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
     ):

test/rota_constraints/test_avoid_workers_by_week.py

@@ -0,0 +1,196 @@
+import datetime
+import pytest
+from rota.shifts import InvalidShift, NoWorkers, RotaBuilder, SingleShift, days
+
+from rota.workers import Worker
+
+import itertools
+
+
+def generate_basic_rota(weeks_to_rota=9):
+    start_date = datetime.date(2022, 3, 7)
+
+    Rota = RotaBuilder(
+        start_date,
+        weeks_to_rota=weeks_to_rota,
+    )
+
+    # Add a few workers
+    Rota.add_workers(
+        [
+            Worker(name="worker1", site="group1", grade=1),
+            Worker(name="worker2", site="group1", grade=2),
+            Worker(name="worker3", site="group1", grade=3),
+        ]
+    )
+
+    return Rota
+
+
+def date_generator(from_date, days):
+    n = 0
+    while True:
+        yield from_date
+
+        n = n + 1
+        if n >= days:
+            break
+        from_date = from_date + datetime.timedelta(days=1)
+
+
+class TestWorkerRequests:
+    def test_avoid_worker_constraint(self):
+        Rota = generate_basic_rota()
+
+
+        Rota.add_shifts(
+            SingleShift(
+                sites=("group1",), name="a", length= 12.5, days=days,
+                workers_required=2,
+                force_as_block=False,
+            ),
+        )
+
+        Rota.add_worker_name_constraint_by_week(["worker1"], [1,2,3], ["a"])
+        Rota.add_worker_name_constraint_by_week(["worker2"], [4,5,6], ["a"])
+        Rota.add_worker_name_constraint_by_week(["worker3"], [7,8,9], ["a"])
+
+        Rota.build_and_solve(options={"ratio": 0.000})
+        Rota.export_rota_to_html("avoid_grade_constraint")
+
+        shift_summary = Rota.get_shift_summary_dict()
+        for worker_name in shift_summary:
+            worker_shifts = shift_summary[worker_name]
+
+            worker = Rota.get_worker_by_name(worker_name)
+
+            shift_string = Rota.get_worker_shift_list_string(worker)
+
+            match worker_name:
+                case "worker1":
+                    assert shift_string.startswith("-"*21)
+                case "worker2":
+                    assert shift_string.startswith(21*"a"+"-"*21)
+                case "worker3":
+                    assert shift_string.endswith("-"*21)
+
+
+    def test_avoid_worker_constraint_invalid_shift(self):
+        Rota = generate_basic_rota()
+
+        Rota.add_shifts(
+            SingleShift(
+                sites=("group1",), name="a", length= 12.5, days=days,
+                workers_required=1,
+                force_as_block=False,
+            ),
+        )
+        with pytest.raises(InvalidShift):
+
+            Rota.add_worker_name_constraint_by_week(["worker1"], [1,2,3], ["b"])
+            Rota.build_and_solve(options={"ratio": 0.000})
+
+
+        Rota.add_shifts(
+            SingleShift(
+                sites=("group1",), name="b", length= 12.5, days=days,
+                workers_required=1,
+                force_as_block=False,
+            ),
+        )
+
+        Rota.add_worker_name_constraint_by_week([1], [1,2,3], ["b"])
+        Rota.build_and_solve(options={"ratio": 0.000})
+        assert Rota.results.solver.status == "ok"
+
+
+# TODO: implement check for invalid workers
+##    def test_avoid_grade_constraint_invalid_worker(self):
+##        Rota = generate_basic_rota()
+##
+##        Rota.add_shifts(
+##            SingleShift(
+##                sites=("group1",), name="a", length= 12.5, days=days,
+##                workers_required=2,
+##                force_as_block=False,
+##            ),
+##        )
+##        with pytest.raises(ValueError):
+##
+##            Rota.add_worker_name_constraint_by_week([4], [1,2,3], ["a"])
+##            Rota.build_and_solve(options={"ratio": 0.000})
+##
+##        Rota.add_worker(
+##                Worker(name="worker4", site="group1", grade=4),
+##        )
+##
+##
+##        Rota.add_worker_name_constraint_by_week([4], [1,2,3], ["a"])
+##        Rota.build_and_solve(options={"ratio": 0.000})
+##        assert Rota.results.solver.status == "ok"
+
+    def test_avoid_worker_constraint_multiple_workers(self):
+        Rota = generate_basic_rota()
+
+        Rota.add_shifts(
+            SingleShift(
+                sites=("group1",), name="a", length= 12.5, days=days,
+                workers_required=1,
+                force_as_block=False,
+            ),
+        )
+
+        Rota.add_worker_name_constraint_by_week(["worker1", "worker2"], [1,2,3], ["a"])
+        Rota.build_and_solve(options={"ratio": 0.000})
+        assert Rota.results.solver.status == "ok"
+
+        Rota.add_worker_name_constraint_by_week(["worker3"], [1,2,3], ["a"])
+        Rota.build_and_solve(options={"ratio": 0.000})
+        assert Rota.results.solver.status == "warning"
+
+    def test_avoid_worker_constraint_multiple_shifts(self):
+        Rota = generate_basic_rota()
+
+        Rota.add_shifts(
+            SingleShift(
+                sites=("group1",), name="a", length= 12.5, days=days,
+                workers_required=1,
+                force_as_block=False,
+            ),
+            SingleShift(
+                sites=("group1",), name="b", length= 12.5, days=days,
+                workers_required=1,
+                force_as_block=False,
+            ),
+        )
+
+        Rota.add_worker_name_constraint_by_week(["worker1"], [1,2,3], ["a", "b"])
+        Rota.add_worker_name_constraint_by_week(["worker2"], [4,5,6], ["a", "b"])
+        Rota.add_worker_name_constraint_by_week(["worker3"], [7,8,9], ["a", "b"])
+
+        Rota.build_and_solve(options={"ratio": 0.000})
+        Rota.export_rota_to_html("avoid_grade_constraint")
+
+        shift_summary = Rota.get_shift_summary_dict()
+        for worker_name in shift_summary:
+            worker_shifts = shift_summary[worker_name]
+
+            worker = Rota.get_worker_by_name(worker_name)
+
+            shift_string = Rota.get_worker_shift_list_string(worker)
+
+            match worker_name:
+                case "worker1":
+                    assert shift_string.startswith("-"*21)
+                case "worker2":
+                    assert "-"*21 in shift_string # hacky
+                case "worker3":
+                    assert shift_string.endswith("-"*21)
+
+        Rota.add_worker_name_constraint_by_week(["worker2"], [7,8,9], ["a"])
+        Rota.build_and_solve(options={"ratio": 0.000})
+        assert Rota.results.solver.status == "ok"
+
+        Rota.add_worker_name_constraint_by_week(["worker1"], [7,8,9], ["a"])
+        Rota.build_and_solve(options={"ratio": 0.000})
+        assert Rota.results.solver.status == "warning"