#!/usr/bin/env node
// neutralize-cosmo-headings.mjs — R13 Cosmo del 1: apply the ratified heading
// neutralisation across the reference corpus, rewriting each persona heading and the TOC
// entries anchored to it in ONE per-file operation, so no intermediate state leaves a
// dead fragment link.
//
// SCOPE (operator-ratified 2026-09-12, alternative A). In: the 401 persona headings in
// 374 reference files (40 measured variants) plus the 327 TOC entries that anchor to
// them. OUT: the 4 SKILL.md files, the 23 commands, CLAUDE.md / README.md / NOTICE.md,
// the docs/ files (all R14), and the 132 persona occurrences in prose, tables, dialogue
// and provenance lines — those need editorial judgement, not a scripted transform, and
// are booked as an open decision for R13b/R14.
//
// INVARIANTS asserted per file BEFORE any write (a throw aborts the whole run and
// writes nothing — the plan-then-write discipline of strip-stale-verified-pipe.mjs):
//   - zero persona occurrences remain on heading lines
//   - product occurrence count byte-for-byte unchanged (the 451 Azure Cosmos DB mentions)
//   - line count unchanged (headings are edited in place, never added or removed)
//   - no NEW dead fragment link
//   - only heading lines and TOC-entry lines differ from the original
// Idempotent: a re-run finds no persona heading and is a no-op, so an interrupted run is
// recovered by re-running.
//
// Usage:  node scripts/kb-update/neutralize-cosmo-headings.mjs [--dry]
import { readFileSync, realpathSync, globSync } from 'node:fs';
import { join, dirname } from 'node:path';
import { fileURLToPath } from 'node:url';
import { atomicWriteSync } from './lib/atomic-write.mjs';
import { classifyCosmo, findDeadAnchors, neutralizeContent } from './lib/cosmo-persona.mjs';

const __dirname = dirname(fileURLToPath(import.meta.url));
const PLUGIN_ROOT = join(__dirname, '..', '..');

/**
 * Assert every per-file invariant. Throws on the first violation so the run aborts
 * before a single byte is written.
 */
function assertInvariant(rel, before, after, changes) {
  const b = classifyCosmo(before);
  const a = classifyCosmo(after);
  if (a.persona.heading !== 0) {
    throw new Error(`${rel}: ${a.persona.heading} persona-forekomst(er) staar igjen paa heading-linjer`);
  }
  if (a.product !== b.product) {
    throw new Error(`${rel}: produkt-forekomster endret ${b.product} -> ${a.product}`);
  }
  const lb = before.split('\n').length;
  const la = after.split('\n').length;
  if (lb !== la) throw new Error(`${rel}: linjeantall endret ${lb} -> ${la}`);

  const deadBefore = new Set(findDeadAnchors(before).map((d) => d.anchor));
  const newDead = findDeadAnchors(after).map((d) => d.anchor).filter((x) => !deadBefore.has(x));
  if (newDead.length) throw new Error(`${rel}: nye doede ankre: ${newDead.join(', ')}`);

  // Only the lines the transform claims to have touched may differ.
  const touched = new Set(changes.map((c) => c.line));
  const lbArr = before.split('\n');
  const laArr = after.split('\n');
  for (let i = 0; i < lbArr.length; i++) {
    if (lbArr[i] === laArr[i]) continue;
    if (!touched.has(i + 1)) {
      throw new Error(`${rel}:${i + 1}: linje endret uten aa staa i endringslista\n`
        + `  foer: ${lbArr[i]}\n  etter: ${laArr[i]}`);
    }
  }
}

function main() {
  const dry = process.argv.includes('--dry');
  const files = globSync('skills/*/references/**/*.md', { cwd: PLUGIN_ROOT }).sort();
  const planned = [];
  const skipped = [];
  let headingChanges = 0;
  let tocChanges = 0;

  for (const rel of files) {
    const abs = join(PLUGIN_ROOT, rel);
    const before = readFileSync(abs, 'utf8');
    const { content: after, changes } = neutralizeContent(before, { relPath: rel });
    if (after === before) { skipped.push(rel); continue; }
    assertInvariant(rel, before, after, changes);
    headingChanges += changes.filter((c) => c.kind === 'heading').length;
    tocChanges += changes.filter((c) => c.kind === 'toc').length;
    planned.push({ rel, out: after, changes });
  }

  console.log(`ref-filer: ${files.length} | aa endre: ${planned.length} | urørt: ${skipped.length}`);
  console.log(`heading-endringer: ${headingChanges} | TOC-endringer: ${tocChanges}`);

  if (dry) {
    console.log('\n(dry run — ingen skriving)');
    const byTarget = new Map();
    for (const p of planned) {
      for (const c of p.changes.filter((x) => x.kind === 'heading')) {
        const k = `${c.from}  ->  ${c.to}`;
        byTarget.set(k, (byTarget.get(k) || 0) + 1);
      }
    }
    console.log('\n--- heading-mapping som vil brukes ---');
    for (const [k, v] of [...byTarget.entries()].sort((x, y) => y[1] - x[1])) {
      console.log(`${String(v).padStart(4)}  ${k}`);
    }
    return;
  }

  for (const p of planned) atomicWriteSync(join(PLUGIN_ROOT, p.rel), p.out);
  console.log(`\nSkrev ${planned.length} filer.`);
}

const isMain = (() => {
  try {
    return realpathSync(process.argv[1]) === realpathSync(fileURLToPath(import.meta.url));
  } catch {
    return false;
  }
})();
if (isMain) main();