nixos-config/home-manager/roles/vdirsyncer.nix

{ pkgs, lib, config, ... }:
let
  addressbooks = pkgs.privateValue [ ] "addressbooks";
  calendars = pkgs.privateValue [ ] "calendars";
  mkConfig = config:
    (pkgs.formats.ini { }).generate "vdirsyncer-config" (
      lib.mapAttrs
        (
          name: section:
            (lib.mapAttrs (name: option: builtins.toJSON option) section)
        )
        config
    );
  mkCalendar = { name, url, username, passwordPath, collections ? [ "from a" "from b" ], readOnly ? false, type ? "caldav" }:
    let
      pairName = "${name}_calendar";
      remoteName = "${pairName}_remote";
      localName = "${pairName}_local";
    in
    {
      "pair ${pairName}" = {
        a = localName;
        b = remoteName;
        inherit collections;
        conflict_resolution = "b wins";
        metadata = [ "color" ];
      };
      "storage ${localName}" = {
        type = "filesystem";
        path = "~/.calendars/${name}/";
        fileext = ".ics";
      };
      "storage ${remoteName}" = {
        inherit type;
        inherit url;
      } // (
        if (type == "caldav") then {
          inherit username;
          "password.fetch" = [ "command" "${pkgs.pass}/bin/pass" passwordPath ];
          read_only = readOnly;
        } else { }
      );
    };
  mkAddressbook = { name, url, username, passwordPath, collections ? [ "from a" "from b" ], readOnly ? false }:
    let
      pairName = "${name}_contacts";
      remoteName = "${pairName}_remote";
      localName = "${pairName}_local";
    in
    {
      "pair ${pairName}" = {
        a = localName;
        b = remoteName;
        inherit collections;
        conflict_resolution = "b wins";
      };
      "storage ${localName}" = {
        type = "filesystem";
        path = "~/.contacts/${name}/";
        fileext = ".vcf";
      };
      "storage ${remoteName}" = {
        type = "carddav";
        inherit url username;
        "password.fetch" = [ "command" "${pkgs.pass}/bin/pass" passwordPath ];
        read_only = readOnly;
      };
    };
in
{
  xdg.configFile."vdirsyncer/config".source = mkConfig
    (
      pkgs.lib.fold (a: b: a // b)
        {
          general.status_path = "~/.vdirsyncer/status";
        }
        (map mkCalendar calendars ++ map mkAddressbook addressbooks)
    );
  home.packages = [ pkgs.vdirsyncer ];

  systemd.user = {
    services.watch-vdir = {
      Unit.Description = "Watch vdir data for changes";
      Service = {
        ExecStart = toString (
          pkgs.writeShellScript "watch-vdir" ''
            while sleep 1s; do
              ${pkgs.vdirsyncer}/bin/vdirsyncer sync
              ${pkgs.inotify-tools}/bin/inotifywait -e move,create,delete,modify -r ${config.home.homeDirectory}/.contacts ${config.home.homeDirectory}/.calendars
            done
          ''
        );
      };
      Install.WantedBy = [ "default.target" ];
    };
    services.vdirsyncer = {
      Unit.Description = "vdirsyncer sync";
      Service = {
        Type = "oneshot";
        ExecStart = "${pkgs.vdirsyncer}/bin/vdirsyncer sync";
      };
    };
    timers.vdirsyncer = {
      Unit.Description = "vdirsync sync timer";
      Timer.OnCalendar = "*:0/15";
      Install.WantedBy = [ "timers.target" ];
    };
  };
}