import os
import time
from dataclasses import dataclass
from typing import Optional


@dataclass(frozen=True)
class LicenseDecision:
    valid: bool
    valid_until: Optional[int]
    status: str  # "active"|"grace"|"expired"|"none"


def compute_license_decision(current_period_end: Optional[int], status: Optional[str]) -> LicenseDecision:
    """
    current_period_end: epoch seconds (UTC)
    status: normalized db status or stripe subscription status (best effort)
    """
    now = int(time.time())

    if not current_period_end:
        return LicenseDecision(valid=False, valid_until=None, status="none")

    grace_days = int(os.getenv("AZA_GRACE_DAYS", "0"))
    grace_seconds = grace_days * 24 * 60 * 60

    # Normalize status (kept for future; time gating is primary)
    _ = (status or "").lower().strip()

    if now <= int(current_period_end):
        return LicenseDecision(valid=True, valid_until=int(current_period_end), status="active")

    if grace_seconds > 0 and now <= int(current_period_end) + grace_seconds:
        return LicenseDecision(valid=True, valid_until=int(current_period_end), status="grace")

    return LicenseDecision(valid=False, valid_until=int(current_period_end), status="expired")