#!/usr/bin/python
#
# Copyright (C) 2014 Red Hat.
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 2 of the License, or (at your
# option) any later version.
# 
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
# for more details.
#

""" Tell how long the system has been running

uptime.py gives a one line display of the following information:
    The current time;
    How long the system has been running;
    How many users are currently logged on; and
    The system load averages for the past 1, 5, and 15 minutes.
"""

from pcp import pmapi
from cpmapi import PM_TYPE_U32, PM_TYPE_FLOAT

def print_timestamp(stamp):
    """ Report the sample time (struct tm) in HH:MM:SS form """
    print " %02d:%02d:%02d" % (stamp.tm_hour, stamp.tm_min, stamp.tm_sec),

def print_uptime(seconds):
    """ Report on system up-time in days, hours and minutes """
    days = seconds / (60 * 60 * 24)
    minutes = seconds / 60
    hours = minutes / 60
    hours = hours % 24
    minutes = minutes % 60
    print "up",
    if days > 1:
        print "%d days," % days,
    elif days != 0:
        print "1 day,",
    if hours != 0:
        print '%2d:%02d,' % (hours, minutes),
    else:
        print '%d min,' % minutes,

def print_users(nusers):
    """ Report the number of logged in users at sample time """
    if nusers == 1:
        print '1 user, ' 
    else:
        print '%2d users, ' % nusers,

def print_load(one, five, fifteen):
    """ Report 1, 5, 15 minute load averages at sample time """
    print 'load average: %.2f, %.2f, %.2f' % (one, five, fifteen),

def uptime():
    """ Create a PMAPI context (could be either host or archive),
        fetch and report a fixed set of values related to uptime.
    """
    context = pmapi.pmContext()
    metrics = ('kernel.all.uptime', 'kernel.all.nusers', 'kernel.all.load')
    pmids = context.pmLookupName(metrics)
    descs = context.pmLookupDescs(pmids)
    result = context.pmFetch(pmids)

    sample_time = result.contents.timestamp.tv_sec
    time_struct = context.pmLocaltime(sample_time)
    print_timestamp(time_struct)

    atom = context.pmExtractValue(
		result.contents.get_valfmt(0),
		result.contents.get_vlist(0, 0),
		descs[0].contents.type, PM_TYPE_U32)
    print_uptime(atom.ul)

    atom = context.pmExtractValue(
		result.contents.get_valfmt(1),
		result.contents.get_vlist(1, 0),
		descs[1].contents.type, PM_TYPE_U32)
    print_users(atom.ul)

    averages = [1, 5, 15]
    for instance in xrange(3):
        averages[instance] = context.pmExtractValue(
				result.contents.get_valfmt(2),
				result.contents.get_vlist(2, instance),
				descs[2].contents.type, PM_TYPE_FLOAT)
    print_load(averages[0].f, averages[1].f, averages[2].f)

    context.pmFreeResult(result)

if __name__ == '__main__':
    uptime()