munch-ease-backend/products/coles.py

import re
from typing import Optional, Tuple

import httpx

HEADERS = {
    "User-Agent": "Mozilla/5.0 (X11; Linux x86_64; rv:121.0) Gecko/20100101 Firefox/121.0",
    "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8",
    "Accept-Language": "en-US,en;q=0.5",
    "Accept-Encoding": "gzip, deflate, br",
    "DNT": "1",
    "Sec-GPC": "1",
    "Connection": "keep-alive",
    "Upgrade-Insecure-Requests": "1",
    "Sec-Fetch-Dest": "document",
    "Sec-Fetch-Mode": "navigate",
    "Sec-Fetch-Site": "none",
    "Sec-Fetch-User": "?1",
    "Pragma": "no-cache",
    "Cache-Control": "no-cache",
}


async def _get_cookies(client):
    # Make a request to https://www.coles.com.au/ as if we were a normal browser, then return the cookies
    response = await client.get(
        "https://www.coles.com.au/product/coles-strawberries-250g-5191256",
        headers=HEADERS,
        follow_redirects=True,
    )
    version = re.findall(r"202[4-9][01]\d[0-2]\d.02_v\d.\d\d.\d", response.text)

    if len(version) == 0:
        raise Exception("Could not find the Coles API")

    return dict(response.cookies), version[0]


def _get_package_size(size: str) -> Tuple[int, str]:
    if size:
        match = re.match(r"(\d+)(.*)", size)
        if match:
            return int(match.group(1)), match.group(2)

    return 1, "items"


def _get_client():
    return httpx.AsyncClient()


api_details = None


async def _request_details(product_id: str) -> Optional[dict]:
    global api_details

    async with _get_client() as client:
        if not api_details:
            api_details = await _get_cookies(client)

        cookies, api_version = api_details

        url = _get_product_details_url(api_version, product_id)
        try:
            response = await client.get(
                url, headers=HEADERS, follow_redirects=True, cookies=cookies
            )
            response.raise_for_status()
            return response.json()
        except httpx.HTTPError as ne:
            print(ne)
            api_details = None

            return None


def _get_product_details_url(version: str, product_id: str) -> str:
    # https://www.coles.com.au/_next/data/20240926.02_v4.18.0/en/product/cadbury-favourites-boxed-chocolate-340g-3571992.json?slug=cadbury-favourites-boxed-chocolate-340g-3571992
    # https://www.coles.com.au/_next/data/20240926.02_v4.18.0/en/product/coles-blueberries-170g-3571948.json?slug=coles-blueberries-170g-3571948
    #
    return f"https://www.coles.com.au/_next/data/{version}/en/product/{product_id}.json"


def get_product_id(url: str) -> Optional[str]:
    # https://www.coles.com.au/product/cadbury-favourites-boxed-chocolate-340g-3571992
    regex = r"https://www.coles.com.au/product/([^/]+)/?.*"
    match = re.match(regex, url)
    if match:
        return match.group(1)
    return None


async def scrape(product_id: str) -> Tuple[dict, dict]:
    raw_data = await _request_details(product_id)
    if raw_data is None:
        raw_data = {"pageProps": {"product": {"size": "", "images": []}}}

    product = raw_data["pageProps"]["product"]

    quantity, unit = _get_package_size(product["size"])

    img_prefix = "https://shop.coles.com.au"
    images = product["images"][0]
    product_data = {
        "name": product["name"],
        "quantity": quantity,
        "unit": unit,
        "img_small": (img_prefix + images["thumb"]["path"]) if images else None,
        "img_large": (img_prefix + images["full"]["path"]) if images else None,
    }

    return product_data, raw_data