Function fetchBlueskyAvatars

modules/blog.ts:26–72

* Fetches Bluesky avatars for a set of authors at build time. * Returns a map of handle → avatar URL.

(
  imagesDir: string,
  handles: string[],
)

 * Returns a map of handle → avatar URL.
 */
async function fetchBlueskyAvatars(
  imagesDir: string,
  handles: string[],
): Promise<Map<string, string>> {
  const avatarMap = new Map<string, string>()
  if (handles.length === 0) return avatarMap

  try {
    const params = new URLSearchParams()
    for (const handle of handles) {
      params.append('actors', handle)
    }

    const response = await fetch(
      `${BLUESKY_API}/xrpc/app.bsky.actor.getProfiles?${params.toString()}`,
    )

    if (!response.ok) {
      console.warn(`[blog] Failed to fetch Bluesky profiles: ${response.status}`)
      return avatarMap
    }

    const data = (await response.json()) as { profiles: Array<{ handle: string; avatar?: string }> }

    for (const profile of data.profiles) {
      if (profile.avatar) {
        const hash = crypto.createHash('sha256').update(profile.avatar).digest('hex')
        const dest = join(imagesDir, `${hash}.png`)

        if (!existsSync(dest)) {
          const res = await fetch(`${profile.avatar}@png`)
          if (!res.ok || !res.body) {
            console.warn(`[blog] Failed to fetch Bluesky avatar: ${profile.avatar}@png`)
            continue
          }
          await writeFile(join(imagesDir, `${hash}.png`), res.body)
        }

        avatarMap.set(profile.handle, `/blog/avatar/${hash}.png`)
      }
    }
  } catch (error) {
    console.warn(`[blog] Failed to fetch Bluesky avatars:`, error)
  }

  return avatarMap
}

/**
 * Resolves authors with their Bluesky avatars and profile URLs.