import type { SlugResolver } from './slug-resolver'
import type { Cache } from '../cache'
/**
* Caching decorator for SlugResolver
* Implements the Decorator pattern to add caching behavior to any SlugResolver
*/
export class CachingSlugService implements SlugResolver {
constructor(
private readonly cache: Cache<number, string>,
private readonly base: SlugResolver
) {}
/**
* Get slug for a user ID with caching, with fallback to handle from profile data
* @param userId - The user ID to resolve slug for
* @param fallbackHandle - Optional fallback handle to use if slug not found
* @returns Promise<string | undefined> - Resolved slug or undefined if not found
*/
async getSlugForUserId(userId: number, fallbackHandle?: string): Promise<string | undefined> {
// Check individual cache first
if (this.cache.has(userId)) {
return this.cache.get(userId)!
}
// If not in individual cache, delegate to base service
const slug = await this.base.getSlugForUserId(userId, fallbackHandle)
// Cache the result if we found a slug (not fallback or undefined)
if (slug && slug !== fallbackHandle) {
this.cache.set(userId, slug)
}
return slug
}
}
