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changedetection.io/changedetectionio/processors/restock_diff/processor.py

275 lines
14 KiB

from .. import difference_detection_processor
from ..exceptions import ProcessorException
from . import Restock
from loguru import logger
import urllib3
import time
urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)
name = 'Re-stock & Price detection for single product pages'
description = 'Detects if the product goes back to in-stock'
class UnableToExtractRestockData(Exception):
def __init__(self, status_code):
# Set this so we can use it in other parts of the app
self.status_code = status_code
return
class MoreThanOnePriceFound(Exception):
def __init__(self):
return
def _search_prop_by_value(matches, value):
for properties in matches:
for prop in properties:
if value in prop[0]:
return prop[1] # Yield the desired value and exit the function
# should return Restock()
# add casting?
def get_itemprop_availability(html_content) -> Restock:
"""
Kind of funny/cool way to find price/availability in one many different possibilities.
Use 'extruct' to find any possible RDFa/microdata/json-ld data, make a JSON string from the output then search it.
"""
from jsonpath_ng import parse
import re
now = time.time()
import extruct
logger.trace(f"Imported extruct module in {time.time() - now:.3f}s")
now = time.time()
# Extruct is very slow, I'm wondering if some ML is going to be faster (800ms on my i7), 'rdfa' seems to be the heaviest.
syntaxes = ['dublincore', 'json-ld', 'microdata', 'microformat', 'opengraph']
try:
data = extruct.extract(html_content, syntaxes=syntaxes)
except Exception as e:
logger.warning(f"Unable to extract data, document parsing with extruct failed with {type(e).__name__} - {str(e)}")
return Restock()
logger.trace(f"Extruct basic extract of all metadata done in {time.time() - now:.3f}s")
# First phase, dead simple scanning of anything that looks useful
value = Restock()
if data:
logger.debug(f"Using jsonpath to find price/availability/etc")
price_parse = parse('$..(price|Price)')
pricecurrency_parse = parse('$..(pricecurrency|currency|priceCurrency )')
availability_parse = parse('$..(availability|Availability)')
price_result = price_parse.find(data)
if price_result:
# Right now, we just support single product items, maybe we will store the whole actual metadata seperately in teh future and
# parse that for the UI?
prices_found = set(str(item.value).replace('$', '') for item in price_result)
if len(price_result) > 1 and len(prices_found) > 1:
# See of all prices are different, in the case that one product has many embedded data types with the same price
# One might have $121.95 and another 121.95 etc
logger.warning(f"More than one price found {prices_found}, throwing exception, cant use this plugin.")
raise MoreThanOnePriceFound()
value['price'] = price_result[0].value
pricecurrency_result = pricecurrency_parse.find(data)
if pricecurrency_result:
value['currency'] = pricecurrency_result[0].value
availability_result = availability_parse.find(data)
if availability_result:
value['availability'] = availability_result[0].value
if value.get('availability'):
value['availability'] = re.sub(r'(?i)^(https|http)://schema.org/', '',
value.get('availability').strip(' "\'').lower()) if value.get('availability') else None
# Second, go dig OpenGraph which is something that jsonpath_ng cant do because of the tuples and double-dots (:)
if not value.get('price') or value.get('availability'):
logger.debug(f"Alternatively digging through OpenGraph properties for restock/price info..")
jsonpath_expr = parse('$..properties')
for match in jsonpath_expr.find(data):
if not value.get('price'):
value['price'] = _search_prop_by_value([match.value], "price:amount")
if not value.get('availability'):
value['availability'] = _search_prop_by_value([match.value], "product:availability")
if not value.get('currency'):
value['currency'] = _search_prop_by_value([match.value], "price:currency")
logger.trace(f"Processed with Extruct in {time.time()-now:.3f}s")
return value
def is_between(number, lower=None, upper=None):
"""
Check if a number is between two values.
Parameters:
number (float): The number to check.
lower (float or None): The lower bound (inclusive). If None, no lower bound.
upper (float or None): The upper bound (inclusive). If None, no upper bound.
Returns:
bool: True if the number is between the lower and upper bounds, False otherwise.
"""
return (lower is None or lower <= number) and (upper is None or number <= upper)
class perform_site_check(difference_detection_processor):
screenshot = None
xpath_data = None
def run_changedetection(self, watch, skip_when_checksum_same=True):
import hashlib
from concurrent.futures import ProcessPoolExecutor
from functools import partial
if not watch:
raise Exception("Watch no longer exists.")
# Unset any existing notification error
update_obj = {'last_notification_error': False, 'last_error': False, 'restock': Restock()}
self.screenshot = self.fetcher.screenshot
self.xpath_data = self.fetcher.xpath_data
# Track the content type
update_obj['content_type'] = self.fetcher.headers.get('Content-Type', '')
update_obj["last_check_status"] = self.fetcher.get_last_status_code()
# Which restock settings to compare against?
restock_settings = watch.get('restock_settings', {})
# See if any tags have 'activate for individual watches in this tag/group?' enabled and use the first we find
for tag_uuid in watch.get('tags'):
tag = self.datastore.data['settings']['application']['tags'].get(tag_uuid, {})
if tag.get('overrides_watch'):
restock_settings = tag.get('restock_settings', {})
logger.info(f"Watch {watch.get('uuid')} - Tag '{tag.get('title')}' selected for restock settings override")
break
itemprop_availability = {}
try:
with ProcessPoolExecutor() as executor:
# Use functools.partial to create a callable with arguments
# anything using bs4/lxml etc is quite "leaky"
future = executor.submit(partial(get_itemprop_availability, self.fetcher.content))
itemprop_availability = future.result()
except MoreThanOnePriceFound as e:
# Add the real data
raise ProcessorException(message="Cannot run, more than one price detected, this plugin is only for product pages with ONE product, try the content-change detection mode.",
url=watch.get('url'),
status_code=self.fetcher.get_last_status_code(),
screenshot=self.fetcher.screenshot,
xpath_data=self.fetcher.xpath_data
)
