os/modules/paperless/default.nix

{
  lib,
  config,
  pkgs,
  ...
}:
with lib; let
  psCfg = config.pub-solar;
  cfg = config.pub-solar.paperless;
  xdg = config.home-manager.users."${psCfg.user.name}".xdg;
in {
  options.pub-solar.paperless = {
    enable = mkEnableOption "All you need to go paperless";
    ocrLanguage = mkOption {
      description = "OCR language";
      type = types.str;
      example = "eng+deu";
      default = "eng";
    };
    consumptionDir = mkOption {
      description = "Directory to be watched";
      type = types.str;
      example = "/var/lib/paperless/consume";
      default = "/home/${psCfg.user.name}/Documents";
    };
    scannerDefaultDevice = mkOption {
      description = ''        The scanner device. To find this, use `scanimage -L`.

                For example, your output might be the following:

                ```
                device `v4l:/dev/video3' is a Noname Logitech StreamCam virtual device
                device `hp3900:libusb:005:002' is a Hewlett-Packard Scanjet G3010 flatbed scanner
                ```

                Here, the scannerDevice is `hp3900:libusb:005:002`.
      '';
      type = types.str;
    };
  };

  config = mkIf cfg.enable {
    services.paperless = {
      enable = true;
      user = psCfg.user.name;
      consumptionDir = cfg.consumptionDir;
      address = "paperless.local";
      extraConfig = {
        PAPERLESS_OCR_LANGUAGE = cfg.ocrLanguage;
        PAPERLESS_ADMIN_USER = psCfg.user.name;
        PAPERLESS_AUTO_LOGIN_USERNAME = psCfg.user.name;
        PAPERLESS_URL = "http://paperless.local";
      };
    };

    home-manager = pkgs.lib.setAttrByPath ["users" psCfg.user.name] {
      home.packages = with pkgs; [
        scan2paperless
      ];
      home.sessionVariables = {
        SCANNER_DEFAULT_DEVICE = cfg.scannerDefaultDevice;
        SCANNER_OUTPUT_DIR = cfg.consumptionDir;
      };
      systemd.user.sessionVariables = {
        SCANNER_DEFAULT_DEVICE = cfg.scannerDefaultDevice;
        SCANNER_OUTPUT_DIR = cfg.consumptionDir;
      };
    };
  };
}