actual solving, minus constraints for non tcc/tif constraints

app/services/loft_service.py

@@ -1,5 +1,7 @@
 import os, json, random, io, logging
 
+from pulp import *
+
 from helpers import aws_helper, tar_helper, csv_helper, service_helper, irt_helper
 
 from models.solver_run import SolverRun
@@ -37,20 +39,74 @@ class LoftService(Base):
     return attributes
 
   def generate_solution(self):
-    logging.info('Processing Solution...')
-    # temporary data for mocks
-    form_count = 10
-
-    # items will be generated from real solver process, this is for mock purposes
-    # real solver will return N forms and process a cut score, this is for mock purposes
-    return Solution(
-      response_id=random.randint(100,5000),
-      forms=[Form.create(random.sample(self.solver_run.items, self.solver_run.total_form_items), self.solver_run) for x in range(form_count)]
+    # unsolved solution
+    solution = Solution(
+      response_id=random.randint(100, 5000),
+      forms=[]
     )
 
+    # counter for number of forms
+    f = 0
+
+    # iterate for number of forms that require creation
+    # currently creates distinc forms with no item overlap
+    while f < self.solver_run.total_forms:
+      # setup vars
+      items = LpVariable.dicts(
+        "Item", [item.id for item in self.solver_run.items], lowBound=1, upBound=1, cat='Binary')
+      used = dict(zip([item.id for item in self.solver_run.items],
+                  [1 for item in self.solver_run.items]))
+      problem_objection_functions = []
+
+      # create problem
+      problem = LpProblem("ata-form-generate", LpMinimize)
+
+      # constraints
+      problem += lpSum([used[i]*items[i]
+                    for i in items]) == self.solver_run.total_form_items
+      
+      # multi-objective functions and constraints
+      for target in self.solver_run.objective_function.tif_targets:
+          tif = lpSum([item.iif(self.solver_run, target.theta)*items[item.id]
+                      for item in self.solver_run.items])
+          problem += lpSum([item.iif(self.solver_run, target.theta)*items[item.id]
+                          for item in self.solver_run.items]) <= target.value
+          problem_objection_functions.append(tif)
+
+      for target in self.solver_run.objective_function.tcc_targets:
+          tcc = lpSum([item.irf(self.solver_run, target.theta)*items[item.id]
+                      for item in self.solver_run.items])
+          problem += lpSum([item.irf(self.solver_run, target.theta)*items[item.id]
+                          for item in self.solver_run.items]) <= target.value
+          problem_objection_functions.append(tcc)
+      
+      # solve problem
+      problem.sequentialSolve(problem_objection_functions)
+
+      # add return items and create as a form
+      form_items = []
+      for v in problem.variables():
+        count = 0
+        if v.varValue > 0:
+          item_id = v.name.replace('Item_', '')
+          for item in self.solver_run.items:
+            if str(item.id) == item_id:
+              # add item to list
+              form_items.append(item)
+              # remove ids from master items list
+              self.solver_run.items.remove(item)
+
+      # add form to solution
+      solution.forms.append(Form.create(form_items, self.solver_run))
+
+      # successfull form, increment
+      f += 1
+
+    return solution
+
   def stream_to_s3_bucket(self):
     self.file_name = f'{service_helper.key_to_uuid(self.key)}.csv'
-    logging.info('Streaming to %s s3 bucket %s', self.file_name, os.environ['S3_PROCESSED_BUCKET'])
+    logging.info('Streaming %s to s3 bucket - %s', self.file_name, os.environ['S3_PROCESSED_BUCKET'])
     # setup writer buffer and write processed forms to file
     buffer = io.StringIO()
     solution_file = service_helper.solution_to_file(buffer, self.solver_run.total_form_items, self.solution.forms)