Update project 2nd iteration

backend/core/minio.py

@@ -0,0 +1,50 @@
+import os
+from contextlib import asynccontextmanager
+from typing import AsyncIterator
+
+import aioboto3
+from botocore.exceptions import ClientError
+
+MINIO_ENDPOINT: str = os.getenv("MINIO_ENDPOINT", "http://minio:9000")
+MINIO_ACCESS_KEY: str = os.getenv("MINIO_ACCESS_KEY", "minioadmin")
+MINIO_SECRET_KEY: str = os.getenv("MINIO_SECRET_KEY", "minioadminpassword")
+MINIO_BUCKET: str = os.getenv("MINIO_BUCKET", "tickets-media")
+
+_session = aioboto3.Session()
+
+
+@asynccontextmanager
+async def _s3_client() -> AsyncIterator:
+    async with _session.client(
+        "s3",
+        endpoint_url=MINIO_ENDPOINT,
+        aws_access_key_id=MINIO_ACCESS_KEY,
+        aws_secret_access_key=MINIO_SECRET_KEY,
+        region_name="us-east-1",  # MinIO не требует региона, но boto3 обязывает передать
+    ) as client:
+        yield client
+
+
+async def ensure_bucket_exists() -> None:
+    """Создаёт бакет при старте воркера, если он ещё не существует."""
+    async with _s3_client() as client:
+        try:
+            await client.head_bucket(Bucket=MINIO_BUCKET)
+        except ClientError as exc:
+            error_code = exc.response["Error"]["Code"]
+            if error_code in ("404", "NoSuchBucket"):
+                await client.create_bucket(Bucket=MINIO_BUCKET)
+            else:
+                raise
+
+
+async def upload_pdf(object_name: str, pdf_bytes: bytes) -> str:
+    """Загружает PDF в MinIO и возвращает публичный URL объекта."""
+    async with _s3_client() as client:
+        await client.put_object(
+            Bucket=MINIO_BUCKET,
+            Key=object_name,
+            Body=pdf_bytes,
+            ContentType="application/pdf",
+        )
+    return f"{MINIO_ENDPOINT}/{MINIO_BUCKET}/{object_name}"

backend/database/models.py

@@ -52,6 +52,7 @@ class Ticket(Base):
         index=True
     )
     idempotency_key: Mapped[str] = mapped_column(String, unique=True, nullable=True)
+    pdf_url: Mapped[str | None] = mapped_column(String, nullable=True)
     created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=lambda: datetime.now(timezone.utc))
     updated_at: Mapped[datetime] = mapped_column(
         DateTime(timezone=True), 

backend/requirements.txt

@@ -7,4 +7,7 @@ psycopg2-binary
 redis
 passlib[bcrypt]
 PyJWT
+aio-pika
+reportlab
+aioboto3
 pydantic[email]>=2.5.0

