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feat: add allocate_assignments method to content_assignments app.
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ENT-7531
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iloveagent57 committed Sep 25, 2023
1 parent 04f88de commit 6ca4793
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Showing 6 changed files with 283 additions and 6 deletions.
141 changes: 137 additions & 4 deletions enterprise_access/apps/content_assignments/api.py
Original file line number Diff line number Diff line change
Expand Up @@ -21,28 +21,161 @@ def get_assignment_configuration(uuid):

def get_assignments_for_configuration(
assignment_configuration,
state=LearnerContentAssignmentStateChoices.ALLOCATED,
**additional_filters,
):
"""
Returns a queryset of all ``LearnerContentAssignment`` records
for the given assignment configuration.
for the given assignment configuration, optionally filtered
further by the provided ``additional_filters``.
"""
queryset = LearnerContentAssignment.objects.select_related(
'assignment_configuration',
).filter(
assignment_configuration=assignment_configuration,
state=state,
**additional_filters,
)
return queryset


def get_assignments_by_learner_email_and_content(
assignment_configuration,
learner_emails,
content_key,
):
"""
Returns a queryset of all ``LearnerContentAssignment`` records
in the given assignment configuration for the provided list
of learner_emails and the given content_key.
"""
return get_assignments_for_configuration(
assignment_configuration,
learner_email__in=learner_emails,
content_key=content_key,
)


def get_allocated_quantity_for_configuration(assignment_configuration):
"""
Returns a float representing the total quantity, in USD cents, currently allocated
via Assignments for the given configuration.
"""
assignments_queryset = get_assignments_for_configuration(assignment_configuration)
assignments_queryset = get_assignments_for_configuration(
assignment_configuration,
state=LearnerContentAssignmentStateChoices.ALLOCATED,
)
aggregate = assignments_queryset.aggregate(
total_quantity=Sum('content_quantity'),
)
return aggregate['total_quantity']


def allocate_assignments(assignment_configuration, learner_emails, content_key, content_price_cents):
"""
Creates or updates an allocated assignment record
for the given ``content_key`` in the given ``assignment_configuration``,
for each email in the list of ``learner_emails``.
For existing assignment records with a (config, learner, content) combination, this function
does the following:
* If the existing record is cancelled or errored, update the existing record state to allocated
* If the existing record is allocated or accepted, don't do anything with the record
Params:
- ``assignment_configuration``: The AssignmentConfiguration record under which assignments should be allocated.
- ``learner_emails``: A list of learner email addresses to whom assignments should be allocated.
- ``content_key``: Typically a *course* key to which the learner is assigned.
- ``content_price_cents``: The cost of redeeming the content, in USD cents, at the time of allocation.
Returns: A dictionary of updated, created, and unchanged assignment records. e.g.
```
{
'updated': [Updated LearnerContentAssignment records],
'created': [Newly-created LearnerContentAssignment records],
'no-change': [LearnerContentAssignment records that matched
the provided (config, learner, content) combination,
but were already in an 'allocated' or 'accepted' state],
}
```
"""
# Fetch any existing assignments for all pairs of (learner, content) in this assignment config.
existing_assignments = get_assignments_by_learner_email_and_content(
assignment_configuration,
learner_emails,
content_key,
)

# Existing Assignments in consideration by state
already_allocated_or_accepted = []
cancelled_or_errored_to_update = []

# Maintain a set of emails with existing records - we know we don't have to create
# new assignments for these.
learner_emails_with_existing_assignments = set()

# Split up the existing assignment records by state
for assignment in existing_assignments:
learner_emails_with_existing_assignments.add(assignment.learner_email)
if assignment.state in LearnerContentAssignmentStateChoices.REALLOCATE_STATES:
assignment.content_quantity = content_price_cents
assignment.state = LearnerContentAssignmentStateChoices.ALLOCATED
cancelled_or_errored_to_update.append(assignment)
else:
already_allocated_or_accepted.append(assignment)

# Bulk update and get a list of refreshed objects
updated_assignments = _update_and_refresh_assignments(
cancelled_or_errored_to_update,
['content_quantity', 'state']
)

# Narrow down creation list of learner emails
learner_emails_for_assignment_creation = set(learner_emails) - learner_emails_with_existing_assignments

# Initialize and save LearnerContentAssignment instances for each of them
created_assignments = _create_new_assignments(
assignment_configuration,
learner_emails_for_assignment_creation,
content_key,
content_price_cents,
)

# Return a mapping of the action we took to lists of relevant assignment records.
return {
'updated': updated_assignments,
'created': created_assignments,
'no_change': already_allocated_or_accepted,
}


def _update_and_refresh_assignments(assignment_records, fields_changed):
"""
Helper to bulk save the given assignment_records
and refresh their state from the DB.
"""
# Save the assignments to update
LearnerContentAssignment.bulk_update(assignment_records, fields_changed)

