dotfiles/dot_config/kitty/tab_bar.py

# ── tab_bar.py · kitty tab titles: program icon + repo dir (or nvim's file) ──
#
# kitty loads this file from the config dir and exposes `draw_title` as the
# `{custom}` field of tab_title_template (kitty/tab_bar.py:
# load_custom_draw_title). kitty still draws the powerline chrome; only the text
# inside a tab comes from here.
#
# A title is `<index> <icon> <label>`:
#     2  chezmoi        repo the tab's cwd belongs to (dir name if no repo)
#     3  astrocore.lua  an editor: the file it is editing
#     4  chezmoi        a known program: its icon, repo as the label
#
# No subprocesses, no timers. The repo root is found by walking up for `.git`;
# the icon comes from the foreground process' cmdline; the edited file comes from
# the title nvim already sets (~/.config/nvim/lua/plugins/astrocore.lua,
# custom_title autocmd: "<file> | <org/repo>" / "<file> | Nvim", and
# "<org/repo>" / "Nvim" with no file). kitty repaints the tab bar when a window
# title changes, so buffer switches and program changes show up on their own.

from __future__ import annotations

import os
from typing import Any

# Nerd Font glyphs; VictorMono Nerd Font Mono covers every codepoint used here
# (checked with `fc-list ":charset=<hex>:family=VictorMono Nerd Font Mono"`).
FOLDER = '\uf07b'  # nf-fa-folder — the fallback: "a shell somewhere"
EDITOR = '\ue62b'  # nf-custom-neovim

ICONS: dict[str, str] = {
    # editors (label becomes the edited file, see EDITORS below)
    'nvim': EDITOR,
    'vim': EDITOR,
    'nvim-qt': EDITOR,
    'hx': EDITOR,
    'helix': EDITOR,
    # agents / harnesses
    'claude': '\U000f06a9',  # nf-md-robot
    'omp': '\U000f09da',  # nf-md-brain
    'opencode': '\uf121',  # nf-fa-code
    'crush': '\uf0e7',  # nf-fa-bolt
    'codex': '\uf120',  # nf-fa-terminal
    'gemini': '\U000f0674',  # nf-md-creation
    'aider': '\U000f0068',  # nf-md-auto_fix
    # git
    'lazygit': '\uf1d3',  # nf-fa-git
    'git': '\uf1d3',
    'gitui': '\uf1d3',
    'tig': '\uf1d3',
    'gh': '\uf113',  # nf-fa-github_alt
    # containers
    'lazydocker': '\uf308',  # nf-linux-docker
    'docker': '\uf308',
    'docker-compose': '\uf308',
    'podman': '\uf308',
    'kubectl': '\ue7b2',  # nf-dev-kubernetes
    # multiplexers / terminals-in-terminals
    'herdr': '\uf009',  # nf-fa-th_large — panes
    'tmux': '\uf00a',  # nf-fa-th
    # files, monitors, history
    'yazi': '\uf07c',  # nf-fa-folder_open
    'ranger': '\uf07c',
    'lf': '\uf07c',
    'btop': '\uf0e4',  # nf-fa-dashboard
    'htop': '\uf0e4',
    'top': '\uf0e4',
    'atuin': '\uf1da',  # nf-fa-history
    'atuin-pick': '\uf1da',
    'ssh': '\uf0ac',  # nf-fa-globe
    'chezmoi': '\uf013',  # nf-fa-cog
    # runtimes / build / data
    'python': '\ue235',  # nf-dev-python
    'python3': '\ue235',
    'ipython': '\ue235',
    'node': '\ue718',  # nf-dev-nodejs_small
    'bun': '\ue718',
    'deno': '\ue718',
    'cargo': '\ue7a8',  # nf-dev-rust
    'rustc': '\ue7a8',
    'make': '\uf085',  # nf-fa-gears
    'just': '\uf085',
    'psql': '\uf1c0',  # nf-fa-database
    'sqlite3': '\uf1c0',
    'duckdb': '\uf1c0',
    'man': '\uf02d',  # nf-fa-book
    'less': '\uf02d',
    'bat': '\uf02d',
    'glow': '\uf02d',
}

# These get the edited file as their label instead of the repo.
EDITORS = frozenset({'nvim', 'vim', 'nvim-qt', 'hx', 'helix'})

