munch-ease-backend/recipes/scraping.py

291 lines
9.8 KiB
Python

import json
from typing import Optional, Iterable, List
import httpx
from bs4 import BeautifulSoup
# A realistic browser header profile improves success rates against some CDNs/bot protections.
DEFAULT_HEADERS = {
"Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8",
"Accept-Language": "en-US,en;q=0.9",
"Accept-Encoding": "gzip, deflate, br",
"Connection": "keep-alive",
"Upgrade-Insecure-Requests": "1",
"Sec-Fetch-Dest": "document",
"Sec-Fetch-Mode": "navigate",
"Sec-Fetch-Site": "none",
"Sec-Fetch-User": "?1",
# A modern desktop Chrome UA with platform tokens; not tied to any user data.
"User-Agent": (
"Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) "
"Chrome/127.0.0.0 Safari/537.36"
),
}
def _is_recipe_ldata(ldata_node) -> bool:
if "@type" in ldata_node:
typ = ldata_node["@type"]
if isinstance(typ, list):
typ = typ[0]
if isinstance(typ, str) and typ.lower() == "recipe":
return True
return False
def _fallback_urls(url: str) -> Iterable[str]:
"""Generate fallback URLs to try if the primary request is blocked.
Strategy:
- original URL
- add `?output=amp` if no existing query
- add `&output=amp` if query exists
- try `/amp` path suffix if not already present
"""
yield url
try:
from urllib.parse import urlparse, urlunparse, parse_qsl, urlencode
parsed = urlparse(url)
q = dict(parse_qsl(parsed.query, keep_blank_values=True))
if q.get("output") != "amp":
q["output"] = "amp"
amp_url = urlunparse(parsed._replace(query=urlencode(q, doseq=True)))
if amp_url != url:
yield amp_url
# Try a path-based AMP fallback
if not parsed.path.endswith("/amp"):
amp_path = parsed.path.rstrip("/") + "/amp"
amp2 = urlunparse(parsed._replace(path=amp_path))
if amp2 != url:
yield amp2
except Exception:
# Be conservative if URL parsing fails
pass
BLOCK_STATUSES = {403, 406, 429, 460}
async def scrape_recipe_ldata(url: str) -> Optional[dict]:
# Try the URL with browser-like headers and fallback strategies when blocked.
async with httpx.AsyncClient() as client:
for candidate in _fallback_urls(url):
# Some CDNs prefer a referer; provide same-origin referer as a harmless hint.
headers = dict(DEFAULT_HEADERS)
headers.setdefault("Referer", candidate)
response = await client.get(candidate, headers=headers, follow_redirects=True)
if response.status_code in BLOCK_STATUSES:
# Try next fallback
continue
if response.status_code >= 300:
# Try next fallback on non-2xx
continue
# Extract the recipe ld+json data from this candidate
soup = BeautifulSoup(response.text, "html.parser")
for ld in soup.find_all("script", type="application/ld+json"):
try:
text = ld.text.strip()
# Some sites embed multiple JSON objects without an array. Try to coerce if needed.
try:
data = json.loads(text)
except json.decoder.JSONDecodeError:
