def yes_no(lightbar, msg, prompt_msg='are you sure? ', attr=None):
    """ Prompt user for yes/no, returns True for yes, False for no. """
    term = getterminal()
    keyset = {
        'yes': (u'y', u'Y'),
        'no': (u'n', u'N'),
    }
    echo(u''.join((
        lightbar.border(),
        lightbar.pos(lightbar.yloc + lightbar.height - 1, lightbar.xpadding),
        msg, u' ', prompt_msg,)))
    sel = Selector(yloc=lightbar.yloc + lightbar.height - 1,
                   xloc=term.width - 25, width=18,
                   left='Yes', right=' No ')
    sel.colors['selected'] = term.reverse_red if attr is None else attr
    sel.keyset['left'].extend(keyset['yes'])
    sel.keyset['right'].extend(keyset['no'])
    echo(sel.refresh())
    term = getterminal()
    while True:
        inp = term.inkey()
        echo(sel.process_keystroke(inp))
        if((sel.selected and sel.selection == sel.left)
                or inp in keyset['yes']):
            # selected 'yes',
            return True
        elif((sel.selected or sel.quit)
                or inp in keyset['no']):
            # selected 'no'
            return False

def main(anonymous=False, new=False):
    """
    Script entry point.

    This is the default login matrix for the bbs system.

    It takes no arguments or keyword arguments, because it assumes
    the user should now be authenticated, such as occurs for example
    on telnet.
    """
    term = getterminal()

    display_banner(term)

    if anonymous:
        # user rlogin'd in as [email protected]
        goto(top_script, 'anonymous')
    elif new:
        # user rlogin'd in as [email protected]
        goto(new_script)

    # do_login will goto/gosub various scripts, if it returns, then
    # either the user entered 'bye', or had too many failed attempts.
    do_login(term)

    log.debug('Disconnecting.')

    # it is necessary to provide sufficient time to send any pending
    # output across the transport before disconnecting.
    term.inkey(1.5)

def chk_save_location(location):
    """
    Prompt user to save location for quick re-use
    """
    from x84.bbs import getterminal, getsession, echo, getch
    session, term = getsession(), getterminal()
    stored_location = session.user.get('location', dict()).items()
    if (sorted(location.items()) == sorted(stored_location)):
        # location already saved
        return
    if session.user.handle == 'anonymous':
        # anonymous cannot save preferences
        return

    # prompt to store (unsaved/changed) location
    echo(u'\r\n\r\n')
    echo(term.yellow(u'Save Location'))
    echo(term.bold_yellow(u' ('))
    echo(term.bold_black(u'private'))
    echo(term.bold_yellow(u') '))
    echo(term.yellow(u'? '))
    echo(term.bold_yellow(u'['))
    echo(term.underline_yellow(u'yn'))
    echo(term.bold_yellow(u']'))
    echo(u': ')
    while True:
        inp = getch()
        if inp is None or inp in (u'n', u'N', u'q', u'Q', term.KEY_EXIT):
            break
        if inp in (u'y', u'Y', u' ', term.KEY_ENTER):
            session.user['location'] = location
            break

def display_banner(filepattern, encoding=None, vertical_padding=0):
    """ Start new screen and show artwork, centered.

    :param filepattern: file to display
    :type filepattern: str
    :param encoding: encoding of art file(s).
    :type encoding: str or None
    :param vertical_padding: number of blank lines to prefix art
    :type vertical_padding: int
    :returns: number of lines displayed
    :rtype: int
    """
    term = getterminal()

    # move to bottom of screen, reset attribute
    echo(term.pos(term.height) + term.normal)

    # create a new, empty screen
    echo(u'\r\n' * (term.height + 1))

    # move to home, insert vertical padding
    echo(term.home + (u'\r\n' * vertical_padding))

    # show art
    art_generator = showart(filepattern, encoding=encoding,
                            auto_mode=False, center=True)
    line_no = 0
    for line_no, txt in enumerate(art_generator):
        echo(txt)

