| from __future__ import annotations |
|
|
| import json |
| from pathlib import Path |
| from typing import Any, Mapping |
| from urllib.parse import urlparse |
|
|
|
|
| HOME_COMMERCE_FIXTURE = "home-commerce-complete-2026-07-25.json" |
| HOME_COMMERCE_EVIDENCE_CLASSES = frozenset( |
| { |
| "direct-home-commerce", |
| "regional-converted-home-commerce", |
| "local-simulation-home-commerce", |
| } |
| ) |
|
|
|
|
| class HomeCommerceError(ValueError): |
| pass |
|
|
|
|
| def load_home_commerce_offers( |
| fixture_root: Path, |
| home_catalog: Mapping[str, Mapping[str, Any]], |
| ) -> tuple[dict[str, Any], ...]: |
| """Load dated default offers without widening their evidence boundary.""" |
|
|
| fixture_root = fixture_root.resolve() |
| candidate = (fixture_root / HOME_COMMERCE_FIXTURE).resolve() |
| if fixture_root not in candidate.parents or not candidate.is_file(): |
| raise HomeCommerceError("home commerce fixture does not exist") |
| try: |
| payload = json.loads(candidate.read_text(encoding="utf-8")) |
| except (OSError, json.JSONDecodeError) as exc: |
| raise HomeCommerceError("home commerce fixture is invalid") from exc |
| if payload.get("schema") != "amazon-clone.home-commerce-offers.v2": |
| raise HomeCommerceError("unsupported home commerce fixture schema") |
| offers = payload.get("offers") |
| if not isinstance(offers, list) or not offers: |
| raise HomeCommerceError("home commerce offers must be a non-empty array") |
| if payload.get("sourceHomepageProducts") != 157: |
| raise HomeCommerceError("home commerce fixture has an invalid source denominator") |
| if payload.get("sourceOfferCount") != len(offers): |
| raise HomeCommerceError("home commerce fixture offer count is inconsistent") |
| if len(offers) != 157: |
| raise HomeCommerceError("home commerce fixture must cover all homepage products") |
| expected_counts = payload.get("evidenceClassCounts") |
| if not isinstance(expected_counts, dict): |
| raise HomeCommerceError("home commerce evidence counts are missing") |
|
|
| normalized: list[dict[str, Any]] = [] |
| seen: set[str] = set() |
| for offer in offers: |
| if not isinstance(offer, dict): |
| raise HomeCommerceError("home commerce offers must be objects") |
| asin = offer.get("asin") |
| home_product = home_catalog.get(str(asin)) |
| title = offer.get("title") |
| price_minor = offer.get("price_minor") |
| currency = offer.get("currency") |
| source_url = offer.get("source_url") |
| evidence_class = offer.get("evidence_class") |
| if ( |
| not isinstance(asin, str) |
| or len(asin) != 10 |
| or asin in seen |
| or home_product is None |
| ): |
| raise HomeCommerceError("home commerce offer has an invalid ASIN") |
| if not isinstance(title, str) or not title.strip(): |
| raise HomeCommerceError(f"home commerce offer {asin} has no title") |
| if ( |
| isinstance(price_minor, bool) |
| or not isinstance(price_minor, int) |
| or price_minor <= 0 |
| or currency != "USD" |
| ): |
| raise HomeCommerceError(f"home commerce offer {asin} has an invalid price") |
| if evidence_class not in HOME_COMMERCE_EVIDENCE_CLASSES: |
| raise HomeCommerceError( |
| f"home commerce offer {asin} has an invalid evidence class" |
| ) |
| if not isinstance(source_url, str): |
| raise HomeCommerceError(f"home commerce offer {asin} has an invalid source URL") |
| parsed_source = urlparse(source_url) |
| if ( |
| parsed_source.scheme != "https" |
| or parsed_source.hostname not in {"www.amazon.com", "www.amazon.sg"} |
| or asin not in parsed_source.path |
| ): |
| raise HomeCommerceError(f"home commerce offer {asin} has an invalid source URL") |
| if evidence_class == "regional-converted-home-commerce": |
| source_price_minor = offer.get("source_price_minor") |
| if ( |
| parsed_source.hostname != "www.amazon.sg" |
| or isinstance(source_price_minor, bool) |
| or not isinstance(source_price_minor, int) |
| or source_price_minor <= 0 |
| or offer.get("source_currency") != "SGD" |
| or not offer.get("conversion_rate_source") |
| ): |
| raise HomeCommerceError( |
| f"regional home commerce offer {asin} is incomplete" |
| ) |
| if evidence_class == "local-simulation-home-commerce" and not offer.get( |
| "simulation_disclosure" |
| ): |
| raise HomeCommerceError( |
| f"local simulation home commerce offer {asin} is undisclosed" |
| ) |
| if not ( |
| offer.get("local_add_to_cart_enabled") |
| and offer.get("local_buy_now_enabled") |
| ): |
| raise HomeCommerceError( |
| f"home commerce offer {asin} has incomplete local purchase controls" |
| ) |
| image_path = home_product.get("image_path") |
| if not isinstance(image_path, str) or not image_path.startswith("/static/"): |
| raise HomeCommerceError(f"home commerce offer {asin} has no local image") |
| seen.add(asin) |
| normalized.append( |
| { |
| "asin": asin, |
| "slug": "home-offer", |
| "canonical_path": f"/dp/{asin}", |
| "title": title, |
| "brand": "", |
| "capacity": "", |
| "color": "", |
| "price_minor": price_minor, |
| "list_price_minor": None, |
| "currency": "USD", |
| "rating": "", |
| "reviews": 0, |
| "image_path": image_path, |
| "badge": "", |
| "evidence_class": evidence_class, |
| "offer_observation_source": str( |
| offer.get("price_observation_source") or "" |
| ), |
| "purchase_state": str(offer.get("purchase_state") or ""), |
| "source_capture": str(offer.get("source_capture") or ""), |
| "source_url": source_url, |
| "offer_disclosure": ( |
| "Direct USD offer captured from the product's Amazon purchase surface." |
| if evidence_class == "direct-home-commerce" |
| else "USD quote converted from a dated Amazon regional offer." |
| if evidence_class == "regional-converted-home-commerce" |
| else "Offline-only local simulation quote." |
| ), |
| } |
| ) |
| observed_counts = { |
| evidence_class: sum( |
| offer["evidence_class"] == evidence_class for offer in normalized |
| ) |
| for evidence_class in HOME_COMMERCE_EVIDENCE_CLASSES |
| } |
| if observed_counts != expected_counts: |
| raise HomeCommerceError("home commerce evidence counts are inconsistent") |
| return tuple(normalized) |
|
|
