import type { SubstackPost, SubstackFullPost } from '../types'
import { SubstackPostCodec, SubstackFullPostCodec } from '../types'
import { decodeOrThrow } from '../validation'
import type { HttpClient } from '../http-client'
/**
* Service responsible for post-related HTTP operations
* Returns internal types that can be transformed into domain models
*/
export class PostService {
constructor(
private readonly globalHttpClient: HttpClient,
private readonly httpClient: HttpClient
) {}
/**
* Get a post by ID from the API
* @param id - The post ID
* @returns Promise<SubstackFullPost> - Raw full post data from API (validated)
* @throws {Error} When post is not found, API request fails, or validation fails
*
* Note: Uses SubstackFullPostCodec to validate the full post response from /posts/by-id/:id
* which includes body_html, postTags, reactions, and other fields not present in preview responses.
* This codec is specifically designed for FullPost construction.
*/
async getPostById(id: number): Promise<SubstackFullPost> {
// Post lookup by ID must use the global substack.com endpoint, not publication-specific hostnames
const rawResponse = await this.globalHttpClient.get<{ post: unknown }>(
`/api/v1/posts/by-id/${id}`
)
// Extract the post data from the wrapper object
if (!rawResponse.post) {
throw new Error('Invalid response format: missing post data')
}
// Transform the raw post data to match our codec expectations
const postData = this.transformPostData(rawResponse.post as any)
// Validate the response with SubstackFullPostCodec for full post data including body_html
return decodeOrThrow(SubstackFullPostCodec, postData, 'Full post response')
}
/**
* Transform raw API post data to match our codec structure
*/
private transformPostData(rawPost: any): any {
const transformedPost = { ...rawPost }
// Transform postTags from objects to string array
if (rawPost.postTags && Array.isArray(rawPost.postTags)) {
transformedPost.postTags = rawPost.postTags.map((tag: any) => tag.name || tag)
}
return transformedPost
}
/**
* Get posts for a profile
* @param profileId - The profile user ID
* @param options - Pagination options
* @returns Promise<SubstackPost[]> - Raw post data from API (validated)
* @throws {Error} When posts cannot be retrieved or validation fails
*/
async getPostsForProfile(
profileId: number,
options: { limit: number; offset: number }
): Promise<SubstackPost[]> {
const response = await this.httpClient.get<{ posts?: unknown[] }>(
`/api/v1/profile/posts?profile_user_id=${profileId}&limit=${options.limit}&offset=${options.offset}`
)
const posts = response.posts || []
// Validate each post with io-ts
return posts.map((post, index) =>
decodeOrThrow(SubstackPostCodec, post, `Post ${index} in profile response`)
)
}
}
