import scrapy
from scrapy.exceptions import CloseSpider
from scrapy.http import JsonRequest


class CountriesSpider(scrapy.Spider):
    name = "countries"
    allowed_domains = ["countries.trevorblades.com"]
    url = "https://countries.trevorblades.com/"
    custom_settings = {
        "FEED_EXPORT_ENCODING": "utf-8",
    }

    async def start(self):
        query = """
query ContinentCountries($code: ID!) {
  continent(code: $code) {
    countries {
      code
      name
      capital
    }
  }
}
""".strip()

        body = {
            "operationName": "ContinentCountries",
            "query": query,
            "variables": {"code": "EU"},
        }

        yield JsonRequest(
            url=self.url,
            data=body,
            callback=self.parse,
        )

    def parse(self, response):
        body = response.json()
        if body.get("errors"):
            raise CloseSpider("GraphQL errors returned.")

        data = body.get("data") or {}
        continent = data.get("continent") or {}
        countries = continent.get("countries") or []
        if not countries:
            raise CloseSpider("No countries returned.")

        for row in countries:
            yield {
                "code": row.get("code"),
                "name": row.get("name"),
                "capital": row.get("capital"),
            }