git worktree helper / manager

gwt.sh

# Git Worktree Manager (bare repo workflow)
# Works in bash and zsh

gwt() {
    case "$1" in
    init)
        shift
        _gwt_init "$@"
        ;;
    add | a)
        shift
        _gwt_add "$@"
        ;;
    fork | f)
        shift
        _gwt_fork "$@"
        ;;
    jump | j) _gwt_jump ;;
    rm)
        shift
        _gwt_rm "$@"
        ;;
    ls) _gwt_ls ;;
    st) _gwt_st ;;
    *) _gwt_help ;;
    esac
}

_gwt_root() {
    local root
    root=$(git rev-parse --git-common-dir 2>/dev/null)

    if [[ -z "$root" ]] || [[ "$root" == "." ]]; then
        if [[ -f "HEAD" ]] && [[ -d "objects" ]] && [[ -d "refs" ]]; then
            root=$PWD
        else
            echo "Not a git repo" >&2
            return 1
        fi
    fi

    echo "$root"
}

_gwt_init() {
    [[ -z "$1" ]] && {
        echo "Usage: gwt init <repo> [name]" >&2
        return 1
    }
    local repo="$1"
    local name="${2:-$(basename "$repo" .git)}"

    git clone --bare "$repo" "$name" && cd "$name" || return 1
    git config remote.origin.fetch '+refs/heads/*:refs/remotes/origin/*'
    git fetch origin

    local default
    default=$(git symbolic-ref --short refs/remotes/origin/HEAD 2>/dev/null)
    default=${default#origin/}
    : "${default:=main}"

    mkdir -p trees
    git worktree add "trees/$default" "$default"
    cd "trees/$default"
}

_gwt_add() {
    [[ -z "$1" ]] && {
        echo "Usage: gwt add <branch> [dir]" >&2
        return 1
    }
    local branch="$1"
    local name="${2:-$1}"
    local root
    root=$(_gwt_root) || return 1
    local dir="$root/trees/$name"

    mkdir -p "$root/trees"

    if git show-ref --verify --quiet "refs/heads/$branch"; then
        git worktree add "$dir" "$branch"
    elif git show-ref --verify --quiet "refs/remotes/origin/$branch"; then
        git worktree add -b "$branch" "$dir" "origin/$branch"
    else
        git worktree add -b "$branch" "$dir"
    fi && cd "$dir"
}

_gwt_fork() {
    [[ -z "$1" ]] && {
        echo "Usage: gwt fork <new-branch> [dir]" >&2
        return 1
    }
    local new_branch="$1"
    local name="${2:-$1}"
    local root
    root=$(_gwt_root) || return 1
    local dir="$root/trees/$name"

    mkdir -p "$root/trees"
    git worktree add -b "$new_branch" "$dir" && cd "$dir"
}

_gwt_jump() {
    command -v fzf >/dev/null || {
        echo "fzf required" >&2
        return 1
    }
    local root
    root=$(_gwt_root) || return 1
    local dir
    dir=$(git worktree list | grep "/trees/" | fzf --height=40% --reverse | awk '{print $1}')
    [[ -n "$dir" ]] && cd "$dir"
}

_gwt_rm() {
    [[ -z "$1" ]] && {
        echo "Usage: gwt rm <name>" >&2
        return 1
    }
    local root
    root=$(_gwt_root) || return 1
    git worktree remove "$root/trees/$1"
}

_gwt_ls() {
    local root
    root=$(_gwt_root) || return 1
    git --git-dir="$root" worktree list
}

_gwt_st() {
    local root
    root=$(_gwt_root) || return 1
    for wt in "$root"/trees/*/; do
        [[ -f "$wt/.git" ]] || continue
        printf "\n\033[1m%s\033[0m\n" "$(basename "${wt%/}")"
        git -C "$wt" status -sb
    done
}

_gwt_help() {
    cat <<'EOF'
Git Worktree Manager (bare repo workflow)

Usage: gwt <command> [args]

Commands:
  init <repo> [name]    Clone bare repo + setup structure
  add <branch> [dir]    Add worktree (existing branch or from origin)
  fork <branch> [dir]   Add worktree branched from current HEAD
  jump                  fzf picker
  rm <name>             Remove worktree
  ls                    List worktrees
  st                    Status all

Aliases: a=add, f=fork, j=jump

Examples:
  gwt init git@github.com:user/repo.git
  gwt add feature-x           # checkout existing branch
  gwt fork spike-idea         # new branch from current HEAD
  gwt jump                    # switch worktrees
EOF
}