/**
 * Patch: replace ap_followers.countDocuments() with estimatedDocumentCount()
 * in syndicator.js log statement.
 *
 * countDocuments() runs an aggregate({$match:{}, $group:{n:$sum:1}}) scan.
 * For a logging call this is unnecessary — estimatedDocumentCount() reads
 * collection metadata (O(1), no lock contention).
 */

import { access, readFile, writeFile } from "node:fs/promises";

const candidates = [
  "node_modules/@rmdes/indiekit-endpoint-activitypub/lib/syndicator.js",
  "node_modules/@indiekit/indiekit/node_modules/@rmdes/indiekit-endpoint-activitypub/lib/syndicator.js",
];

const MARKER = "// [patch] followers-count-estimate";

const OLD = `        // Count followers for logging
        const followerCount =
          await plugin._collections.ap_followers.countDocuments();`;

const NEW = `        // Count followers for logging
        const followerCount =
          await plugin._collections.ap_followers.estimatedDocumentCount(); ${MARKER}`;

async function exists(p) {
  try { await access(p); return true; } catch { return false; }
}

let patched = false;
for (const filePath of candidates) {
  if (!(await exists(filePath))) continue;
  const src = await readFile(filePath, "utf8");
  if (src.includes(MARKER)) {
    console.log(`[postinstall] patch-ap-followers-count-estimate: already applied in ${filePath}`);
    patched = true;
    break;
  }
  if (!src.includes(OLD)) {
    console.log(`[postinstall] patch-ap-followers-count-estimate: target snippet not found in ${filePath}`);
    continue;
  }
  await writeFile(filePath, src.replace(OLD, NEW), "utf8");
  console.log(`[postinstall] patch-ap-followers-count-estimate: applied to ${filePath}`);
  patched = true;
  break;
}

if (!patched) {
  console.log("[postinstall] patch-ap-followers-count-estimate: no target file found");
}