Add support for avoiding shifts on specific dates with reasons

rota_generator/shifts.py

@@ -4165,6 +4165,7 @@ class RotaBuilder(object):
         start_date: datetime.date | str | None = None,
         end_date: datetime.date | str | None = None,
         dates: Iterable[datetime.date] | None = None,
+        reason: str | None = None,
     ):
         """Add a rule preventing the given workers from being assigned the given shifts
         on the provided date range or explicit dates.
@@ -4190,7 +4191,7 @@ class RotaBuilder(object):
         sd = _coerce_date(start_date)
         ed = _coerce_date(end_date)
 
-        entry = {"names": list(names), "shifts": list(shifts), "start_date": sd, "end_date": ed, "dates": None}
+        entry = {"names": list(names), "shifts": list(shifts), "start_date": sd, "end_date": ed, "dates": None, "reason": reason}
         if dates is not None:
             entry["dates"] = [d if isinstance(d, datetime.date) else _coerce_date(d) for d in dates]
 
@@ -5104,6 +5105,49 @@ class RotaBuilder(object):
     ):
         model = self.model
 
+        # Build a lookup of per-worker/day avoid-shift rules (worker.id, week, day) -> {shifts: [...], reason: str}
+        avoid_lookup: dict[tuple, dict] = {}
+        try:
+            for entry in getattr(self.constraint_options_model, "avoid_shifts_by_worker_dates", []):
+                names = entry.get("names", []) or []
+                shifts = entry.get("shifts", []) or []
+                reason = entry.get("reason")
+                dates = entry.get("dates")
+                sd = entry.get("start_date")
+                ed = entry.get("end_date")
+
+                date_list = []
+                if dates:
+                    date_list = dates
+                elif sd is not None or ed is not None:
+                    try:
+                        for d in self.get_date_range(sd, ed):
+                            date_list.append(d)
+                    except Exception:
+                        # fall back to trying to iterate
+                        pass
+
+                for name in names:
+                    matching_workers = [w for w in self.workers if w.name.strip() == name.strip()]
+                    if not matching_workers:
+                        continue
+                    wid = matching_workers[0].id
+                    for d in date_list:
+                        try:
+                            wk, day = self.get_week_day_by_date(d)
+                        except Exception:
+                            continue
+                        key = (wid, wk, day)
+                        existing = avoid_lookup.get(key, {"shifts": [], "reason": None})
+                        existing["shifts"].extend(shifts)
+                        # preserve reason if provided
+                        if reason:
+                            existing["reason"] = reason
+                        avoid_lookup[key] = existing
+        except Exception:
+            # If constraint options not present or parsing fails, continue without avoid info
+            avoid_lookup = {}
+
         timetable = []
 
         if self.run_start_time is not None and self.run_end_time is not None:
@@ -5252,6 +5296,16 @@ class RotaBuilder(object):
                 if locum:
                     css_class = " ".join((css_class, "locum-shift"))
 
+                # Add visual marker/data if this day/worker has avoid-shift rules
+                avoid_info = avoid_lookup.get((worker.id, week, day))
+                avoid_attr = ""
+                if avoid_info is not None:
+                    # mark the cell as having avoids; include which shifts and the reason
+                    avoid_shifts = ",".join(avoid_info.get("shifts", []))
+                    avoid_reason = avoid_info.get("reason") or ""
+                    css_class = " ".join((css_class, "avoid-shift"))
+                    avoid_attr = f" data-avoid-shifts='{avoid_shifts}' data-avoid-reason='{avoid_reason}'"
+
                 remote_site = ""
                 if shift_name:
                     shift = self.get_shift_by_name(shift_name)
@@ -5267,7 +5321,7 @@ class RotaBuilder(object):
                     f" data-available='{available}'"
                     f" data-unavailable_reason='{unavailable_reason}'"
                     f" data-date='{d}' data-week='{week}' data-day='{day}'"
-                    f"{remote_site}{requests}{bank_holiday}>{shift_display_char}</td>"
+                    f"{remote_site}{requests}{bank_holiday}{avoid_attr}>{shift_display_char}</td>"
                 )
 
             shift_count = ""

rota_generator/workers.py

@@ -117,6 +117,7 @@ class AvoidShiftOnDates(BaseModel):
     start_date: Optional[datetime.date] = None
     end_date: Optional[datetime.date] = None
     dates: Optional[list[datetime.date]] = None
+    reason: Optional[str] = None
 
     @field_validator("start_date", "end_date", mode="before")
     def coerce_dates(cls, v):
@@ -428,6 +429,7 @@ class Worker(BaseModel):
                     "start_date": av.start_date,
                     "end_date": av.end_date,
                     "dates": av.dates,
+                    "reason": getattr(av, "reason", None),
                 }
                 # append to rota-level list; the model builder will enforce these
                 if hasattr(Rota.constraint_options_model, "avoid_shifts_by_worker_dates"):