# -*- coding: UTF-8 -*-

# Copyright (c) 2010 - 2013, Pascal Volk

# See COPYING for distribution information.

"""

    VirtualMailManager.cli

    ~~~~~~~~~~~~~~~~~~~~~~

    VirtualMailManager's command line interface.

"""

import os

from array import array

from fcntl import ioctl

from getpass import getpass

from termios import TIOCGWINSZ

from VirtualMailManager import ENCODING

from VirtualMailManager.constants import VMM_TOO_MANY_FAILURES

from VirtualMailManager.errors import VMMError

__all__ = ('prog', 'get_winsize', 'read_pass', 'w_err', 'w_std')

_ = lambda msg: msg

_std_write = os.sys.stdout.write

_err_write = os.sys.stderr.write

prog = os.path.basename(os.sys.argv[0])

def w_std(*args):

    """Writes a line for each arg of *args*, encoded in the current

    ENCODING, to stdout.

    """

    _std_write('\n'.join(a.encode(ENCODING, 'replace') for a in args) + '\n')

def w_err(code, *args):

    """Writes a line for each arg of *args*, encoded in the current

    ENCODING, to stderr.

    This function optionally interrupts the program execution if *code*

    does not equal to 0. *code* will be used as the system exit status.

    """

    _err_write('\n'.join(a.encode(ENCODING, 'replace') for a in args) + '\n')

    if code:

        os.sys.exit(code)

def get_winsize():

    """Returns a tuple of integers ``(ws_row, ws_col)`` with the height and

    width of the terminal."""

    fd = None

    for dev in (os.sys.stdout, os.sys.stderr, os.sys.stdin):

        if hasattr(dev, 'fileno') and os.isatty(dev.fileno()):

            fd = dev.fileno()

            break

    if fd is None:  # everything seems to be redirected

        # fall back to environment or assume some common defaults

        ws_row, ws_col = 24, 80

        try:

            ws_col = int(os.environ.get('COLUMNS', 80))

            ws_row = int(os.environ.get('LINES', 24))

        except ValueError:

            pass

        return ws_row, ws_col

    #"struct winsize" with the ``unsigned short int``s ws_{row,col,{x,y}pixel}

    ws = array('H', (0, 0, 0, 0))

    ioctl(fd, TIOCGWINSZ, ws, True)

    ws_row, ws_col = ws[:2]

    return ws_row, ws_col

def read_pass():

    """Interactive 'password chat', returns the password in plain format.

    Throws a VMMError after the third failure.

    """

    # TP: Please preserve the trailing space.

    readp_msg0 = _(u'Enter new password: ').encode(ENCODING, 'replace')

    # TP: Please preserve the trailing space.

    readp_msg1 = _(u'Retype new password: ').encode(ENCODING, 'replace')

    mismatched = True

    failures = 0

    while mismatched:

        if failures > 2:

            raise VMMError(_(u'Too many failures - try again later.'),

                           VMM_TOO_MANY_FAILURES)

        clear0 = getpass(prompt=readp_msg0)

        clear1 = getpass(prompt=readp_msg1)

        if clear0 != clear1:

            failures += 1

            w_err(0, _(u'Sorry, passwords do not match.'))

            continue

        if not clear0:

            failures += 1

            w_err(0, _(u'Sorry, empty passwords are not permitted.'))

            continue

        mismatched = False

    return clear0

del _