from __future__ import annotations

import time
from dataclasses import dataclass
from urllib.parse import parse_qs, urlencode

from django.conf import settings

CONSENT_COOKIE_NAME = "nhAiConsent"


@dataclass
class ConsentState:
    analytics: bool = False
    advertising: bool = False
    policy_version: int = 0
    timestamp: int = 0

    @property
    def requires_prompt(self) -> bool:
        return self.policy_version != settings.CONSENT_POLICY_VERSION


class ConsentService:
    @staticmethod
    def get_consent(request) -> ConsentState:
        raw = request.COOKIES.get(CONSENT_COOKIE_NAME, "")
        if not raw:
            return ConsentState()

        try:
            data = {k: v[0] for k, v in parse_qs(raw).items()}
            return ConsentState(
                analytics=data.get("a", "0") == "1",
                advertising=data.get("d", "0") == "1",
                policy_version=int(data.get("v", "0")),
                timestamp=int(data.get("ts", "0")),
            )
        except (ValueError, AttributeError):
            return ConsentState()

    @staticmethod
    def set_consent(response, *, analytics: bool, advertising: bool) -> None:
        payload = urlencode(
            {
                "a": int(analytics),
                "d": int(advertising),
                "v": settings.CONSENT_POLICY_VERSION,
                "ts": int(time.time()),
            }
        )
        response.set_cookie(
            CONSENT_COOKIE_NAME,
            payload,
            max_age=60 * 60 * 24 * 365,
            httponly=False,
            samesite="Lax",
            secure=not settings.DEBUG,
        )