"""Client HTTP partagé pour le scraping (httpx async, headers navigateur, retries)."""

import asyncio
import logging

import httpx
from bs4 import BeautifulSoup

from app.config import get_settings
from app.scrapers.base import ScrapeError

logger = logging.getLogger(__name__)

_client: httpx.AsyncClient | None = None


def get_client() -> httpx.AsyncClient:
    global _client
    if _client is None:
        settings = get_settings()
        _client = httpx.AsyncClient(
            timeout=settings.http_timeout,
            follow_redirects=True,
            headers={
                "User-Agent": settings.user_agent,
                "Accept-Language": "fr-FR,fr;q=0.9,en;q=0.8",
            },
        )
    return _client


async def close_client() -> None:
    global _client
    if _client is not None:
        await _client.aclose()
        _client = None


async def fetch(
    url: str,
    *,
    referer: str | None = None,
    retries: int = 2,
    headers: dict[str, str] | None = None,
    data: dict[str, str] | None = None,
) -> str:
    """GET (ou POST si `data` est fourni) avec retries ; lève ScrapeError en cas d'échec définitif."""
    request_headers = dict(headers) if headers else {}
    if referer:
        request_headers.setdefault("Referer", referer)
    last_error: Exception | None = None
    for attempt in range(retries + 1):
        try:
            if data is None:
                response = await get_client().get(url, headers=request_headers)
            else:
                response = await get_client().post(url, headers=request_headers, data=data)
            response.raise_for_status()
            return response.text
        except httpx.HTTPStatusError as exc:
            status = exc.response.status_code
            if 400 <= status < 500 and status not in (408, 429):
                raise ScrapeError(f"Échec de récupération de {url} : HTTP {status} (définitif)") from exc
            last_error = exc
            logger.warning("fetch %s — HTTP %d, tentative %d/%d", url, status, attempt + 1, retries + 1)
            if attempt < retries:
                await asyncio.sleep(1.0 * (attempt + 1))
        except (httpx.HTTPError, httpx.InvalidURL) as exc:
            last_error = exc
            logger.warning("fetch %s — tentative %d/%d : %s", url, attempt + 1, retries + 1, exc)
            if attempt < retries:
                await asyncio.sleep(1.0 * (attempt + 1))
    raise ScrapeError(f"Échec de récupération de {url} : {last_error}")


async def fetch_soup(url: str, *, referer: str | None = None) -> BeautifulSoup:
    html = await fetch(url, referer=referer)
    return BeautifulSoup(html, "lxml")