refactor of model targets and constraints, addition of new constraint types and constraint construction process

app/models/objective_function.py

@@ -2,10 +2,11 @@ from __future__ import annotations
 
 from pydantic import BaseModel
 from typing import Dict, List, AnyStr
+from pulp import lpSum
 
-from models.tif_target import TifTarget
-from models.tcc_target import TccTarget
-
+from models.targets.tif_target import TifTarget
+from models.targets.tcc_target import TccTarget
+from models.problem import Problem
 
 class ObjectiveFunction(BaseModel):
     # minimizing tif/tcc target value is only option currently
@@ -17,6 +18,15 @@ class ObjectiveFunction(BaseModel):
     objective: AnyStr = "minimize"
     weight: Dict = {'tif': 1, 'tcc': 1}
 
+    def for_problem(self, problem_handler: Problem) -> None:
+        problem_handler.problem += lpSum([
+            bundle.count * problem_handler.solver_bundles_var[bundle.id]
+            for bundle in problem_handler.bundles
+        ] + [
+            problem_handler.solver_items_var[item.id]
+            for item in problem_handler.items
+        ])
+
     def increment_targets_drift(self,
                                 limit: float or bool,
                                 all: bool = False,