// tests/integration/annotation-roundtrip.test.mjs
// SC2 + SC3 + SC7 integration tests for the annotation round-trip pipeline.
//
// SC2 (byte-identical empty round-trip):
//   For each target fixture (brief/plan/review), assert that
//   stripAnchors(addAnchors(body, [])) === body, byte-for-byte.
//
// SC3 (scale: >=50 steps + >=100 anchors):
//   On the 51-step scale fixture, generate 100 anchors above varied lines,
//   run addAnchors -> stripAnchors, assert the original body is restored
//   byte-for-byte.
//
// SC7 (per-target isolation):
//   parseAnchors(stripAnchors(addAnchors(body, anchors))) === [] — once
//   anchors are stripped, no residual voyage:anchor markers remain that
//   parseAnchors would re-detect.

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

const HERE = dirname(fileURLToPath(import.meta.url));
const ROOT = join(HERE, '..', '..');
const FIX_DIR = join(ROOT, 'tests/fixtures/annotation');

function readBody(fixture) {
  const text = readFileSync(join(FIX_DIR, fixture), 'utf-8');
  const doc = parseDocument(text);
  assert.ok(doc.valid, `fixture ${fixture} did not parse: ${(doc.errors || []).map(e => e.message).join(', ')}`);
  return doc.parsed.body;
}

test('annotation-brief.md byte-identical empty round-trip (SC2)', () => {
  const body = readBody('annotation-brief.md');
  const out = stripAnchors(addAnchors(body, []));
  assert.strictEqual(out, body, 'empty addAnchors+stripAnchors must be byte-identical');
});

test('annotation-plan.md byte-identical empty round-trip (SC2)', () => {
  const body = readBody('annotation-plan.md');
  const out = stripAnchors(addAnchors(body, []));
  assert.strictEqual(out, body, 'empty addAnchors+stripAnchors must be byte-identical');
});

test('annotation-review.md byte-identical empty round-trip (SC2)', () => {
  const body = readBody('annotation-review.md');
  const out = stripAnchors(addAnchors(body, []));
  assert.strictEqual(out, body, 'empty addAnchors+stripAnchors must be byte-identical');
});

test('annotation-plan-large.md scale (51 steps + 100 anchors) round-trip (SC3)', () => {
  const body = readBody('annotation-plan-large.md');
  const lineCount = body.split('\n').length;
  // Generate 100 anchors targeting safe paragraph lines. Place them above
  // line numbers that are deliberately avoided by anchor-parser placement
  // rules: skip anchor insertion above headings and inside fenced blocks.
  // Strategy: pick 100 safe insertion points by walking blank lines outside
  // fenced blocks; anchor at line N inserts above line N (so line N must
  // be a content line, not a fence delimiter).
  const lines = body.split('\n');
  const safe = [];
  let inFence = false;
  for (let i = 0; i < lines.length; i++) {
    const ln = lines[i];
    if (/^```/.test(ln)) { inFence = !inFence; continue; }
    if (inFence) continue;
    // Skip headings, blank lines, list items, and structural anchors
    if (ln.startsWith('#') || ln.trim() === '' || /^\s*[-*+]\s/.test(ln)) continue;
    safe.push(i + 1); // 1-indexed line number
  }
  assert.ok(safe.length >= 100, `need >=100 safe insertion points; got ${safe.length}`);
  const anchors = [];
  for (let n = 0; n < 100; n++) {
    anchors.push({
      id: `ANN-${String(n + 1).padStart(4, '0')}`,
      target: `step-${(n % 51) + 1}`,
      line: safe[n],
      intent: ['fix', 'change', 'question', 'block'][n % 4],
    });
  }
  const annotated = addAnchors(body, anchors);
  // sanity: 100 anchors produced
  const parsed = parseAnchors(annotated);
  assert.ok(parsed.valid, `parseAnchors on annotated body failed: ${(parsed.errors || []).map(e => e.message).join('; ')}`);
  assert.strictEqual(parsed.parsed.length, 100, `expected 100 anchors after addAnchors, got ${parsed.parsed.length}`);
  // Round-trip restores body byte-for-byte.
  const restored = stripAnchors(annotated);
  assert.strictEqual(restored, body, 'addAnchors -> stripAnchors must round-trip byte-identical at scale');
});

test('parseAnchors(stripAnchors(addAnchors(brief, anchors))) === [] (SC7 brief)', () => {
  const body = readBody('annotation-brief.md');
  const lines = body.split('\n');
  // Pick a content line — first non-blank, non-heading line
  const target = lines.findIndex(l => l.length > 0 && !l.startsWith('#')) + 1;
  assert.ok(target > 0, 'brief fixture has no content lines');
  const anchors = [{ id: 'ANN-0001', target: 'intent', line: target, intent: 'change' }];
  const annotated = addAnchors(body, anchors);
  const stripped = stripAnchors(annotated);
  const result = parseAnchors(stripped);
  assert.ok(result.valid, 'parseAnchors on stripped body should be valid');
  assert.deepStrictEqual(result.parsed, [], 'no anchors should remain after stripAnchors');
});

test('parseAnchors(stripAnchors(addAnchors(plan, anchors))) === [] (SC7 plan)', () => {
  const body = readBody('annotation-plan.md');
  const lines = body.split('\n');
  const target = lines.findIndex(l => l.startsWith('A minimal')) + 1;
  assert.ok(target > 0, 'plan fixture missing expected content line');
  const anchors = [{ id: 'ANN-0001', target: 'context', line: target, intent: 'fix' }];
  const annotated = addAnchors(body, anchors);
  const stripped = stripAnchors(annotated);
  const result = parseAnchors(stripped);
  assert.ok(result.valid);
  assert.deepStrictEqual(result.parsed, []);
});

test('parseAnchors(stripAnchors(addAnchors(review, anchors))) === [] (SC7 review)', () => {
  const body = readBody('annotation-review.md');
  const lines = body.split('\n');
  const target = lines.findIndex(l => l.startsWith('Verdict')) + 1;
  assert.ok(target > 0, 'review fixture missing Verdict line');
  const anchors = [{ id: 'ANN-0001', target: 'executive-summary', line: target, intent: 'question' }];
  const annotated = addAnchors(body, anchors);
  const stripped = stripAnchors(annotated);
  const result = parseAnchors(stripped);
  assert.ok(result.valid);
  assert.deepStrictEqual(result.parsed, []);
});