Update app.py

app.py

@@ -1,21 +1,48 @@
 # app.py
-from fastapi import FastAPI, Request
-from fastapi.responses import JSONResponse
+from fastapi import FastAPI, Request, HTTPException
+from fastapi.responses import StreamingResponse
+import qrcode
+import io
 
 app = FastAPI()
 
+def stylize_text(text: str) -> str:
+    """Return the text with alternating upper/lower‑case characters (old behaviour)."""
+    return "".join(ch.upper() if idx % 2 == 0 else ch.lower() for idx, ch in enumerate(text))
+
+
 @app.post("/echo")
 async def echo(request: Request):
-    data = await request.json()
-    if len(data)==0:
-        return JSONResponse(content={"you_sent": "F you"})
-    lst=""
-    c=0
-    for i in data:
-        if c%2==0:
-            lst+=i.upper()
-        else:
-            lst+=i.lower()
-        c+=1
-        
-    return JSONResponse(content={"you_sent": lst})
+    """Accept JSON payload and respond with a QR‑code PNG encoding the stylised text."""
+    try:
+        payload = await request.json()
+    except Exception:
+        raise HTTPException(status_code=400, detail="Expected a JSON body")
+
+    if not payload:
+        raise HTTPException(status_code=400, detail="Payload cannot be empty")
+
+    # Normalise input
+    if isinstance(payload, str):
+        raw_text = payload
+    elif isinstance(payload, dict) and "text" in payload:
+        raw_text = str(payload["text"])
+    else:
+        # Fallback: convert entire JSON object to string
+        raw_text = str(payload)
+
+    # Apply old alternating‑case transformation
+    qr_text = stylize_text(raw_text)
+
+    # Build QR‑code
+    qr = qrcode.QRCode(box_size=10, border=4)
+    qr.add_data(qr_text)
+    qr.make(fit=True)
+    img = qr.make_image(fill_color="black", back_color="white")
+
+    # Send back PNG
+    buffer = io.BytesIO()
+    img.save(buffer, format="PNG")
+    buffer.seek(0)
+
+    return StreamingResponse(buffer, media_type="image/png")