/**
 * Pure API error types/helpers (no $env / $app) — safe for node:test.
 */

export class ApiError extends Error {
	status: number;
	body: unknown;

	constructor(message: string, status: number, body: unknown) {
		super(message);
		this.name = "ApiError";
		this.status = status;
		this.body = body;
	}
}

/** HTTP status phrases that should not be shown as form copy. */
const OPAQUE_HTTP_STATUS = new Set([
	"",
	"bad request",
	"unauthorized",
	"forbidden",
	"not found",
	"conflict",
	"too many requests",
	"internal server error",
	"service unavailable",
	"method not allowed",
	"request failed"
]);

function isOpaqueHttpStatus(msg: string): boolean {
	return OPAQUE_HTTP_STATUS.has(msg.trim().toLowerCase());
}

/** User-visible message from an `api()` / `apiDownload()` catch value (or any thrown Error). */
export function failureMessage(err: unknown, fallback: string): string {
	if (err instanceof Error) {
		const msg = err.message.trim();
		if (msg && !isOpaqueHttpStatus(msg)) return msg;
	}
	return fallback;
}