bot/listPosts",
      params);
    if (verbose) print(+_result);
    
    S error = cast _result.get("error");
    if (error != null) {
      print("Server ERROR: " + error);
      sleepSeconds(errorDelay);
      ret;
    }
    
    L<Map> posts = cast _result.get("result");
    print("Found " + n2(posts, "new post"));
  
      
    L<GazellePost> posts2 = map(posts, p -> GazellePost(p));
    for (GazellePost p : posts2)
      setField(changedAfter := max(changedAfter, p.modified));
      
    if (nempty(posts2))
      handlePosts(posts2);
    firstGrab = false;
  }
  
  swappable void handlePosts(Cl<GazellePost> posts) {
    for (GazellePost p : posts) pcall {
      handlePost(p);
    }
  }
  
  transient swappable void handlePost(GazellePost post) {
  }
  
  void reset { setField(changedAfter := 0L); }
  
  Cl<Long> allPostIDs() {
    Map _result = cast postJSONPage(server + "bot/listPosts",
      +_user, +_botToken);
    L<Map> posts = cast _result.get("result");
    ret allToLong(collect id(posts));
  }
}