from datetime import date
import os
from urllib.parse import urlencode

import scrapy


class ChartSpider(scrapy.Spider):
    name = "chart"
    allowed_domains = ["data.example.net"]
    api_url = "https://data.example.net/v1/charts"

    def __init__(
        self,
        symbol="MSFT",
        interval="1d",
        start="2026-04-01",
        end="2026-04-03",
        *args,
        **kwargs,
    ):
        super().__init__(*args, **kwargs)
        self.symbol = symbol.strip().upper()
        self.interval = interval.strip()
        self.start_date = self._parse_day(start, "start")
        self.end_date = self._parse_day(end, "end")

    def _parse_day(self, value, label):
        try:
            return date.fromisoformat(str(value)).isoformat()
        except ValueError as exc:
            raise ValueError(f"{label} must use YYYY-MM-DD") from exc

    def _headers(self):
        headers = {"Accept": "application/json"}
        api_token = os.getenv("CHART_API_TOKEN")
        if api_token:
            headers["Authorization"] = f"Bearer {api_token}"
        return headers

    async def start(self):
        params = urlencode(
            {
                "symbol": self.symbol,
                "interval": self.interval,
                "start": self.start_date,
                "end": self.end_date,
            }
        )
        yield scrapy.Request(
            url=f"{self.api_url}?{params}",
            headers=self._headers(),
            callback=self.parse,
        )

    def parse(self, response):
        payload = response.json()
        bars = payload.get("bars")
        if not isinstance(bars, list):
            self.logger.error("Missing bars list")
            return

        symbol = payload.get("symbol") or self.symbol
        for bar in bars:
            if not isinstance(bar, dict):
                continue

            yield {
                "symbol": symbol,
                "date": bar.get("date"),
                "open": bar.get("open"),
                "high": bar.get("high"),
                "low": bar.get("low"),
                "close": bar.get("close"),
                "volume": bar.get("volume"),
            }