"""
Shlink short-URL client.
Provides a single async helper, ``shorten(url)``, that calls the Shlink
REST API via httpx. Returns the original URL unchanged on any error.
"""

import logging
import httpx

log = logging.getLogger("shlink")

class ShlinkClient:
    def __init__(self, base_url: str, api_key: str,
                 timeout: int = 5, domain: str | None = None):
        self._base = base_url.rstrip("/")
        self._api_key = api_key
        self._timeout = timeout
        self._domain = domain
        self._endpoint = f"{self._base}/rest/v3/short-urls"

    async def shorten(self, url: str) -> str:
        """Return a shortened URL, or ``url`` unchanged on failure."""
        payload = {
            "longUrl": url,
            "findIfExists": True
        }
        if self._domain:
            payload["domain"] = self._domain

        headers = {
            "X-Api-Key": self._api_key,
            "Content-Type": "application/json",
        }

        try:
            async with httpx.AsyncClient(timeout=self._timeout) as client:
                resp = await client.post(self._endpoint, json=payload, headers=headers)
                resp.raise_for_status()
                data = resp.json()
                
                short = data["shortUrl"]
                log.debug("Shortened %s → %s", url, short)
                return short
        except Exception as e:
            log.warning("Shlink error for %s: %s", url, e)
            return url

def from_config(cfg: dict) -> "ShlinkClient | None":
    """Build a ShlinkClient from the [shlink] config section."""
    if not cfg.get("enabled", True):
        return None
    base = cfg.get("url", "").strip()
    api_key = cfg.get("api_key", "").strip()
    if not base or not api_key:
        if base or api_key:
            log.warning("[shlink] Both 'url' and 'api_key' are required — disabling")
        return None
    return ShlinkClient(
        base_url=base,
        api_key=api_key,
        timeout=int(cfg.get("timeout", 5)),
        domain=cfg.get("domain") or None,
    )