# Attempt to split objects and wrap in a list (best-effort)
# Very conservative: only try if it looks like multiple root objects.
if text.count("{") > 1 and "}\n{" in text:
parts = [p for p in text.split("\n") if p.strip()]
maybe = "[" + ",".join(parts) + "]"
data = json.loads(maybe)
else:
raise
# _dump_json_data_to_log(data)
if _is_recipe_ldata(data):
return data
if "@graph" in data:
for item in data["@graph"]:
if _is_recipe_ldata(item):
return item
if isinstance(data, list):
for item in data:
if _is_recipe_ldata(item):
return item
except (json.decoder.JSONDecodeError, KeyError):
pass
# Fallback 1: microdata (itemtype Recipe, itemprop recipeIngredient)
md = _extract_recipe_from_microdata(soup)
if md:
return md
# Fallback 2: heuristic DOM extraction around "Ingredients" section
hd = _extract_recipe_heuristic(soup, candidate)
if hd:
return hd
return None
# Fallback return to satisfy static analysis
return None
def _dump_json_data_to_log(data: dict) -> str:
import os
import re
dir = "./data/dump"
if not os.path.exists(dir):
os.makedirs(dir)
prefix = "ldata_"
suffix = ".json"
file_ids = [
int(re.findall(r"\d+", f)[0])
for f in os.listdir(dir)
if re.match(prefix + r"\d+" + suffix, f)
]
id = max(file_ids) + 1 if file_ids else 0
filename = f"{prefix}{id}{suffix}"
full_path = os.path.join(dir, filename)
with open(full_path, "w") as f:
json.dump(data, f, indent=4)
return full_path
def _extract_text(el) -> str:
return " ".join(el.get_text(" ", strip=True).split()) if el else ""
def _extract_recipe_from_microdata(soup: BeautifulSoup) -> Optional[dict]:
import re
candidates = []
for node in soup.find_all(attrs={"itemtype": re.compile(r"schema\.org/Recipe", re.I)}):
candidates.append(node)
# Some sites omit itemtype but use itemprop markers globally
if not candidates:
candidates = [soup]
def get_itemprop(node, prop) -> Optional[str]:
el = node.find(attrs={"itemprop": prop})
if not el:
return None
# Support <meta content>, <img src>, or text
if el.has_attr("content"):
return el["content"]
if el.has_attr("src"):
return el["src"]
if el.has_attr("href"):
return el["href"]
return _extract_text(el)
for node in candidates:
# Gather ingredients by itemprop
ingredients: List[str] = []
for prop in ("recipeIngredient", "ingredients"):
for ing_el in node.find_all(attrs={"itemprop": prop}):
t = _extract_text(ing_el)
if t:
ingredients.append(t)
name = get_itemprop(node, "name") or get_itemprop(soup, "og:title") or None
image = (
get_itemprop(node, "image")
or get_itemprop(soup, "og:image")
or get_itemprop(soup, "twitter:image")
)
if image:
images = [image]
else:
images = []
ry = get_itemprop(node, "recipeYield") or get_itemprop(soup, "recipeYield")
# Minimal viability: at least one ingredient and a name
if ingredients and (name or len(ingredients) >= 2):
out = {"@type": "Recipe", "recipeIngredient": ingredients}
if name:
out["name"] = name
if images:
out["image"] = images
if ry:
out["recipeYield"] = ry
return out
return None
def _extract_recipe_heuristic(soup: BeautifulSoup, page_url: str) -> Optional[dict]:
"""Best-effort heuristic extraction when no structured data is present.
- Finds an Ingredients heading and the nearest list (ul/ol)
- Or any element with class/id containing 'ingredient' and list items
- Derives name from og:title or <title>
- Derives image from og:image if available
"""
import re
# Try explicit ingredients container by class/id
candidates = []
for el in soup.find_all(True, attrs={"class": re.compile("ingredient", re.I)}):
candidates.append(el)
for el in soup.find_all(True, attrs={"id": re.compile("ingredient", re.I)}):
candidates.append(el)
def collect_list_items(node) -> List[str]:
items: List[str] = []
for ul in node.find_all(["ul", "ol"]):
for li in ul.find_all("li"):
t = _extract_text(li)
if t:
items.append(t)
return items
ingredients: List[str] = []
for node in candidates:
ingredients = collect_list_items(node)
if ingredients:
break
# Try heading-based approach
if not ingredients:
for h in soup.find_all(["h1", "h2", "h3", "h4", "h5", "h6"]):
if "ingredient" in _extract_text(h).lower():
# Try next sibling lists or parent lists
sib = h.find_next_sibling()
tries = [sib, h.parent]
for t in tries:
if not t:
continue
lst = collect_list_items(t)
if lst:
ingredients = lst
break
if ingredients:
break
if not ingredients:
return None
# Name and image fallbacks
name = None
og_title = soup.find("meta", attrs={"property": "og:title"})
if og_title and og_title.has_attr("content"):
name = og_title["content"]
if not name and soup.title:
name = _extract_text(soup.title)
image = None
og_image = soup.find("meta", attrs={"property": "og:image"})
if og_image and og_image.has_attr("content"):
image = og_image["content"]
out = {"@type": "Recipe", "recipeIngredient": ingredients}
out["name"] = name or page_url
if image:
out["image"] = [image]
return out