#!/usr/bin/env python3
"""
sort processes by oom_score
"""
from operator import itemgetter
from os import listdir
from argparse import ArgumentParser
'''
oom-sort -n 9
oom-sort -c
oom-sort --cmdline 20
watch oom-sort
'''


parser = ArgumentParser()

parser.add_argument(
    '--number',
    '-n',
    help="""number of lines; integer, not negative; 0 - unlimited; unlimited by default""",
    default=None,
    type=str
)

parser.add_argument(
    '--cmdline',
    '-c',
    help="""display cmdlines""",
    default=None,
    type=str
)


args = parser.parse_args()

display_cmdline = args.cmdline
num_lines = args.number


if num_lines == None:
    num_lines = 99999


if display_cmdline == None:
    display_cmdline = 9999





#print([num_lines], [display_cmdline])





def human(num):
    '''KiB to MiB'''
    return str(round(num / 1024.0)).rjust(6, ' ')


with open('/proc/self/status') as file:
    status_list = file.readlines()

# список имен из /proc/*/status для дальнейшего поиска позиций VmRSS and VmSwap
status_names = []
for s in status_list:
    status_names.append(s.split(':')[0])

vm_rss_index = status_names.index('VmRSS')
vm_swap_index = status_names.index('VmSwap')
uid_index = status_names.index('Uid')

oom_list = []
for pid in listdir('/proc'):
    # пропускаем элементы, состоящие не из цифр и PID 1
    if pid.isdigit() is not True or pid == '1':
        continue
    try:
        with open('/proc/' + pid + '/cmdline') as file:
            try:
                cmdline = file.readlines()[0].replace('\x00', ' ')
            except IndexError:
                continue
        with open('/proc/' + pid + '/oom_score') as file:
            oom_score = int(file.readlines()[0][:-1])
        with open('/proc/' + pid + '/oom_score_adj') as file:
            oom_score_adj = int(file.readlines()[0][:-1])
    except FileNotFoundError:
        continue
    except ProcessLookupError:
        continue

    oom_list.append((pid, oom_score, oom_score_adj, cmdline))

# list sorted by oom_score
oom_list_sorted = sorted(oom_list, key=itemgetter(1), reverse=True)

print('oom_score oom_score_adj   Uid   Pid Name             VmRSS   VmSwap   cmdline')
print('--------- ------------- ----- ----- --------------- -------- -------- -------')

# итерируемся по сортированному списку oom_score, печатая name, pid etc
for i in oom_list_sorted[:int(num_lines)]:
    pid = i[0]
    oom_score = i[1]
    oom_score_adj = i[2]
    cmdline = i[3].strip()

    try:
        # читать часть файла не дальше VmSwap - когда-нибудь
        with open('/proc/' + pid + '/status') as file:
            status_list = file.readlines()

        vm_rss = int(status_list[vm_rss_index].split(':')[1].split(' ')[-2])
        vm_swap = int(status_list[vm_swap_index].split(':')[1].split(' ')[-2])
        name = status_list[0][:-1].split('\t')[1]
        uid = status_list[uid_index].split('\t')[1]

    except FileNotFoundError:
        continue

    except ProcessLookupError:
        continue

    print(
        '{} {} {} {} {} {} M {} M {}'.format(
            str(oom_score).rjust(9),
            str(oom_score_adj).rjust(13),
            uid.rjust(5),
            str(pid).rjust(5),
            name.ljust(15),
            human(vm_rss),
            human(vm_swap),
            cmdline[:int(display_cmdline)]
        )
    )