/**
 * Pure plan-cohort classifiers (no $lib) — mirrors billing A1 PAYG vs Legacy vs Growth.
 * Used by admin-plan-permissions and unit tests.
 */

export function isLegacyPlanNamePure(name: string | null | undefined): boolean {
	const n = (name ?? "").trim().toLowerCase();
	if (!n) return false;
	if (n === "legacy") return true;
	if (n.includes("a1 slovenija")) return true;
	if (n === "a1" || n.startsWith("a1 ") || n.startsWith("a1-") || n.startsWith("a1_")) return true;
	return false;
}

export type PlanCohortFlags = {
	name: string;
	is_custom?: boolean;
	is_legacy?: boolean;
};

/** Restricted Legacy matrix (processing off). */
export function isRestrictedLegacyPlan(plan: PlanCohortFlags | null | undefined): boolean {
	if (!plan) return false;
	if (plan.is_legacy === true) return true;
	const n = (plan.name ?? "").trim().toLowerCase();
	if (n === "legacy") return true;
	if (plan.is_custom) return false;
	return isLegacyPlanNamePure(plan.name);
}

/** A1* PAYG client deal (processing on; stores/marketing/integrations off). */
export function isA1PaygPlanPure(plan: PlanCohortFlags | null | undefined): boolean {
	if (!plan) return false;
	if (plan.is_legacy === true) return false;
	if (!plan.is_custom) return false;
	const n = (plan.name ?? "").trim().toLowerCase();
	if (n === "legacy") return false;
	return isLegacyPlanNamePure(plan.name);
}

export function isA1PaygDeniedKey(key: string): boolean {
	if (
		key === "dashboard.etl_gaps" ||
		key === "dashboard.store_reconnect" ||
		key === "dashboard.migrated_checklist"
	) {
		return true;
	}
	return key.startsWith("stores.") || key.startsWith("marketing.") || key.startsWith("integrations.");
}

/** Resolve whether a feature is ON by default for the named cohort. */
export function defaultAllowsFeature(
	plan: PlanCohortFlags,
	key: string,
	opts?: { freeOff?: ReadonlySet<string>; starterOff?: ReadonlySet<string>; legacyAllow?: ReadonlySet<string> }
): boolean {
	if (isRestrictedLegacyPlan(plan)) {
		if (opts?.legacyAllow) return opts.legacyAllow.has(key);
		// Fallback for audit keys when allowlist not provided.
		if (key === "processing.monitor" || key.startsWith("stores.") || key.startsWith("marketing.") || key.startsWith("integrations.") || key.startsWith("support.")) {
			return false;
		}
		return true;
	}
	if (isA1PaygPlanPure(plan)) {
		return !isA1PaygDeniedKey(key);
	}
	const n = (plan.name ?? "").trim().toLowerCase();
	if (n === "free" && opts?.freeOff?.has(key)) return false;
	if ((n === "starter" || n === "plus") && opts?.starterOff?.has(key)) return false;
	return true;
}