Worktree

project/
  .git/          (directory)
  src/
  README.md

project/                          (main worktree)
  .git/                           (the actual git directory)
    worktrees/
      review/                     (metadata for linked worktree)
        HEAD
        commondir
        gitdir

/tmp/review/                      (linked worktree)
  .git                            (file, not directory)
  src/
  README.md

gitdir: ../../path/to/project/.git/worktrees/review

$repo = Pitmaster::open('/path/to/project');

// Create a linked worktree on a new branch
$wt = $repo->addWorktree('/tmp/review', 'feature/review');

echo $wt->path;        // '/tmp/review'
echo $wt->branch;      // 'feature/review'
echo $wt->gitDir;      // '/path/to/project/.git/worktrees/review'
var_dump($wt->isMain);      // bool(false)
var_dump($wt->isDetached);  // bool(false)

$wt = $repo->addWorktree(
    '/tmp/sandboxes/app',
    'feature/review',
    name: 'sandbox-app',
);

$wt = $repo->addWorktree('/tmp/hotfix', 'hotfix/urgent', $repo->resolve('v1.0.0'));

$worktrees = $repo->worktrees();

foreach ($worktrees as $wt) {
    $type = $wt->isMain ? 'main' : 'linked';
    $branch = $wt->branch ?? 'detached';
    $locked = $wt->isLocked ? ' [locked]' : '';

    echo "{$wt->path} ({$type}) [{$branch}]{$locked}\n";
}

$repo->removeWorktree('review');          // by metadata name
$repo->removeWorktree('/tmp/review');     // or by worktree path

// Force remove (even if locked)
$repo->removeWorktree('review', force: true);

$repo = Pitmaster::open('/tmp/review');

// Pitmaster detects the .git file and follows the gitdir reference
echo $repo->isLinkedWorktree();  // true
echo $repo->gitDir();            // '/path/to/project/.git/worktrees/review'
echo $repo->commonGitDir();      // '/path/to/project/.git'
echo $repo->workDir();           // '/tmp/review'

use Pitmaster\Worktree\Worktree;

$wt->name;          // Metadata name (null for the main worktree)
$wt->path;          // Working directory path
$wt->gitDir;        // Per-worktree git dir
$wt->branch;        // Branch name (null if detached)
$wt->head;          // ObjectId of HEAD commit
$wt->isMain;        // true for the main worktree
$wt->isDetached;    // true if HEAD is detached
$wt->isLocked;      // true if worktree is locked
$wt->lockReason;    // Lock reason, or null when there is none (an empty reason is also null)

use Pitmaster\Worktree\WorktreeManager;

$manager = new WorktreeManager($repo->commonGitDir(), $mainWorkDir);

// List
$worktrees = $manager->list();

// Add
$wt = $manager->add('/tmp/review', 'feature/review');
$wt = $manager->add('/tmp/review', 'feature/review', 'review-app');

// Remove
$manager->remove('review');
$manager->remove('review', force: true);

// Lock/unlock (metadata name only)
$manager->lock('review', 'Do not delete, code review in progress');
$manager->unlock('review');

// Lock (prevents removal)
$manager->lock('review', 'Code review in progress');

// Attempt to remove locked worktree
try {
    $manager->remove('review');
} catch (\RuntimeException $e) {
    // "Worktree is locked: review (Code review in progress)"
}

// Force remove ignores the lock
$manager->remove('review', force: true);

// Unlock
$manager->unlock('review');

// Check if a path is a linked worktree
if (Pitmaster::isWorktree('/tmp/review')) {
    echo "This is a linked worktree\n";
}

// Resolve the common git dir from any path
$common = Pitmaster::commonGitDir('/tmp/review');
// '/path/to/project/.git'

// Resolve a .git file to the actual git directory
$gitDir = WorktreeManager::resolveGitFile('/tmp/review');
// '/path/to/project/.git/worktrees/review'

.git/worktrees/<name>/
  HEAD         Per-worktree HEAD (symbolic ref or detached hash)
  commondir    Relative path to the shared git dir ("../..")
  gitdir       Path back to the worktree's .git file, as passed to addWorktree()
  locked       Present if locked (content = reason)
  index        Per-worktree index/staging area

gitdir: <relative path to>/project/.git/worktrees/<name>