// tests/kb-update/test-transform.test.mjs
// TDD for lag 4 — TRANSFORMASJON (doc → KB-fil). lib/transform.mjs is a pure
// helper library (mirrors decisions-io / verify-out): it builds the deterministic
// KB-file header, validates the mandatory-field contract, routes the file to its
// owning skill via the taxonomy (lag 0), and constructs the lag-5 `change` object.
// It NEVER writes — applying the file is the operator gate's job (commands/kb-update.md).
//
// Why Source lives in the HEADER block: build-registry / kb-headers.parseSourceHeader
// scan only the top 500 bytes, so a source buried in a bottom section (as the old
// prompt-template did) is invisible → the 0% authority_source coverage. Putting
// **Source:** in the header is what lets lag 3 backfill authority_source and lag-5
// rule 3 (authority mismatch) eventually fire.

import { test } from 'node:test';
import assert from 'node:assert/strict';
import { readFileSync } from 'node:fs';
import { dirname, join } from 'node:path';
import { fileURLToPath } from 'node:url';
import {
  buildKbHeader,
  validateKbFile,
  buildChange,
  resolveTargetPath,
} from '../../scripts/kb-update/lib/transform.mjs';
import { parseSourceHeader } from '../../scripts/kb-update/lib/kb-headers.mjs';
import { classifyChange } from '../../scripts/kb-update/lib/verify-out.mjs';
import { loadTaxonomy } from '../../scripts/kb-update/lib/taxonomy.mjs';

const __dirname = dirname(fileURLToPath(import.meta.url));

const META = {
  title: 'Azure AI Search - Hybrid Retrieval',
  status: 'GA',
  category: 'rag-architecture',
  source: 'https://learn.microsoft.com/azure/search/hybrid-search-overview',
  lastUpdated: '2026-06',
};

// --- buildKbHeader: mandatory fields, parseable by the real header scanners ----

test('buildKbHeader emits title, Last updated, Status, Source, Category in the header block', () => {
  const h = buildKbHeader(META);
  assert.match(h, /^# Azure AI Search - Hybrid Retrieval/m);
  assert.match(h, /\*\*Last updated:\*\*\s*2026-06/);
  assert.match(h, /\*\*Status:\*\*\s*GA/);
  assert.match(h, /\*\*Category:\*\*\s*rag-architecture/);
  assert.match(h, /\*\*Source:\*\*\s*https:\/\/learn\.microsoft\.com/);
});

test('buildKbHeader Source is within the top-500-byte region kb-headers scans', () => {
  const h = buildKbHeader(META);
  // The whole point: parseSourceHeader (top 500 bytes) must find it.
  assert.equal(parseSourceHeader(h), META.source);
});

test('buildKbHeader throws when a mandatory field is missing (status-felt obligatorisk)', () => {
  assert.throws(() => buildKbHeader({ ...META, status: undefined }), /status/i);
  assert.throws(() => buildKbHeader({ ...META, source: '' }), /source/i);
  assert.throws(() => buildKbHeader({ ...META, title: null }), /title/i);
  assert.throws(() => buildKbHeader({ ...META, lastUpdated: undefined }), /last.?updated/i);
});

// --- validateKbFile: catches files missing the mandatory contract -------------

test('validateKbFile accepts a header-conformant file', () => {
  const file = buildKbHeader(META) + '\n## Introduksjon\n\nNoe innhold.\n';
  const r = validateKbFile(file);
  assert.equal(r.valid, true);
  assert.deepEqual(r.missing, []);
});

test('validateKbFile reports each missing mandatory field', () => {
  // No Status, no Source, no Last updated, no title.
  const r = validateKbFile('Bare brødtekst uten header.\n');
  assert.equal(r.valid, false);
  for (const f of ['title', 'last_updated', 'status', 'source']) {
    assert.ok(r.missing.includes(f), `expected '${f}' in missing: ${r.missing}`);
  }
});

test('validateKbFile flags a file with body-only source (the 0%-coverage failure mode)', () => {
  // Source in a bottom section, NOT the header → invisible to top-500-byte scan.
  const file =
    '# Tittel\n\n**Last updated:** 2026-06\n**Status:** Preview\n\n---\n\n' +
    'Mye innhold ...\n'.repeat(40) +
    '\n## Kilder\n\n**Source:** https://learn.microsoft.com/x\n';
  const r = validateKbFile(file);
  assert.equal(r.valid, false);
  assert.ok(r.missing.includes('source'));
});

// --- buildChange: the lag-4 → lag-5 contract ----------------------------------

test('buildChange produces a classifyChange-compatible object with safe defaults', () => {
  const c = buildChange({
    field: 'status',
    oldValue: 'Preview',
    newValue: 'GA',
    sourceUrl: META.source,
  });
  assert.equal(c.field, 'status');
  assert.equal(c.old_value, 'Preview');
  assert.equal(c.new_value, 'GA');
  assert.equal(c.source_url, META.source);
  assert.equal(c.authority_source, null); // pre-lag-3 default
  assert.deepEqual(c.refutations, []);
});

test('buildChange output flows through lag 5 — a status change is flagged, never auto-applied', () => {
  const c = buildChange({ field: 'status', oldValue: 'Preview', newValue: 'GA', sourceUrl: META.source });
  const verdict = classifyChange(c);
  assert.equal(verdict.verdict, 'flagged');
  assert.equal(verdict.status_claim, true);
});

test('buildChange output flows through lag 5 — a non-status change can auto-apply', () => {
  const c = buildChange({
    field: 'description',
    oldValue: 'En kort beskrivelse.',
    newValue: 'En litt lengre, oppdatert beskrivelse.',
    sourceUrl: META.source,
  });
  assert.equal(classifyChange(c).verdict, 'auto-applied');
});

// --- resolveTargetPath: taxonomy-driven routing (replaces category-skill-map) --

test('resolveTargetPath routes via the taxonomy category_skill (disk-truth)', () => {
  const tax = loadTaxonomy();
  assert.equal(
    resolveTargetPath(tax, 'rag-architecture', 'hybrid-retrieval.md'),
    'skills/ms-ai-engineering/references/rag-architecture/hybrid-retrieval.md',
  );
  // a former divergence — taxonomy says advisor, not engineering
  assert.equal(
    resolveTargetPath(tax, 'prompt-engineering', 'few-shot.md'),
    'skills/ms-ai-advisor/references/prompt-engineering/few-shot.md',
  );
});

test('resolveTargetPath returns null for an unknown category (caller must gate)', () => {
  const tax = loadTaxonomy();
  assert.equal(resolveTargetPath(tax, 'does-not-exist', 'x.md'), null);
});

// --- ARCHITECTURE INVARIANT: transform.mjs is a pure lib, imports NO write-utils

test('transform.mjs imports NO write-utils (pure transformer, never writes)', () => {
  const src = readFileSync(join(__dirname, '../../scripts/kb-update/lib/transform.mjs'), 'utf8');
  const importLines = src.split('\n').filter((l) => /^\s*import\b/.test(l)).join('\n');
  assert.doesNotMatch(importLines, /\bsaveDecisions\b/);
  assert.doesNotMatch(importLines, /\bsaveRegistry\b/);
  assert.doesNotMatch(importLines, /\bsaveReport\b/);
  assert.doesNotMatch(importLines, /from\s+'[^']*atomic-write[^']*'/);
  assert.doesNotMatch(importLines, /from\s+'[^']*\/backup\.mjs'/);
});