import json
from json import JSONDecodeError

import scrapy


class JsonldProductSpider(scrapy.Spider):
    name = "jsonld_product"
    start_urls = ["https://shop.example.com/products/starter-plan"]

    def parse(self, response):
        for raw in response.css('script[type="application/ld+json"]::text').getall():
            for obj in self.iter_jsonld_objects(raw):
                if not self.is_target_type(obj, "Product"):
                    continue

                offers = obj.get("offers") or {}
                yield {
                    "name": obj.get("name"),
                    "sku": obj.get("sku"),
                    "price": offers.get("price"),
                    "currency": offers.get("priceCurrency"),
                    "url": response.url,
                    "jsonld_type": obj.get("@type"),
                }

    def iter_jsonld_objects(self, raw):
        try:
            data = json.loads(raw.strip())
        except JSONDecodeError:
            return

        if isinstance(data, dict) and isinstance(data.get("@graph"), list):
            for node in data["@graph"]:
                if isinstance(node, dict):
                    yield node
            return

        if isinstance(data, list):
            for node in data:
                if isinstance(node, dict):
                    yield node
            return

        if isinstance(data, dict):
            yield data

    def is_target_type(self, obj, target):
        value = obj.get("@type")

        if isinstance(value, str):
            return value == target

        if isinstance(value, list):
            return target in value

        return False