"""
CLI auth status for both Claude and Gemini backends.

GET /auth/status  — returns per-backend auth info and warning flags

Claude:  warns when OAuth token is < WARN_HOURS from expiry (requires
         user to re-run `claude` to refresh via browser flow).
Gemini:  warns only when oauth_creds.json is missing or has no
         refresh_token (access token rotates automatically every ~1h).
"""
import json
import logging
from datetime import datetime, timezone
from pathlib import Path
from fastapi import APIRouter
from config import settings

logger = logging.getLogger(__name__)
router = APIRouter(prefix="/auth")

CLAUDE_CREDS  = Path.home() / ".claude" / ".credentials.json"
GEMINI_CREDS  = Path.home() / ".gemini" / "oauth_creds.json"
GEMINI_ACCTS  = Path.home() / ".gemini" / "google_accounts.json"
WARN_HOURS = 24          # no refresh token — warn a day ahead
WARN_HOURS_REFRESH = 1  # refresh token present — only warn if CLI hasn't rotated in time


def _claude_status() -> dict:
    try:
        data = json.loads(CLAUDE_CREDS.read_text())
        oauth = data["claudeAiOauth"]
        has_refresh = bool(oauth.get("refreshToken"))
        expires_dt = datetime.fromtimestamp(oauth["expiresAt"] / 1000, tz=timezone.utc)
        now = datetime.now(tz=timezone.utc)
        hours_remaining = (expires_dt - now).total_seconds() / 3600
        # When a refresh token is present the CLI *should* auto-rotate the access
        # token, but sometimes it doesn't.  Use a tight 1-hour window so a fresh
        # 8-hour token doesn't immediately trigger a warning, but a stale token
        # that the CLI missed will still surface before it expires.
        expired = hours_remaining <= 0
        threshold = WARN_HOURS_REFRESH if has_refresh else WARN_HOURS
        warning = expired or hours_remaining < threshold
        return {
            "ok": True,
            "has_refresh_token": has_refresh,
            "access_token_expires_at": expires_dt.isoformat(),
            "access_token_hours_remaining": round(hours_remaining, 1),
            "warning": warning,
            "expired": expired,
        }
    except Exception as e:
        logger.warning("claude auth check failed: %s", e)
        return {"ok": False, "error": str(e), "warning": True, "expired": False}


def _gemini_status() -> dict:
    try:
        creds = json.loads(GEMINI_CREDS.read_text())
        if not creds.get("refresh_token"):
            return {"ok": True, "authenticated": False, "warning": True, "account": None}
        account = None
        try:
            accts = json.loads(GEMINI_ACCTS.read_text())
            account = accts.get("active")
        except Exception:
            pass
        return {"ok": True, "authenticated": True, "warning": False, "account": account}
    except FileNotFoundError:
        return {"ok": True, "authenticated": False, "warning": True, "account": None}
    except Exception as e:
        logger.warning("gemini auth check failed: %s", e)
        return {"ok": False, "error": str(e), "warning": True, "authenticated": False}


async def _local_status(username: str = "scott") -> dict:
    """Check reachability of the user's configured local model host."""
    import model_registry
    cfg = model_registry.get_best_local_model(username)
    if not cfg:
        return {"configured": False}
    api_url = cfg.get("api_url", "")
    if not api_url:
        return {"configured": False}
    try:
        import httpx
        url = api_url.rstrip("/") + "/api/models"
        headers = {}
        api_key = cfg.get("api_key", "")
        if api_key:
            headers["Authorization"] = f"Bearer {api_key}"
        async with httpx.AsyncClient(timeout=5) as client:
            resp = await client.get(url, headers=headers)
        reachable = resp.status_code < 400
        return {
            "configured": True,
            "reachable": reachable,
            "model": cfg.get("model_name", ""),
            "label": cfg.get("label", ""),
        }
    except Exception as e:
        return {"configured": True, "reachable": False, "error": str(e), "model": cfg.get("model_name", "")}


@router.get("/status")
async def auth_status() -> dict:
    return {
        "claude": _claude_status(),
        "gemini": _gemini_status(),
        "local": await _local_status(),
    }