    # return line number
    return line_no + vertical_padding

def display_msg(msg):
    """ Display full message """
    from x84.bbs import getterminal, getsession, echo, decode_pipe
    session, term = getsession(), getterminal()
    body = msg.body.splitlines()
    style = getstyle()

    receipt = (msg.recipient if msg.recipient is not None
               else u'<(None)=All users>')

    echo(u'    AUthOR: ' + style['highlight'](msg.author) + u'\r\n\r\n')
    echo(u'   RECiPiENt: ')
    echo(style['lowlight'](receipt))
    echo(u'\r\n\r\n')
    echo(u'     SUBjECt: ')
    echo(style['lowlight'](msg.subject))
    echo(u'\r\n\r\n')
    echo(u'        tAGS: ')
    echo(style['lowlight'](u', '.join(msg.tags)))
    echo(u'\r\n\r\n')
    echo(term.underline(u'        bOdY: '.ljust(term.width - 1)) + u'\r\n')
    echo(decode_pipe(u'\r\n'.join(body)) + term.normal)
    echo(u'\r\n' + term.underline(u''.ljust(term.width - 1)))
    echo(u'\r\n\r\n')
    session.activity = 'Constructing a %s message' % (
        u'public' if u'public' in msg.tags else u'private',)
    return

def main(handle=u''):
    """ Main procedure. """
    # pylint: disable=R0914
    #        Too many local variables
    from x84.bbs import getsession, getterminal, echo, ini, User, goto
    from x84.bbs import showcp437
    session, term = getsession(), getterminal()
    import os
    session.activity = u'Applying for an account'
    artfile = os.path.join(os.path.dirname(__file__), 'art', 'nua.asc')
    msg_header = u'NEW USER APPliCAtiON'
    # pylint: disable=E1103
    #         Instance of '_Chainmap' has no 'split' member
    #         (but some types could not be inferred)
    newcmds = ini.CFG.get('matrix', 'newcmds').split()
    topscript = ini.CFG.get('matrix', 'topscript')

    # display art and msg_header as banner
    echo(u'\r\n\r\n')
    for line in showcp437(artfile):
        echo(line)
    echo(u'\r\n\r\n' + term.reverse + msg_header.center(term.width))

    # create new user record for manipulation
    user = User(handle if handle.lower() not in newcmds else u'')
    while True:
        set_handle(user)
        set_location(user)
        set_email(user)
        set_password(user)
        set_sacookies(user)
        if prompt_ok():
            user.save()
            goto(topscript, user.handle)

def set_password(user):
    """
    Prompt for user.password, minimum length.
    """
    # pylint: disable=R0914
    #        Too many local variables
    from x84.bbs import getterminal, echo, ini, LineEditor
    term = getterminal()
    hidden_ch = u'x'
    prompt_password = u'password: '
    prompt_verify = u'   again: '
    msg_empty = u'ENtER A PASSWORd!'
    msg_tooshort = u'TOO ShORt, MUSt bE At lEASt %s.'
    msg_unmatched = u'VERifY MUSt MAtCH!'
    width = ini.CFG.getint('nua', 'max_pass')
    min_pass = ini.CFG.getint('nua', 'min_pass')
    while True:
        echo(u'\r\n\r\n' + term.clear_eol + term.normal + prompt_password)
        led = LineEditor(width)
        led.hidden = hidden_ch
        password = led.read()
        if password == u'' or password is None:
            warning(msg_empty)
        elif len(password) < min_pass:
            warning(msg_tooshort % min_pass)
        else:
            echo(u'\r\n\r\n' + term.clear_eol + term.normal + prompt_verify)
            led = LineEditor(width)
            led.hidden = hidden_ch
            verify = led.read()
            if password != verify:
                warning(msg_unmatched)
                continue
            user.password = password
            return

def add_comment(key):
    """ Prompt user to add a comment about a bbs. """
    # pylint: disable=R0914
    #        Too many local variables.
    from x84.bbs import getsession, getterminal, echo, DBProxy, LineEditor
    from x84.bbs import getch
    session, term = getsession(), getterminal()
    prompt_comment = u'\r\n\r\nWhAt YOU GOt tO SAY? '
    prompt_chg = u'\r\n\r\nChANGE EXiStiNG ? [yn] '
    echo(term.move(term.height, 0))
    echo(prompt_comment)
    comment = LineEditor(max(10, term.width - len(prompt_comment) - 5)).read()
    if comment is None or 0 == len(comment.strip()):
        return
    new_entry = (session.handle, comment)
    comments = DBProxy('bbslist', 'comments')
    comments.acquire()
    existing = comments[key]
    if session.handle in (_nick for (_nick, _cmt) in comments[key]):
        # change existing comment,
        echo(prompt_chg)
        if getch() not in (u'y', u'Y'):
            comments.release()
            return
        # re-define list without existing entry, + new entry
        comments[key] = [(_enick, _ecmt) for (_enick, _ecmt) in existing
                         if session.handle != _enick] + [new_entry]
        comments.release()
        return
    # re-define as existing list + new entry
    comments[key] = existing + [new_entry]
    comments.release()

def chk_save_location(location):
    """
    Prompt user to save location for quick re-use
    """
    from x84.bbs import getterminal, getsession, echo, getch
    session, term = getsession(), getterminal()
    stored_location = session.user.get('location', dict()).items()
    if (sorted(location.items()) == sorted(stored_location)):
        return

