add calendar alarms

hosts/profiles/desktop/cal-alarms.nix

@@ -0,0 +1,65 @@
+{ pkgs, ... }:
+
+{
+  systemd.services.cal-alarms = {
+    serviceConfig.Type = "simple";
+    path = [
+      pkgs.libnotify
+      pkgs.dunstify
+      pkgs.khal
+    ];
+    startAt = "*08:00:00";
+    script = ''
+      #!/usr/bin/env bash
+
+      cache_file="${XDG_CACHE_HOME:-$HOME/.cache}/khal-events"
+      # events starting in the next TIMESPAN will trigger an alarm
+      timespan='60min'
+
+      # this is needed for cronjobs and Xorg
+      export DISPLAY=":0"
+      snooze_string='💤 Snooze all.'
+      dismiss_string='✅ Dismiss all.'
+      # only show events with ⏰ symbol (=has alarm set)
+      # remove arrows for all-day events to only have one notification
+      # remove ⏰ symbol because it is obvious
+      events="$(khal list --format \
+        '{cancelled}{start-style}{to-style}{end-style} {title}{description-separator}{description}{location}{repeat-symbol}{alarm-symbol}' \
+        now "${timespan}" \
+        | sed -ne '/⏰/ p' \
+        | sed -e 's/⏰//g' -e 's/\(↦\|↔\|⇥\)[^[:blank:]]*/all-day/g' \
+        | column -tl 3)"
+
+      # get events that are new compared to cache file
+      new_events="$(diff -NwU 0 "${cache_file}" - << EOF | sed -ne '/^\+[^+]/ p' \
+        | sed -ne 's/^\+\([[:print:]].*\)$/\1/p'
+      ${events}
+      EOF
+      )"
+
+      [ -z "${new_events}" ] && exit 0
+
+      action="$(dunstify --action="default,Dismiss" --action="snooze,Snooze" "${new_events}")"
+
+      case "${action}" in
+        "snooze")
+          ;;
+        "default")
+          printf '%s' "${events}" > "${cache_file}"
+          ;;
+        *)
+          printf '%s' "${events}" | grep -Fve "${input}" > "${cache_file}"
+          ;;
+      esac
+    '';
+    serviceConfig = {
+      User = "anish";
+      Environment = "DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus";
+    };
+  };
+  systemd.timers.cal-alarms = {
+    wantedBy = [ "timers.target" ];
+    partOf = [ "cal-alarms.service" ];
+    timerConfig.OnCalendar = [ "*:0/10" ];
+  };
+}

hosts/profiles/desktop/default.nix

@@ -16,7 +16,10 @@ let
 in
 {
   # TODO modularize
-  imports = [ ./battery-low-timer.nix ];
+  imports = [
+    ./battery-low-timer.nix
+    ./cal-alarms.nix
+  ];
 
   # Secrets used by home-manager modules 
   age.secrets.fastmail.file = "${self}/secrets/fastmail.age";