#!/usr/bin/env node
// Build guard: fails if any private owner note (authorNotes) appears anywhere in dist/,
// including inside the Pagefind search index. Runs at the end of `npm run build`.
// Pass a folder to scan something else, e.g. `node scripts/check-notes.mjs src/content/articles`.
//
// It looks for each whole note and for every run of 8 consecutive words from it, after
// normalising case, punctuation, tags and HTML entities, so a partial leak is caught too.

import { readFileSync, readdirSync, statSync } from "node:fs";
import { join } from "node:path";
import { gunzipSync } from "node:zlib";

const WINDOW = 8;
const data = JSON.parse(readFileSync("src/data/questions.json", "utf8"));

const normalise = (s) =>
  s
    .replace(/<[^>]+>/g, " ")
    .replace(/&#(\d+);/g, (_, n) => String.fromCodePoint(Number(n)))
    .replace(/&#x([0-9a-f]+);/gi, (_, n) => String.fromCodePoint(parseInt(n, 16)))
    .replace(/&quot;/g, '"')
    .replace(/&amp;/g, "&")
    .replace(/&[a-z]+;/g, " ")
    .replace(/\\u([0-9a-f]{4})/gi, (_, n) => String.fromCharCode(parseInt(n, 16)))
    .toLowerCase()
    .replace(/[^\p{L}\p{N}]+/gu, " ")
    .trim();

// Every phrase to look for, remembering which question's note it came from.
const needles = [];
for (const q of data.questions) {
  if (!q.authorNotes) continue;
  const words = normalise(q.authorNotes).split(" ");
  if (words.length <= WINDOW) needles.push({ id: q.id, text: words.join(" ") });
  else
    for (let i = 0; i + WINDOW <= words.length; i++)
      needles.push({ id: q.id, text: words.slice(i, i + WINDOW).join(" ") });
}

const walk = (dir) =>
  readdirSync(dir).flatMap((f) => {
    const p = join(dir, f);
    return statSync(p).isDirectory() ? walk(p) : [p];
  });

function readText(file) {
  const buf = readFileSync(file);
  // Pagefind's index files are gzipped.
  if (buf[0] === 0x1f && buf[1] === 0x8b) {
    try {
      return gunzipSync(buf).toString("utf8");
    } catch {
      return "";
    }
  }
  return /\.(html|js|mjs|json|css|xml|txt|webmanifest|svg|mdx|md|pf_\w+)$/.test(file)
    ? buf.toString("utf8")
    : "";
}

const problems = [];
let scanned = 0;
const root = process.argv[2] ?? "dist";
for (const file of walk(root)) {
  const raw = readText(file);
  if (!raw) continue;
  scanned++;
  if (raw.includes("authorNotes")) problems.push(`${file}: contains the "authorNotes" field`);
  const text = ` ${normalise(raw)} `;
  const found = new Set();
  for (const { id, text: needle } of needles) {
    if (!found.has(id) && text.includes(` ${needle} `)) {
      found.add(id);
      problems.push(`${file}: contains owner notes from question ${id}`);
    }
  }
}

if (problems.length) {
  console.error(
    `Owner notes leaked into the build (${problems.length}):\n- ${problems.join("\n- ")}`,
  );
  process.exit(1);
}
console.log(
  `Owner notes check passed: ${scanned} files scanned, ${needles.length} phrases from ${data.questions.filter((q) => q.authorNotes).length} notes, none found.`,
);