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

let
  hostname = config.networking.hostName or (builtins.getEnv "HOSTNAME");
  backupTarget = "/mnt/backup/borg"; # Adjust this path to your remote or local backup repo
  backupRepo = "${backupTarget}/${hostname}";
  backupPaths = {
    "t440p" = [ "Documents" "Projects" ];
    "steamdeck" = [ ".config" ];
    "xaorus" = [ "Pictures" "Videos" ];
  };
  folders = builtins.map (dir: "${config.home.homeDirectory}/${dir}") (backupPaths.${hostname} or []);
  cfg = config.homeModules.backup;
in

lib.mkIf cfg.enable {
  home.packages = with pkgs; [ borgbackup ];

  systemd.user.services.borg-backup = {
    Unit = {
      Description = "Borg Backup for ${hostname}";
      Wants = [ "network-online.target" ];
      After = [ "network-online.target" ];
    };

    Service = {
      Type = "oneshot";
      ExecStart = ''
        ${pkgs.borgbackup}/bin/borg create \
          --verbose \
          --filter AME \
          --list \
          --stats \
          --show-rc \
          --compression lz20 \
          ${backupRepo}::"{now:%Y-%m-%d_%H-%M}" \
          ${builtins.concatStringsSep " \\\n  " folders} \
          --exclude ${config.home.homeDirectory}/.cache \
          --exclude ${config.home.homeDirectory}/Downloads \
          --exclude ${config.home.homeDirectory}/node_modules \
          --exclude '*/.git' \
          --exclude '*/venv' \
          --exclude '*/target'
      '';
      ExecStopPost = ''
        ${pkgs.borgbackup}/bin/borg prune -v --list ${backupRepo} \
          --keep-daily=7 \
          --keep-weekly=4 \
          --keep-monthly=3
      '';
    };

    Install = {
      WantedBy = [ "default.target" ];
    };
  };

  # Optional: allow the backup location to be automounted
  xdg.userDirs.extraConfig = {
    XDG_BACKUP_DIR = "${backupTarget}";
  };

  # Optional: set environment variable to simplify CLI usage
  home.sessionVariables = {
    BORG_REPO = backupRepo;
    BORG_PASSPHRASE = ""; # or use environment.d or a secrets mechanism
  };
}