nixos-config/modules/restic.nix

{ pkgs, config, lib, options, ... }:
let
  cfg = config.sbruder.restic;

  name = "${config.networking.hostName}-system";
  excludes = [
    # General
    "/home/*/Downloads/"
    "/home/*/.cache/"
    "/home/*/**/cache/"
    "/home/*/.claws-mail/imapcache"
    "/home/*/.local/share/Trash"
    "/home/*/.local/share/nvim/"

    # Rust
    "/home/*/**/target/debug/"
    "/home/*/**/target/doc/"
    "/home/*/**/target/release/"
    "/home/*/**/target/rls/"
    "/home/*/**/target/tarpaulin/"
    "/home/*/**/target/wasm32-unknown-unknown/"
    "/home/*/.rustup/toolchains/"
    "/home/*/.cargo"

    # Python
    "/home/*/.local/share/pyppeteer"
    "/home/*/.local/share/virtualenvs/"
    "/home/*/.platformio/"

    # Node
    "/home/*/**/.local-chromium"

    # Project related
    "/home/*/mount"
    "/home/*/projects/vapoursynth/data/"
    "/home/*/projects/vapoursynth/out/"
    "/home/*/projects/vapoursynth/src/"

    # Docker
    "/var/lib/docker/"

    # Stuff I do not want to back up
    "/data/cache/"
  ];
  excludesFile = pkgs.writeText "exludes.txt" (builtins.concatStringsSep "\n" excludes);
  maybePath = path: (lib.optional (builtins.pathExists path) (toString path));
in
{
  options.sbruder.restic = {
    enable = lib.mkEnableOption "restic";
    timerConfig =
      lib.recursiveUpdate
        (
          (builtins.elemAt
            (builtins.elemAt
              options.services.restic.backups.type.getSubModules
              0
            ).imports
            0)
            { name = ""; }
        ).options.timerConfig
        {
          default = {
            OnCalendar = "20:00";
            RandomizedDelaySec = "2h";
          };
        };
  };

  config = lib.mkIf cfg.enable {
    services.restic.backups."${name}" = {
      passwordFile = toString <secrets/restic-password>;
      s3CredentialsFile = toString <secrets/restic-s3>;
      repository = "s3:https://s3.eu-central-1.wasabisys.com/sbruder-restic";
      paths = lib.mkDefault (
        [ ]
        ++ maybePath /data
        ++ maybePath /home
        ++ maybePath /srv
        ++ maybePath /var
      );
      initialize = true;
      extraBackupArgs = [
        "--exclude-caches"
        "--exclude-file=${excludesFile}"
        "--verbose"
      ];
      timerConfig = cfg.timerConfig;
    };

    systemd.services."restic-backups-${name}".serviceConfig = {
      "Nice" = 10;
      "IOSchedulingClass" = "best-effort";
      "IOSchedulingPriority" = 7;
    };
  };
}