app.py

import os
import tempfile
import asyncio
from fastapi import FastAPI, UploadFile, File, Request, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from paddleocr import PaddleOCR

MAX_FILE_SIZE = 900 * 1024
MAX_CONCURRENT_REQUESTS = 6

ALLOWED_ORIGINS = {
    "https://delivqr.com",
    "https://www.delivqr.com",
    "https://kreeboo.com",
    "https://www.kreeboo.com",
}

app = FastAPI(title="Paddle OCR API")

app.add_middleware(
    CORSMiddleware,
    allow_origins=list(ALLOWED_ORIGINS),
    allow_credentials=True,
    allow_methods=["POST"],
    allow_headers=["*"],
)

semaphore = asyncio.Semaphore(MAX_CONCURRENT_REQUESTS)
ocr_models = {}

@app.on_event("startup")
def load_model():
    ocr_models["en"] = PaddleOCR(
        lang="en",
        use_angle_cls=False,
        show_log=False
    )

@app.middleware("http")
async def restrict_domain(request: Request, call_next):
    origin = request.headers.get("origin")
    referer = request.headers.get("referer")

    if origin not in ALLOWED_ORIGINS and not (
        referer and any(referer.startswith(o) for o in ALLOWED_ORIGINS)
    ):
        raise HTTPException(status_code=403, detail="Access denied")

    return await call_next(request)


@app.post("/ocr")
async def ocr_api(file: UploadFile = File(...)):
    async with semaphore:

        data = await file.read()

        if len(data) > MAX_FILE_SIZE:
            raise HTTPException(413, "Image too large")

        if not file.content_type or not file.content_type.startswith("image/"):
            raise HTTPException(400, "Only image files allowed")

        with tempfile.NamedTemporaryFile(delete=False) as tmp:
            tmp.write(data)
            tmp_path = tmp.name

        try:
            result = ocr_models["en"].ocr(tmp_path)
        except Exception as e:
            raise HTTPException(500, f"OCR failed: {str(e)}")
        finally:
            os.remove(tmp_path)

        return {
            "language": "en",
            "lines": [line[1][0] for line in result[0]]
        }