fix(commands): remove the binding constraints that are related to the…

… area

antarest/study/storage/variantstudy/model/command/remove_area.py

@@ -38,11 +38,11 @@ def _remove_area_from_links_in_config(self, study_data_config: FileStudyTreeConf
             del study_data_config.areas[area_name].links[link]
 
     def _remove_area_from_sets_in_config(self, study_data_config: FileStudyTreeConfig) -> None:
-        for id, set in study_data_config.sets.items():
-            if set.areas and self.id in set.areas:
+        for id_, set_ in study_data_config.sets.items():
+            if set_.areas and self.id in set_.areas:
                 with contextlib.suppress(ValueError):
-                    set.areas.remove(self.id)
-                    study_data_config.sets[id] = set
+                    set_.areas.remove(self.id)
+                    study_data_config.sets[id_] = set_
 
     def _apply_config(self, study_data_config: FileStudyTreeConfig) -> Tuple[CommandOutput, Dict[str, Any]]:
         del study_data_config.areas[self.id]
@@ -78,21 +78,50 @@ def _remove_area_from_links(self, study_data: FileStudy) -> None:
                         )
 
     def _remove_area_from_binding_constraints(self, study_data: FileStudy) -> None:
-        binding_constraints = study_data.tree.get(["input", "bindingconstraints", "bindingconstraints"])
+        """
+        Remove the binding constraints that are related to the area.
 
-        id_to_remove = {bc_id for bc_id, bc in binding_constraints.items() for key in bc if self.id in key}
+        Notes:
+            A binding constraint has properties, a list of terms (which form a linear equation) and
+            a right-hand side (which is the matrix of the binding constraint).
+            The terms are of the form `area1%area2` or `area.cluster` where `area` is the ID of the area
+            and `cluster` is the ID of the cluster.
 
-        for bc_id in id_to_remove:
-            if study_data.config.version < 870:
-                study_data.tree.delete(["input", "bindingconstraints", binding_constraints[bc_id]["id"]])
-            else:
-                for name in ["lt", "gt", "eq"]:
-                    study_data.tree.delete(
-                        ["input", "bindingconstraints", f"{binding_constraints[bc_id]['id']}_{name}"]
-                    )
-            del binding_constraints[bc_id]
+            When an area is removed, it has an impact on the terms of the binding constraints.
+            At first, we could decide to remove the terms that are related to the area.
+            However, this would lead to a linear equation that is not valid anymore.
 
-        study_data.tree.save(binding_constraints, ["input", "bindingconstraints", "bindingconstraints"])
+            Instead, we decide to remove the binding constraints that are related to the area.
+        """
+        # noinspection SpellCheckingInspection
+        url = ["input", "bindingconstraints", "bindingconstraints"]
+        binding_constraints = study_data.tree.get(url)
+
+        # Collect the binding constraints that are related to the area to remove
+        # by searching the terms that contain the ID of the area.
+        bc_to_remove = {}
+        for bc_index, bc in list(binding_constraints.items()):
+            for key in bc:
+                # Term IDs are in the form `area1%area2` or `area.cluster`
+                if "%" in key:
+                    related_areas = key.split("%")
+                elif "." in key:
+                    related_areas = key.split(".")[:-1]
+                else:
+                    # This key belongs to the set of properties, it isn't a term ID, so we skip it
+                    continue
+                if self.id.lower() in related_areas:
+                    bc_to_remove[bc_index] = binding_constraints.pop(bc_index)
+                    break
+
+        matrix_suffixes = ["_lt", "_gt", "_eq"] if study_data.config.version >= 870 else [""]
+
+        for bc_index, bc in bc_to_remove.items():
+            for suffix in matrix_suffixes:
+                # noinspection SpellCheckingInspection
+                study_data.tree.delete(["input", "bindingconstraints", f"{bc['id']}{suffix}"])
+
+        study_data.tree.save(binding_constraints, url)
 
     def _remove_area_from_hydro_allocation(self, study_data: FileStudy) -> None:
         """