with some tests

backend/main.py

@@ -1,7 +1,21 @@
-from fastapi import FastAPI
+from contextlib import asynccontextmanager
+from fastapi import FastAPI, Depends
 from fastapi.middleware.cors import CORSMiddleware
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
 
-app = FastAPI()
+from database import engine, get_db, Base
+from models import Counter
+
+
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    async with engine.begin() as conn:
+        await conn.run_sync(Base.metadata.create_all)
+    yield
+
+
+app = FastAPI(lifespan=lifespan)
 
 app.add_middleware(
     CORSMiddleware,
@@ -11,7 +25,27 @@ app.add_middleware(
 )
 
 
-@app.get("/api/hello")
-def hello():
-    return {"message": "Hello from FastAPI"}
+async def get_or_create_counter(db: AsyncSession) -> Counter:
+    result = await db.execute(select(Counter).where(Counter.id == 1))
+    counter = result.scalar_one_or_none()
+    if not counter:
+        counter = Counter(id=1, value=0)
+        db.add(counter)
+        await db.commit()
+        await db.refresh(counter)
+    return counter
+
+
+@app.get("/api/counter")
+async def get_counter(db: AsyncSession = Depends(get_db)):
+    counter = await get_or_create_counter(db)
+    return {"value": counter.value}
+
+
+@app.post("/api/counter/increment")
+async def increment_counter(db: AsyncSession = Depends(get_db)):
+    counter = await get_or_create_counter(db)
+    counter.value += 1
+    await db.commit()
+    return {"value": counter.value}