import fs from 'node:fs';
import path from 'node:path';

export const RUN_PUBLIC_HTML_LOOKBACK_MS = 0;

export function listRecentlyModifiedPublicHtmlRelativePaths(
  publishDir,
  { sinceMs = null, lookbackMs = RUN_PUBLIC_HTML_LOOKBACK_MS } = {},
) {
  const startedAt = Number(sinceMs);
  if (!Number.isFinite(startedAt) || startedAt <= 0) return [];

  const publicDir = path.join(path.resolve(String(publishDir ?? '')), 'public');
  if (!fs.existsSync(publicDir) || !fs.statSync(publicDir).isDirectory()) return [];

  const cutoff = Math.max(0, startedAt - Math.max(0, Number(lookbackMs) || 0));
  return fs.readdirSync(publicDir)
    .filter((name) => name.toLowerCase().endsWith('.html'))
    .filter((name) => {
      try {
        return fs.statSync(path.join(publicDir, name)).mtimeMs >= cutoff;
      } catch {
        return false;
      }
    })
    .map((name) => `public/${name}`)
    .sort();
}