from __future__ import annotations

import time
from abc import ABC, abstractmethod
from typing import Any

from scrapling import Fetcher, StealthyFetcher, PlayWrightFetcher

from ..models.request import ScrapeRequest, SelectorDef
from ..models.response import ScrapeResponse


def apply_selectors(page: Any, selectors: list[SelectorDef]) -> dict[str, Any]:
    """Extract data from a Scrapling page object using CSS/XPath selectors."""
    result: dict[str, Any] = {}
    for sel in selectors:
        try:
            if sel.selector_type == "css":
                if sel.multiple:
                    elements = page.css(sel.selector)
                else:
                    elements = [page.css_first(sel.selector)]
            else:
                if sel.multiple:
                    elements = page.xpath(sel.selector)
                else:
                    elements = [page.xpath_first(sel.selector)]

            def extract_value(el: Any) -> str | None:
                if el is None:
                    return None
                if sel.attribute:
                    return el.attrib.get(sel.attribute)
                return el.text

            if sel.multiple:
                result[sel.name] = [extract_value(el) for el in (elements or [])]
            else:
                result[sel.name] = extract_value(elements[0] if elements else None)
        except Exception as exc:
            result[sel.name] = None
            result[f"{sel.name}_error"] = str(exc)
    return result


class BaseScraper(ABC):
    @abstractmethod
    async def scrape(self, req: ScrapeRequest) -> ScrapeResponse:
        ...

    def _build_response(
        self,
        req: ScrapeRequest,
        page: Any,
        fetcher_name: str,
        start: float,
    ) -> ScrapeResponse:
        elapsed = (time.perf_counter() - start) * 1000
        html = page.html if req.return_html else None
        data = apply_selectors(page, req.selectors) if req.selectors else {}
        return ScrapeResponse(
            url=req.url,
            status_code=page.status if hasattr(page, "status") else 200,
            html=html,
            data=data,
            fetcher_used=fetcher_name,
            elapsed_ms=round(elapsed, 2),
        )