{ config, lib, pkgs, ... }:
with lib;
let cfg = config.services.joann-pupper-bot; in {
  options.services.joann-pupper-bot = {
    enable = mkEnableOption "Joann's Pupper Bot";
    user = mkOption {
      type = types.str;
      default = "joann-pupper-bot";
      example = "myuser";
      description = "Which user should be running Joann's Pupper Bot";
    };
    group = mkOption {
      type = types.str;
      default = "joann-pupper-bot";
      example = "mygroup";
      description = "Which group should be running Joann's Pupper Bot";
    };
    stateDir = mkOption {
      type = types.str;
      default = "/var/lib/joann-pupper-bot";
      description = "Which directory the bot should use for storage";
    };
    config.token = mkOption {
      type = types.str;
      description = "Bot token used for Telegram";
    };
    config.subreddits = mkOption {
      type = types.listOf types.str;
      description = "Which subreddits to draw images from";
      default = ["rarepuppers"];
    };
    config.sendCron = mkOption {
      type = types.str;
      description = "cron-style string determining when images should be sent";
      default = "*/30 8-21 * * *";
    };
    config.refreshCron = mkOption {
      type = types.str;
      description = "cron-style string determining when the bot polls Reddit for new images";
      default = "*/15 * * * *";
    };
    config.recipients = mkOption {
      type = types.listOf types.int;
      description = "Telegram chat IDs for each of the image recipients";
    };
  };

  config = mkIf cfg.enable {
    systemd.tmpfiles.rules = [
      "d '${cfg.stateDir}' 0750 ${cfg.user} ${cfg.group} - -"
    ];
    systemd.services.joann-pupper-bot = {
      description = "Joann's Pupper Bot";
      wantedBy = [ "multi-user.target" ];

      preStart =
        let
          yml = generators.toYAML {} cfg.config;
          configFile = pkgs.writeText "config.yaml" yml;
        in
        ''
          cp -f '${configFile}' '${cfg.stateDir}'/config.yaml
        '';

      serviceConfig = {
	Type = "oneshot";
        ExecStart = "/bin/sh -c :";
      };
    };
  };
}