/**
 * Independent source-adapted synthetic model; consult verification-results.json for actual execution status.
 * An independent stdlib model of the source-visible anchor decisions in:
 * https://github.com/moritzwilksch/diffle/blob/a69274d512a588dd86714bef103c8dbc2cadb2cf/src/server/comments/anchor.ts
 * https://github.com/moritzwilksch/diffle/blob/a69274d512a588dd86714bef103c8dbc2cadb2cf/src/server/comments/hunks.ts
 * This does NOT import or run Diffle and cannot establish CLI/UI behavior.
 */
import test from 'node:test';
import assert from 'node:assert/strict';

function lines(s) {
  const a = s.split('\n');
  if (a.at(-1) === '') a.pop();
  return a;
}
function relocateModel({ startLine, quoted }, contents) {
  const haystack = lines(contents);
  const needle = lines(quoted);
  if (needle.length === 0) return { startLine, endLine: startLine };
  const candidates = [];
  for (let i = 0; i + needle.length <= haystack.length; i++) {
    if (needle.every((l, j) => haystack[i + j] === l)) candidates.push(i + 1);
  }
  if (candidates.length === 0) return null;
  const winner = candidates.reduce((best, p) =>
    Math.abs(p - startLine) < Math.abs(best - startLine) ? p : best);
  return { startLine: winner, endLine: winner + needle.length - 1 };
}
function isShownModel(ranges, a) {
  return ranges.some(([start, end]) => a.startLine >= start && a.endLine <= end);
}
test('unique quote moves', () => {
  assert.deepEqual(relocateModel({startLine:2,quoted:'target();'},'a();\nb();\nc();\ntarget();\n'),{startLine:4,endLine:4});
});
test('deleted quote has no text match', () => {
  assert.equal(relocateModel({startLine:2,quoted:'target();'},'a();\nb();\nc();\n'),null);
});
test('duplicate quote can select a nearer occurrence than the intended one', () => {
  const contents = [
    'header();',       // line 1
    'repeat();',       // line 2: lexical duplicate, nearer
    'other();',        // line 3: original anchor position before edit
    'new();',
    'changed();',
    'gap();',
    'repeat();',       // line 7: hypothetical semantic target after refactor
  ].join('\n') + '\n';
  const r = relocateModel({startLine:3,quoted:'repeat();'}, contents);
  assert.deepEqual(r,{startLine:2,endLine:2});
  assert.notEqual(r.startLine,7); // heuristic ambiguity, NOT an observed Diffle UI defect
});
test('a matching line beyond shown hunks is not visible', () => {
  const r = relocateModel({startLine:2,quoted:'target();'},'a();\nb();\nc();\ntarget();\n');
  assert.equal(isShownModel([[1,2]],r),false);
});

TAP version 13
# Subtest: unique quote moves
ok 1 - unique quote moves
  ---
  duration_ms: 7.325889
  type: 'test'
  ...
# Subtest: deleted quote has no text match
ok 2 - deleted quote has no text match
  ---
  duration_ms: 0.916348
  type: 'test'
  ...
# Subtest: duplicate quote can select a nearer occurrence than the intended one
ok 3 - duplicate quote can select a nearer occurrence than the intended one
  ---
  duration_ms: 4.069714
  type: 'test'
  ...
# Subtest: a matching line beyond shown hunks is not visible
ok 4 - a matching line beyond shown hunks is not visible
  ---
  duration_ms: 2.261519
  type: 'test'
  ...
1..4
# tests 4
# suites 0
# pass 4
# fail 0
# cancelled 0
# skipped 0
# todo 0
# duration_ms 1124.334836