    # prompt to store (unsaved/changed) location
    echo(u'\r\n\r\n')
    echo(term.yellow(u'SAVE lOCAtION'))
    echo(term.bold_yellow(' ('))
    echo(term.bold_black(u'PRiVAtE'))
    echo(term.bold_yellow(') '))
    echo(term.yellow('? '))
    echo(term.bold_yellow(u'['))
    echo(term.underline_yellow(u'yn'))
    echo(term.bold_yellow(u']'))
    echo(u': ')
    while True:
        inp = getch()
        if inp is None or inp in (u'n', u'N', u'q', u'Q', term.KEY_EXIT):
            break
        if inp in (u'y', u'Y', u' ', term.KEY_ENTER):
            session.user['location'] = location
            break

def get_centigrade():
    """
    Blocking prompt for setting C/F preference
    """
    from x84.bbs import getterminal, getsession, echo, getch
    term = getterminal()
    session = getsession()
    echo(u'\r\n\r\n')
    echo(term.yellow(u'CElCiUS'))
    echo(term.bold_yellow(u'('))
    echo(term.bold_yellow_reverse(u'C'))
    echo(term.bold_yellow(u')'))
    echo(u' or ')
    echo(term.yellow(u'fAhRENhEit'))
    echo(term.bold_yellow(u'('))
    echo(term.bold_yellow_reverse(u'F'))
    echo(term.bold_yellow(u')'))
    echo('? ')
    while True:
        inp = getch()
        if inp in (u'c', u'C'):
            session.user['centigrade'] = True
            session.user.save()
            break
        elif inp in (u'f', u'F'):
            session.user['centigrade'] = False
            session.user.save()
            break
        elif inp in (u'q', u'Q', term.KEY_EXIT):
            break

def get_centigrade():
    """ Blocking prompt for setting C/F preference. """
    from x84.bbs import getterminal, getsession, echo
    term = getterminal()
    session = getsession()
    if bool(session.user.handle == 'anonymous'):
        # anonymous cannot set a preference.
        return

    echo(u''.join((
        u'\r\n\r\n',
        term.yellow(u'Celcius'),
        term.bold_yellow(u'('),
        term.bold_yellow_reverse(u'C'),
        term.bold_yellow(u')'),
        u' or ',
        term.yellow(u'Fahrenheit'),
        term.bold_yellow(u'('),
        term.bold_yellow_reverse(u'F'),
        term.bold_yellow(u')'),
        u'? ')))

    while True:
        inp = term.inkey()
        if inp in (u'c', u'C'):
            session.user['centigrade'] = True
            session.user.save()
            break
        elif inp in (u'f', u'F'):
            session.user['centigrade'] = False
            session.user.save()
            break
        elif inp in (u'q', u'Q', term.KEY_EXIT):
            break

def displayfile(filename):
    term = getterminal()
    echo(term.clear + term.move(0, 0) + term.normal)

    text = {}
    counter = 0
    offset = 0
    keypressed = ''

    # the string array named text will be zerobased
    for line in showart(filename):
        text[counter] = line
        counter = counter + 1

    while True:
        echo(term.move(0, 0) + term.normal)
        # -2 om man vill spara en rad i botten
        for i in range(0, term.height - 1):
            if len(text) > i + offset:
                echo(term.clear_eol + u'\r' + text[i + offset])

        keypressed = getch()
        echo(term.hide_cursor)
        if keypressed == 'q' or keypressed == 'Q' or keypressed == term.KEY_ESCAPE or keypressed == term.KEY_ENTER:
            break

        if keypressed == term.KEY_HOME:
            offset = 0

        if keypressed == term.KEY_END:
            # if the textline has fewer lines than the screen..
            if len(text) < term.height:
                offset = 0
            else:
                offset = len(text) - term.height + 1

        if keypressed == term.KEY_DOWN:
            # offset < len(text) + term.height:
            if len(text) > offset + term.height - 1:
                offset = offset + 1

