// tests/parsers/anchor-parser.test.mjs
// Unit tests for lib/parsers/anchor-parser.mjs (v4.2)

import { test } from 'node:test';
import { strict as assert } from 'node:assert';
import { readFileSync } from 'node:fs';
import { dirname, resolve } from 'node:path';
import { fileURLToPath } from 'node:url';
import {
  parseAnchors,
  addAnchors,
  stripAnchors,
  validateAnchorPlacement,
} from '../../lib/parsers/anchor-parser.mjs';

const __dirname = dirname(fileURLToPath(import.meta.url));
const EXAMPLE_PATH = resolve(__dirname, '..', 'fixtures', 'annotation', 'annotation-example.md');

const PLAIN = `# Title

A normal paragraph.

## Section

More text.
`;

test('parseAnchors — empty array on plain markdown without anchors', () => {
  const r = parseAnchors(PLAIN);
  assert.equal(r.valid, true);
  assert.deepEqual(r.parsed, []);
});

test('parseAnchors — extracts id/target/line/intent from valid anchor', () => {
  const md = readFileSync(EXAMPLE_PATH, 'utf-8');
  const r = parseAnchors(md);
  assert.equal(r.valid, true, JSON.stringify(r.errors));
  assert.equal(r.parsed.length, 1);
  assert.equal(r.parsed[0].id, 'ANN-0001');
  assert.equal(r.parsed[0].target, 'section-b');
  assert.equal(r.parsed[0].line, 20);
  assert.equal(r.parsed[0].intent, 'change');
});

test('parseAnchors — rejects ID not matching ANN-NNNN', () => {
  const md = `# X\n\n<!-- voyage:anchor id="X-001" target="foo" line="3" -->\n`;
  const r = parseAnchors(md);
  assert.equal(r.valid, false);
  assert.ok(r.errors.find(e => e.code === 'ANCHOR_BAD_ID'));
});

test('parseAnchors — rejects malformed (missing id)', () => {
  const md = `# X\n\n<!-- voyage:anchor target="foo" line="3" -->\n`;
  const r = parseAnchors(md);
  assert.equal(r.valid, false);
  assert.ok(r.errors.find(e => e.code === 'ANCHOR_MALFORMED'));
});

test('parseAnchors — rejects duplicate IDs', () => {
  const md = `# X\n\n<!-- voyage:anchor id="ANN-0001" target="a" line="3" -->\n\nFoo.\n\n<!-- voyage:anchor id="ANN-0001" target="b" line="9" -->\n`;
  const r = parseAnchors(md);
  assert.equal(r.valid, false);
  assert.ok(r.errors.find(e => e.code === 'ANCHOR_DUPLICATE_ID'));
});

test('parseAnchors — ignores anchors inside fenced code blocks', () => {
  const md = `# X\n\n\`\`\`yaml\n<!-- voyage:anchor id="ANN-0001" target="a" line="4" -->\n\`\`\`\n`;
  const r = parseAnchors(md);
  assert.equal(r.valid, true);
  assert.deepEqual(r.parsed, []);
});

test('addAnchors — empty list returns input byte-identical', () => {
  const r = addAnchors(PLAIN, []);
  assert.equal(r, PLAIN);
});

test('addAnchors — inserts anchor on its own line with blank-line separation', () => {
  const md = `# Title\n\nLine 3.\n`;
  const result = addAnchors(md, [{ id: 'ANN-0001', target: 'title', line: 3, intent: 'change' }]);
  assert.match(result, /<!-- voyage:anchor id="ANN-0001" target="title" line="3" intent="change" -->/);
  // Anchor inserted above target line
  const lines = result.split('\n');
  const anchorIdx = lines.findIndex(l => l.startsWith('<!-- voyage:anchor'));
  assert.ok(anchorIdx >= 0);
});

test('addAnchors -> stripAnchors round-trips byte-identical', () => {
  const md = `# Title\n\nLine 3.\n\nLine 5.\n`;
  const withAnchors = addAnchors(md, [
    { id: 'ANN-0001', target: 'title', line: 3 },
    { id: 'ANN-0002', target: 'title', line: 5 },
  ]);
  const stripped = stripAnchors(withAnchors);
  assert.equal(stripped, md, 'addAnchors then stripAnchors must round-trip byte-identical');
});

test('parseAnchors(stripAnchors(addAnchors(md, []))) returns []', () => {
  const md = `# Title\n\nBody.\n`;
  const result = parseAnchors(stripAnchors(addAnchors(md, [])));
  assert.equal(result.valid, true);
  assert.deepEqual(result.parsed, []);
});

test('validateAnchorPlacement — rejects anchor in list-item', () => {
  const md = `# X\n\n- item\n  <!-- voyage:anchor id="ANN-0001" target="x" line="4" -->\n- next\n`;
  const r = validateAnchorPlacement(md, []);
  assert.equal(r.valid, false);
  assert.ok(r.errors.find(e => e.code === 'ANCHOR_IN_LIST_ITEM'));
});

test('validateAnchorPlacement — rejects anchor inside fenced yaml block', () => {
  const md = `# X\n\n\`\`\`yaml\nfoo: bar\n<!-- voyage:anchor id="ANN-0001" target="x" line="5" -->\n\`\`\`\n`;
  const r = validateAnchorPlacement(md, []);
  assert.equal(r.valid, false);
  assert.ok(r.errors.find(e => e.code === 'ANCHOR_IN_FENCED_BLOCK'));
});

test('validateAnchorPlacement — accepts anchor in body paragraph', () => {
  const md = readFileSync(EXAMPLE_PATH, 'utf-8');
  const r = validateAnchorPlacement(md, []);
  assert.equal(r.valid, true, JSON.stringify(r.errors));
});

test('parseAnchors — anchor with intent block sets intent field', () => {
  const md = `# X\n\n<!-- voyage:anchor id="ANN-0001" target="x" line="3" intent="block" -->\n`;
  const r = parseAnchors(md);
  assert.equal(r.valid, true);
  assert.equal(r.parsed[0].intent, 'block');
});