import os, uuid, qrcode
from PIL import Image
from fastapi import UploadFile

UPLOAD_DIR = os.getenv("UPLOAD_DIR", "/uploads")

def save_upload(file: UploadFile, sub_dir: str = "general") -> str:
    """파일을 저장하고 /uploads 기준 상대 경로 반환"""
    ext = os.path.splitext(file.filename or "file")[1].lower() or ".jpg"
    folder = os.path.join(UPLOAD_DIR, sub_dir)
    os.makedirs(folder, exist_ok=True)
    filename = f"{uuid.uuid4().hex}{ext}"
    filepath = os.path.join(folder, filename)
    with open(filepath, "wb") as f:
        f.write(file.file.read())
    return f"/uploads/{sub_dir}/{filename}"

def generate_qr(charger_id: str, domain: str) -> str:
    """QR 이미지를 저장하고 /uploads 기준 경로 반환"""
    url = f"https://{domain}/report/{charger_id}"
    qr = qrcode.QRCode(version=1, box_size=10, border=4)
    qr.add_data(url)
    qr.make(fit=True)
    img = qr.make_image(fill_color="black", back_color="white")
    folder = os.path.join(UPLOAD_DIR, "qr")
    os.makedirs(folder, exist_ok=True)
    filepath = os.path.join(folder, f"{charger_id}.png")
    img.save(filepath)
    return f"/uploads/qr/{charger_id}.png"