pkmntrade.club/trades/models.py

445 lines
18 KiB
Python

from django.db import models
from django.core.exceptions import ValidationError
from django.db.models import Q
import hashlib
from cards.models import Card
from accounts.models import FriendCode
class TradeOffer(models.Model):
id = models.AutoField(primary_key=True)
manually_closed = models.BooleanField(default=False, db_index=True)
hash = models.CharField(max_length=9, editable=False)
initiated_by = models.ForeignKey(
"accounts.FriendCode",
on_delete=models.PROTECT,
related_name='initiated_trade_offers'
)
# Use custom through models to support multiples.
want_cards = models.ManyToManyField(
"cards.Card",
related_name='trade_offers_want',
through="TradeOfferWantCard"
)
have_cards = models.ManyToManyField(
"cards.Card",
related_name='trade_offers_have',
through="TradeOfferHaveCard"
)
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)
# New denormalized fields for aggregated counts
total_have_quantity = models.PositiveIntegerField(default=0, editable=False)
total_want_quantity = models.PositiveIntegerField(default=0, editable=False)
total_have_accepted = models.PositiveIntegerField(default=0, editable=False)
total_want_accepted = models.PositiveIntegerField(default=0, editable=False)
def __str__(self):
want_names = ", ".join([x.name for x in self.want_cards.all()])
have_names = ", ".join([x.name for x in self.have_cards.all()])
return f"Want: {want_names} -> Have: {have_names}"
def save(self, *args, **kwargs):
is_new = self.pk is None
super().save(*args, **kwargs)
if is_new and not self.hash:
self.hash = hashlib.md5((str(self.id) + "z").encode("utf-8")).hexdigest()[:8] + "z"
super().save(update_fields=["hash"])
def update_aggregates(self):
"""
Recalculate and update aggregated fields from related have/want cards and acceptances.
"""
from django.db.models import Sum
from trades.models import TradeAcceptance
# Calculate total quantities from through models
have_agg = self.trade_offer_have_cards.aggregate(total=Sum("quantity"))
want_agg = self.trade_offer_want_cards.aggregate(total=Sum("quantity"))
self.total_have_quantity = have_agg["total"] or 0
self.total_want_quantity = want_agg["total"] or 0
# Define acceptance states that count as active.
active_states = [
TradeAcceptance.AcceptanceState.ACCEPTED,
TradeAcceptance.AcceptanceState.SENT,
TradeAcceptance.AcceptanceState.RECEIVED,
TradeAcceptance.AcceptanceState.THANKED_BY_INITIATOR,
TradeAcceptance.AcceptanceState.THANKED_BY_ACCEPTOR,
TradeAcceptance.AcceptanceState.THANKED_BY_BOTH,
]
# Compute accepted counts based on matching card IDs.
have_card_ids = list(self.trade_offer_have_cards.values_list("card_id", flat=True))
want_card_ids = list(self.trade_offer_want_cards.values_list("card_id", flat=True))
self.total_have_accepted = TradeAcceptance.objects.filter(
trade_offer=self,
state__in=active_states,
requested_card_id__in=have_card_ids,
).count()
self.total_want_accepted = TradeAcceptance.objects.filter(
trade_offer=self,
state__in=active_states,
offered_card_id__in=want_card_ids,
).count()
# Save updated aggregate values so they are denormalized in the database.
self.save(update_fields=[
"total_have_quantity",
"total_want_quantity",
"total_have_accepted",
"total_want_accepted",
])
@property
def is_closed(self):
if self.manually_closed:
return True
# Utilize denormalized fields for faster check.
return not (self.total_have_accepted < self.total_have_quantity and
self.total_want_accepted < self.total_want_quantity)
class Meta:
indexes = [
models.Index(fields=['manually_closed']),
]
class TradeOfferHaveCard(models.Model):
"""
Through model for TradeOffer.have_cards.
Represents the card the initiator is offering along with the quantity available.
