import type { SubstackSubscriptionsResponse, SubstackSubscriptionPublication } from '../types'
import type { HttpClient } from '../http-client'
import type { SlugResolver } from './slug-resolver'
/**
* Service responsible for slug resolution and user handle management
* Returns internal types that can be transformed into domain models
* This is a pure service without caching - use CachingSlugService for cached behavior
*/
export class SlugService implements SlugResolver {
constructor(private readonly httpClient: HttpClient) {}
/**
* Get or build the user_id to slug mapping from subscriptions
* @returns Promise<Map<number, string>> - Mapping of user IDs to slugs
* @throws {Error} When subscriptions cannot be fetched (falls back to empty mapping)
*/
async getSlugMapping(): Promise<Map<number, string>> {
try {
// Fetch subscriptions data
const subscriptionsResponse =
await this.httpClient.get<SubstackSubscriptionsResponse>('/api/v1/subscriptions')
// Build user_id -> slug mapping
const mapping = new Map<number, string>()
for (const publication of subscriptionsResponse.publications as SubstackSubscriptionPublication[]) {
if (publication.author_id) {
// Use author_handle as the slug, but only if it's not empty
const slug = publication.author_handle?.trim() || undefined
if (slug) {
mapping.set(publication.author_id, slug)
}
}
}
return mapping
} catch {
// If subscriptions endpoint fails, return empty mapping
// This ensures graceful fallback
return new Map<number, string>()
}
}
/**
* Get slug for a user ID, 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> {
const slugMapping = await this.getSlugMapping()
return slugMapping.get(userId) || fallbackHandle
}
}
