niveum/modules/telegram-bot.nix

{
  lib,
  config,
  pkgs,
  ...
}:
with lib; let
  cfg = config.niveum.telegramBots;

  botService = name: bot:
    nameValuePair "telegram-bot-${name}" {
      enable = bot.enable;
      startAt = bot.time;
      serviceConfig.Type = "oneshot";
      wants = ["network-online.target"];
      script = strings.concatStringsSep "\n" (["QUOTE=$(${bot.command})" "if [ -n \"$QUOTE\" ]; then"]
      ++ map (chatId: ''
        ${pkgs.curl}/bin/curl -s -X POST "https://api.telegram.org/bot${bot.token}/sendMessage" \
          -d chat_id="${chatId}" \
          -d text="$QUOTE" ${
          lib.strings.optionalString (bot.parseMode != null)
          "-d parse_mode=${bot.parseMode}"
        }
      '')
      bot.chatIds
      ++ ["fi"]);
    };
in {
  options.niveum.telegramBots = mkOption {
    type = types.attrsOf (types.submodule {
      options = {
        enable = mkEnableOption "Telegram bot";
        time = mkOption {type = types.str;};
        token = mkOption {type = types.strMatching "[0-9A-Za-z:-]+";};
        chatIds = mkOption {
          type = types.listOf (types.strMatching "-?[0-9]+|@[A-Za-z0-9]+");
        };
        command = mkOption {type = types.str;};
        parseMode = mkOption {
          type = types.nullOr (types.enum ["HTML" "Markdown"]);
          default = null;
        };
      };
    });
    default = {};
  };

  config = {systemd.services = attrsets.mapAttrs' botService cfg;};
}