// tests/kb-update/test-authority.test.mjs
// TDD for lag 3 — VERIFISERING-INN. lib/authority.mjs establishes the per-file
// authority binding: the **Source:** header IS the designated authority for a
// file's claims (operatør-valg 2026-06-19: header-as-truth). This is what feeds
// verify-out rule 3 (authority mismatch) — the regression's root cause — and what
// build-registry uses to populate the per-URL authority_source field.
//
// Pure lib (mirrors decisions-io / verify-out / transform): no write-util imports.

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 {
  resolveAuthority,
  collectDeclaredSources,
  markUrlAuthority,
  authorityCoverage,
} from '../../scripts/kb-update/lib/authority.mjs';
import { classifyChange } from '../../scripts/kb-update/lib/verify-out.mjs';

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

const FILE_WITH_SOURCE =
  '# Tittel\n\n**Last updated:** 2026-06\n**Status:** GA\n' +
  '**Source:** https://learn.microsoft.com/azure/search/hybrid-search-overview\n\n---\n\n## Innhold\n';

// --- resolveAuthority: the **Source:** header is the per-file authority ---------

test('resolveAuthority returns the declared **Source:** URL', () => {
  assert.equal(
    resolveAuthority(FILE_WITH_SOURCE),
    'https://learn.microsoft.com/azure/search/hybrid-search-overview',
  );
});

test('resolveAuthority returns null when no Source header is present', () => {
  assert.equal(resolveAuthority('# Tittel\n\n**Status:** GA\n\n---\n'), null);
});

test('resolveAuthority rejects a non-URL Source value (no guessed authority)', () => {
  // Verifiseringsplikt: a free-text "source" is not an authority binding.
  assert.equal(resolveAuthority('# T\n\n**Source:** se Microsoft-dokumentasjonen\n\n---\n'), null);
});

test('resolveAuthority accepts a non-Microsoft authority (e.g. EU regulation)', () => {
  // Governance files may anchor on the regulation itself, not a learn.microsoft.com page.
  const c = '# T\n\n**Source:** https://eur-lex.europa.eu/eli/reg/2024/1689/oj\n\n---\n';
  assert.equal(resolveAuthority(c), 'https://eur-lex.europa.eu/eli/reg/2024/1689/oj');
});

// --- collectDeclaredSources: normalized set for registry matching --------------

test('collectDeclaredSources returns the normalized MS-Learn sources declared across files', () => {
  const set = collectDeclaredSources([
    FILE_WITH_SOURCE,
    '# B\n\n**Source:** https://learn.microsoft.com/azure/foundry/openai/how-to/batch-blob-storage\n\n---\n',
    '# C — no source\n\n**Status:** GA\n\n---\n',
    '# D — non-MS authority\n\n**Source:** https://eur-lex.europa.eu/x\n\n---\n',
  ]);
  assert.ok(set.has('https://learn.microsoft.com/azure/search/hybrid-search-overview'));
  assert.ok(set.has('https://learn.microsoft.com/azure/foundry/openai/how-to/batch-blob-storage'));
  // non-MS authority is not a tracked registry URL → excluded from the matching set
  assert.equal(set.size, 2);
});

test('collectDeclaredSources normalizes (trailing slash / locale) to match registry keys', () => {
  const set = collectDeclaredSources([
    '# T\n\n**Source:** https://learn.microsoft.com/en-us/azure/search/hybrid-search-overview/\n\n---\n',
  ]);
  assert.ok(set.has('https://learn.microsoft.com/azure/search/hybrid-search-overview'));
});

// --- markUrlAuthority: a URL entry is an authority iff a file declares it -------

test('markUrlAuthority returns the URL when it is a declared authority, else null', () => {
  const declared = new Set(['https://learn.microsoft.com/azure/search/hybrid-search-overview']);
  assert.equal(
    markUrlAuthority('https://learn.microsoft.com/azure/search/hybrid-search-overview', declared),
    'https://learn.microsoft.com/azure/search/hybrid-search-overview',
  );
  assert.equal(markUrlAuthority('https://learn.microsoft.com/azure/other/page', declared), null);
});

// --- authorityCoverage: the coverage metric (criterion: > 0%) ------------------

test('authorityCoverage counts entries with a non-null authority_source', () => {
  const registry = {
    urls: {
      'https://learn.microsoft.com/a': { authority_source: 'https://learn.microsoft.com/a' },
      'https://learn.microsoft.com/b': { authority_source: null },
      'https://learn.microsoft.com/c': { authority_source: 'https://learn.microsoft.com/c' },
    },
  };
  const cov = authorityCoverage(registry);
  assert.equal(cov.withAuthority, 2);
  assert.equal(cov.total, 3);
  assert.ok(cov.ratio > 0);
});

// --- END-TO-END: header → authority → verify-out rule 3 (the criterion) --------

test('rule 3 fires end-to-end on a real authority: source_url ≠ header authority → flagged', () => {
  // A NON-status change so rules 1 (status-gate) and 2 (refutation) stay silent —
  // this isolates rule 3 and proves the header→authority→mismatch path works.
  const authority = resolveAuthority(FILE_WITH_SOURCE);
  const verdict = classifyChange({
    field: 'description',
    old_value: 'En setning.',
    new_value: 'En annen setning.',
    source_url: 'https://learn.microsoft.com/azure/search/some-other-tangential-page',
    authority_source: authority,
    refutations: [],
  });
  assert.equal(verdict.verdict, 'flagged');
  assert.equal(verdict.status_claim, false); // not a status claim — rule 3 alone flagged it
  assert.ok(verdict.reasons.some((r) => /authority/i.test(r)), `expected an authority reason: ${verdict.reasons}`);
});

test('rule 3 stays silent when source_url matches the header authority', () => {
  const authority = resolveAuthority(FILE_WITH_SOURCE);
  const verdict = classifyChange({
    field: 'description',
    old_value: 'En setning.',
    new_value: 'En annen setning.',
    source_url: authority, // same as authority → no mismatch
    authority_source: authority,
    refutations: [],
  });
  assert.equal(verdict.verdict, 'auto-applied');
});

// --- ARCHITECTURE INVARIANT: authority.mjs imports NO write-utils --------------

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