        if keypressed == term.KEY_UP:
            if offset > 0:
                offset = offset - 1

        if keypressed == term.KEY_LEFT or keypressed == term.KEY_PGUP:
            if offset > term.height:
                offset = offset - term.height + 2
            else:
                offset = 0

        if keypressed == term.KEY_RIGHT or keypressed == term.KEY_PGDOWN:
            if (offset + term.height * 2) - 1 < len(text):
                offset = offset + term.height - 2
            else:
                # if the textline has fewer lines than the screen..
                if len(text) < term.height:
                    offset = 0
                else:
                    offset = len(text) - term.height + 1

def display_banner(filepattern, vertical_padding=0, **kwargs):
    """
    Start new screen and show artwork, centered.

    :param str filepattern: file to display
    :param int vertical_padding: number of blank lines to prefix art
    :return: number of lines displayed
    :rtype: int

    Remaining parameters are inherited from :func:`showart`, such
    as ``center`` and ``encoding``.  By default, ``center`` is True.
    """
    # This is unfortunate, we should use 'term' as first argument
    term = getterminal()
    kwargs['center'] = kwargs.get('center', True)

    # move to bottom of screen, reset attribute
    echo(term.move(term.height, 0) + term.normal)

    # create a new, empty screen
    echo(u'\r\n' * (term.height + 1))

    # move to home, insert vertical padding
    echo(term.home + (u'\r\n' * vertical_padding))

    art_generator = showart(filepattern, **kwargs)
    line_no = 0
    for line_no, txt in enumerate(art_generator):
        echo(txt)

    # return line number
    return line_no + vertical_padding

def main(anonymous=False, new=False, username=''):
    """ Main procedure. """
    from x84.bbs import (
        getsession,
        getterminal,
        find_user,
        get_user,
        User,
    )

    session, term = getsession(), getterminal()
    session.activity = 'sftp'

    if anonymous:
        user = User(u'anonymous')
    else:
        assert not new, ("[email protected] user not supported by SFTP.")

        # ProperCase user-specified handle
        handle = find_user(username)
        assert handle is not None, handle

        # fetch user record
        user = get_user(handle)

    # assign session user, just as top.py function login()
    session.user = user

    while True:
        inp = term.inkey()  # should block indefinately
        log = logging.getLogger(__name__)
        log.warn('Got inkey: {0!r}'.format(inp))

def prompt():
    """
    Return string suitable for displaying prompt and available commands.
    """
    from x84.bbs import getsession, getterminal

    session, term = getsession(), getterminal()
    decorate = lambda key, desc: u"".join(
        (u"(", term.magenta_underline(key), u")", term.cyan(desc.split()[0]), u" ", u" ".join(desc.split()[1:]), u" ")
    )
    return term.wrap(
        u"".join(
            (
                u" " * 2,
                term.green_reverse(":keys"),
                u" ",
                decorate("c", "hAt USR"),
                decorate("s", "ENd MSG"),
                (
                    u"".join(
                        (decorate("d", "iSCONNECt SiD"), decorate("e", "diT USR"), decorate("v", "iEW SiD AttRS"), u" ")
                    )
                    if "sysop" in session.user.groups
                    else u""
                ),
                decorate("Escape/q", "Uit"),
                decorate("Spacebar", "REfRESh"),
            )
        ),
        int(term.width * 0.8),
        subsequent_indent=u" " * 8,
    )

def get_ui(position=None):
    """
    Returns user interface (lightbar, pager).
    Optional argument position is tuple position of prior lightbar instance.
    """
    from x84.bbs import getterminal, Lightbar, Pager
    term = getterminal()
    assert term.height > 10 and term.width >= 40
    # +-+ +----+
    # |lb |pager
    # +-+ +----+
    height = term.height - 7
    lb_width = int(term.width * .3)
    pg_width = term.width - (lb_width)
    lb_xloc = (term.width / 2) - (term.width / 2)
    pg_xloc = lb_xloc + lb_width
    lightbar = Lightbar(height, lb_width, (term.height - height - 1), lb_xloc)
    pager = Pager(height, pg_width, (term.height - height - 1), pg_xloc)
    pager.ypadding = 2
    pager.xpadding = 2
    lightbar.update(get_bbslist(max_len=lightbar.visible_width))
    ## pressing Return is same as 't'elnet
    lightbar.keyset['enter'].extend((u't', u'T'))
    ## re-select previous selection
    if position is not None:
        lightbar.position = position
    return (pager, lightbar)

