import type { ExistsResult, ExistsOptions } from './npm.js';
interface PurlObject {
    name: string;
    namespace?: string | undefined;
    qualifiers?: Record<string, string> | undefined;
    subpath?: string | undefined;
    type?: string | undefined;
    version?: string | undefined;
}
/**
 * Normalize PyPI package URL.
 * Lowercases namespace, name, and version, replaces underscores with dashes in name.
 * Spec: namespace, name, and version are all case-insensitive.
 */
export declare function normalize(purl: PurlObject): PurlObject;
/**
 * Validate PyPI package URL.
 * Name must not contain injection characters.
 */
export declare function validate(purl: PurlObject, throws: boolean): boolean;
/**
 * Check if a PyPI package exists in the registry.
 *
 * Queries PyPI at https://pypi.org/pypi to verify package existence and
 * optionally validate a specific version. Returns the latest version from
 * package metadata.
 *
 * **Caching:** Responses can be cached using a TTL cache to reduce registry
 * requests. Pass `{ cache }` option with a cache instance from `createTtlCache()`.
 *
 * @param name - Package name (e.g., 'requests', 'django')
 * @param version - Optional version to validate (e.g., '2.28.1')
 * @param options - Optional configuration including cache
 * @returns Promise resolving to existence result with latest version
 *
 * @example
 * ```typescript
 * // Check if package exists
 * const result = await pypiExists('requests')
 * // -> { exists: true, latestVersion: '2.31.0' }
 *
 * // Validate specific version
 * const result = await pypiExists('django', '4.2.0')
 * // -> { exists: true, latestVersion: '5.0.0' }
 *
 * // With caching
 * import { createTtlCache } from '@socketsecurity/lib/cache-with-ttl'
 * const cache = createTtlCache({ ttl: 5 * 60 * 1000, prefix: 'pypi' })
 * const result = await pypiExists('requests', undefined, { cache })
 *
 * // Non-existent package
 * const result = await pypiExists('this-package-does-not-exist')
 * // -> { exists: false, error: 'Package not found' }
 * ```
 */
export declare function pypiExists(name: string, version?: string, options?: ExistsOptions): Promise<ExistsResult>;
export {};