"""Shared, bounded provider liveness probes."""
from __future__ import annotations

from typing import Any, Iterable

import requests


def probe_provider(
    base_url: str,
    checks: Iterable[tuple[str, str | None]],
    *,
    headers: dict[str, str] | None = None,
    timeout: float = 3.0,
) -> dict[str, Any]:
    """Try provider endpoints in order with normalized, body-free results."""
    base = str(base_url or '').rstrip('/')
    limit = max(0.5, float(timeout))
    last_error = 'No response'
    for path, json_key in checks:
        endpoint = path or '/'
        try:
            response = requests.get(base + path, timeout=limit, headers=headers or {}, allow_redirects=True)
            if response.status_code >= 500:
                last_error = f'HTTP {response.status_code} on {endpoint}'
                continue
            if response.status_code >= 400:
                last_error = f'HTTP {response.status_code} on {endpoint}'
                continue
            payload = None
            if json_key:
                try:
                    payload = response.json()
                except Exception:
                    last_error = f'{endpoint} returned non-JSON (HTTP {response.status_code})'
                    continue
                if not isinstance(payload, dict) or json_key not in payload:
                    last_error = f"Unexpected response from {endpoint} (missing '{json_key}')"
                    continue
            return {'ok': True, 'status': response.status_code, 'endpoint': endpoint, 'payload': payload}
        except requests.exceptions.ConnectionError:
            last_error = 'Connection refused'
        except requests.exceptions.Timeout:
            last_error = f'Timeout ({limit:g} s)'
        except Exception as exc:
            last_error = str(exc)
    return {'ok': False, 'error': last_error}