!7

srecord HCRUD_TextArea(S field, int cols, int rows) {}

sclass HCRUD_Data {
  //LS fields() { null; }
  L<Map<S, O>> list() { null; }
  S fieldNameToHTML(S name) { ret htmlencode(humanizeLabel(name)); }
  S idField() { ret "id"; }
  Map<S, O> emptyObject() { null; }
  
  // return ID
  O createObject(SS map) { throw unimplemented(); }
  
  // return msg
  S deleteObject(S id) { throw unimplemented(); }
}

sclass HCRUD {
  HCRUD_Data data;
  S baseLink;
  
  S newLink() { ret appendQueryToURL(baseLink, cmd := "new"); }
  S deleteLink(O id) { ret appendQueryToURL(baseLink, "delete_" + id, 1); }
  
  // also handles commands if withCmds=true
  S render(bool withCmds, SS params) {
    if (!withCmds) ret renderTable(false);
    
    try answer handleCommands(params);
    
    ret pUnlessEmpty(params.get("msg"))
      + p(ahref(newLink(), "New entry"))
      + renderTable(withCmds);
  }
  
  S refreshWithMsgs(LS msgs) {
    ret hrefresh(appendQueryToURL(baseLink, msg := htmlEncode_nlToBr(lines_rtrim(msgs))));
  }

  S handleCommands(SS params) {
    new LS msgs;
    
    if (eqGet(params, "action", "create")) {
      O id = data.createObject(subMapStartingWith_dropPrefix(params, "f_"));
      msgs.add("Object created (ID: " + id + ")");
    }
    
    for (S toDelete : keysDeprefixNemptyValue(params, "delete_"))
      msgs.add(data.deleteObject(toDelete));

    ret nempty(msgs) ? refreshWithMsgs(msgs) : "";
  }
  
  S encodeField(S s) {
    ret or(data.fieldNameToHTML(s), s);
  }
  
  S renderTable(bool withCmds) {
    L<Map<S, O>> l = data.list();
    if (empty(l)) ret p("No entries");
    //LS fields = data.fields();
    //if (fields == null) fields = allKeysFromList_inOrder();
    l = map(l, map -> {
      Map<S, O> map2 = mapKeysAndValues(
        s -> encodeField(s),
        value -> htmlEncode2(strOrEmpty(value)),
        map);
      if (withCmds) {
        O id = map.get(data.idField());
        map2.put("<!-- cmds -->", ahrefWithConfirm(
          "Really delete item " + id + "?",
          deleteLink(id), "delete"));
      }
      ret map2;
    });
    ret htmlTable2_noHtmlEncode(l);
  }
  
  S renderNewForm() {
    Map<S, O> map = data.emptyObject();
    ret hpostform(
      hhidden("action", "create") +
      htableRaw_valignTop(
        map(map, (field, value) -> ll(
          encodeField(field),
          htextfield("f_" + field, strOrEmpty(value))
        ))
      , border := 1)
      + p(hsubmit("Create")),
      action := baseLink);
  }
}

concept Car {
  S brand, model;
}

p { db(); }

html {
  new HCRUD crud;
  crud.baseLink = appendSlash(rawLink());
  crud.data = new HCRUD_Data {
    //LS fields() { ret conceptFields(Car); }
    L<Map<S, O>> list() { ret (L) conceptsToMaps_gen(main list(Car)); }
    Map<S, O> emptyObject() { ret mapWithoutKey(conceptToMap_gen_withNullValues(unlisted(Car)), idField()); }
    
    O createObject(SS map) {
      ret cnew(Car, mapToParams(map)).id;
    }
    
    S deleteObject(S id) {
      Concept c = getConcept(Car, parseLong(id));
      if (c == null) ret "Object not found";
      deleteConcept(c);
      ret "Object deleted";
    }
  };
  if (eqGet(params, "cmd", "new"))
    ret h1_title("New car") + crud.renderNewForm();
  ret h1_title("Cars") + crud.render(true, params);
}