// tests/integration/annotation-block-boundary.test.mjs
// Step 17 — verify relocateAnchorsToBlockBoundaries pure-function transforms
// markdown anchors away from atomic-block interiors (fenced code, tables,
// deeply-nested lists) toward the block-boundary line.
//
// Function lives in playground/voyage-playground.html as inline-script (file://
// compat). We extract it via balanced-brace scan and exercise via Function().

import { test } from 'node:test';
import { strict as assert } from 'node:assert';
import { readFileSync } from 'node:fs';
import { dirname, resolve, join } from 'node:path';
import { fileURLToPath } from 'node:url';

const __dirname = dirname(fileURLToPath(import.meta.url));
const ROOT = resolve(__dirname, '..', '..');
const HTML = join(ROOT, 'playground', 'voyage-playground.html');

function extractFunctionSource(text, fnName) {
  const needle = `function ${fnName}`;
  const start = text.indexOf(needle);
  if (start === -1) return null;
  const braceStart = text.indexOf('{', start);
  if (braceStart === -1) return null;
  let depth = 0;
  for (let i = braceStart; i < text.length; i++) {
    if (text[i] === '{') depth++;
    else if (text[i] === '}') {
      depth--;
      if (depth === 0) return text.slice(start, i + 1);
    }
  }
  return null;
}

function loadRelocate() {
  const html = readFileSync(HTML, 'utf-8');
  const src = extractFunctionSource(html, 'relocateAnchorsToBlockBoundaries');
  if (!src) throw new Error('relocateAnchorsToBlockBoundaries not found in HTML');
  // Function() factory creates an isolated scope; safe for pure function.
  // eslint-disable-next-line no-new-func
  const factory = new Function(`${src}; return relocateAnchorsToBlockBoundaries;`);
  return factory();
}

const relocate = loadRelocate();

test('relocateAnchorsToBlockBoundaries returns input unchanged when anchors empty', () => {
  const md = 'Line 1\nLine 2\nLine 3\n';
  assert.equal(relocate(md, []), md);
});

test('relocateAnchorsToBlockBoundaries leaves anchor outside atomic block at original line', () => {
  const lines = [];
  for (let i = 1; i <= 20; i++) lines.push(`Line ${i}`);
  const md = lines.join('\n');
  const out = relocate(md, [{ id: 'ANN-0001', target: 'sec-a', line: 5 }]);
  const outLines = out.split('\n');
  // Anchor injected at output line 5 (1-indexed = index 4); blank line at index 5
  assert.match(outLines[4], /<!-- voyage:anchor id="ANN-0001"/);
  assert.equal(outLines[5], '');
  // Original line 5 ("Line 5") shifted to output line 7 (index 6)
  assert.equal(outLines[6], 'Line 5');
});

test('relocateAnchorsToBlockBoundaries moves anchor inside fenced code-block to block-boundary', () => {
  const md = [
    'Line 1',                 // 1
    'Line 2',                 // 2
    'Line 3',                 // 3
    'Line 4',                 // 4
    'Line 5',                 // 5
    'Line 6',                 // 6
    'Line 7',                 // 7
    'Line 8',                 // 8
    'Line 9',                 // 9
    '```js',                  // 10 - fence opens
    'const x = 1;',           // 11
    'const y = 2;',           // 12
    'const z = 3;',           // 13
    'const a = 4;',           // 14
    'const b = 5;',           // 15  <- anchor target
    'const c = 6;',           // 16
    'const d = 7;',           // 17
    'const e = 8;',           // 18
    'const f = 9;',           // 19
    '```',                    // 20 - fence closes
    'Line 21',                // 21
  ].join('\n');
  const out = relocate(md, [{ id: 'ANN-0002', target: 'code-block', line: 15 }]);
  const outLines = out.split('\n');
  // Anchor was at line 15 inside fence (10-20); block-boundary insertion at fence.start - 1 = 9
  assert.match(outLines[8], /<!-- voyage:anchor id="ANN-0002"/, `expected anchor at output line 9, got: ${JSON.stringify(outLines.slice(7, 12))}`);
  // Fence-opening still intact further down (shifted by 2 inserted lines)
  assert.equal(outLines.find((l) => l === '```js'), '```js');
});

