feat: end-point for bill of payment generation

services/billing.py

@@ -1,19 +1,30 @@
 import datetime
+import locale
+from ast import Bytes
+from io import BytesIO
+from pathlib import Path
 from typing import List
 
 from fastapi import HTTPException
+from jinja2 import Environment, FileSystemLoader
+from number_to_string import get_string_by_number
 from sqlalchemy import select
+from sqlalchemy.orm import selectinload
 from starlette import status
+from weasyprint import HTML
 
 import backend.config
 from external.billing import BillingClient, CreateBillingRequestValue, CreateBillRequestSchema, CreateBillRequestItems, \
-    BillStatusUpdateRequest, NotificationChannel, NotifyReceivedBillRequestSchema, BillPaymentInfo, \
-    DeleteBillRequestSchema
-from models import DealBillRequest, Deal
+    BillStatusUpdateRequest, NotificationChannel, NotifyReceivedBillRequestSchema, DeleteBillRequestSchema
+from models import DealBillRequest, Deal, DealProduct, DealService as DealServiceModel
 from schemas.billing import *
 from services.base import BaseService
 from services.deal import DealService
 
+locale.setlocale(locale.LC_TIME, "ru_RU.UTF-8")
+
+env = Environment(loader=FileSystemLoader(Path("templates") / Path("documents")))
+
 
 class BillingService(BaseService):
     async def _process_update_details(
@@ -132,3 +143,60 @@ class BillingService(BaseService):
             return CancelDealBillResponse(ok=True, message='Заявка успешно отозвана')
         except Exception as e:
             return CancelDealBillResponse(ok=False, message=str(e))
+
+    async def _get_services_for_deal(self, deal: Deal) -> List[CreateBillingRequestValue]:
+        services: List[CreateBillingRequestValue] = []
+
+        for product in deal.products:
+            for service in product.services:
+                services.append(
+                    CreateBillingRequestValue(
+                        name=f'[{product.product.name}] - {service.service.name}',
+                        price=service.price,
+                        amount=product.quantity
+                    )
+                )
+        for service in deal.services:
+            services.append(
+                CreateBillingRequestValue(
+                    name=f'{service.service.name}',
+                    price=service.price,
+                    amount=service.quantity
+                )
+            )
+
+        return services
+
+    async def _create_billing_document_html(self, deal_id: int):
+        deal: Deal | None = await self.session.scalar(
+            select(Deal)
+            .where(Deal.id == deal_id)
+            .options(
+                selectinload(Deal.products).selectinload(DealProduct.services),
+                selectinload(Deal.services).selectinload(DealServiceModel.service),
+            )
+        )
+
+        if not deal:
+            return ""
+
+        services = await self._get_services_for_deal(deal)
+
+        deal_price = sum((service.price for service in services))
+        deal_price_words = get_string_by_number(deal_price)[0:-10]
+        template = env.get_template("bill-of-payment.html")
+        return template.render({
+            "services": services,
+            "deal_price": deal_price,
+            "deal_price_words": deal_price_words,
+            "deal": deal,
+            "curr_date": datetime.datetime.now().strftime("%d %B %Y г.")
+        })
+
+    async def create_billing_document_pdf(self, deal_id) -> BytesIO:
+        doc = await self._create_billing_document_html(deal_id)
+
+        pdf_file = BytesIO()
+        HTML(string=doc).write_pdf(pdf_file)
+
+        return pdf_file