# Get a list of refreshed objects that we just updated
return LearnerContentAssignment.objects.filter(
uuid__in=[record.uuid for record in assignment_records],
)


def _create_new_assignments(assignment_configuration, learner_emails, content_key, content_price_cents):
"""
Helper to bulk save new LearnerContentAssignment instances.
"""
assignments_to_create = [
LearnerContentAssignment(
assignment_configuration=assignment_configuration,
learner_email=learner_email,
content_key=content_key,
content_quantity=content_price_cents,
state=LearnerContentAssignmentStateChoices.ALLOCATED,
)
for learner_email in learner_emails
]

# Do the bulk creation to save these records
return LearnerContentAssignment.bulk_create(assignments_to_create)
2 changes: 2 additions & 0 deletions enterprise_access/apps/content_assignments/constants.py
Original file line number Diff line number Diff line change
Expand Up @@ -17,3 +17,5 @@ class LearnerContentAssignmentStateChoices:
(CANCELLED, 'Cancelled'),
(ERRORED, 'Errored'),
)

REALLOCATE_STATES = (CANCELLED, ERRORED)
48 changes: 48 additions & 0 deletions enterprise_access/apps/content_assignments/models.py
Original file line number Diff line number Diff line change
Expand Up @@ -5,11 +5,15 @@

from django.core.exceptions import ObjectDoesNotExist
from django.db import models
from django.utils import timezone
from django_extensions.db.models import TimeStampedModel
from simple_history.models import HistoricalRecords
from simple_history.utils import bulk_create_with_history, bulk_update_with_history

from .constants import LearnerContentAssignmentStateChoices

BULK_OPERATION_BATCH_SIZE = 50


class AssignmentConfiguration(TimeStampedModel):
"""
Expand Down Expand Up @@ -46,6 +50,9 @@ class AssignmentConfiguration(TimeStampedModel):

history = HistoricalRecords()

def __str__(self):
return f'uuid={self.uuid}, customer={self.enterprise_customer_uuid}'

def delete(self, *args, **kwargs):
"""
Perform a soft-delete, overriding the standard delete() method to prevent hard-deletes.
Expand Down Expand Up @@ -160,3 +167,44 @@ class Meta:
),
)
history = HistoricalRecords()

def __str__(self):
return (
f'uuid={self.uuid}, state={self.state}, learner_email={self.learner_email}, content_key={self.content_key}'
)

@classmethod
def bulk_create(cls, assignment_records):
"""
Creates new ``LearnerContentAssignment`` records in bulk,
while saving their history:
https://django-simple-history.readthedocs.io/en/latest/common_issues.html#bulk-creating-a-model-with-history
"""
return bulk_create_with_history(
assignment_records,
cls,
batch_size=BULK_OPERATION_BATCH_SIZE,
)

@classmethod
def bulk_update(cls, assignment_records, updated_field_names):
"""
Updates and saves the given ``assignment_records`` in bulk,
while saving their history:
https://django-simple-history.readthedocs.io/en/latest/common_issues.html#bulk-updating-a-model-with-history-new
Note that the simple-history utility function uses Django's bulk_update() under the hood:
https://docs.djangoproject.com/en/3.2/ref/models/querysets/#bulk-update
which does *not* call save(), so we have to manually update the `modified` field
during this bulk operation in order for that field's value to be updated.
"""
for record in assignment_records:
record.modified = timezone.now()

return bulk_update_with_history(
assignment_records,
cls,
updated_field_names + ['modified'],
batch_size=BULK_OPERATION_BATCH_SIZE,
)
88 changes: 86 additions & 2 deletions enterprise_access/apps/content_assignments/tests/test_api.py
Original file line number Diff line number Diff line change
Expand Up @@ -3,7 +3,7 @@
"""
from django.test import TestCase

from ..api import get_allocated_quantity_for_configuration, get_assignments_for_configuration
from ..api import allocate_assignments, get_allocated_quantity_for_configuration, get_assignments_for_configuration
from ..constants import LearnerContentAssignmentStateChoices
from ..models import AssignmentConfiguration
from .factories import LearnerContentAssignmentFactory
Expand Down Expand Up @@ -65,7 +65,10 @@ def test_get_assignments_for_configuration_different_states(self):
):
with self.assertNumQueries(1):
actual_assignments = list(
get_assignments_for_configuration(self.assignment_configuration, filter_state)
get_assignments_for_configuration(
self.assignment_configuration,
state=filter_state
)
)

