/**
 * Basemap preset registry (spec: "Basemap presets & switching") — the sixth
 * plugin surface, alongside registerLayer/Widget/Action/Source/Format.
 * Deliberately maplibre-free: validation, html-data generation, and om-map
 * all consult it without pulling the ~326 KB gz maplibre chunk; only
 * basemap.ts (already inside that chunk) consumes the resolved style.
 *
 * A MapTiler key is a PUBLISHABLE, origin-restricted client key — it ships
 * in page source by design, so unlike data credentials (configureData) it
 * may appear in markup (`basemap-key`) or be configured once
 * (`OmMap.configureBasemap({ maptilerKey })`).
 */
/** A MapLibre style: a URL string (possibly with a `{key}` placeholder) or an inline style-spec object. */
export type BasemapStyle = string | Record<string, unknown>;
export interface BasemapPreset {
    style: BasemapStyle;
    /** Extra attribution line beyond what the style's tile sources declare (MapLibre renders source attributions automatically). */
    attribution?: string;
    /** Display name for the basemap-switcher widget (falls back to the preset name). */
    label?: string;
    /** Which key `{key}` substitutes — currently only "maptiler". */
    requiresKey?: "maptiler";
}
/** MapLibre's own official, freely-hosted demo style — the zero-config `basemap="maplibre"` default (back-compat). */
export declare const MAPLIBRE_DEMO_STYLE = "https://demotiles.maplibre.org/style.json";
/**
 * Is this `basemap` value a bring-your-own style URL rather than a preset
 * name? Any URL scheme counts, not just http(s) — desktop webviews serve
 * styles over custom protocols (Tauri `asset://` / `nika-file://`, Electron
 * equivalents), and a query string must not defeat the `.json` path form
 * (`nika-file:///styles/dark.json?v=2`).
 */
export declare function isStyleUrl(raw: string): boolean;
export declare function registerBasemap(name: string, preset: BasemapPreset): void;
export declare function getBasemap(name: string): BasemapPreset | undefined;
export declare function getAllBasemaps(): ReadonlyMap<string, BasemapPreset>;
/** Provider keys for keyed presets — one call covers every layer of the app. */
export declare function configureBasemap(config: {
    maptilerKey?: string;
}): void;
/** Static-validation support: is a key available for this provider (from configureBasemap)? */
export declare function hasConfiguredKey(provider: "maptiler"): boolean;
/** The configured key itself — terrain presets substitute it the way resolveBasemapStyle does (publishable client key, internal use). */
export declare function getConfiguredKey(provider: "maptiler"): string | undefined;
export interface ResolvedBasemap {
    style: BasemapStyle;
    attribution?: string;
    /** Resolution problem (unknown name / missing key) — the caller decides how loudly to fail; `style` is always usable (demo fallback). */
    error?: string;
}
/**
 * `basemap` attribute value → concrete style. Precedence: explicit URL /
 * `.json` path passes through untouched (bring-your-own, keys inline);
 * `maplibre` / `maplibre-*` → the demo style (back-compat); anything else
 * is a registry lookup. Unknown names and keyless keyed presets resolve to
 * the demo style WITH an `error` — the live path logs it, validation turns
 * it into a structured entry, and the map still renders something.
 */
export declare function resolveBasemapStyle(raw: string, keyAttr?: string): ResolvedBasemap;