feat(recurrence): add daily recurrence support

- Add `simple_daily` type and `daily` field to `rem`
- Implement `render_daily`, `add_interval_daily`, and `add_until_daily`
- Extend `simple_recurrence` collector to handle `FREQ=DAILY` alongside
  `FREQ=WEEKLY`
- Remove dead `expand_recurrence` collector
- Mark P06 pattern as implemented (✅)

bin/remind.ml

@@ -10,6 +10,13 @@ type simple_weekly = {
 }
 (** A simple weekly REM command *)
 
+type simple_daily = {
+  count_or_until : Icalendar.count_or_until option;
+  interval : int option;  (** Optional interval for daily recurrence, default is 1 *)
+  week_start : week_first_day option;  (** First day of the week for weekly recurrence *)
+}
+(** A simple daily REM command *)
+
 type rem = {
   source : string;  (** Source file or identifier for the reminder *)
   original_uuid : string;  (** Original UID from the iCalendar event *)
@@ -20,6 +27,7 @@ type rem = {
   duration : Timedesc.Span.t option;  (** Optional duration for timed events *)
   yearly : (int * int) option;  (** Optional simple yearly recurrence (month, day) *)
   weekly : simple_weekly option;  (** Optional simple weekly recurrence *)
+  daily : simple_daily option;  (** Optional simple daily recurrence *)
   recurring : Icalendar.event list;
       (** List of events that are part of the same recurring series: these are only the overrides, not the master event
       *)
@@ -38,6 +46,7 @@ let empty =
     duration = None;
     yearly = None;
     weekly = None;
+    daily = None;
     recurring = [];
     exdate = [];
   }
@@ -49,11 +58,15 @@ let add_info b uuid = Buffer.add_string b (spf "INFO \"UID: %s\" " uuid)
 let add_date b date = Buffer.add_string b (Timedesc.Date.to_rfc3339 date)
 let add_weekday b wd = Buffer.add_string b (spf "%s " (string_of_weekday wd))
 
-let add_interval b w =
+let add_interval b (w : simple_weekly) =
   let n = Option.value ~default:1 w.interval in
   Buffer.add_string b (spf "*%d " (n * 7))
 
-let add_until b rem w =
+let add_interval_daily b (d : simple_daily) =
+  let n = Option.value ~default:1 d.interval in
+  Buffer.add_string b (spf "*%d " n)
+
+let add_until b rem (w : simple_weekly) =
   match w.count_or_until with
   | None -> ()
   | Some (`Until d) ->
@@ -71,6 +84,17 @@ let add_until b rem w =
       let until = Timedesc.Date.add ~days:((count * 7 * iv) - sub) rem.date in
       Buffer.add_string b (spf "UNTIL %s " (Timedesc.Date.to_rfc3339 until))
 
+let add_until_daily b rem (d : simple_daily) =
+  match d.count_or_until with
+  | None -> ()
+  | Some (`Until dt) ->
+      let ts = timedesc_of_utc_or_timestamp_local dt in
+      Buffer.add_string b (spf "UNTIL %s " (Timedesc.Date.to_rfc3339 (Timedesc.date ts)))
+  | Some (`Count count) ->
+      let iv = Option.value ~default:1 d.interval in
+      let until = Timedesc.Date.add ~days:((count - 1) * iv) rem.date in
+      Buffer.add_string b (spf "UNTIL %s " (Timedesc.Date.to_rfc3339 until))
+
 let add_at b = function
   | Some t -> Buffer.add_string b (spf " AT %s" (string_of_time t))
   | None -> ()
@@ -87,7 +111,20 @@ let add_msg b summary = Buffer.add_string b (spf " MSG %s\n" summary)
 
 (* ── rendering ────────────────────────────────────────────────── *)
 
-let render_weekly rem w =
+let render_daily rem (d : simple_daily) =
+  let b = Buffer.create 256 in
+  add_rem b;
+  add_info b rem.original_uuid;
+  add_date b rem.date;
+  Buffer.add_char b ' ';
+  add_interval_daily b d;
+  add_until_daily b rem d;
+  add_at b rem.time;
+  add_duration b rem.duration;
+  add_msg b rem.summary;
+  Buffer.contents b
+
+let render_weekly rem (w : simple_weekly) =
   let b = Buffer.create 256 in
   List.iter
     (fun wd ->
@@ -125,9 +162,12 @@ let render_yearly month day summary =
 (* ── dispatcher ───────────────────────────────────────────────── *)
 
 let string_of_rem rem =
-  match rem.weekly with
-  | Some w -> render_weekly rem w
+  match rem.daily with
+  | Some d -> render_daily rem d
   | None -> (
-      match rem.yearly with
-      | Some (month, day) -> render_yearly month day rem.summary
-      | None -> render_single rem)
+      match rem.weekly with
+      | Some w -> render_weekly rem w
+      | None -> (
+          match rem.yearly with
+          | Some (month, day) -> render_yearly month day rem.summary
+          | None -> render_single rem))