"""
trade_offer = models.ForeignKey(
TradeOffer,
on_delete=models.CASCADE,
related_name='trade_offer_have_cards',
db_index=True
)
card = models.ForeignKey("cards.Card", on_delete=models.PROTECT, db_index=True)
quantity = models.PositiveIntegerField(default=1)
def __str__(self):
return f"{self.card.name} x{self.quantity}"
class Meta:
unique_together = ("trade_offer", "card")
class TradeOfferWantCard(models.Model):
"""
Through model for TradeOffer.want_cards.
Represents the card the initiator is requesting along with the quantity requested.
"""
trade_offer = models.ForeignKey(
TradeOffer,
on_delete=models.CASCADE,
related_name='trade_offer_want_cards'
)
card = models.ForeignKey("cards.Card", on_delete=models.PROTECT)
quantity = models.PositiveIntegerField(default=1)
def __str__(self):
return f"{self.card.name} x{self.quantity}"
class Meta:
unique_together = ("trade_offer", "card")
class TradeAcceptance(models.Model):
class AcceptanceState(models.TextChoices):
ACCEPTED = 'ACCEPTED', 'Accepted'
SENT = 'SENT', 'Sent'
RECEIVED = 'RECEIVED', 'Received'
THANKED_BY_INITIATOR = 'THANKED_BY_INITIATOR', 'Thanked by Initiator'
THANKED_BY_ACCEPTOR = 'THANKED_BY_ACCEPTOR', 'Thanked by Acceptor'
THANKED_BY_BOTH = 'THANKED_BY_BOTH', 'Thanked by Both'
REJECTED_BY_INITIATOR = 'REJECTED_BY_INITIATOR', 'Rejected by Initiator'
REJECTED_BY_ACCEPTOR = 'REJECTED_BY_ACCEPTOR', 'Rejected by Acceptor'
trade_offer = models.ForeignKey(
TradeOffer,
on_delete=models.CASCADE,
related_name='acceptances',
db_index=True
)
accepted_by = models.ForeignKey(
"accounts.FriendCode",
on_delete=models.PROTECT,
related_name='trade_acceptances'
)
# The acceptor selects one card the initiator is offering (from have_cards)
requested_card = models.ForeignKey(
"cards.Card",
on_delete=models.PROTECT,
related_name='accepted_requested',
db_index=True
)
# And one card from the initiator's wanted cards (from want_cards)
offered_card = models.ForeignKey(
"cards.Card",
on_delete=models.PROTECT,
related_name='accepted_offered',
db_index=True
)
state = models.CharField(
max_length=25,
choices=AcceptanceState.choices,
default=AcceptanceState.ACCEPTED,
db_index=True
)
hash = models.CharField(max_length=9, editable=False, blank=True)
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)
def mark_thanked(self, friend_code):
"""
Mark this acceptance as "thanked" by the given friend_code.
Allowed transitions:
- If the current state is RECEIVED:
* If the initiator thanks, transition to THANKED_BY_INITIATOR.
* If the acceptor thanks, transition to THANKED_BY_ACCEPTOR.
- If already partially thanked:
* If state is THANKED_BY_INITIATOR and the acceptor thanks, transition to THANKED_BY_BOTH.
* If state is THANKED_BY_ACCEPTOR and the initiator thanks, transition to THANKED_BY_BOTH.
Only parties involved in the trade (either the initiator or the acceptor) can mark it as thanked.
"""
if self.state not in [self.AcceptanceState.RECEIVED,
self.AcceptanceState.THANKED_BY_INITIATOR,
self.AcceptanceState.THANKED_BY_ACCEPTOR]:
raise ValidationError("Cannot mark thanked in the current state.")
if friend_code == self.trade_offer.initiated_by:
# Initiator is marking thanks.
if self.state == self.AcceptanceState.RECEIVED:
self.state = self.AcceptanceState.THANKED_BY_INITIATOR
elif self.state == self.AcceptanceState.THANKED_BY_ACCEPTOR:
self.state = self.AcceptanceState.THANKED_BY_BOTH
elif self.state == self.AcceptanceState.THANKED_BY_INITIATOR:
# Already thanked by the initiator.
return
elif friend_code == self.accepted_by:
# Acceptor is marking thanks.
if self.state == self.AcceptanceState.RECEIVED:
self.state = self.AcceptanceState.THANKED_BY_ACCEPTOR
elif self.state == self.AcceptanceState.THANKED_BY_INITIATOR:
self.state = self.AcceptanceState.THANKED_BY_BOTH
elif self.state == self.AcceptanceState.THANKED_BY_ACCEPTOR:
# Already thanked by the acceptor.
return
else:
from django.core.exceptions import PermissionDenied
raise PermissionDenied("You are not a party to this trade acceptance.")
