import { type ComputedRef, type Ref } from 'vue';
import type { Fetcher, PreviewFile, RequestHandler, RequestInitFactory, ShouldFetchAsBlob } from '@eternalheart/file-preview-core';
export interface RequestContextValue {
    fetcher: Fetcher;
    shouldFetchAsBlob?: ShouldFetchAsBlob;
}
export declare function provideRequestContext(options: {
    requestInit?: RequestInitFactory;
    requestHandler?: RequestHandler;
    shouldFetchAsBlob?: ShouldFetchAsBlob;
} | (() => {
    requestInit?: RequestInitFactory;
    requestHandler?: RequestHandler;
    shouldFetchAsBlob?: ShouldFetchAsBlob;
})): ComputedRef<RequestContextValue>;
export declare function useRequestContext(): ComputedRef<RequestContextValue>;
export declare function useFetcher(): ComputedRef<Fetcher>;
/**
 * 解析 file 的可消费 URL：
 * - 未配置 shouldFetchAsBlob 或返回 false：直接派生自 file.url（不入 ref，避免切换文件时残留旧值）
 * - 返回 true：用 fetcher 拉成 blob: URL，组件卸载或 file 变化时 revoke
 */
export declare function useResolvedUrl(file: Ref<PreviewFile | undefined>): ComputedRef<string>;