def main():
    """ Main menu entry point. """
    from x84.default.common import display_banner
    session, term = getsession(), getterminal()

    text, width, height, dirty = u'', -1, -1, 2
    menu_items = get_menu_items(session)
    editor = get_line_editor(term, menu_items)
    while True:
        if dirty == 2:
            # set syncterm font, if any
            if syncterm_font and term.kind.startswith('ansi'):
                echo(syncterm_setfont(syncterm_font))
        if dirty:
            session.activity = 'main menu'
            top_margin = display_banner(art_file, encoding=art_encoding) + 1
            echo(u'\r\n')
            if width != term.width or height != term.height:
                width, height = term.width, term.height
                text = render_menu_entries(term, top_margin, menu_items)
            echo(u''.join((text, display_prompt(term), editor.refresh())))
            dirty = 0

        event, data = session.read_events(('input', 'refresh'))

        if event == 'refresh':
            dirty = True
            continue

        elif event == 'input':
            session.buffer_input(data, pushback=True)

            # we must loop over inkey(0), we received a 'data'
            # event, though there may be many keystrokes awaiting for our
            # decoding -- or none at all (multibyte sequence not yet complete).
            inp = term.inkey(0)
            while inp:
                if inp.code == term.KEY_ENTER:
                    # find matching menu item,
                    for item in menu_items:
                        if item.inp_key == editor.content.strip():
                            echo(term.normal + u'\r\n')
                            gosub(item.script, *item.args, **item.kwargs)
                            editor.content = u''
                            dirty = 2
                            break
                    else:
                        if editor.content:
                            # command not found, clear prompt.
                            echo(u''.join((
                                (u'\b' * len(editor.content)),
                                (u' ' * len(editor.content)),
                                (u'\b' * len(editor.content)),)))
                            editor.content = u''
                            echo(editor.refresh())
                elif inp.is_sequence:
                    echo(editor.process_keystroke(inp.code))
                else:
                    echo(editor.process_keystroke(inp))
                inp = term.inkey(0)

def process_keystroke(inp, key=None):
    """ Process general keystroke and call routines.  """
    from x84.bbs import getsession, DBProxy, gosub, echo
    session = getsession()
    if inp is None:
        return False
    elif type(inp) is int:
        return False
    elif inp in (u't', u'T') and key is not None:
        bbs = DBProxy('bbslist')[key]
        gosub('telnet', bbs['address'], bbs['port'],)
    elif inp in (u'a', u'A'):
        add_bbs()
    elif inp in (u'c', u'C') and key is not None:
        add_comment(key)
    elif inp in (u'r', u'R') and key is not None:
        rate_bbs(key)
    elif inp in (u'i', u'I') and key is not None:
        echo(get_bbsinfo(key) + '\r\n')
    elif inp in (u'v', u'V') and key is not None:
        view_ansi(key)
    elif inp in (u'd', u'D') and key is not None and (
            'sysop' in session.user.groups):
        del DBProxy('bbslist')[key]
    else:
        return False  # unhandled
    return True

def edit(sessions):
    """ Prompt for node and gosub profile.py script for user of target session.
    """
    from x84.bbs import gosub
    (node, tgt_session) = get_node(sessions)
    if node is not None:
        gosub('profile', tgt_session['handle'])
        return True

def playback(sessions):
    """ Prompt for node and gosub ttyplay script for ttyrec of target session.
    """
    from x84.bbs import gosub
    (node, tgt_session) = get_node(sessions)
    if node is not None:
        gosub('ttyplay', tgt_session['ttyrec'])
        return True

def chat(sessions):
    """
    Prompt for node and page target session for chat.
    Sysop will send session id of -1, indicating the chat is forced.
    """
    from x84.bbs import gosub, getsession

    (_, tgt_session) = get_node(sessions)
    if tgt_session and tgt_session["sid"] != getsession().sid:
        gosub("chat", dial=tgt_session["handle"], other_sid=tgt_session["sid"])

def watch(sessions):
    """
    Prompt for node and gosub ttyplay script for ttyrec of target session,
    with 'peek' boolean set to True.
    """
    from x84.bbs import gosub
    (node, tgt_session) = get_node(sessions)
    if node is not None:
        gosub('ttyplay', tgt_session['ttyrec'], True)
        return True

def chat(sessions):
    """
    Prompt for node and page target session for chat.
    Sysop will send session id of -1, indicating the chat is forced.
    """
    from x84.bbs import gosub, getsession
    session = getsession()
    (node, tgt_session) = get_node(sessions)
    if tgt_session and tgt_session != session:
        gosub('chat', dial=tgt_session['handle'],
              other_sid=tgt_session['sid'])

def sendmsg(sessions):
    """
    Prompt for node and gosub 'writemsg' with recipient set to target user.
    """
    from x84.bbs import gosub, Msg
    (node, tgt_session) = get_node(sessions)
    if node is not None:
        msg = Msg()
        msg.recipient = tgt_session['handle']
        msg.tags.add('private')
        gosub('writemsg', msg)
        return True

def do_intro_art(term, session):
    """
    Display random art file, prompt for quick login.

