/**
 * Canonical file-format registry — the single source of truth for
 * extension ↔ MIME ↔ FileType ↔ modality.
 *
 * ## Why this exists
 *
 * The same knowledge used to live in five hand-maintained tables that had no
 * way of agreeing with each other:
 *
 *   1. `EXTENSION_MIME_MAP`                      (config/mimeConstants.ts)
 *   2. the `*_EXTENSIONS` category arrays        (config/fileExtensions.ts)
 *   3. `ExtensionStrategy.typeMap` + `.mimeMap`  (utils/fileDetector.ts)
 *   4. `EXTENSION_TYPE_MAP`                      (utils/messageBuilder.ts)
 *   5. each processor's `supportedExtensions` / `supportedMimeTypes`
 *
 * They drifted, and the drift was not cosmetic — a format that a processor
 * declared it supported was routinely invisible to the detector standing in
 * front of it, so the file never reached the processor at all. Measured on real
 * ffmpeg-generated media before this registry existed:
 *
 *   .aiff .m2ts .mts .vob .3g2 .3gp   → "unknown"  (downgraded to metadata text)
 *   .mpg .mpeg                        → "csv"      (binary parsed as a spreadsheet)
 *   .ts                               → "text"     (MPEG-TS inlined as source code)
 *
 * Deriving all five consumers from one table makes that class of drift
 * structurally impossible rather than merely fixed once.
 *
 * ## Invariants
 *
 * - `extensions[0]` is canonical for the format; the rest are accepted aliases.
 * - `mimeTypes[0]` is canonical; the rest are aliases seen in the wild
 *   (`audio/x-wav`, `image/x-icon`, vendor prefixes, …).
 * - Every extension and every MIME type appears in exactly one entry. The
 *   `assertRegistryIsUnambiguous()` check below is executed at module load, so
 *   a duplicate is a startup failure rather than a silent last-write-wins.
 * - `fileType` is the *routing* type the detector emits (what processor to
 *   use); `modality` is the *category* a human means. They deliberately differ:
 *   an .odt is `fileType: "docx"` (the Word processor handles it) but
 *   `modality: "document"`, and .svg is `fileType: "svg"` (sanitised as markup,
 *   never sent to a vision API) but `modality: "image"`.
 *
 * @module processors/config/fileTypeRegistry
 */
import type { FileFormatEntry, FileModality, FileType } from "../../types/index.js";
/**
 * Every file format NeuroLink can identify, grouped by modality.
 *
 * Adding a format here is all that is required — the extension map, the MIME
 * map, the detector's lookup tables, the category arrays and the media
 * processors' supported-format lists are all derived from this array.
 */
export declare const FILE_TYPE_REGISTRY: readonly FileFormatEntry[];
/**
 * Extensions that must NOT be treated as belonging to their registry entry's
 * modality when only a filename is available.
 *
 * Derived from {@link EXTENSION_OVERRIDES}: `extensionsForModality("video")`
 * feeds both `VIDEO_EXTENSIONS` and `VideoProcessor`'s supported list, and
 * `BaseFileProcessor.isFileSupported` accepts a file when the *extension*
 * matches even if the supplied mimetype says otherwise. Leaving `.ts` in that
 * list made `isVideoFile("text/plain", "app.ts")` return true.
 */
/**
 * Extension → MIME for the overridden extensions only.
 *
 * Exported so `EXTENSION_MIME_MAP` can apply the override as its FINAL layer.
 * That map is built by spreading the registry over the text map, so without
 * this the registry's `.ts → video/mp2t` won again and `getMimeTypeForExtension`
 * disagreed with `mimeTypeForExtension` about the very same file.
 */
export declare const EXTENSION_MIME_OVERRIDES: Readonly<Record<string, string>>;
/**
 * Normalize an extension to the registry's key form: lowercased, with a leading
 * dot. Accepts `"png"`, `".PNG"`, `"image.png"` and `"/tmp/a.png"` alike.
 *
 * Compound extensions (`.tar.gz`) are matched before the single-segment form so
 * a `.tar.gz` resolves to the gzip entry rather than to `.gz` by accident —
 * they happen to agree today, but the lookup should not depend on that.
 */
export declare function normalizeExtension(raw: string): string;
/** Look up the registry entry for a file extension, or undefined. */
export declare function lookupByExtension(ext: string): FileFormatEntry | undefined;
/**
 * Look up the registry entry for a MIME type, or undefined. Any `;charset=…`
 * parameter is stripped, matching how Content-Type headers arrive.
 */
export declare function lookupByMimeType(mime: string): FileFormatEntry | undefined;
/**
 * Routing {@link FileType} for an extension, honouring {@link EXTENSION_OVERRIDES}.
 * Returns undefined when the extension is not in the registry.
 */
export declare function fileTypeForExtension(ext: string): FileType | undefined;
/** Canonical MIME type for an extension, or undefined when unknown. */
export declare function mimeTypeForExtension(ext: string): string | undefined;
/** Canonical extension (with leading dot) for a MIME type, or undefined. */
export declare function extensionForMimeType(mime: string): string | undefined;
/** Every extension registered for a modality, in registry order. */
export declare function extensionsForModality(modality: FileModality): readonly string[];
/** Every MIME type registered for a modality, in registry order. */
export declare function mimeTypesForModality(modality: FileModality): readonly string[];
/**
 * True when the extension belongs to the given modality. Uses the entry's
 * modality, not its routing `fileType`, so `.svg` counts as an image and `.odt`
 * counts as a document.
 */
export declare function isModalityExtension(ext: string, modality: FileModality): boolean;