# --------------------------------------------------------------------------------------------
# Copyright (c) Microsoft Corporation. All rights reserved.
# Licensed under the MIT License. See License.txt in the project root for license information.
# --------------------------------------------------------------------------------------------

import sys
from subprocess import check_output, STDOUT, CalledProcessError

def mean(data):
    """Return the sample arithmetic mean of data."""
    n = len(data)
    if n < 1:
        raise ValueError('len < 1')
    return sum(data)/float(n)


def sq_deviation(data):
    """Return sum of square deviations of sequence data."""
    c = mean(data)
    return sum((x-c)**2 for x in data)


def pstdev(data):
    """Calculates the population standard deviation."""
    n = len(data)
    if n < 2:
        raise ValueError('len < 2')
    ss = sq_deviation(data)
    return (ss/n) ** 0.5


def scenario(command, loop=10):
    real = []
    user = []
    syst = []

    test_command = 'time -p ' + command
    for i in range(loop):
        try:
            lines = check_output([test_command], shell=True, stderr=STDOUT).split('\n')
        except CalledProcessError as e:
            lines = e.output.split('\n')
        real_time = float(lines[-4].split()[1])
        real.append(float(lines[-4].split()[1]))
        user.append(float(lines[-3].split()[1]))
        syst.append(float(lines[-2].split()[1]))
        sys.stdout.write('Loop {} => {} \n'.format(i, real_time))
        sys.stdout.flush()

    print('Command: {}'.format(command))
    print('Real: mean => {} \t pstdev => {}'.format(mean(real), pstdev(real)))
    print('User: mean => {} \t pstdev => {}'.format(mean(user), pstdev(user)))
    print('Syst: mean => {} \t pstdev => {}'.format(mean(syst), pstdev(syst)))
    print('')

scenario('az')
scenario('az cl')
scenario('az cloud')
scenario('az cloud list')
scenario('az cloud show --this-does-not-exist')