irt-service/app/models/problem.py

131 lines
5.0 KiB
Python

from __future__ import annotations
from typing import TYPE_CHECKING
from pydantic import BaseModel
from typing import Any, List
from pulp import LpProblem, LpVariable, LpStatus, lpSum
import logging
from helpers import service_helper, irt_helper
from models.solution import Solution
from models.item import Item
from models.bundle import Bundle
from lib.errors.item_generation_error import ItemGenerationError
if TYPE_CHECKING:
from models.solver_run import SolverRun
class Problem(BaseModel):
items: List[Item]
bundles: List[Bundle]
problem: Any
solver_items_var: Any = None
solver_bundles_var: Any = None
def __init__(self, **data) -> None:
super().__init__(**data)
# setup common Solver variables
self.solver_items_var = LpVariable.dicts("Item",
[item.id for item in self.items],
lowBound=0,
upBound=1,
cat='Binary')
self.solver_bundles_var = LpVariable.dicts("Bundle",
[bundle.id for bundle in self.bundles],
lowBound=0,
upBound=1,
cat='Binary')
def solve(self, solver_run: SolverRun) -> LpProblem:
logging.info('solving problem...')
# if we allow enemies, go through the normal solving process
if solver_run.allow_enemies:
logging.info('enemes allowed, so just solving')
self.problem.solve()
# otherwise begin the process of filtering enemies
else:
self.problem.solve()
# however, if the solve was infeasible, kick it back
# to the normal process
if LpStatus[self.problem.status] == 'Infeasible':
return self.problem
# otherwise continue
else:
# get items from solution
solved_items, _ = service_helper.solution_items(self.problem.variables(), solver_run)
sacred_ids = []
enemy_ids = []
# get all enemies
for item in solved_items:
# if it has enemies, check if it exists as part of the solved items
for enemy_id in item.enemies:
# if it does, it's a true enemy
if enemy_id in (item.id for item in solved_items):
enemy_ids.append(enemy_id)
# remove enemy from solved items,
# lest it has this sacred item added to enemies
solved_items = [i for i in solved_items if i.id != enemy_id]
# the item is cleansed, now it's sacred
sacred_ids.append(item.id)
if enemy_ids:
logging.info('enemies found, adding constraints...')
# remove old enemy/sacred constraints
self.problem.constrants.pop('Exclude_enemy_items')
self.problem.constrants.pop('Include_sacred_items')
# add constraint to not allow enemy items
self.problem += lpSum([
len(bundle.find_items(enemy_ids)) * self.solver_bundles_var[bundle.id]
for bundle in self.bundles
] + [
(item.id in enemy_ids) * self.solver_items_var[item.id]
for item in self.items
]) == 0, 'Exclude enemy items'
# add constraint to use sacred items
self.problem += lpSum([
len(bundle.find_items(sacred_ids)) * self.solver_bundles_var[bundle.id]
for bundle in self.bundles
] + [
(item.id in sacred_ids) * self.solver_items_var[item.id]
for item in self.items
]) == len(sacred_ids), 'Include sacred items'
# recursively solve until no enemies exist or infeasible
logging.info('recursively solving...')
self.solve(solver_run)
return self.problem
def generate(self, solution: Solution, solver_run: SolverRun) -> None:
try:
# creating problem objective function
solver_run.objective_function.for_problem(self)
logging.info('Creating Constraints...')
# generic constraints
for constraint in solver_run.constraints:
constraint.build(self, solver_run=solver_run, solution=solution)
# irt target constraints
for target in solver_run.objective_function.all_targets():
target.constraints(self, solver_run)
logging.info('Constraints Created...')
except ValueError as error:
logging.error(error)
raise ItemGenerationError(
error.msg,
error.args[0])