# Copyright (c) 2026 PowerOn AG
# All rights reserved.
"""
Trusted Device Service.

After successful MFA verification a device can be marked as trusted for a
configurable duration (default 60 days). On subsequent logins from the same
device the MFA step is skipped.

Cookie: ``mfa_trusted`` (httpOnly, Secure, SameSite policy from jwtService).
DB: ``TrustedDevice`` table in poweron_app.

Regulatory basis:
- NIST SP 800-63B Section 5.2.8: Verifier MAY re-authenticate only after a
  configurable period when a device is bound to the subscriber.
- Microsoft, Google, AWS implement identical patterns.
"""

import logging
import secrets
from typing import Optional

from fastapi import Request, Response

from modules.shared.configuration import APP_CONFIG
from modules.shared.timeUtils import getUtcNow, getUtcTimestamp
from modules.datamodels.datamodelSecurity import TrustedDevice

logger = logging.getLogger(__name__)

_COOKIE_NAME = "mfa_trusted"
_DEFAULT_TRUST_DAYS = 60
_TOKEN_BYTES = 32


def _getTrustDurationDays() -> int:
    raw = (APP_CONFIG.get("MFA_TRUST_DURATION_DAYS") or "").strip()
    if raw.isdigit() and int(raw) > 0:
        return int(raw)
    return _DEFAULT_TRUST_DAYS


def createTrustedDevice(userId: str, request: Request, response: Response, db) -> str:
    """Create a TrustedDevice entry and set the cookie on the response.

    Returns the device token (cookie value).
    """
    from modules.auth.jwtService import _cookiePolicy

    trustDays = _getTrustDurationDays()
    deviceToken = secrets.token_urlsafe(_TOKEN_BYTES)

    now = getUtcTimestamp()
    trustedUntil = now + (trustDays * 86400)

    device = TrustedDevice(
        id=deviceToken,
        userId=userId,
        trustedUntil=trustedUntil,
        userAgent=(request.headers.get("user-agent") or "")[:512],
        ipAddress=_getClientIp(request),
        createdAt=now,
    )

    try:
        db.recordCreate(TrustedDevice, device.model_dump())
    except Exception as e:
        logger.error(f"Failed to persist TrustedDevice for userId={userId}: {e}")
        return ""

    useSecure, samesite, _ = _cookiePolicy()
    response.set_cookie(
        key=_COOKIE_NAME,
        value=deviceToken,
        httponly=True,
        secure=useSecure,
        samesite=samesite,
        path="/",
        max_age=trustDays * 86400,
    )

    logger.info(f"Trusted device created for userId={userId}, valid {trustDays}d")
    return deviceToken


def isTrustedDevice(request: Request, userId: str, db) -> bool:
    """Check if the current request comes from a trusted device for the given user."""
    deviceToken = request.cookies.get(_COOKIE_NAME)
    if not deviceToken:
        return False

    try:
        records = db.getRecordset(
            TrustedDevice,
            recordFilter={"id": deviceToken, "userId": userId},
        )
        if not records:
            return False

        device = records[0]
        trustedUntil = device.get("trustedUntil", 0)
        if isinstance(trustedUntil, (int, float)) and trustedUntil > getUtcTimestamp():
            return True

        return False
    except Exception as e:
        logger.warning(f"Error checking trusted device for userId={userId}: {e}")
        return False


def revokeTrustedDevices(userId: str, db) -> int:
    """Revoke all trusted devices for a user. Returns count of deleted entries."""
    try:
        records = db.getRecordset(TrustedDevice, recordFilter={"userId": userId})
        count = 0
        for rec in records:
            db.recordDelete(TrustedDevice, rec["id"])
            count += 1
        if count:
            logger.info(f"Revoked {count} trusted device(s) for userId={userId}")
        return count
    except Exception as e:
        logger.error(f"Failed to revoke trusted devices for userId={userId}: {e}")
        return 0


def clearTrustedDeviceCookie(response: Response) -> None:
    """Clear the mfa_trusted cookie."""
    from modules.auth.jwtService import _cookiePolicy

    useSecure, samesite, samesiteHeader = _cookiePolicy()
    secure_flag = "; Secure" if useSecure else ""
    response.headers.append(
        "Set-Cookie",
        f"{_COOKIE_NAME}=deleted; Path=/; Max-Age=0; Expires=Thu, 01 Jan 1970 00:00:00 GMT; HttpOnly{secure_flag}; SameSite={samesiteHeader}"
    )
    response.delete_cookie(
        key=_COOKIE_NAME,
        path="/",
        secure=useSecure,
        httponly=True,
        samesite=samesite,
    )


def cleanupExpiredDevices(db) -> int:
    """Remove TrustedDevice entries past their trustedUntil. Returns deleted count."""
    try:
        records = db.getRecordset(TrustedDevice, recordFilter={})
        now = getUtcTimestamp()
        count = 0
        for rec in records:
            if rec.get("trustedUntil", 0) < now:
                db.recordDelete(TrustedDevice, rec["id"])
                count += 1
        if count:
            logger.info(f"Cleaned up {count} expired trusted device(s)")
        return count
    except Exception as e:
        logger.error(f"Error cleaning up expired trusted devices: {e}")
        return 0


def _getClientIp(request: Request) -> Optional[str]:
    """Extract client IP from request (respects X-Forwarded-For)."""
    forwarded = request.headers.get("x-forwarded-for")
    if forwarded:
        return forwarded.split(",")[0].strip()
    if request.client:
        return request.client.host
    return None


# --- Scheduler Integration ---

async def _runTokenAndDeviceCleanup() -> None:
    """Scheduled task: remove expired tokens and trusted devices."""
    try:
        from modules.connectors.connectorDbPostgre import ConnectorPostgre

        db = ConnectorPostgre("poweron_app")
        now = getUtcTimestamp()

        # Expired auth-session tokens
        tokens = db.getRecordset(
            Token,
            recordFilter={"tokenPurpose": TokenPurpose.AUTH_SESSION.value},
        )
        expiredCount = 0
        for t in tokens:
            if t.get("expiresAt", 0) < now:
                db.recordDelete(Token, t["id"])
                expiredCount += 1

        # Expired trusted devices
        deviceCount = cleanupExpiredDevices(db)

        if expiredCount or deviceCount:
            logger.info(
                f"Token cleanup: {expiredCount} expired token(s), "
                f"{deviceCount} expired trusted device(s) removed"
            )
    except Exception as e:
        logger.error(f"Token/device cleanup failed: {e}")


def registerTokenCleanupScheduler() -> None:
    """Register daily token cleanup job. Call during app startup."""
    try:
        from modules.shared.eventManagement import eventManager

        eventManager.registerCron(
            jobId="token_device_cleanup",
            func=_runTokenAndDeviceCleanup,
            cronKwargs={"hour": "4", "minute": "0"},
        )
        logger.info("Token/device cleanup scheduler registered (daily 04:00)")
    except Exception as e:
        logger.warning(f"Failed to register token cleanup scheduler: {e}")