# Skipped when reading a cmdline, so `node .../claude` is claude and
# `uv run python x.py` is python — unless nothing else is left, in which case the
# interpreter itself is the program (a bare `python` REPL).
INTERPRETERS = frozenset({
    'sh', 'bash', 'zsh', 'fish', 'env', 'sudo', 'doas', 'nohup', 'setsid',
    'node', 'bun', 'deno', 'npx', 'uv', 'uvx', 'python', 'python3',
})

# Subcommands of the runners above ("uv run python x.py"), skipped only after a
# runner has been skipped so a program genuinely called `run` still resolves.
RUNNER_WORDS = frozenset({'run', 'exec', 'x', 'tool', '--'})

MAX_LEN = 28

# wd -> repo root (or ''), memoized: a working dir keeps its answer for the life
# of the kitty instance, so `git init` in an already-open dir needs a config
# reload (ctrl+shift+f5) to show up.
_repo: dict[str, str] = {}


def draw_title(data: dict[str, Any]) -> str:
    tab = data['tab']
    program = _program(_cmdline(data['tab_id']), tab.active_exe)
    index = data['index']
    if program in EDITORS:
        edited = _nvim_file(data['title'])
        if edited:
            return f'{index} {ICONS[program]} {_elide(edited)}'
    icon = ICONS.get(program, FOLDER)
    wd = tab.active_wd
    label = ''
    if wd:
        label = '~' if wd == os.path.expanduser('~') else os.path.basename(_repo_root(wd) or wd.rstrip('/'))
    return f'{index} {icon} {_elide(label or data["title"])}'


def _cmdline(tab_id: int) -> list[str]:
    """argv of the tab's active window's foreground process, [] if unavailable."""
    from kitty.boss import get_boss

    try:
        tab = get_boss().tab_for_id(tab_id)
        window = tab.active_window if tab is not None else None
        return list(window.child.foreground_cmdline) if window is not None else []
    except Exception:
        return []


def _program(cmdline: list[str], fallback_exe: str) -> str:
    """Program name a tab should be iconified by.

    Walks the cmdline past runners and flags: `node …/claude` is claude, an
    unknown script keeps its runtime's icon (`uv run python train.py` is
    python, `bun run dev` is bun), and a bare `python` stays python. Falls back
    to kitty's own exe for the active window when the cmdline is unreadable.
    """
    runtime = ''
    skipped = False
    for arg in cmdline:
        if arg.startswith('-'):
            continue
        name = os.path.basename(arg).lower()
        if name.endswith(('.js', '.mjs', '.cjs', '.py', '.ts')):
            name = name.rsplit('.', 1)[0]
        if not name:
            continue
        name = _canonical(name)
        if name in INTERPRETERS or (skipped and name in RUNNER_WORDS):
            skipped = True
            runtime = runtime or (name if name in ICONS else '')
            continue
        return name if name in ICONS or not runtime else runtime
    return runtime or _canonical(os.path.basename(fallback_exe or '').lower())


def _canonical(name: str) -> str:
    """`omp-linux-x64` -> `omp`, `docker-compose` stays itself."""
    if name in ICONS:
        return name
    for known in ICONS:
        if name.startswith(known + '-'):
            return known
    return name


def _repo_root(wd: str) -> str:
    root = _repo.get(wd)
    if root is None:
        root = ''
        path = wd
        while True:
            if os.path.exists(os.path.join(path, '.git')):
                root = path
                break
            parent = os.path.dirname(path)
            if parent == path:
                break
            path = parent
        _repo[wd] = root
    return root


def _nvim_file(title: str) -> str:
    """The file name out of an editor window title, '' when it is editing none.

    Handles this config's "<file> | <org/repo>" / "<file> | Nvim" and nvim's own
    default "%t - Nvim" / "<file> (<dir>) - NVIM".
    """
    text = title.strip()
    for suffix in (' - NVIM', ' - Nvim', ' - nvim'):
        if text.endswith(suffix):
            text = text[: -len(suffix)]
    text = text.split(' | ', 1)[0].strip()
    if text.endswith(')') and ' (' in text:
        text = text.split(' (', 1)[0].strip()
    # Left with a bare repo slug ("org/repo") or the placeholder: no file open.
    if not text or '/' in text or text.lower() == 'nvim':
        return ''
    return text


def _elide(label: str) -> str:
    return label if len(label) <= MAX_LEN else label[: MAX_LEN - 1] + '…'