2 files changed, 71 insertions, 1 deletions

diff --git a/libs/__init__.py b/libs/__init__.py
index 65f8ab7..55e6b19 100644
--- a/libs/__init__.py
+++ b/libs/__init__.py
@@ -1,8 +1,9 @@
-from . import fsm, msg, storage, user
+from . import fsm, invoice, msg, storage, user
 
 __all__ = [
     "storage",
     "fsm",
     "msg",
     "user",
+    "invoice",
 ]
diff --git a/libs/invoice.py b/libs/invoice.py
new file mode 100644
index 0000000..92b82f7
--- /dev/null
+++ b/libs/invoice.py
@@ -0,0 +1,69 @@
+from enum import StrEnum, auto
+
+from pydantic import BaseModel
+from sqlalchemy import and_, select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from models import Invoice, Payment, PaymentStatus, User, UserRole
+
+
+class InvoiceStatus(StrEnum):
+    PAID = auto()
+    UNPAID = auto()
+
+
+class InvoicePayments(BaseModel):
+    user_status: dict[int, PaymentStatus]
+    status: InvoiceStatus
+
+
+async def get_invoice_payments(
+    session: AsyncSession,
+    invoice: Invoice,
+) -> InvoicePayments:
+    users = await session.scalars(
+        select(User).where(
+            and_(
+                User.role != UserRole.ADMIN,
+                User.datetime <= invoice.datetime,
+            )
+        )
+    )
+    payments = await session.scalars(
+        select(Payment).where(Payment.invoice_id == invoice.id)
+    )
+
+    user_status = {u.id: PaymentStatus.REJECTED for u in users}
+    for p in payments:
+        if (
+            p.status != PaymentStatus.REJECTED
+            and user_status[p.user_id] == PaymentStatus.REJECTED
+        ):
+            user_status[p.user_id] = p.status
+
+    status = (
+        InvoiceStatus.PAID
+        if all(s == PaymentStatus.ACCEPTED for s in user_status.values())
+        else InvoiceStatus.UNPAID
+    )
+
+    return InvoicePayments(user_status=user_status, status=status)
+
+
+async def get_payment_status(
+    session: AsyncSession,
+    invoice_id: int,
+    user_id: int,
+) -> PaymentStatus:
+    payments = await session.scalars(
+        select(Payment).where(
+            and_(
+                Payment.invoice_id == invoice_id,
+                Payment.user_id == user_id,
+            )
+        )
+    )
+    for p in payments:
+        if p.status != PaymentStatus.REJECTED:
+            return p.status
+    return PaymentStatus.REJECTED