feat: implement sub-block handling for shifts and update constraints in RotaBuilder

test/test_nwds.py

@@ -163,7 +163,7 @@ def test_nwd_force_as_block_force_split():
     for worker in Rota.workers:
         shifts = Rota.get_worker_shift_list(worker)
         shifts_string = "".join([i if i != "" else "-" for i in shifts])
-        for week in weeks_from_list(shifts_string[7 * 5 :]):
+        for week in weeks_from_list(shifts_string[7 * 6 :]):
             assert week in ("-----ww", "dddddww")
         if worker.name == "worker1":
             assert shifts_string[: 7 * 5].count("ww-") == 4
@@ -213,4 +213,61 @@ def test_nwd_testing():
             if worker.name == "worker1":
                 assert week == "dddddww"
             else:
-                assert week == "-----ww"
+                assert week == "-----ww"
+
+
+def test_force_as_block_unless_nwd_with_subblocks():
+    # Test that a Fri/Sat/Sun shift can be split into Fri and Sat/Sun blocks
+    # if a worker does not work on Fridays.
+    Rota = setup_rota(weeks_to_rota=2)
+    start_date = Rota.start_date
+    
+    # worker1 does not work on Fridays (Fri is NWD)
+    worker1 = Worker(
+        name="worker1", site="group1", grade=1,
+        nwds=[{"day": "Fri", "start_date": start_date, "end_date": start_date + datetime.timedelta(weeks=2)}],
+    )
+    # worker2 works normally
+    worker2 = Worker(name="worker2", site="group1", grade=1)
+    
+    Rota.add_workers((worker1, worker2))
+    
+    # Fri/Sat/Sun shift, requiring 1 worker, forced as block unless NWD
+    # We specify sub-blocks: [["Fri"], ["Sat", "Sun"]]
+    Rota.add_shifts(
+        SingleShift(
+            sites=("group1",), name="weekend", length=12.5,
+            days=["Fri", "Sat", "Sun"],
+            workers_required=1,
+            force_as_block_unless_nwd=[["Fri"], ["Sat", "Sun"]],
+        ),
+    )
+    
+    # We remove no valid shifts warning
+    Rota.terminate_on_warning.remove("Worker/no valid shifts")
+    
+    Rota.build_and_solve()
+    assert Rota.results.solver.status == "ok"
+    
+    # Check assignments:
+    # Since worker1 has NWD on Friday:
+    # - worker1 cannot work Friday.
+    # - But worker1 can work Sat and Sun as a block!
+    # So on Saturday and Sunday, worker1 should be assigned.
+    # On Friday, worker2 should be assigned.
+    for week in Rota.weeks:
+        w1_fri = Rota.model.works[worker1.id, week, "Fri", "weekend"].value
+        w1_sat = Rota.model.works[worker1.id, week, "Sat", "weekend"].value
+        w1_sun = Rota.model.works[worker1.id, week, "Sun", "weekend"].value
+        
+        w2_fri = Rota.model.works[worker2.id, week, "Fri", "weekend"].value
+        w2_sat = Rota.model.works[worker2.id, week, "Sat", "weekend"].value
+        w2_sun = Rota.model.works[worker2.id, week, "Sun", "weekend"].value
+        
+        assert w1_fri == 0
+        
+        # Either worker1 works Sat/Sun and worker2 works Fri (split block)
+        # OR worker2 works Fri/Sat/Sun (full block) and worker1 works nothing
+        is_split = (w1_sat == 1 and w1_sun == 1 and w2_fri == 1 and w2_sat == 0 and w2_sun == 0)
+        is_full_w2 = (w1_sat == 0 and w1_sun == 0 and w2_fri == 1 and w2_sat == 1 and w2_sun == 1)
+        assert is_split or is_full_w2