"""The record a collector produces for one product page / search result."""
from __future__ import annotations

from dataclasses import dataclass, field
from decimal import Decimal
from typing import Any, Dict, List, Optional

SOURCE_TYPES = ("scraped_page", "search_snippet", "brand_official")


@dataclass
class Listing:
    site_domain: str
    source_sku: str
    source_url: str
    source_type: str
    brand_slug: str
    category: str
    title: str
    evidence_text: str
    confidence: float
    parser: str
    family: Optional[str] = None
    model: Optional[str] = None
    model_number: Optional[str] = None
    ram_gb: Optional[Decimal] = None
    storage_gb: Optional[Decimal] = None
    colour: Optional[str] = None
    price: Optional[Decimal] = None
    mrp: Optional[Decimal] = None
    availability: Optional[str] = None
    in_stock: Optional[bool] = None
    pincode: Optional[str] = None
    pincode_applied: bool = False
    rating: Optional[Decimal] = None
    review_count: Optional[int] = None
    # Customer reviews the page itself publishes (schema.org Review); stored
    # in elec.listing_review, not on the listing row.
    reviews: List[Dict[str, Any]] = field(default_factory=list)
    gtin: Optional[str] = None
    image_urls: List[str] = field(default_factory=list)
    specs_raw: Dict[str, Any] = field(default_factory=dict)
    specs: Dict[str, Any] = field(default_factory=dict)
    spec_sources: Dict[str, str] = field(default_factory=dict)
    search_query: Optional[str] = None
    content_hash: Optional[str] = None
    # Not stored on the listing; used for matching.
    variant_key: Optional[str] = None
    model_norm: Optional[str] = None
    processor: Optional[str] = None

    def validate(self) -> None:
        """The anti-fabrication contract, checked before anything is written."""
        if self.source_type not in SOURCE_TYPES:
            raise ValueError(f"bad source_type {self.source_type!r}")
        if not self.source_url.startswith(("http://", "https://")):
            raise ValueError("listing without a real source URL")
        if not self.evidence_text.strip():
            raise ValueError("listing without evidence text")
        if self.price is not None:
            if not (Decimal(500) <= self.price <= Decimal(1000000)):
                raise ValueError(f"implausible price {self.price}")
        if self.mrp is not None and self.price is not None and self.mrp < self.price:
            self.mrp = None
        if self.pincode_applied and not self.pincode:
            raise ValueError("pincode_applied without a pincode")
        if not 0 <= self.confidence <= 1:
            raise ValueError("confidence out of range")