Backend

@cli.callback(invoke_without_command=True)
def backend_state_verification(ctx: Context) -> None:
    """
    Perform cli commands and docker engine verification (state checking).

    Parameters
    ----------
    ctx : Context
        Typer (Click like) special internal object that holds state relevant
        for the script execution at every single level.

    """

    from trecover.config import log
    from trecover.utils.docker import is_docker_running, get_container

    if not is_docker_running():
        log.project_console.print('Docker engine is not running', style='red')
        ctx.exit(1)

    elif container := get_container(var.BACKEND_ID):
        if container.status == 'running' and ctx.invoked_subcommand in ('start', None):
            log.project_console.print(':rocket: The backend service is already started', style='bright_blue')
            ctx.exit(0)

    elif ctx.invoked_subcommand is None:
        backend_start(port=var.BACKEND_PORT, auto_remove=False, attach=False)

    elif ctx.invoked_subcommand != 'start':
        log.project_console.print('The backend service is not started', style='yellow')
        ctx.exit(1)

@cli.command(name='start', help='Start service')
def backend_start(port: int = Option(var.BACKEND_PORT, '--port', '-p',
                                     help='Bind socket to this port.'),
                  auto_remove: bool = Option(False, '--rm', is_flag=True,
                                             help='Remove docker container after service exit'),
                  attach: bool = Option(False, '--attach', '-a', is_flag=True,
                                        help='Attach local standard input, output, and error streams')

                  ) -> None:
    """
    Start backend service.

    Parameters
    ----------
    port : int, default=ENV(BACKEND_PORT) or 6379
        Bind backend socket to this port.
    auto_remove : bool, default=False
        Remove backend docker container after service exit.
    attach : bool, default=False
        Attach output and error streams.

    """
    from rich.prompt import Confirm

    from trecover.config import log
    from trecover.utils.docker import get_client, get_container, get_image, pull_image

    if not (image := get_image(var.BACKEND_IMAGE)):
        with log.project_console.screen(hide_cursor=False):
            if not Confirm.ask(f"The backend image '{var.BACKEND_IMAGE}' is needed to be pulled.\nContinue?",
                               default=True):
                return

        image = pull_image(var.BACKEND_IMAGE)

    if container := get_container(var.BACKEND_ID):
        container.start()

        log.project_console.print(f'The backend service is started', style='bright_blue')

    else:
        get_client().containers.run(image=image.id,
                                    name=var.BACKEND_ID,
                                    auto_remove=auto_remove,
                                    detach=True,
                                    stdin_open=True,
                                    stdout=True,
                                    tty=True,
                                    stop_signal='SIGTERM',
                                    ports={6379: port},
                                    volumes=[f'{var.BACKEND_VOLUME_ID}:/data'])

        log.project_console.print(f'The backend service is launched', style='bright_blue')

    if attach:
        backend_attach()

@cli.command(name='stop', help='Stop service')
def backend_stop(prune: bool = Option(False, '--prune', '-p', is_flag=True,
                                      help='Prune backend.'),
                 v: bool = Option(False, '--volume', '-v', is_flag=True,
                                  help='Remove the volumes associated with the container')
                 ) -> None:
    """ Stop backend service. """

    from trecover.config import log
    from trecover.utils.docker import get_container

    get_container(var.BACKEND_ID).stop()

    log.project_console.print('The backend service is stopped', style='bright_blue')

    if prune:
        backend_prune(force=False, v=v)

@cli.command(name='prune', help='Prune docker container')
def backend_prune(force: bool = Option(False, '--force', '-f', is_flag=True,
                                       help='Force the removal of a running container'),
                  v: bool = Option(False, '--volume', '-v', is_flag=True,
                                   help='Remove the volumes associated with the container')
                  ) -> None:
    """
    Prune backend service docker container.

    Parameters
    ----------
    force : bool, default=False
        Force the removal of a running container.
    v : bool, default=False
        Remove the volumes associated with the container.

    """

    from trecover.config import log
    from trecover.utils.docker import get_container, get_volume

    container = get_container(var.BACKEND_ID)

    if container.status == 'running' and not force:
        log.project_console.print('You need to stop backend service before pruning or use --force flag', style='yellow')
    else:
        container.remove(force=force)

        if v and (volume := get_volume(var.BACKEND_VOLUME_ID)):
            volume.remove(force=force)

        log.project_console.print('The backend service is pruned', style='bright_blue')

@cli.command(name='status', help='Display service status')
def backend_status() -> None:
    """ Display backend service status. """

    from trecover.config import log
    from trecover.utils.docker import get_container

    if (container := get_container(var.BACKEND_ID)) and container.status == 'running':
        log.project_console.print(':rocket: The backend status: running', style='bright_blue')
    else:
        log.project_console.print('The backend service is not started', style='yellow')

@cli.command(name='attach', help='Attach local output stream to a service')
def backend_attach() -> None:
    """ Attach local output stream to a running backend service. """

    from trecover.config import log
    from trecover.utils.docker import get_container

    with log.project_console.screen(hide_cursor=True):
        for line in get_container(var.BACKEND_ID).attach(stream=True, logs=True):
            log.project_console.print(line.decode().strip())

    log.project_console.clear()