/** How the file is handled, which decides everything downstream. */
export type AssetFileKind = 'glb-voxelize' | 'glb-keep' | 'vxl' | 'image' | 'audio' | 'json';
export interface AssetFileClass {
    kind: AssetFileKind;
    /** The `type` recorded on the world.json asset entry. */
    assetType: 'vxl' | 'glb' | 'image' | 'audio' | 'json';
    /** What the upload is signed for; the server decides gzip from this. */
    contentType: string;
    /** Lower-case extension without the dot. */
    extension: string;
}
/** Extensions `classifyVideoFile` accepts, for help text and the README. */
export declare const VIDEO_EXTENSIONS: string[];
export interface VideoFileClass {
    contentType: string;
    /** Lower-case extension without the dot. */
    extension: string;
}
export declare function classifyVideoFile(filename: string): VideoFileClass;
/** Every extension `classifyAssetFile` accepts, for help text and the README. */
export declare const ACCEPTED_EXTENSIONS: string[];
/**
 * The extension, treating a dotfile as having one.
 *
 * `path.extname('.vxl')` is `''` — Node reads a leading dot as the start of the basename, not an
 * extension — so a file literally named `.vxl` (what an export tool that names by extension alone
 * produces) fell through to the catch-all and was refused with a message listing `.vxl` among the
 * types it takes.
 */
export declare function fileExtension(filename: string): string;
export declare function classifyAssetFile(filename: string, options: {
    keepGlb: boolean;
}): AssetFileClass;
/**
 * The asset's name when `--name` is not given: the file's basename without its extension, which
 * is what the Creator pre-fills its name prompt with.
 */
export declare function defaultAssetName(filename: string): string;
/**
 * A name the engine can build a filename from. `CREATE_ASSET_FROM_GLB_URL` uploads its bake as
 * `<gameId>-<name>-<timestamp>.vxl`, and api-server refuses a filename carrying a separator or
 * `..` — so a name that would trip that fails HERE, before the file has been uploaded and the
 * browser launched, instead of as an opaque "Failed to upload VXL file" minutes later.
 *
 * The length cap and the URL-unsafe set are part of the same job: both produce a failure that only
 * appears after the upload (or after a ten-minute bake), which is precisely what this is for.
 */
export declare function validateAssetName(name: string): string;
/**
 * The upload filename: a bare basename, which is all api-server accepts.
 *
 * Mirrors `sanitizeUploadFilename` in full — separators AND `..`, as three independent checks.
 * `path.basename` strips `/` on POSIX but leaves `\`, so a legal `my\model.glb` used to pass here
 * and then eat a network round-trip to be refused by the server with a message naming nothing the
 * creator could act on. The URL-unsafe and length checks are here for the same reason as on the
 * name above.
 */
export declare function uploadFilename(filePath: string): string;
/**
 * `asset_<timestamp>_<random>` — byte-compatible with the engine's `ObjectIdService.generateId`
 * and with what api-server mints for the generators (`cli-assets.ts`), so an id minted here is
 * indistinguishable from one minted anywhere else in the system.
 */
export declare function mintAssetId(now?: () => number, random?: () => number): string;
/**
 * Said once per audio upload that the Creator would have transcoded. The engine plays the file
 * as-is; this is about download size, and it names the exact command rather than a vague "consider".
 */
export declare function audioTranscodeNote(extension: string): string | null;