# Something valid in get_itemprop_availability() by scraping metadata ?
if itemprop_availability.get('price') or itemprop_availability.get('availability'):
# Store for other usage
update_obj['restock'] = itemprop_availability
if itemprop_availability.get('availability'):
# @todo: Configurable?
if any(substring.lower() in itemprop_availability['availability'].lower() for substring in [
'instock',
'instoreonly',
'limitedavailability',
'onlineonly',
'presale']
):
update_obj['restock']['in_stock'] = True
else:
update_obj['restock']['in_stock'] = False
# Main detection method
fetched_md5 = None
# store original price if not set
if itemprop_availability and itemprop_availability.get('price') and not itemprop_availability.get('original_price'):
itemprop_availability['original_price'] = itemprop_availability.get('price')
update_obj['restock']["original_price"] = itemprop_availability.get('price')
if not self.fetcher.instock_data and not itemprop_availability.get('availability'):
raise ProcessorException(
message=f"Unable to extract restock data for this page unfortunately. (Got code {self.fetcher.get_last_status_code()} from server), no embedded stock information was found and nothing interesting in the text, try using this watch with Chrome.",
url=watch.get('url'),
status_code=self.fetcher.get_last_status_code(),
screenshot=self.fetcher.screenshot,
xpath_data=self.fetcher.xpath_data
)
# Nothing automatic in microdata found, revert to scraping the page
if self.fetcher.instock_data and itemprop_availability.get('availability') is None:
# 'Possibly in stock' comes from stock-not-in-stock.js when no string found above the fold.
# Careful! this does not really come from chrome/js when the watch is set to plaintext
update_obj['restock']["in_stock"] = True if self.fetcher.instock_data == 'Possibly in stock' else False
logger.debug(f"Watch UUID {watch.get('uuid')} restock check returned '{self.fetcher.instock_data}' from JS scraper.")
# What we store in the snapshot
price = update_obj.get('restock').get('price') if update_obj.get('restock').get('price') else ""
snapshot_content = f"In Stock: {update_obj.get('restock').get('in_stock')} - Price: {price}"
# Main detection method
fetched_md5 = hashlib.md5(snapshot_content.encode('utf-8')).hexdigest()
# The main thing that all this at the moment comes down to :)
changed_detected = False
logger.debug(f"Watch UUID {watch.get('uuid')} restock check - Previous MD5: {watch.get('previous_md5')}, Fetched MD5 {fetched_md5}")
# out of stock -> back in stock only?
if watch.get('restock') and watch['restock'].get('in_stock') != update_obj['restock'].get('in_stock'):
# Yes if we only care about it going to instock, AND we are in stock
if restock_settings.get('in_stock_processing') == 'in_stock_only' and update_obj['restock']['in_stock']:
changed_detected = True
if restock_settings.get('in_stock_processing') == 'all_changes':
# All cases
changed_detected = True
if restock_settings.get('follow_price_changes') and watch.get('restock') and update_obj.get('restock') and update_obj['restock'].get('price'):
price = float(update_obj['restock'].get('price'))
# Default to current price if no previous price found
if watch['restock'].get('original_price'):
previous_price = float(watch['restock'].get('original_price'))
# It was different, but negate it further down
if price != previous_price:
changed_detected = True
# Minimum/maximum price limit
if update_obj.get('restock') and update_obj['restock'].get('price'):
logger.debug(
f"{watch.get('uuid')} - Change was detected, 'price_change_max' is '{restock_settings.get('price_change_max', '')}' 'price_change_min' is '{restock_settings.get('price_change_min', '')}', price from website is '{update_obj['restock'].get('price', '')}'.")
if update_obj['restock'].get('price'):
min_limit = float(restock_settings.get('price_change_min')) if restock_settings.get('price_change_min') else None
max_limit = float(restock_settings.get('price_change_max')) if restock_settings.get('price_change_max') else None
price = float(update_obj['restock'].get('price'))
logger.debug(f"{watch.get('uuid')} after float conversion - Min limit: '{min_limit}' Max limit: '{max_limit}' Price: '{price}'")
if min_limit or max_limit:
if is_between(number=price, lower=min_limit, upper=max_limit):
# Price was between min/max limit, so there was nothing todo in any case
logger.trace(f"{watch.get('uuid')} {price} is between {min_limit} and {max_limit}, nothing to check, forcing changed_detected = False (was {changed_detected})")
changed_detected = False
else:
logger.trace(f"{watch.get('uuid')} {price} is between {min_limit} and {max_limit}, continuing normal comparison")
# Price comparison by %
if watch['restock'].get('original_price') and changed_detected and restock_settings.get('price_change_threshold_percent'):
previous_price = float(watch['restock'].get('original_price'))
pc = float(restock_settings.get('price_change_threshold_percent'))
change = abs((price - previous_price) / previous_price * 100)
if change and change <= pc:
logger.debug(f"{watch.get('uuid')} Override change-detected to FALSE because % threshold ({pc}%) was {change:.3f}%")
changed_detected = False
else:
logger.debug(f"{watch.get('uuid')} Price change was {change:.3f}% , (threshold {pc}%)")
# Always record the new checksum
update_obj["previous_md5"] = fetched_md5
return changed_detected, update_obj, snapshot_content.encode('utf-8').strip()