76 lines
3.5 KiB
Python
76 lines
3.5 KiB
Python
from pulp import lpSum
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from random import randint, sample
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import logging
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from models.bundle import Bundle
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from lib.errors.item_generation_error import ItemGenerationError
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def build_constraints(solver_run, problem, items, bundles):
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try:
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total_form_items = solver_run.total_form_items
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constraints = solver_run.constraints
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for constraint in constraints:
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attribute = constraint.reference_attribute
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min = constraint.minimum
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max = constraint.maximum
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if attribute.type == 'metadata':
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con = dict(zip([item.id for item in solver_run.items],
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[item.attribute_exists(attribute)
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for item in solver_run.items]))
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problem += lpSum([con[item.id]
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* items[item.id]
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for item in solver_run.items]) >= round(total_form_items * (min / 100)), f'{attribute.id} - {attribute.value} - min'
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problem += lpSum([con[item.id]
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* items[item.id]
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for item in solver_run.items]) <= round(total_form_items * (max / 100)), f'{attribute.id} - {attribute.value} - max'
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elif attribute.type == 'bundle':
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# TODO: account for many different bundle types, since the id condition in L33 could yield duplicates
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if solver_run.bundles != None:
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# total_bundles = randint(constraint.minimum, constraint.maximum)
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# selected_bundles = sample(solver_run.bundles, total_bundles, solver_run.bundles)
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total_bundle_items = 0
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selected_bundles = get_random_bundles(solver_run.total_form_items, solver_run.bundles, int(constraint.minimum), int(constraint.maximum))
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for bundle in selected_bundles:
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con = dict(zip([item.id for item in solver_run.items],
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[(getattr(item, bundle.type, False) == bundle.id)
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for item in solver_run.items]))
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problem += lpSum([con[item.id]
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* items[item.id]
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for item in solver_run.items]) == bundle.count, f'Bundle constraint for {bundle.type} ({bundle.id})'
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total_bundle_items += bundle.count
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# make sure all other items added to the form
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# are not a part of any bundle
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# currently only supports single bundle constraints, will need refactoring for multiple bundle constraints
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con = dict(zip([item.id for item in solver_run.items],
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[(getattr(item, attribute.id, None) == None)
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for item in solver_run.items]))
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problem += lpSum([con[item.id]
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* items[item.id]
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for item in solver_run.items]) == solver_run.total_form_items - total_bundle_items, f'Remaining items are not of a bundle type'
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return problem
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except ValueError as error:
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logging.error(error)
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raise ItemGenerationError("Bundle min and/or max larger than bundle amount provided", error.args[0])
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def get_random_bundles(total_form_items: int, bundles: list[Bundle], min: int , max: int, found_bundles = False) -> list[Bundle]:
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selected_bundles = None
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total_bundle_items = 0
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total_bundles = randint(min, max)
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while found_bundles == False:
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selected_bundles = sample(bundles, total_bundles)
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total_bundle_items = sum(bundle.count for bundle in selected_bundles)
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if total_bundle_items <= total_form_items:
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found_bundles = True
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if found_bundles == True:
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return selected_bundles
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else:
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return get_random_bundles(total_form_items, total_bundles - 1, bundles) |