{ config, pkgs, lib, ... }:

with lib;

let
  cfg = config.services.certspotter;

  script = pkgs.writeShellApplication {
    name = "certspotter-script";
    runtimeInputs = with pkgs; [ coreutils ];
    text = ''
      mkdir -p "''${LOGS_DIRECTORY}"
      env > $(mktemp -p "''${LOGS_DIRECTORY}" "$(date -Ins).XXXXXXXXXX.env)"
    '';
  };

  startOptions = cfg.extraOptions
                 ++ optionals (cfg.logs != null) ["-logs" cfg.logs]
                 ++ ["-watchlist" (pkgs.writeText "watchlist" (concatStringsSep "\n" cfg.watchList))
                     "-script" "${script}/bin/certspotter-script"
                    ];
in {
  options = {
    services.certspotter = {
      watchList = mkOption {
        type = types.listOf types.str;
        default = [];
      };

      logs = mkOption {
        type = types.nullOr types.str;
        default = null;
      };

      extraOptions = mkOption {
        type = types.listOf types.str;
        default = [ "-verbose" ];
      };

      package = mkPackageOption pkgs "certspotter" {};
    };
  };

  config = mkIf (cfg.watchList != []) {
    systemd.services.certspotter = {
      serviceConfig = {
        Type = "oneshot";
        ExecStartPre = "${pkgs.coreutils}/bin/rm -f $STATE_DIRECTORY/lock";
        ExecStart = "${cfg.package}/bin/certspotter -state_dir $STATE_DIRECTORY ${escapeShellArgs startOptions}";
        StateDirectory = "certspotter";
        LogsDirectory = "certspotter";
        DynamicUser = true;
      };
    };
  };
}