#!/usr/bin/python
# -*- coding: utf-8 -*-

import os
import msvcrt
import subprocess

# PyWin32
import winerror, win32con, win32console

def runas(args, username, domain=None, password=None, savecred=False):
    if domain is not None:
        username = r"{}\{}".format(domain, username)
    runas = os.path.join(os.environ['SystemRoot'], 'System32', 'runas.exe')
    runas_args = [runas, '/user:{}'.format(username)]
    if savecred or password is None:
        runas_args.append('/savecred')

    if isinstance(args, (type(''), type(u''))):
        runas_args.append(args)
    else:
        runas_args.append(subprocess.list2cmdline(args))

    if password is None:
        p = subprocess.Popen(runas_args,
                             creationflags=win32con.DETACHED_PROCESS)
        return p.wait()

    if isinstance(password, bytes):
        password = password.decode('utf-8')

    free_console = True
    try:
        win32console.AllocConsole()
    except win32console.error as exc:
        if exc.winerror != winerror.ERROR_ACCESS_DENIED:
            raise
        free_console = False

    try:
        fdin = os.open('CONIN$', os.O_RDWR)
        stdin = None
        try:
            stdin = win32console.PyConsoleScreenBufferType(
                        msvcrt.get_osfhandle(fdin))
            p = subprocess.Popen(runas_args, stdout=subprocess.PIPE)
            while p.poll() is None:
                if p.stdout.read(1) == b":":
                    records = []
                    for c in u"{}\r".format(password):
                        x = win32console.PyINPUT_RECORDType(
                                win32console.KEY_EVENT)
                        x.Char = c
                        x.KeyDown = True
                        x.RepeatCount = 1
                        records.append(x)
                    stdin.WriteConsoleInput(records)
                    break
            return p.wait()
        finally:
            os.close(fdin)
            if stdin is not None:
                # close the duplicate handle
                stdin.Close()
    finally:
        if free_console:
            win32console.FreeConsole()