Das-OS/srcpkgs/das-shell/files/python/das_shell/cli_banner.py

"""dbanner: the banner shown at SSH login. Without arguments it opens the editor."""

import json
import os
import subprocess
import sys
import time

from . import banner, widgets
from .cli import die, need_root, resolve, run_tui
from .i18n import t

PROG = "dbanner"
SERVICE = "/etc/sv/das-banner"
SERVICE_LINK = "/var/service/das-banner"


def text(design, use_cache, color):
    values = widgets.Values(design.get("vars"))
    blocks = widgets.blocks(design, values, use_cache=use_cache)
    return banner.render(design, values, blocks, color=color)


def wants_login_banner(design):
    if os.path.exists(banner.OFF_FILE) or os.path.exists(os.path.expanduser("~/.hushlogin")):
        return False
    if not sys.stdout.isatty():
        return False
    return bool(os.environ.get("SSH_TTY")) or bool(design.get("local"))


def has_cached(design):
    return any(w.get("enabled") is not False and widgets.mode_of(w) == "cached"
               for w in design.get("widgets", []))


def set_service(enabled):
    """Enables the das-banner service (runit) that keeps cached widgets fresh."""
    if not os.path.isdir(os.path.dirname(SERVICE_LINK)) or not os.path.isdir(SERVICE):
        return False
    if enabled and not os.path.lexists(SERVICE_LINK):
        os.symlink(SERVICE, SERVICE_LINK)
    elif not enabled and os.path.lexists(SERVICE_LINK):
        os.remove(SERVICE_LINK)
    return True


def apply(design):
    design = banner.normalize(design)
    banner.save(design, banner.SYSTEM_FILE)
    os.chmod(banner.SYSTEM_FILE, 0o644)
    cached = has_cached(design)
    service = set_service(cached)
    if service and cached:
        # The service fills the cache in a moment; this makes the first login see it too
        subprocess.Popen([sys.executable, os.path.abspath(sys.argv[0]), "refresh"],
                         stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, start_new_session=True)
    return cached and service


USAGE = t("""Використання: dbanner [команда]
  (без команди)          редактор банера з готовими варіантами
  list                   готові банери, ваші чернетки й малюнки
  show [НАЗВА|ФАЙЛ]      показати банер (типово — системний) зі свіжими даними
       --no-color        без кольорів
  apply НАЗВА|ФАЙЛ       зробити банером при вході по SSH (/etc/das/banner.json)
  off | on               вимкнути або ввімкнути банер
  refresh [--force]      оновити віджети з кешем (робить служба das-banner)
Банер показується при вході по SSH; "local": true у файлі — і при вході в консоль.
Окремий користувач вимикає його файлом ~/.hushlogin.""",
          """Usage: dbanner [command]
  (no command)           banner editor with ready-made designs
  list                   ready-made banners, your drafts and pictures
  show [NAME|FILE]       show a banner (default: the system one) with fresh data
       --no-color        without colors
  apply NAME|FILE        make it the SSH login banner (/etc/das/banner.json)
  off | on               turn the banner off or on
  refresh [--force]      update the cached widgets (the das-banner service does it)
The banner is shown at SSH logins; "local": true in the file shows it on the
console too. A user turns it off for themselves with ~/.hushlogin.""")


def main(argv=None):
    argv = sys.argv[1:] if argv is None else argv
    if not argv:
        from . import banner_app
        return run_tui(PROG, banner_app.BannerApp)
    cmd, args = argv[0], argv[1:]
    flags = {a for a in args if a.startswith("--")}
    args = [a for a in args if not a.startswith("--")]
    try:
        if cmd in ("-h", "--help", "help"):
            print(USAGE)
        elif cmd == "list":
            print(t("Готові:", "Ready-made:"))
            for name, title in banner.list_presets():
                print(f"  {name:<14} {title}")
            drafts = banner.list_drafts()
            if drafts:
                print(t("Чернетки:", "Drafts:"))
                for name, path in drafts:
                    print(f"  {name:<14} {path}")
            print(t("Малюнки (вставляються в редакторі):", "Pictures (inserted in the editor):"))
            for name, title, _ in banner.list_art():
                print(f"  {name:<14} {title}")
        elif cmd == "show":
            if "--login" in flags:
                design = banner.system_design()
                if wants_login_banner(design):
                    sys.stdout.write(text(design, use_cache=True, color=True))
                    sys.stdout.flush()
                # A hung widget thread must not hold the login
                os._exit(0)
            design = banner.load(args[0]) if args else banner.system_design()
            color = "--no-color" not in flags and sys.stdout.isatty() or "--color" in flags
            sys.stdout.write(text(design, use_cache=not args, color=color))
        elif cmd == "apply":
            if not args:
                die(PROG, "вкажіть назву або файл", "name a design or a file")
            spec = resolve(args[0])
            design = banner.load(spec)
            need_root(["apply", spec])
            cached = apply(design)
            print(t("Банер записано в /etc/das/banner.json, його видно при наступному вході по SSH.",
                    "The banner is written to /etc/das/banner.json; it shows at the next SSH login."))
            if cached:
                print(t("Віджети з кешем оновлює служба das-banner (увімкнено).",
                        "Cached widgets are updated by the das-banner service (enabled)."))
        elif cmd in ("off", "on"):
            need_root([cmd])
            if cmd == "off":
                open(banner.OFF_FILE, "w").close()
            elif os.path.exists(banner.OFF_FILE):
                os.remove(banner.OFF_FILE)
            print(t("Банер вимкнено." if cmd == "off" else "Банер увімкнено.",
                    "The banner is off." if cmd == "off" else "The banner is on."))
        elif cmd == "refresh":
            if "--loop" in flags:
                while True:
                    widgets.refresh(banner.system_design())
                    time.sleep(60)
            widgets.refresh(banner.system_design(), force="--force" in flags)
        else:
            die(PROG, f"невідома команда: {cmd}\n{USAGE}", f"unknown command: {cmd}\n{USAGE}", 2)
    except FileNotFoundError as e:
        die(PROG, f"не знайдено: {e.filename or e}", f"not found: {e.filename or e}")
    except (ValueError, json.JSONDecodeError) as e:
        die(PROG, f"помилка у файлі: {e}", f"bad file: {e}")
    except PermissionError as e:
        die(PROG, f"немає доступу: {e.filename}", f"permission denied: {e.filename}")
    return 0

if __name__ == "__main__":
    sys.exit(main())