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

# Copyright (c) 2010, Pascal Volk

# See COPYING for distribution information.

"""

    VirtualMailManager.cli

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

    VirtualMailManager's command line interface.

"""

import os

from array import array

from cStringIO import StringIO

from fcntl import ioctl

from getpass import getpass

from termios import TIOCGWINSZ

from VirtualMailManager import ENCODING

from VirtualMailManager.constants.ERROR import VMM_TOO_MANY_FAILURES

from VirtualMailManager.errors import VMMError

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

_ = lambda msg: msg

_std_write = os.sys.stdout.write

_err_write = os.sys.stderr.write

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

def string_io():

    """Returns a new `cStringIO.StringIO` instance."""

    return StringIO()

del _