    Bonus: allow chosing other artfiles with '<' and '>'.
    """
    from x84.bbs import ini
    show_intro_art = False
    if ini.CFG.has_option('system', 'show_intro_art'):
        show_intro_art = ini.CFG.getboolean('system', 'show_intro_art')
    # set syncterm font, if any
    if syncterm_font and term.kind.startswith('ansi'):
        echo(syncterm_setfont(syncterm_font))

    index = int(time.time()) % len(art_files)
    dirty = True
    echo(u'\r\n')
    while True:
        session.activity = 'top'
        if session.poll_event('refresh') or dirty:
            if show_intro_art:
                display_intro(term, index)
            else:
                return True
            display_prompt(term)
            dirty = False
        dirty = True
        inp = LineEditor(1, colors={'highlight': term.normal}).read()
        if inp is None or inp.lower() == u'y':
            # escape/yes: quick login
            return True
        # issue #242 : set 'N' as default, by adding a check for an empty
        # unicode string.
        elif inp.lower() in (u'n', u'\r', u'\n', u''):
            break

        if len(inp) == 1:
            echo(u'\b')
        if inp == u'!':
            echo(u'\r\n' * 3)
            gosub('charset')
            dirty = True
        elif inp == u'<':
            index -= 1
        elif inp == u'>':
            index += 1
        else:
            dirty = False

def do_login(term):
    sep_ok = getattr(term, color_secondary)(u'::')
    sep_bad = getattr(term, color_primary)(u'::')
    colors = {'highlight': getattr(term, color_primary)}
    for _ in range(login_max_attempts):
        echo(u'\r\n\r\n{sep} Login: '.format(sep=sep_ok))
        handle = LineEditor(username_max_length, colors=colors
                            ).read() or u''

        if handle.strip() == u'':
            continue

        # user says goodbye
        if handle.lower() in bye_usernames:
            return

        # user applies for new account
        if new_allowed and handle.lower() in new_usernames:
            gosub(new_script)
            display_banner(term)
            continue

        # user wants to reset password
        if reset_allowed and handle.lower() == 'reset':
            gosub(reset_script)
            display_banner(term)
            continue

        # user wants to login anonymously
        if anonymous_allowed and handle.lower() in anonymous_names:
            user = User('anonymous')
        else:
            # authenticate password
            echo(u'\r\n\r\n{sep} Password: '.format(sep=sep_ok))
            password = LineEditor(password_max_length,
                                  colors=colors,
                                  hidden=hidden_char
                                  ).read() or u''

            user = authenticate_user(handle, password)
            if not user:
                echo(u'\r\n\r\n{sep} Login failed.'.format(sep=sep_bad))
                continue

        goto(top_script, handle=user.handle)

    echo(u'\r\n\r\n{sep} Too many authentication attempts.\r\n'
         .format(sep=sep_bad))

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 chat(sessions):
    """
    Prompt for node and page target session for chat.
    Sysop will send session id of -1, indicating the chat is forced.
    """
    from x84.bbs import gosub, getsession
    session = getsession()
    (node, tgt_session) = get_node(sessions)
    if node is not None:
        # page other user,
        channel = tgt_session['sid']
        sender = (session.user.handle
                  if not 'sysop' in session.user.groups else -1)
        session.send_event('route', (
            tgt_session['sid'], 'page', channel, sender))
        gosub('chat', channel)
        return True

def main():
    """ Main procedure. """
    # by default, nothing is done.
    from x84.bbs import getsession, gosub
    assert 'sysop' in getsession().user.groups

    #return migrate_105lc()
    #return nothing()
    return gosub('test_keyboard_keys')

def do_intro_art(term, session):
    """
    Display random art file, prompt for quick login.

