Initial commit

.envrc

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+layout python

.gitignore

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+__pycache__
+/.direnv

inflatinator/__main__.py

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+import revbank
+import sys
+
+
+def main(product_file):
+    with open(product_file, 'r') as fd:
+        src = fd.read()
+
+    new_src = revbank.update_product_pricings(src)
+
+    with open(product_file, 'w') as fd:
+        fd.write(new_src)
+
+
+if __name__ == '__main__':
+    main(sys.argv[1])

inflatinator/revbank.py

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+import re
+import scrapers
+from decimal import Decimal, ROUND_UP
+
+
+our_margin = Decimal('1.3')
+
+
+def find_product_details(vendor_and_sku):
+    [vendor, sku] = vendor_and_sku.split(':', 2)
+
+    if vendor == 'ah':
+        return scrapers.ah_get_by_sku(sku)
+
+    raise Exception(f'unknown vendor: {vendor}')
+
+
+def update_product_pricings(src):
+    lines = src.split('\n')
+
+    find_updatable = re.compile(r'#\s*(?P<sku>\S+)\s+(?P<units>\d+)x$')
+    find_aliases = re.compile(r'^(?P<aliases>\S+)')
+
+    lines_out = []
+
+    for line in lines:
+        m = find_updatable.search(line)
+        if not m:
+            lines_out.append(line)
+            continue
+
+        d = find_product_details(m['sku'])
+
+        product_aliases = set()
+        if not line.startswith('#'):
+            product_aliases = set(find_aliases.search(line)['aliases'].split(','))
+        product_aliases.add(d['ean'])
+
+        aliases = ','.join(sorted(product_aliases))
+        units = int(m["units"])
+        price = d['price']
+
+        # Apply a 30% margin and divide by the number of units per sold packaging.
+        unit_price = price * our_margin / units
+        # Round up to 5ct.
+        unit_price = (unit_price * 20).quantize(Decimal('1'), rounding=ROUND_UP) / 20
+
+        lines_out.append(f'{aliases}\t{unit_price:.2f}\t{d["name"]}  # {m["sku"]} {units}x')
+
+    return '\n'.join(lines_out)

inflatinator/scrapers.py

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+from decimal import Decimal
+from pyquery import PyQuery as pq
+import json
+import re
+import subprocess
+
+
+def get(url):
+    compl = subprocess.run(['links', '-source', url], capture_output=True)
+    return compl.stdout
+
+
+def ah_get_by_sku(ah_sku):
+    assert re.match('^wi\d+$', ah_sku)
+
+    html_src = get(f'https://www.ah.nl/producten/product/{ah_sku}')
+    doc = pq(html_src)
+
+    ld_jsons = doc('script[type="application/ld+json"]')
+    for j in ld_jsons:
+        schema = json.loads(j.text)
+        if schema['@type'] == 'Product' and schema['sku'] == ah_sku:
+            break
+    else:
+        raise Exception(f'ah.nl returned no JSON metadata for SKU {ah_sku}')
+
+    name = schema['name']
+    ean = schema['gtin13']
+    sku = schema['sku']
+    price = Decimal(schema['offers']['price'])
+
+    return {
+        'name': name,
+        'price': price,
+        'ean': ean,
+        'sku': sku,
+    }