test('relocateAnchorsToBlockBoundaries moves anchor inside table to block-boundary', () => {
  const md = [
    'Intro paragraph 1',  // 1
    'Intro paragraph 2',  // 2
    'Intro paragraph 3',  // 3
    'Intro paragraph 4',  // 4
    '',                   // 5
    '| Col A | Col B |',  // 6 - table header
    '|-------|-------|',  // 7 - separator
    '| a1    | b1    |',  // 8  <- anchor target inside table
    '| a2    | b2    |',  // 9
    '| a3    | b3    |',  // 10
    '',                   // 11
    'After table',        // 12
  ].join('\n');
  const out = relocate(md, [{ id: 'ANN-0003', target: 'table-row', line: 8 }]);
  const outLines = out.split('\n');
  // Table starts at line 6; anchor relocated to line 5 (start-1)
  assert.match(outLines[4], /<!-- voyage:anchor id="ANN-0003"/, `expected anchor at output line 5, got: ${JSON.stringify(outLines.slice(3, 8))}`);
});

test('relocateAnchorsToBlockBoundaries moves anchor inside deeply-nested list to block-boundary', () => {
  const md = [
    'Heading paragraph',          // 1
    '',                           // 2
    '- Top-level item A',         // 3
    '  - Second-level A.1',       // 4
    '    - Third-level A.1.a',    // 5  <- nested-list start (4-space indent = depth >= 2)
    '    - Third-level A.1.b',    // 6  <- anchor target inside nest
    '    - Third-level A.1.c',    // 7
    '  - Second-level A.2',       // 8
    '- Top-level item B',         // 9
  ].join('\n');
  const out = relocate(md, [{ id: 'ANN-0004', target: 'list-item', line: 6 }]);
  const outLines = out.split('\n');
  // Deeply-nested list starts at line 5; anchor relocated to line 4
  assert.match(outLines[3], /<!-- voyage:anchor id="ANN-0004"/, `expected anchor at output line 4, got: ${JSON.stringify(outLines.slice(2, 7))}`);
});

test('relocateAnchorsToBlockBoundaries handles multiple anchors mixed inside/outside blocks', () => {
  const md = [
    'Para A',         // 1
    'Para B',         // 2  <- anchor 1 (outside, stays)
    'Para C',         // 3
    'Para D',         // 4
    'Para E',         // 5
    '```py',          // 6 - fence open
    'x = 1',          // 7
    'y = 2',          // 8  <- anchor 2 (inside fence, moves to 5)
    'z = 3',          // 9
    '```',            // 10 - fence close
    'Para K',         // 11
  ].join('\n');
  const out = relocate(md, [
    { id: 'ANN-0010', target: 'p', line: 2 },
    { id: 'ANN-0011', target: 'code', line: 8 },
  ]);
  // Both anchors must appear; ANN-0011 must precede the fence-opening in output
  assert.match(out, /<!-- voyage:anchor id="ANN-0010"/);
  assert.match(out, /<!-- voyage:anchor id="ANN-0011"/);
  const outLines = out.split('\n');
  const ann11Idx = outLines.findIndex((l) => /ANN-0011/.test(l));
  const fenceIdx = outLines.findIndex((l) => l === '```py');
  assert.ok(ann11Idx < fenceIdx, `ANN-0011 (${ann11Idx}) must precede fence-open (${fenceIdx})`);
});

test('relocateAnchorsToBlockBoundaries returns string (basic shape)', () => {
  const out = relocate('a\nb\nc\n', [{ id: 'ANN-0099', target: 't', line: 2 }]);
  assert.equal(typeof out, 'string');
  assert.ok(out.length > 0);
});