/**
 * Pure Consent Mode v2 helpers (no $app / $env) — safe for node:test.
 *
 * Categories:
 * - Necessary: always on (session, CSRF, theme, locale, consent preference)
 * - Analytics → analytics_storage
 * - Marketing → ad_storage, ad_user_data, ad_personalization
 */

export const CONSENT_STORAGE_KEY = "descrybe-cookie-consent";
export const CONSENT_VERSION = 1;
export const CONSENT_WAIT_FOR_UPDATE_MS = 500;

export type ConsentPreferences = {
	analytics: boolean;
	marketing: boolean;
};

export type StoredConsent = ConsentPreferences & {
	v: number;
	updatedAt: string;
};

/** Google Consent Mode v2 signal map (string literals for gtag). */
export type ConsentModeSignals = {
	ad_storage: "granted" | "denied";
	ad_user_data: "granted" | "denied";
	ad_personalization: "granted" | "denied";
	analytics_storage: "granted" | "denied";
	functionality_storage: "granted" | "denied";
	personalization_storage: "granted" | "denied";
	security_storage: "granted" | "denied";
};

export const DENIED_CONSENT_DEFAULTS: ConsentModeSignals = {
	ad_storage: "denied",
	ad_user_data: "denied",
	ad_personalization: "denied",
	analytics_storage: "denied",
	functionality_storage: "granted",
	personalization_storage: "denied",
	security_storage: "granted"
};

export function preferencesToConsentSignals(
	prefs: ConsentPreferences
): ConsentModeSignals {
	const analytics = prefs.analytics ? "granted" : "denied";
	const marketing = prefs.marketing ? "granted" : "denied";
	return {
		ad_storage: marketing,
		ad_user_data: marketing,
		ad_personalization: marketing,
		analytics_storage: analytics,
		functionality_storage: "granted",
		personalization_storage: analytics,
		security_storage: "granted"
	};
}

export function parseStoredConsent(raw: string | null | undefined): StoredConsent | null {
	if (!raw?.trim()) return null;
	try {
		const parsed: unknown = JSON.parse(raw);
		if (!parsed || typeof parsed !== "object") return null;
		const obj = parsed as Record<string, unknown>;
		if (obj.v !== CONSENT_VERSION) return null;
		if (typeof obj.analytics !== "boolean" || typeof obj.marketing !== "boolean") {
			return null;
		}
		const updatedAt =
			typeof obj.updatedAt === "string" && obj.updatedAt.trim()
				? obj.updatedAt
				: new Date(0).toISOString();
		return {
			v: CONSENT_VERSION,
			analytics: obj.analytics,
			marketing: obj.marketing,
			updatedAt
		};
	} catch {
		return null;
	}
}

export function serializeConsent(prefs: ConsentPreferences, updatedAt = new Date().toISOString()): string {
	const stored: StoredConsent = {
		v: CONSENT_VERSION,
		analytics: prefs.analytics,
		marketing: prefs.marketing,
		updatedAt
	};
	return JSON.stringify(stored);
}

/** Accept all non-necessary categories. */
export function acceptAllPreferences(): ConsentPreferences {
	return { analytics: true, marketing: true };
}

/** Reject analytics and marketing (necessary remains on). */
export function rejectNonEssentialPreferences(): ConsentPreferences {
	return { analytics: false, marketing: false };
}

/** Coarse SKU-volume bucket for lead events — never send the raw count as PII-adjacent precision. */
export function estimatedSkusBucket(n: number | null | undefined): string {
	if (n == null || !Number.isFinite(n) || n < 0) return "unknown";
	if (n < 1_000) return "0_999";
	if (n < 5_000) return "1000_4999";
	if (n < 20_000) return "5000_19999";
	if (n < 100_000) return "20000_99999";
	return "100000_plus";
}