"""ADTClient base — connection, authentication, and generic request helpers."""

from __future__ import annotations

import logging

import requests
from requests.auth import HTTPBasicAuth

from sapcli.exceptions import LoginError

logger = logging.getLogger("sapcli.client")


class ADTClientBase:
    """Connection / authentication foundation shared by all mixins."""

    def __init__(
        self,
        host: str,
        client: str,
        user: str,
        password: str,
        verify_ssl: bool = False,
    ) -> None:
        self.host: str = host.rstrip("/")
        self.csrf_token: str = "fetch"
        self.session: requests.Session = requests.Session()
        self.session.auth = HTTPBasicAuth(user, password)
        self.session.verify = verify_ssl
        self._stateful: bool = False
        self.sap_client: str = client

    # ------------------------------------------------------------------
    #  Context-manager protocol
    # ------------------------------------------------------------------

    def __enter__(self):  # type: ignore[override]
        self.login()
        return self

    def __exit__(self, exc_type, exc_val, exc_tb) -> None:
        self.session.close()

    # ------------------------------------------------------------------
    #  Headers / auth helpers
    # ------------------------------------------------------------------

    def _headers(self, content_type: str = "application/xml") -> dict[str, str]:
        return {
            "Accept": "*/*",
            "Cache-Control": "no-cache",
            "x-csrf-token": self.csrf_token,
            "X-sap-adt-sessiontype": "stateful" if self._stateful else "stateless",
            "content-type": content_type,
            "sap-client": self.sap_client,
        }

    def login(self) -> bool:
        url = f"{self.host}/sap/bc/adt/compatibility/graph"
        hdrs = self._headers()
        logger.info("LOGIN: GET %s", url)
        resp = self.session.get(url, headers=hdrs)
        logger.info("LOGIN RESPONSE: HTTP %s", resp.status_code)
        if resp.status_code == 200:
            self.csrf_token = resp.headers.get("x-csrf-token", "")
            if self.csrf_token:
                logger.info(
                    "CSRF Token: %s...(%d chars)",
                    self.csrf_token[:8],
                    len(self.csrf_token),
                )
                return True
        raise LoginError(f"登录失败: HTTP {resp.status_code}")

    def object_exists(self, obj_uri: str) -> bool:
        url = f"{self.host}{obj_uri}"
        hdrs = self._headers()
        hdrs["Accept"] = "*/*"
        logger.info("CHECK EXISTS: GET %s", url)
        resp = self.session.get(url, headers=hdrs)
        logger.info("CHECK EXISTS RESPONSE: HTTP %s", resp.status_code)
        if resp.status_code == 200:
            return True
        if resp.status_code == 404:
            return False
        logger.warning("Unexpected status %d for existence check", resp.status_code)
        return resp.status_code < 400