Launch Multiple Cursor Composer AI Agents to Work in Parallel

# wtree: Create a new worktree for each given branch.
# Usage: wtree [ -p|--pnpm ] branch1 branch2 ...
#
# This function does the following:
#   1. Parses command-line arguments; if -p/--pnpm is provided, it will later run "pnpm install".
#   2. Determines the current branch and repository root.
#   3. Uses a fixed parent directory (~/dev) to house all worktree directories.
#   4. For each branch passed:
#        - If the branch does not exist, it is created from the current branch.
#        - It checks that a worktree for that branch does not already exist.
#        - It then creates a worktree in ~/dev using a naming convention: <repoName>-<branch>.
#        - If the install-deps flag is true, it runs "pnpm install" inside the new worktree.
#        - Finally, it either opens the new worktree via the custom "cursor" command (if defined)
#          or prints its path.
wtree() {
  # Flag to determine whether to run "pnpm install"
  local install_deps=false
  local branches=()

  # Parse command-line arguments
  while [[ $# -gt 0 ]]; do
    case "$1" in
      -p|--pnpm)
        install_deps=true
        shift
        ;;
      *)
        branches+=("$1")
        shift
        ;;
    esac
  done

  # Ensure at least one branch name is provided.
  if [[ ${#branches[@]} -eq 0 ]]; then
    echo "Usage: wtree [ -p|--pnpm ] branch1 branch2 ..."
    return 1
  fi

  # Determine the current branch; exit if not in a git repository.
  local current_branch
  current_branch=$(git rev-parse --abbrev-ref HEAD) || {
    echo "Error: Not a git repository."
    return 1
  }

  # Determine repository root and name.
  local repo_root repo_name
  repo_root=$(git rev-parse --show-toplevel) || {
    echo "Error: Cannot determine repository root."
    return 1
  }
  repo_name=$(basename "$repo_root")

  # Set fixed parent directory for worktrees.
  local worktree_parent="$HOME/dev"
  # Ensure the worktree parent directory exists.
  if [[ ! -d "$worktree_parent" ]]; then
    if ! mkdir -p "$worktree_parent"; then
      echo "Error: Failed to create worktree parent directory: $worktree_parent"
      return 1
    fi
  fi

  # Loop over each branch provided as argument.
  for branch in "${branches[@]}"; do
    # Define the target path using a naming convention: <repoName>-<branch>
    local target_path="$worktree_parent/${repo_name}-${branch}"
    
    echo "Processing branch: ${branch}"

    # Check if a worktree already exists at the target path.
    if git worktree list | grep -q "^${target_path}[[:space:]]"; then
      echo "Error: Worktree already exists at ${target_path}. Skipping branch '${branch}'."
      continue
    fi

    # If the branch does not exist, create it from the current branch.
    if ! git show-ref --verify --quiet "refs/heads/${branch}"; then
      echo "Branch '${branch}' does not exist. Creating it from '${current_branch}'..."
      if ! git branch "${branch}"; then
        echo "Error: Failed to create branch '${branch}'. Skipping."
        continue
      fi
    fi

    # Create the new worktree for the branch.
    echo "Creating worktree for branch '${branch}' at ${target_path}..."
    if ! git worktree add "$target_path" "${branch}"; then
      echo "Error: Failed to create worktree for branch '${branch}'. Skipping."
      continue
    fi

    # If the install flag is set, run "pnpm install" in the new worktree.
    if $install_deps; then
      echo "Installing dependencies in worktree for branch '${branch}'..."
      if ! ( cd "$target_path" && pnpm install ); then
        echo "Warning: Failed to install dependencies in '${target_path}'."
      fi
    fi

    # Optionally, open the worktree directory via a custom "cursor" command if available.
    if type cursor >/dev/null 2>&1; then
      cursor "$target_path"
    else
      echo "Worktree created at: ${target_path}"
    fi

    echo "Worktree for branch '${branch}' created successfully."
    echo "-----------------------------------------------------"
  done
}


