Implement multi-card payment method management and enhance user notifications

- Added support for saving multiple payment methods, allowing users to bind and manage their cards effectively.
- Introduced a new paginated list view for displaying saved payment methods, improving user experience.
- Enhanced user notifications for successful binding of payment methods, including localized messages.
- Updated the database models and data access layer to accommodate multi-card functionality.
- Refactored existing payment method handlers to integrate with the new multi-card system.

db/dal/user_billing_dal.py

@@ -1,9 +1,9 @@
-from typing import Optional, Dict, Any
+from typing import Optional, Dict, Any, List
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy import select, update
 from sqlalchemy.sql import func
 
-from db.models import UserBilling
+from db.models import UserBilling, UserPaymentMethod
 
 
 async def get_user_billing(session: AsyncSession, user_id: int) -> Optional[UserBilling]:
@@ -52,3 +52,91 @@ async def delete_yk_payment_method(session: AsyncSession, user_id: int) -> bool:
     await session.flush()
     await session.refresh(existing)
     return True
+
+
+# Multi-card support API
+async def upsert_user_payment_method(
+    session: AsyncSession,
+    *,
+    user_id: int,
+    provider_payment_method_id: str,
+    provider: str = "yookassa",
+    card_last4: Optional[str] = None,
+    card_network: Optional[str] = None,
+    set_default: bool = False,
+) -> UserPaymentMethod:
+    existing_stmt = select(UserPaymentMethod).where(UserPaymentMethod.provider_payment_method_id == provider_payment_method_id)
+    result = await session.execute(existing_stmt)
+    existing: Optional[UserPaymentMethod] = result.scalar_one_or_none()
+    if existing:
+        existing.card_last4 = card_last4
+        existing.card_network = card_network
+        if set_default:
+            # unset previous defaults
+            await session.execute(
+                update(UserPaymentMethod)
+                .where(UserPaymentMethod.user_id == user_id)
+                .values(is_default=False)
+            )
+            existing.is_default = True
+        existing.updated_at = func.now()
+        await session.flush()
+        await session.refresh(existing)
+        return existing
+    if set_default:
+        await session.execute(
+            update(UserPaymentMethod)
+            .where(UserPaymentMethod.user_id == user_id)
+            .values(is_default=False)
+        )
+    record = UserPaymentMethod(
+        user_id=user_id,
+        provider=provider,
+        provider_payment_method_id=provider_payment_method_id,
+        card_last4=card_last4,
+        card_network=card_network,
+        is_default=set_default,
+    )
+    session.add(record)
+    await session.flush()
+    await session.refresh(record)
+    return record
+
+
+async def list_user_payment_methods(session: AsyncSession, user_id: int, provider: Optional[str] = None) -> List[UserPaymentMethod]:
+    stmt = select(UserPaymentMethod).where(UserPaymentMethod.user_id == user_id)
+    if provider:
+        stmt = stmt.where(UserPaymentMethod.provider == provider)
+    stmt = stmt.order_by(UserPaymentMethod.is_default.desc(), UserPaymentMethod.created_at.desc())
+    result = await session.execute(stmt)
+    return result.scalars().all()
+
+
+async def get_user_default_payment_method(session: AsyncSession, user_id: int, provider: str = "yookassa") -> Optional[UserPaymentMethod]:
+    stmt = select(UserPaymentMethod).where(
+        UserPaymentMethod.user_id == user_id,
+        UserPaymentMethod.provider == provider,
+        UserPaymentMethod.is_default == True,
+    )
+    result = await session.execute(stmt)
+    return result.scalar_one_or_none()
+
+
+async def set_user_default_payment_method(session: AsyncSession, user_id: int, method_id: int) -> bool:
+    methods = await list_user_payment_methods(session, user_id)
+    if not any(m.method_id == method_id for m in methods):
+        return False
+    await session.execute(update(UserPaymentMethod).where(UserPaymentMethod.user_id == user_id).values(is_default=False))
+    await session.execute(update(UserPaymentMethod).where(UserPaymentMethod.method_id == method_id).values(is_default=True))
+    return True
+
+
+async def delete_user_payment_method(session: AsyncSession, user_id: int, method_id: int) -> bool:
+    stmt = select(UserPaymentMethod).where(UserPaymentMethod.method_id == method_id, UserPaymentMethod.user_id == user_id)
+    result = await session.execute(stmt)
+    method = result.scalar_one_or_none()
+    if not method:
+        return False
+    await session.delete(method)
+    await session.flush()
+    return True

db/models.py

@@ -126,6 +126,24 @@ class UserBilling(Base):
 
     user = relationship("User")
 
+class UserPaymentMethod(Base):
+    __tablename__ = "user_payment_methods"
+
+    method_id = Column(Integer, primary_key=True, autoincrement=True)
+    user_id = Column(BigInteger, ForeignKey("users.user_id"), nullable=False, index=True)
+    provider = Column(String, nullable=False, default="yookassa", index=True)
+    provider_payment_method_id = Column(String, nullable=False, unique=True, index=True)
+    card_last4 = Column(String, nullable=True)
+    card_network = Column(String, nullable=True)
+    is_default = Column(Boolean, default=False, index=True)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now(), nullable=True)
+
+    user = relationship("User")
+    __table_args__ = (
+        UniqueConstraint('user_id', 'provider_payment_method_id', name='uq_user_provider_method'),
+    )
+
 class PromoCode(Base):
     __tablename__ = "promo_codes"