/**
 * Regression test for #2112: gsd-tools commit --files commits the entire
 * index, not the declared paths.
 *
 * `cmdCommit` staged exactly the files named in --files but then ran a bare
 * `git commit` with no pathspec, absorbing anything else that happened to be
 * staged into a commit whose message described only the named files.
 *
 * The fix adds `'--', ...stagedPaths` to the commit args **only when** the
 * caller declared a scope (explicitFiles), and only for paths that were
 * actually staged (skipped missing files are excluded to avoid #2014).
 */

const { describe, test, beforeEach, afterEach } = require('node:test');
const assert = require('node:assert/strict');
const fs = require('fs');
const path = require('path');
const { execSync } = require('child_process');

const { createTempGitProject, cleanup, runGsdTools } = require('./helpers.cjs');

describe('commit --files: pathspec honors declared scope (#2112)', () => {
  let tmpDir;

  beforeEach(() => {
    tmpDir = createTempGitProject();
  });

  afterEach(() => {
    cleanup(tmpDir);
  });

  test('commit --files does not absorb unrelated staged files', () => {
    // Developer stages a WIP file via git add (not via --files).
    fs.writeFileSync(path.join(tmpDir, 'src-wip.txt'), 'work in progress\n');
    execSync('git add src-wip.txt', { cwd: tmpDir, stdio: 'pipe' });

    // GSD writes and commits a planning artifact, naming ONLY that file.
    fs.writeFileSync(path.join(tmpDir, '.planning', 'PLAN.md'), '# Plan\n');
    runGsdTools(
      ['commit', 'docs(01): add PLAN.md', '--files', '.planning/PLAN.md'],
      tmpDir,
    );

    // The commit must contain ONLY .planning/PLAN.md.
    const diffOutput = execSync('git diff HEAD~1 HEAD --name-only', {
      cwd: tmpDir,
      encoding: 'utf-8',
    }).trim();
    assert.strictEqual(
      diffOutput,
      '.planning/PLAN.md',
      'commit --files must contain only the named files, got:\n' + diffOutput,
    );

    // The WIP file must still be staged, not committed.
    const statusOutput = execSync('git status --porcelain', {
      cwd: tmpDir,
      encoding: 'utf-8',
    }).trim();
    assert.ok(
      statusOutput.includes('A  src-wip.txt') || statusOutput.includes('A\tsrc-wip.txt'),
      'src-wip.txt should remain staged, not committed. Status:\n' + statusOutput,
    );
  });

  test('commit --files with two files commits exactly those two', () => {
    fs.writeFileSync(path.join(tmpDir, '.planning', 'PLAN.md'), '# Plan\n');
    fs.writeFileSync(path.join(tmpDir, '.planning', 'RESEARCH.md'), '# Research\n');

    runGsdTools(
      ['commit', 'docs: artifacts', '--files', '.planning/PLAN.md', '.planning/RESEARCH.md'],
      tmpDir,
    );

    const diffOutput = execSync('git diff HEAD~1 HEAD --name-only', {
      cwd: tmpDir,
      encoding: 'utf-8',
    });
    const files = diffOutput.trim().split('\n').sort();
    assert.deepEqual(
      files,
      ['.planning/PLAN.md', '.planning/RESEARCH.md'],
      'commit should contain exactly the two named files',
    );
  });

  test('commit without --files still commits the entire .planning/ index (default path)', () => {
    // Write a planning artifact and stage it.
    fs.writeFileSync(path.join(tmpDir, '.planning', 'PLAN.md'), '# Plan\n');
    execSync('git add .planning/PLAN.md', { cwd: tmpDir, stdio: 'pipe' });

    // Also stage an unrelated file.
    fs.writeFileSync(path.join(tmpDir, 'extra.txt'), 'extra\n');
    execSync('git add extra.txt', { cwd: tmpDir, stdio: 'pipe' });

    runGsdTools(['commit', 'docs: default commit'], tmpDir);

    // Default path (no --files) commits everything staged.
    const diffOutput = execSync('git diff HEAD~1 HEAD --name-only', {
      cwd: tmpDir,
      encoding: 'utf-8',
    });
    const files = diffOutput.trim().split('\n').sort();
    assert.ok(
      files.includes('.planning/PLAN.md') && files.includes('extra.txt'),
      'default commit (no --files) should commit everything staged, got:\n' + files,
    );
  });

  test('missing tracked file in --files is still not committed as deletion (#2014 guard)', () => {
    // Create and commit STATE.md, then remove it from disk.
    fs.writeFileSync(path.join(tmpDir, '.planning', 'STATE.md'), '# State\n');
    execSync('git add .planning/STATE.md', { cwd: tmpDir, stdio: 'pipe' });
    execSync('git commit -m "add STATE.md"', { cwd: tmpDir, stdio: 'pipe' });
    fs.unlinkSync(path.join(tmpDir, '.planning', 'STATE.md'));

    // Also create a valid file to commit.
    fs.writeFileSync(path.join(tmpDir, '.planning', 'PLAN.md'), '# Plan\n');

    runGsdTools(
      ['commit', 'docs: add plan', '--files', '.planning/PLAN.md', '.planning/STATE.md'],
      tmpDir,
    );

    const diffOutput = execSync('git diff HEAD~1 HEAD --name-status', {
      cwd: tmpDir,
      encoding: 'utf-8',
    });
    assert.ok(
      !diffOutput.includes('D\t.planning/STATE.md'),
      'missing tracked file must not appear as a deletion, diff was:\n' + diffOutput,
    );
    assert.ok(
      diffOutput.includes('.planning/PLAN.md'),
      'PLAN.md should be committed',
    );
  });

  test('commit --files with only missing files returns nothing_to_commit', () => {
    // Create and commit STATE.md, then remove it from disk.
    fs.writeFileSync(path.join(tmpDir, '.planning', 'STATE.md'), '# State\n');
    execSync('git add .planning/STATE.md', { cwd: tmpDir, stdio: 'pipe' });
    execSync('git commit -m "add STATE.md"', { cwd: tmpDir, stdio: 'pipe' });
    fs.unlinkSync(path.join(tmpDir, '.planning', 'STATE.md'));

    // Stage an unrelated file so the index is non-empty.
    fs.writeFileSync(path.join(tmpDir, 'extra.txt'), 'extra\n');
    execSync('git add extra.txt', { cwd: tmpDir, stdio: 'pipe' });

    const result = runGsdTools(
      ['commit', 'docs: try', '--files', '.planning/STATE.md'],
      tmpDir,
    );

    const parsed = JSON.parse(result.output);
    assert.strictEqual(
      parsed.committed, false,
      'should not commit when all --files are missing',
    );
    assert.strictEqual(
      parsed.reason, 'nothing_to_commit',
      'should report nothing_to_commit, not absorb the index',
    );

    // The unrelated staged file must still be staged, not committed.
    const statusOutput = execSync('git status --porcelain', {
      cwd: tmpDir,
      encoding: 'utf-8',
    }).trim();
    assert.ok(
      statusOutput.includes('extra.txt'),
      'extra.txt should remain staged, not absorbed into a commit',
    );
  });
});