    Bonus: allow chosing other artfiles with '<' and '>'.
    """
    editor_colors = {'highlight': term.black_on_red}

    # set syncterm font, if any
    if syncterm_font and term._kind.startswith('ansi'):
        echo(syncterm_setfont(syncterm_font))

    index = int(time.time()) % len(art_files)
    dirty = True
    echo(u'\r\n')
    while True:
        session.activity = 'top'
        if session.poll_event('refresh') or dirty:
            display_intro(term, index)
            display_prompt(term)
            dirty = False
        dirty = True
        inp = LineEditor(1, colors=editor_colors).read()
        if inp is None or inp.lower() == u'y':
            # escape/yes: quick login
            return True
        elif inp.lower() == u'n':
            break

        if len(inp) == 1:
            echo(u'\b')
        if inp == u'!':
            echo(u'\r\n' * 3)
            gosub('charset')
            dirty = True
        elif inp == u'<':
            index -= 1
        elif inp == u'>':
            index += 1
        else:
            dirty = False

def main():
    """ Main procedure. """
    from x84.bbs import getsession, getterminal, echo, getch, gosub
    session, term = getsession(), getterminal()
    lcallers, lcalls_txt = lc_retrieve()
    lbr = None
    dirty = True
    handle = None

    if (0 == term.number_of_colors
            or session.user.get('expert', False)):
        echo(redraw(None))
        return dummy_pager(lcalls_txt.split('\n'))

    while lbr is None or not lbr.quit:
        if dirty or lbr is None or session.poll_event('refresh'):
            session.activity = u'Viewing last callers'
            lcallers, lcalls_txt = lc_retrieve()
            pos = lbr.position if lbr is not None else (0, 0)
            lbr = get_lightbar(lcallers, lcalls_txt)
            if pos:
                lbr.position = pos
            echo(redraw(lbr))
            echo(refresh_opts(lbr, handle))
        sel = lbr.selection[0]
        if sel != handle or dirty:
            handle = sel
            echo(refresh_opts(lbr, handle))
            echo(lbr.pos(lbr.yloc + (lbr.height - 1)))
            dirty = False
            continue
        inp = getch(1)
        if inp is not None:
            if inp in (u'v', u'V'):
                view_plan(handle)
                dirty = True
            elif inp in (u'e', u'E') and 'sysop' in session.user.groups:
                gosub('profile', handle)
                dirty = True
            else:
                echo(lbr.process_keystroke(inp))

def edit_description(filepath, db_desc):
    """ Edit file description. """
    from x84.bbs import gosub
    new_desc = None
    if filepath in db_desc:
        new_desc = u'\r\n'.join([line.decode('cp437_art')
                                 for line in db_desc[filepath]])
    new_desc = gosub('editor', continue_draft=new_desc)
    if not new_desc:
        return
    with db_desc:
        db_desc[filepath] = new_desc.splitlines()

def try_reset(user):
    """ Prompt for password reset. """
    from x84.bbs import echo, getch, gosub
    prompt_reset = u'RESEt PASSWORD (bY E-MAil)? [yn]'
    echo(prompt_reset)
    while True:
        inp = getch()
        if inp in (u'y', u'Y'):
            return gosub('pwreset', user.handle)
        elif inp in (u'n', u'N'):
            echo(u'\r\n\r\n')
            return False

def main(handle=None):
    """ Main procedure. """
    # pylint: disable=R0914,R0912,R0915
    #         Too many local variables
    #         Too many branches
    #         Too many statements
    session, term = getsession(), getterminal()
    session.activity = 'top'

    # attempt to coerce encoding of terminal to match session.
    coerce_terminal_encoding(term, session.encoding)

    # fetch user record
    user = get_user_record(handle)

    # register call
    login(session, user)

    # display art and prompt for quick login
    quick = do_intro_art(term, session)

    echo(term.move_down() * 3)

    # only display news if the account has not
    # yet read the news since last update.
    gosub('news', quick=True)

    if not quick:
        # display last 10 callers, if any
        gosub('lc')

        # one-liners
        gosub('ol')

    goto('main')

def main():
    session, term = getsession(), getterminal()
    session.activity = u'bulletins menu'
    dirty = True

    while True:
        if dirty or session.poll_event('refresh'):
            echo(term.clear())
            showansi('bulletinsmenu.ans')
        echo(u'\r\n' + term.normal + term.white +
             u'  [' + term.blue + u'Select bulletin' + term.white + u']: ')
        inp = getch()

        dirty = True
        if inp == u'1':
            toplist('calls')
        elif inp == u'2':
            toplist('msgs')
        elif inp == u'3':
            gosub('textbrowse')
        else:                      # any other key will return to main menu
            return

def prompt_body(term, msg, colors):
    """ Prompt for and set 'body' of message by executing 'editor' script. """
    with term.fullscreen():
        content = gosub("editor", save_key=None, continue_draft=msg.body)
    # set syncterm font, if any
    if term.kind.startswith("ansi"):
        echo(syncterm_setfont(syncterm_font))
    echo(term.move(term.height, 0) + term.normal + u"\r\n")
    if content and content.strip():
        msg.body = content
        return True
    xpos = max(0, (term.width // 2) - (80 // 2))
    echo(u"".join((term.move_x(xpos), colors["highlight"]("Message canceled."), term.clear_eol)))
    term.inkey(1)
    return False