/**
 * Asset management types for ECSpresso ECS framework
 */
/**
 * Status of an asset in the loading lifecycle
 */
export type AssetStatus = 'pending' | 'loading' | 'loaded' | 'failed';
/**
 * Definition for an asset including its loader and configuration
 */
export interface AssetDefinition<T> {
    readonly loader: () => Promise<T>;
    readonly eager?: boolean;
    readonly group?: string;
}
/**
 * Handle to an asset that provides status information and access methods
 */
export interface AssetHandle<T> {
    readonly status: AssetStatus;
    readonly isLoaded: boolean;
    /**
     * Get the asset value. Throws if asset is not loaded.
     */
    get(): T;
    /**
     * Get the asset value if loaded, undefined otherwise.
     */
    tryGet(): T | undefined;
}
/**
 * Resource interface for accessing assets in systems
 * Exposed as $assets resource
 */
export interface AssetsResource<A extends Record<string, unknown>, G extends string = string> {
    /**
     * Get the loading status of an asset
     */
    getStatus<K extends keyof A>(key: K): AssetStatus;
    /**
     * Check if an asset is loaded
     */
    isLoaded<K extends keyof A>(key: K): boolean;
    /**
     * Check if all assets in a group are loaded
     */
    isGroupLoaded(groupName: G): boolean;
    /**
     * Get the loading progress of a group (0-1)
     */
    getGroupProgress(groupName: G): number;
    /**
     * Get a loaded asset. Throws if not loaded.
     */
    get<K extends keyof A>(key: K): A[K];
    /**
     * Get a loaded asset or undefined if not loaded
     */
    tryGet<K extends keyof A>(key: K): A[K] | undefined;
    /**
     * Get a handle to an asset with status information
     */
    getHandle<K extends keyof A>(key: K): AssetHandle<A[K]>;
}
/**
 * Events emitted by the asset system.
 * @typeParam K - Asset key type (defaults to `string` for backward compatibility)
 * @typeParam G - Asset group name type (defaults to `string` for backward compatibility)
 */
export interface AssetEvents<K extends string = string, G extends string = string> {
    assetLoaded: {
        key: K;
    };
    assetFailed: {
        key: K;
        error: Error;
    };
    assetGroupLoaded: {
        group: G;
    };
    assetGroupProgress: {
        group: G;
        progress: number;
        loaded: number;
        total: number;
    };
}
/**
 * Configuration for asset definitions during builder setup
 */
export interface AssetConfigurator<Assets extends Record<string, unknown> = {}, AssetGroups extends string = never> {
    /**
     * Add a single eager asset
     */
    add<K extends string, T>(key: K, loader: () => Promise<T>): AssetConfigurator<Assets & Record<K, T>, AssetGroups>;
    /**
     * Add a single asset with full configuration
     */
    addWithConfig<K extends string, T>(key: K, definition: AssetDefinition<T>): AssetConfigurator<Assets & Record<K, T>, AssetGroups>;
    /**
     * Add a group of assets that can be loaded together
     */
    addGroup<GN extends string, T extends Record<string, () => Promise<unknown>>>(groupName: GN, assets: T): AssetConfigurator<Assets & {
        [K in keyof T]: Awaited<ReturnType<T[K]>>;
    }, AssetGroups | GN>;
}
/**
 * Callback shape for extracted asset configurator helpers.
 */
export type AssetConfiguratorFn<Assets extends Record<string, unknown>, AssetGroups extends string = never> = (assets: AssetConfigurator) => AssetConfigurator<Assets, AssetGroups>;