def redraw_lightbar(lightbar, active=True):
    """
    Display bbs listing in lightbar.
    """
    from x84.bbs import getterminal
    term = getterminal()
    lightbar.colors['border'] = term.bold_green if active else term.bold_black
    output = lightbar.border()
    if active:
        lightbar.colors['selected'] = term.green_reverse
    else:
        lightbar.colors['selected'] = term.blue_reverse
#        output += lightbar.footer(u''.join((
#            u'- ',
#            fancy_green('up', '.'),
#            fancy_green('down', '.'),
#            fancy_green('right', u''),
#            u' -')))
#        output += lightbar.footer(u''.join((
#            u'- ',
#            fancy_blue('up', '.'),
#            fancy_blue('down', '.'),
#            fancy_green('left', u''),
#            u' -')))
    output += lightbar.title(u'- ' + fancy_green('a', 'add') + ' -')
    output += lightbar.refresh()
    return output

def prompt_body(msg):
    """ Prompt for 'body' of message, executing 'editor' script. """
    from x84.bbs import echo, Selector, getterminal, getsession, gosub
    term = getterminal()
    session = getsession()
    inp = Selector(yloc=term.height - 1,
                   xloc=term.width - 22,
                   width=20,
                   left=u'CONtiNUE', right=u'CANCEl')

    # check for previously existing draft
    if 0 != len(session.user.get('draft', u'')):
        # XXX display age of message
        inp = Selector(yloc=term.height - 1,
                       xloc=term.width - 22,
                       width=20,
                       left=u'REStORE', right=u'ERASE')
        blurb = u'CONtiNUE PREViOUSlY SAVEd dRAft ?'
        echo(u'\r\n\r\n')
        echo(term.move(inp.yloc, inp.xloc - len(blurb)))
        echo(term.bold_yellow(blurb))
        selection = inp.read()
        echo(term.move(inp.yloc, 0) + term.clear_eol)
        if selection == u'REStORE':
            msg.body = session.user['draft']

    echo(u'\r\n\r\n')
    session.user['draft'] = msg.body
    if gosub('editor', 'draft'):
        echo(u'\r\n\r\n' + term.normal)
        msg.body = session.user.get('draft', u'')
        del session.user['draft']
        return 0 != len(msg.body.strip())
    return False

def main():
    session, term = getsession(), getterminal()
    session.activity = 'Viewing Userlist'

    colors = {'highlight': term.red,
              'lowlight': term.green, }

    line_no = display_banner(filepattern=art_file, encoding=art_encoding)

    # get and format userlist
    userlist = (
        u'{sp}{handle} {location} {lastcall}'
        .format(sp=u' ' * 4,
                handle=ur.handle.ljust(username_max_length),
                location=colors['lowlight'](
                    ur.location.ljust(location_max_length)),
                lastcall=timeago(ur.timeago))
        for ur in iter_userlist())

    echo(u'\r\n')

    # display users, using a command-prompt pager.
    prompt_pager(content=userlist,
                 line_no=line_no + 1,
                 colors={'highlight': term.red,
                         'lowlight': term.green,
                         },
                 width=80, breaker=None)

def saysomething(dumb=True):
    """
    Prompt user to post oneliner, also prompt user to post
    to bbs-scene.org if configured, returning background Thread.
    """
    import time
    from x84.bbs import getsession, getterminal, echo, LineEditor, ini
    session, term = getsession(), getterminal()
    prompt_say = u'SAY WhAt ?! '
    # heard_msg = u'YOUR MESSAGE hAS bEEN VOiCEd.'

    yloc = term.height - 3
    xloc = max(0, ((term.width / 2) - (MAX_INPUT / 2)))
    if dumb:
        echo(u'\r\n\r\n' + term.bold_blue(prompt_say))
    else:
        echo(term.move(yloc, xloc) or u'\r\n\r\n')
        echo(term.bold_blue(prompt_say))
    ole = LineEditor(MAX_INPUT)
    ole.highlight = term.green_reverse
    oneliner = ole.read()
    if oneliner is None or 0 == len(oneliner.strip()):
        if not dumb:
            # clear input line,
            echo(term.normal + term.move(yloc, 0) + term.clear_eol)
        return None

    session.user['lastliner'] = time.time()
    # post local-onlyw hen bbs-scene.org is not configured
    if not ini.CFG.has_section('bbs-scene'):
        add_oneline(oneliner.strip())
        return None
    return post_bbs_scene(oneliner, dumb)