self.save(update_fields=["state"])
@property
def is_completed(self):
"""
Computed boolean property indicating whether the trade acceptance has been
marked as thanked by one or both parties.
"""
return self.state in {
self.AcceptanceState.RECEIVED,
self.AcceptanceState.THANKED_BY_INITIATOR,
self.AcceptanceState.THANKED_BY_ACCEPTOR,
self.AcceptanceState.THANKED_BY_BOTH,
}
@property
def is_thanked(self):
"""
Computed boolean property indicating whether the trade acceptance has been
marked as thanked by one or both parties.
"""
return self.state == self.AcceptanceState.THANKED_BY_BOTH
@property
def is_rejected(self):
"""
Computed boolean property that is True if the trade acceptance has been rejected
by either the initiator or the acceptor.
"""
return self.state in {
self.AcceptanceState.REJECTED_BY_INITIATOR,
self.AcceptanceState.REJECTED_BY_ACCEPTOR,
}
@property
def is_completed_or_rejected(self):
"""
Computed boolean property that is True if the trade acceptance is either completed
(i.e., thanked) or rejected.
"""
return self.is_completed or self.is_rejected
@property
def is_active(self):
"""
Computed boolean property that is True if the trade acceptance is still active,
meaning it is neither completed (thanked) nor rejected.
"""
return not self.is_completed_or_rejected
def clean(self):
"""
Validate that:
- The requested_card is associated with the trade offer's have_cards (via the through model).
- The offered_card is associated with the trade offer's want_cards (via the through model).
- The trade offer is not already closed.
- The total number of active acceptances for each chosen card does not exceed the available quantity.
"""
# Validate that requested_card is in trade_offer.have_cards
try:
have_through_obj = self.trade_offer.trade_offer_have_cards.get(card=self.requested_card)
except TradeOfferHaveCard.DoesNotExist:
raise ValidationError("The requested card must be one of the trade offer's available cards (have_cards).")
# Validate that offered_card is in trade_offer.want_cards
try:
want_through_obj = self.trade_offer.trade_offer_want_cards.get(card=self.offered_card)
except TradeOfferWantCard.DoesNotExist:
raise ValidationError("The offered card must be one of the trade offer's requested cards (want_cards).")
# For new acceptances, do not allow creation if the trade offer is closed.
if not self.pk and self.trade_offer.is_closed:
raise ValidationError("This trade offer is closed. No more acceptances are allowed.")
active_states = [
self.AcceptanceState.ACCEPTED,
self.AcceptanceState.SENT,
self.AcceptanceState.RECEIVED,
self.AcceptanceState.THANKED_BY_INITIATOR,
self.AcceptanceState.THANKED_BY_ACCEPTOR,
self.AcceptanceState.THANKED_BY_BOTH,
]
active_acceptances = self.trade_offer.acceptances.filter(state__in=active_states)
if self.pk:
active_acceptances = active_acceptances.exclude(pk=self.pk)
# Count active acceptances for the requested card.
requested_count = active_acceptances.filter(requested_card=self.requested_card).count()
if requested_count >= have_through_obj.quantity:
raise ValidationError("This requested card has been fully accepted.")
# Count active acceptances for the offered card.
offered_count = active_acceptances.filter(offered_card=self.offered_card).count()
if offered_count >= want_through_obj.quantity:
raise ValidationError("This offered card has already been fully used.")
def get_step_number(self):
"""
Return the step number for the current state.
