import test from 'node:test';
import assert from 'node:assert/strict';
import os from 'node:os';
import path from 'node:path';
import fs from 'node:fs/promises';
import { execFile } from 'node:child_process';
import { promisify } from 'node:util';
import gitModule from '../src/main/git-service.cjs';

const exec = promisify(execFile);
const git = (args, cwd) => exec('git', args, { cwd, encoding: 'utf8' });
const { GitService, parseUnifiedDiff } = gitModule;

test('unified diff parser separates selectable hunks', () => {
  const parsed = parseUnifiedDiff('diff --git a/a b/a\n--- a/a\n+++ b/a\n@@ -1 +1 @@\n-old\n+new\n@@ -10 +10 @@\n-x\n+y\n');
  assert.equal(parsed.hunks.length, 2);
  assert.equal(parsed.hunks[0].additions, 1);
  assert.equal(parsed.hunks[1].deletions, 1);
});

test('stages only selected hunks using a server-generated patch', async (t) => {
  const root = await fs.mkdtemp(path.join(os.tmpdir(), 'forgeflow-hunks-'));
  t.after(() => fs.rm(root, { recursive: true, force: true }));
  await git(['init'], root);
  await git(['config', 'user.name', 'ForgeFlow Test'], root);
  await git(['config', 'user.email', 'forgeflow@example.invalid'], root);
  const original = [...Array(20)].map((_, index) => `line ${index + 1}`).join('\n') + '\n';
  await fs.writeFile(path.join(root, 'file.txt'), original);
  await git(['add', '.'], root); await git(['commit', '-m', 'Initial'], root);
  const lines = original.trimEnd().split('\n'); lines[0] = 'first changed'; lines[19] = 'last changed';
  await fs.writeFile(path.join(root, 'file.txt'), `${lines.join('\n')}\n`);
  const service = new GitService();
  const hunks = await service.diffHunks(root, 'file.txt');
  assert.equal(hunks.hunks.length, 2);
  await service.stageHunks(root, 'file.txt', [0]);
  const staged = (await git(['diff', '--cached'], root)).stdout;
  const unstaged = (await git(['diff'], root)).stdout;
  assert.match(staged, /first changed/); assert.doesNotMatch(staged, /last changed/);
  assert.match(unstaged, /last changed/); assert.doesNotMatch(unstaged, /first changed/);
  await service.commitStaged(root, 'Commit reviewed hunk');
  const afterCommit = (await git(['diff'], root)).stdout;
  assert.match(afterCommit, /last changed/);
  assert.doesNotMatch(afterCommit, /first changed/);
});