self.assertEqual(
Expand All @@ -87,3 +90,84 @@ def test_get_allocated_quantity_for_configuration(self):
with self.assertNumQueries(1):
actual_amount = get_allocated_quantity_for_configuration(self.assignment_configuration)
self.assertEqual(actual_amount, 6000)

def test_allocate_assignments_happy_path(self):
"""
Tests the allocation of new assignments against a given configuration.
"""
content_key = 'demoX'
content_price_cents = 100
learners_to_assign = [
f'{name}@foo.com' for name in ('alice', 'bob', 'carol', 'david', 'eugene')
]

allocated_assignment = LearnerContentAssignmentFactory.create(
assignment_configuration=self.assignment_configuration,
learner_email='[email protected]',
content_key=content_key,
content_quantity=content_price_cents,
state=LearnerContentAssignmentStateChoices.ALLOCATED,
)
accepted_assignment = LearnerContentAssignmentFactory.create(
assignment_configuration=self.assignment_configuration,
learner_email='[email protected]',
content_key=content_key,
content_quantity=content_price_cents,
state=LearnerContentAssignmentStateChoices.ACCEPTED,
)
cancelled_assignment = LearnerContentAssignmentFactory.create(
assignment_configuration=self.assignment_configuration,
learner_email='[email protected]',
content_key=content_key,
content_quantity=200,
state=LearnerContentAssignmentStateChoices.CANCELLED,
)
errored_assignment = LearnerContentAssignmentFactory.create(
assignment_configuration=self.assignment_configuration,
learner_email='[email protected]',
content_key=content_key,
content_quantity=200,
state=LearnerContentAssignmentStateChoices.ERRORED,
)

allocation_results = allocate_assignments(
self.assignment_configuration,
learners_to_assign,
content_key,
content_price_cents,
)

# Refresh from db to get any updates reflected in the python objects.
for record in (allocated_assignment, accepted_assignment, cancelled_assignment, errored_assignment):
record.refresh_from_db()

# The errored and cancelled assignments should be the only things updated
self.assertEqual(
{record.uuid for record in allocation_results['updated']},
{cancelled_assignment.uuid, errored_assignment.uuid},
)
for record in (cancelled_assignment, errored_assignment):
self.assertEqual(len(record.history.all()), 2)

# The allocated and accepted assignments should be the only things with no change
self.assertEqual(
{record.uuid for record in allocation_results['no_change']},
{allocated_assignment.uuid, accepted_assignment.uuid},
)
for record in (allocated_assignment, accepted_assignment):
self.assertEqual(len(record.history.all()), 1)

# The existing assignments should be 'allocated' now, except for the already accepted one
self.assertEqual(cancelled_assignment.state, LearnerContentAssignmentStateChoices.ALLOCATED)
self.assertEqual(errored_assignment.state, LearnerContentAssignmentStateChoices.ALLOCATED)
self.assertEqual(allocated_assignment.state, LearnerContentAssignmentStateChoices.ALLOCATED)
self.assertEqual(accepted_assignment.state, LearnerContentAssignmentStateChoices.ACCEPTED)

# We should have created only one new, allocated assignment for [email protected]
self.assertEqual(len(allocation_results['created']), 1)
created_assignment = allocation_results['created'][0]
self.assertEqual(created_assignment.assignment_configuration, self.assignment_configuration)
self.assertEqual(created_assignment.learner_email, '[email protected]')
self.assertEqual(created_assignment.content_key, content_key)
self.assertEqual(created_assignment.content_quantity, content_price_cents)
self.assertEqual(created_assignment.state, LearnerContentAssignmentStateChoices.ALLOCATED)
8 changes: 8 additions & 0 deletions enterprise_access/apps/subsidy_access_policy/models.py
Original file line number Diff line number Diff line change
Expand Up @@ -905,3 +905,11 @@ def can_allocate(self, number_of_learners, content_key, content_price_cents):
return (False, REASON_POLICY_SPEND_LIMIT_REACHED)

return (True, None)

def allocate(self, learner_emails, content_key, content_price_cents):
"""
Creates allocated ``LearnerContentAssignment`` records.
"""
# this will eventually lean on assignments_api.allocate_assignments()
# to do the heavy lifting.
raise NotImplementedError
2 changes: 2 additions & 0 deletions enterprise_access/settings/devstack.py
Original file line number Diff line number Diff line change
Expand Up @@ -93,6 +93,8 @@
# shell_plus
SHELL_PLUS_IMPORTS = [
'from enterprise_access.apps.subsidy_request.utils import localized_utcnow',
'from enterprise_access.apps.content_assignments import api as assignments_api',
'from pprint import pprint',
]


Expand Down

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