"""
if self.state in [
self.AcceptanceState.THANKED_BY_INITIATOR,
self.AcceptanceState.THANKED_BY_ACCEPTOR,
]:
return 4
elif self.state in [
self.AcceptanceState.THANKED_BY_BOTH,
]:
return 5
elif self.state in [
self.AcceptanceState.REJECTED_BY_INITIATOR,
self.AcceptanceState.REJECTED_BY_ACCEPTOR,
]:
return 0
else:
# .choices is a list of tuples, so we need to find the index of the tuple that contains the state.
return (next(index for index, choice in enumerate(self.AcceptanceState.choices) if choice[0] == self.state) + 1)
def update_state(self, new_state, user):
"""
Update the trade acceptance state.
"""
if new_state not in [choice[0] for choice in self.AcceptanceState.choices]:
raise ValueError(f"'{new_state}' is not a valid state.")
# Terminal states: no further transitions allowed.
if self.state in [
self.AcceptanceState.THANKED_BY_BOTH,
self.AcceptanceState.REJECTED_BY_INITIATOR,
self.AcceptanceState.REJECTED_BY_ACCEPTOR
]:
raise ValueError(f"No transitions allowed from the terminal state '{self.state}'.")
allowed = [x for x,y in self.get_allowed_state_transitions(user)]
print(allowed)
print(new_state)
if new_state not in allowed:
raise ValueError(f"Transition from {self.state} to {new_state} is not allowed.")
self.state = new_state
self.save(update_fields=["state"])
def save(self, *args, **kwargs):
is_new = self.pk is None
super().save(*args, **kwargs)
if is_new and not self.hash:
# Append "y" so all trade acceptance hashes differ from trade offers.
self.hash = hashlib.md5((str(self.id) + "y").encode("utf-8")).hexdigest()[:8] + "y"
super().save(update_fields=["hash"])
def __str__(self):
return (f"TradeAcceptance(offer_hash={self.trade_offer.hash}, "
f"accepted_by={self.accepted_by}, "
f"requested_card={self.requested_card}, "
f"offered_card={self.offered_card}, state={self.state})")
def get_allowed_state_transitions(self, user):
"""
Returns a list of allowed state transitions as tuples (value, display_label)
based on the current state of this trade acceptance.
"""
if self.trade_offer.initiated_by in user.friend_codes.all():
allowed_transitions = {
self.AcceptanceState.ACCEPTED: {
self.AcceptanceState.SENT,
self.AcceptanceState.REJECTED_BY_INITIATOR,
},
self.AcceptanceState.SENT: {
self.AcceptanceState.REJECTED_BY_INITIATOR,
},
self.AcceptanceState.RECEIVED: {
self.AcceptanceState.THANKED_BY_INITIATOR,
self.AcceptanceState.REJECTED_BY_INITIATOR,
},
self.AcceptanceState.THANKED_BY_INITIATOR: {
self.AcceptanceState.REJECTED_BY_INITIATOR,
},
self.AcceptanceState.THANKED_BY_ACCEPTOR: {
self.AcceptanceState.REJECTED_BY_INITIATOR,
self.AcceptanceState.THANKED_BY_BOTH,
},
}
elif self.accepted_by in user.friend_codes.all():
allowed_transitions = {
self.AcceptanceState.ACCEPTED: {
self.AcceptanceState.REJECTED_BY_ACCEPTOR,
},
self.AcceptanceState.SENT: {
self.AcceptanceState.RECEIVED,
self.AcceptanceState.REJECTED_BY_ACCEPTOR,
},
self.AcceptanceState.RECEIVED: {
self.AcceptanceState.THANKED_BY_ACCEPTOR,
self.AcceptanceState.REJECTED_BY_ACCEPTOR,
},
self.AcceptanceState.THANKED_BY_ACCEPTOR: {
self.AcceptanceState.REJECTED_BY_ACCEPTOR,
},
self.AcceptanceState.THANKED_BY_INITIATOR: {
self.AcceptanceState.REJECTED_BY_ACCEPTOR,
self.AcceptanceState.THANKED_BY_BOTH,
},
}
else:
allowed_transitions = {}
allowed = allowed_transitions.get(self.state, {})
# Return as a list of tuples (state_value, human-readable label)
return [(state, self.AcceptanceState(state).label) for state in allowed]