add shift worker names constraint

rota/shifts.py

@@ -252,6 +252,7 @@ class RotaBuilder(object):
             "avoid_st2_first_month": False,
             "hard_constrain_pair_separation": False,
             "avoid_shifts_by_grades": [],
+            "avoid_shifts_by_worker_names": [],
         }
 
         self.results = None
@@ -1175,6 +1176,7 @@ class RotaBuilder(object):
                     )
 
         # Most of our constraints apply per worker
+        worker: Worker
         for worker in self.workers:
             console.rule(
                 f"Generate worker constraints: [bold blue]{worker.name}[/bold blue]"
@@ -1209,6 +1211,28 @@ class RotaBuilder(object):
                     )
                     pass
 
+            for constraint_dict in self.constraint_options["avoid_shifts_by_worker_names"]:
+                if invalid_shifts := set(constraint_dict["shifts"]).difference(
+                    set(self.get_shift_names())
+                ):
+                    if self.ignore_valid_shifts:
+                        continue  # Skip if we don't want to raise an error
+                    else:
+                        raise InvalidShift(
+                            f"avoid shifts by grade constraint contains a non existent shift: {invalid_shifts}"
+                        )
+
+                if worker.name in constraint_dict["names"]:
+                    self.model.constraints.add(
+                        0
+                        == sum(
+                            self.model.works[worker.id, week, day, shift]
+                            for week, day, shift in self.get_all_shiftname_combinations()
+                            if week in constraint_dict["weeks"]
+                            and shift in constraint_dict["shifts"]
+                        )
+                    )
+
             for constraint_dict in self.constraint_options["avoid_shifts_by_grades"]:
                 if invalid_shifts := set(constraint_dict["shifts"]).difference(
                     set(self.get_shift_names())
@@ -2522,6 +2546,13 @@ class RotaBuilder(object):
         for p in pairs:
             self.worker_pairs.append(tuple(pairs[p]))
 
+    def add_worker_name_constraint_by_week(
+        self, names: Iterable[str], weeks: Iterable[int], shifts
+    ):
+        self.constraint_options["avoid_shifts_by_worker_names"].append(
+            {"names": names, "weeks": weeks, "shifts": shifts}
+        )
+
     def add_grade_constraint_by_week(
         self, grades: Iterable[int], weeks: Iterable[int], shifts
     ):