irt-service/app/services/loft_service.py
2022-02-09 16:33:38 -05:00

132 lines
5.3 KiB
Python

import os, json, random, io, logging
from pulp import LpProblem, LpVariable, LpMinimize, LpStatus, lpSum
from helpers import aws_helper, tar_helper, csv_helper, service_helper, solver_helper
from lib.errors.item_generation_error import ItemGenerationError
from models.solver_run import SolverRun
from models.solution import Solution
from models.form import Form
from models.item import Item
from services.base import Base
class LoftService(Base):
def process(self):
try:
self.solver_run = self.create_solver_run_from_attributes()
self.solver_run.generate_bundles()
self.solution = self.generate_solution()
self.result = self.stream_to_s3_bucket()
except ItemGenerationError as error:
self.result = self.stream_to_s3_bucket(error)
except TypeError as error:
logging.error(error)
self.result = self.stream_to_s3_bucket(ItemGenerationError("Provided params causing error in calculation results"))
def create_solver_run_from_attributes(self):
logging.info('Retrieving attributes from message...')
# get s3 object
self.key = aws_helper.get_key_from_message(self.source)
s3_object = aws_helper.get_object(self.key, aws_helper.get_bucket_from_message(self.source))
# convert to tar
self.tar = tar_helper.raw_to_tar(s3_object)
# get attributes file and convert to dict
attributes = json.loads(tar_helper.extract_file_from_tar(self.tar , 'solver_run_attributes.json').read())
# create solver run
solver_run = SolverRun.parse_obj(attributes)
# get items file and convert to dict
items_csv = tar_helper.extract_file_from_tar(self.tar , 'items.csv')
items_csv_reader = csv_helper.file_stream_reader(items_csv)
# add items to solver run
for item in service_helper.items_csv_to_dict(items_csv_reader, solver_run):
solver_run.items.append(Item.parse_obj(item))
logging.info('Processed Attributes...')
return solver_run
def generate_solution(self):
# 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')
bundles = LpVariable.dicts(
"Bundle", [bundle.id for bundle in self.solver_run.bundles], lowBound=1, upBound=1, cat='Binary')
problem_objection_functions = []
# create problem
problem = LpProblem("ata-form-generate", LpMinimize)
# dummy objective function, because it just makes things easier™
problem += lpSum([items[item.id]
for item in self.solver_run.items])
# constraints
problem += lpSum([items[item.id]
for item in self.solver_run.items]) == self.solver_run.total_form_items, 'Total form items'
# dynamic constraints
problem = solver_helper.build_constraints(self.solver_run, problem, items, bundles)
# multi-objective constraints
for target in self.solver_run.objective_function.tif_targets:
problem += lpSum([item.iif(self.solver_run, target.theta)*items[item.id]
for item in self.solver_run.items]) >= target.value - 8, f'max tif theta ({target.theta}) target value {target.value}'
problem += lpSum([item.iif(self.solver_run, target.theta)*items[item.id]
for item in self.solver_run.items]) <= target.value + 8, f'min tif theta ({target.theta}) target value {target.value}'
for target in self.solver_run.objective_function.tcc_targets:
problem += lpSum([item.irf(self.solver_run, target.theta)*items[item.id]
for item in self.solver_run.items]) >= target.value - 20, f'max tcc theta ({target.theta}) target value {target.value}'
problem += lpSum([item.irf(self.solver_run, target.theta)*items[item.id]
for item in self.solver_run.items]) <= target.value + 20, f'min tcc theta ({target.theta}) target value {target.value}'
# solve problem
problem.solve()
# add return items and create as a form
form_items = service_helper.solution_items(problem.variables(), self.solver_run)
# add form to solution
solution.forms.append(Form.create(form_items, self.solver_run, LpStatus[problem.status]))
# successfull form, increment
f += 1
return solution
def stream_to_s3_bucket(self, error = None):
self.file_name = f'{service_helper.key_to_uuid(self.key)}.csv'
solution_file = None
# setup writer buffer and write processed forms to file
buffer = io.StringIO()
if error:
logging.info('Streaming %s error response to s3 bucket - %s', self.file_name, os.environ['S3_PROCESSED_BUCKET'])
solution_file = service_helper.error_to_file(buffer, error)
else:
logging.info('Streaming %s to s3 bucket - %s', self.file_name, os.environ['S3_PROCESSED_BUCKET'])
solution_file = service_helper.solution_to_file(buffer, self.solver_run.total_form_items, self.solution.forms)
# upload generated file to s3 and return result
return aws_helper.file_stream_upload(solution_file, self.file_name, os.environ['S3_PROCESSED_BUCKET'])