Slatewave for Sublime Text

/**
 * Build-time GitHub metadata fetchers.
 *
 * Public-repo data only. Unauthenticated requests are rate-limited to
 * 60/hour per IP; set GITHUB_TOKEN in .env (or the CI environment) to
 * raise that to 5000/hour.
 *
 * Results are cached to `node_modules/.cache/slatewave-github/` with a
 * 30-minute TTL so dev hot-reloads don't burn API quota.
 */
import { mkdir, readFile, writeFile } from 'node:fs/promises';
import { join } from 'node:path';

const CACHE_DIR = join(process.cwd(), 'node_modules', '.cache', 'slatewave-github');
const TTL_MS = 30 * 60 * 1000;

export interface RepoMeta {
  stars: number;
  pushedAt: string;
  defaultBranch: string;
  openIssues: number;
  latestRelease: Release | null;
}

export interface Release {
  tag: string;
  name: string;
  publishedAt: string;
  url: string;
  body: string;
  isPrerelease: boolean;
}

const memory = new Map<string, Promise<unknown>>();

function cacheKey(parts: string[]): string {
  return parts.join('__').replace(/[^a-zA-Z0-9_]/g, '_');
}

async function readCache<T>(key: string): Promise<T | null> {
  try {
    const raw = await readFile(join(CACHE_DIR, `${key}.json`), 'utf8');
    const parsed = JSON.parse(raw) as { data: T; at: number };
    if (Date.now() - parsed.at < TTL_MS) return parsed.data;
  } catch {
    /* no cache yet */
  }
  return null;
}