# wtmerge: Merge changes from a specified worktree branch into main,
# then clean up all worktrees and delete their branches.
#
# Usage: wtmerge <branch-to-keep>
#
# This function does the following:
#   1. Verifies that the branch to merge (branch-to-keep) exists as an active worktree.
#   2. Checks for uncommitted changes in that worktree:
#        - If changes exist, it attempts to stage and commit them.
#        - It gracefully handles the situation where there are no changes.
#   3. Switches the current (main) worktree to the "main" branch.
#   4. Merges the specified branch into main, with proper error checking.
#   5. Uses "git worktree list" to retrieve all active worktrees (under ~/dev
#      and matching the naming pattern) and removes them.
#   6. Deletes each branch that was created for a worktree (skipping "main").
wtmerge() {
  # Ensure exactly one argument is passed: the branch to merge.
  if [ $# -ne 1 ]; then
    echo "Usage: wtmerge <branch-to-keep>"
    return 1
  fi

  local branch_to_keep="$1"

  # Determine the repository root and its name.
  local repo_root repo_name
  repo_root=$(git rev-parse --show-toplevel) || {
    echo "Error: Not a git repository."
    return 1
  }
  repo_name=$(basename "$repo_root")

  # Fixed parent directory where worktrees are located.
  local worktree_parent="$HOME/dev"

  # Retrieve all active worktrees (from git worktree list) that match our naming convention.
  local worktrees=()
  while IFS= read -r line; do
    # Extract the worktree path (first field)
    local wt_path
    wt_path=$(echo "$line" | awk '{print $1}')
    # Only consider worktrees under our fixed parent directory that match "<repo_name>-*"
    if [[ "$wt_path" == "$worktree_parent/${repo_name}-"* ]]; then
      worktrees+=("$wt_path")
    fi
  done < <(git worktree list)

  # Check that the target branch worktree exists.
  local target_worktree=""
  for wt in "${worktrees[@]}"; do
    if [[ "$wt" == "$worktree_parent/${repo_name}-${branch_to_keep}" ]]; then
      target_worktree="$wt"
      break
    fi
  done

  if [[ -z "$target_worktree" ]]; then
    echo "Error: No active worktree found for branch '${branch_to_keep}' under ${worktree_parent}."
    return 1
  fi

  # Step 1: In the target worktree, check for uncommitted changes.
  echo "Checking for uncommitted changes in worktree for branch '${branch_to_keep}'..."
  if ! ( cd "$target_worktree" && git diff --quiet && git diff --cached --quiet ); then
    echo "Changes detected in branch '${branch_to_keep}'. Attempting auto-commit..."
    if ! ( cd "$target_worktree" &&
            git add . &&
            git commit -m "chore: auto-commit changes in '${branch_to_keep}' before merge" ); then
      echo "Error: Auto-commit failed in branch '${branch_to_keep}'. Aborting merge."
      return 1
    else
      echo "Auto-commit successful in branch '${branch_to_keep}'."
    fi
  else
    echo "No uncommitted changes found in branch '${branch_to_keep}'."
  fi

  # Step 2: Switch to the main worktree (assumed to be the current directory) and check out main.
  echo "Switching to 'main' branch in the main worktree..."
  if ! git checkout main; then
    echo "Error: Failed to switch to 'main' branch."
    return 1
  fi

  # Step 3: Merge the target branch into main.
  echo "Merging branch '${branch_to_keep}' into 'main'..."
  if ! git merge "${branch_to_keep}" -m "feat: merge changes from '${branch_to_keep}'"; then
    echo "Error: Merge failed. Please resolve conflicts and try again."
    return 1
  fi

  # Step 4: Remove all worktrees that were created via wtree().
  echo "Cleaning up worktrees and deleting temporary branches..."
  for wt in "${worktrees[@]}"; do
    # Extract branch name from worktree path.
    local wt_branch
    wt_branch=$(basename "$wt")
    wt_branch=${wt_branch#${repo_name}-}  # Remove the repo name prefix

    echo "Processing worktree for branch '${wt_branch}' at ${wt}..."
    # Remove the worktree using --force to ensure removal.
    if git worktree remove "$wt" --force; then
      echo "Worktree at ${wt} removed."
    else
      echo "Warning: Failed to remove worktree at ${wt}."
    fi

    # Do not delete the 'main' branch.
    if [[ "$wt_branch" != "main" ]]; then
      if git branch -D "$wt_branch"; then
        echo "Branch '${wt_branch}' deleted."
      else
        echo "Warning: Failed to delete branch '${wt_branch}'."
      fi
    fi
  done

  echo "Merge complete: Branch '${branch_to_keep}' merged into 'main', and all worktrees cleaned up."
}