import { Storage } from '@google-cloud/storage';
import { Adapter, FilesError } from '../index.js';

interface GCSAdapterOptions {
    bucket: string;
    /**
     * GCP project ID. Falls back to `GOOGLE_CLOUD_PROJECT` then
     * `GCLOUD_PROJECT`. Optional — Application Default Credentials carry
     * a project ID and the SDK will discover it automatically.
     */
    projectId?: string;
    /**
     * Path to a service-account JSON file. When set, takes precedence over
     * ADC. Mutually exclusive with `credentials` in practice; if both are
     * passed, the SDK uses `credentials`.
     */
    keyFilename?: string;
    /**
     * Inline service-account credentials. Useful when you only have
     * `client_email` + `private_key` available as separate env vars (e.g.
     * Vercel/Netlify) and don't want to materialize a JSON file. When
     * neither this nor `keyFilename` is set, the SDK falls back to ADC
     * (`GOOGLE_APPLICATION_CREDENTIALS`, `gcloud auth`, GCE metadata).
     */
    credentials?: {
        client_email: string;
        private_key: string;
    };
    /**
     * Origin used to build URLs from `url()`. When set, `url(key)` returns
     * `${publicBaseUrl}/${key}` and skips signing — appropriate for a
     * public bucket or a CDN in front of GCS. When unset, `url()` falls
     * back to a V4 signed read URL (default expiry: 1 hour).
     *
     * For a public GCS bucket, the natural value is
     * `https://storage.googleapis.com/<bucket>`.
     */
    publicBaseUrl?: string;
    /**
     * Default expiry, in seconds, for the V4 signed URLs returned by
     * `url()` when `publicBaseUrl` is not set. Defaults to 3600 (1 hour).
     * Per-call `url(key, { expiresIn })` overrides. GCS V4 caps at 7 days.
     */
    defaultUrlExpiresIn?: number;
}
type GCSAdapter = Adapter<Storage> & {
    readonly bucket: string;
};
declare const mapGCSError: (err: unknown) => FilesError;
declare const gcs: (opts: GCSAdapterOptions) => GCSAdapter;

export { type GCSAdapter, type GCSAdapterOptions, gcs, mapGCSError };