backend/worker.py

@@ -0,0 +1,135 @@
+"""
+Standalone worker: слушает очередь RabbitMQ 'ticket_events',
+генерирует PDF-билет через reportlab, загружает в MinIO,
+сохраняет pdf_url в PostgreSQL.
+"""
+import asyncio
+import io
+import json
+import logging
+import os
+from typing import Any
+
+import aio_pika
+from reportlab.lib.pagesizes import A4
+from reportlab.pdfgen import canvas
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
+
+from core.minio import ensure_bucket_exists, upload_pdf
+from database.models import Ticket
+
+logging.basicConfig(
+    level=logging.INFO,
+    format="%(asctime)s [%(levelname)s] %(name)s: %(message)s",
+)
+log = logging.getLogger("worker")
+
+RABBITMQ_URL: str = os.getenv("RABBITMQ_URL", "amqp://user:password@rabbitmq/")
+DATABASE_URL: str = os.getenv(
+    "DATABASE_URL",
+    "postgresql+asyncpg://admin:your_strong_password@postgres:5432/ticket_db",
+)
+QUEUE_NAME: str = "ticket_events"
+
+
+def _build_pdf(ticket_id: int, seat_id: int, user_id: int) -> bytes:
+    """Генерирует PDF-билет в памяти и возвращает байты."""
+    buffer = io.BytesIO()
+    pdf = canvas.Canvas(buffer, pagesize=A4)
+    width, height = A4
+
+    pdf.setFont("Helvetica-Bold", 24)
+    pdf.drawCentredString(width / 2, height - 80, "TICKET")
+
+    pdf.setFont("Helvetica", 14)
+    pdf.drawCentredString(width / 2, height - 130, f"Ticket ID: {ticket_id}")
+    pdf.drawCentredString(width / 2, height - 160, f"Seat ID:   {seat_id}")
+    pdf.drawCentredString(width / 2, height - 190, f"User ID:   {user_id}")
+
+    pdf.setFont("Helvetica-Oblique", 10)
+    pdf.drawCentredString(width / 2, 40, "Thank you for your purchase!")
+
+    pdf.save()
+    return buffer.getvalue()
+
+
+async def _handle_ticket_paid(
+    payload: dict[str, Any],
+    db_session: AsyncSession,
+) -> None:
+    ticket_id: int | None = payload.get("ticket_id")
+    if ticket_id is None:
+        log.error("Event 'ticket_paid' missing 'ticket_id': %s", payload)
+        return
+
+    result = await db_session.execute(select(Ticket).where(Ticket.id == ticket_id))
+    ticket: Ticket | None = result.scalar_one_or_none()
+
+    if ticket is None:
+        log.error("Ticket %s not found in DB", ticket_id)
+        return
+
+    if ticket.pdf_url:
+        log.info("Ticket %s already has a PDF, skipping (idempotency guard)", ticket_id)
+        return
+
+    log.info("Generating PDF for ticket %s …", ticket_id)
+    pdf_bytes = _build_pdf(
+        ticket_id=ticket.id,
+        seat_id=ticket.seat_id,
+        user_id=ticket.user_id or 0,
+    )
+
+    object_name = f"tickets/ticket_{ticket_id}.pdf"
+    pdf_url = await upload_pdf(object_name, pdf_bytes)
+    log.info("PDF uploaded: %s", pdf_url)
+
+    ticket.pdf_url = pdf_url
+    await db_session.commit()
+    log.info("Ticket %s updated with pdf_url", ticket_id)
+
+
+async def _process_message(
+    message: aio_pika.abc.AbstractIncomingMessage,
+    session_factory: async_sessionmaker[AsyncSession],
+) -> None:
+    async with message.process(requeue=True):
+        try:
+            payload: dict[str, Any] = json.loads(message.body)
+            action: str = payload.get("action", "")
+
+            if action == "ticket_paid":
+                async with session_factory() as session:
+                    await _handle_ticket_paid(payload, session)
+            else:
+                log.debug("Unknown action '%s', skipping", action)
+
+        except json.JSONDecodeError:
+            log.exception("Failed to decode message body: %r", message.body)
+            # Некорректный JSON — не возвращаем в очередь (requeue=False через reject)
+            await message.reject(requeue=False)
+
+
+async def main() -> None:
+    engine = create_async_engine(DATABASE_URL, echo=False)
+    session_factory = async_sessionmaker(engine, expire_on_commit=False, class_=AsyncSession)
+
+    await ensure_bucket_exists()
+    log.info("MinIO bucket ready")
+
+    connection = await aio_pika.connect_robust(RABBITMQ_URL)
+    async with connection:
+        channel = await connection.channel()
+        await channel.set_qos(prefetch_count=10)
+
+        queue = await channel.declare_queue(QUEUE_NAME, durable=True)
+        log.info("Worker started. Listening on queue '%s' …", QUEUE_NAME)
+
+        async with queue.iterator() as queue_iter:
+            async for message in queue_iter:
+                await _process_message(message, session_factory)
+
+
+if __name__ == "__main__":
+    asyncio.run(main())