Creator engagement scoring

import { SocialFetchClient } from "@socialfetch/sdk";

const client = new SocialFetchClient({
  apiKey: process.env.SOCIALFETCH_API_KEY!,
});

function median(nums: number[]): number {
  if (nums.length === 0) return 0;
  const sorted = [...nums].sort((a, b) => a - b);
  return sorted[Math.floor(sorted.length / 2)] ?? 0;
}

async function scoreTikTokCreator(handle: string) {
  const profile = await client.tiktok.getProfile({ handle });
  if (!profile.ok) {
    return { ok: false as const, error: profile.error };
  }

  if (profile.value.data.lookupStatus !== "found") {
    return {
      ok: true as const,
      handle,
      lookupStatus: profile.value.data.lookupStatus,
      score: null,
    };
  }

  const followers = profile.value.data.metrics?.followers ?? 0;
  const videos = await client.tiktok.getProfileVideos({
    handle,
    sortBy: "latest",
  });

  if (!videos.ok) {
    return { ok: false as const, error: videos.error };
  }

  const views = (videos.value.data.videos ?? [])
    .map((v) => v.metrics?.views ?? 0)
    .filter((n) => n > 0);

  const medianViews = median(views);
  const engagementRate =
    followers > 0 ? medianViews / followers : null;

  return {
    ok: true as const,
    handle,
    lookupStatus: "found" as const,
    followers,
    sampleSize: views.length,
    medianViews,
    engagementRate,
    creditsCharged:
      profile.value.meta.creditsCharged + videos.value.meta.creditsCharged,
    requestIds: [
      profile.value.meta.requestId,
      videos.value.meta.requestId,
    ],
  };
}