#!/usr/bin/env python
#
# Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
#
# Use of this source code is governed by a BSD-style license
# that can be found in the LICENSE file in the root of the source
# tree. An additional intellectual property rights grant can be found
# in the file PATENTS.  All contributing project authors may
# be found in the AUTHORS file in the root of the source tree.


import psutil
import sys

import numpy
from matplotlib import pyplot


class CpuSnapshot(object):
  def __init__(self, label):
    self.label = label
    self.samples = []

  def Capture(self, sample_count):
    print ('Capturing %d CPU samples for %s...' %
           ((sample_count - len(self.samples)), self.label))
    while len(self.samples) < sample_count:
      self.samples.append(psutil.cpu_percent(1.0, False))

  def Text(self):
    return ('%s: avg=%s, median=%s, min=%s, max=%s' %
            (self.label, numpy.average(self.samples),
             numpy.median(self.samples),
             numpy.min(self.samples), numpy.max(self.samples)))

  def Max(self):
    return numpy.max(self.samples)


def GrabCpuSamples(sample_count):
  print 'Label for snapshot (enter to quit): '
  label = raw_input().strip()
  if len(label) == 0:
    return None

  snapshot = CpuSnapshot(label)
  snapshot.Capture(sample_count)

  return snapshot


def main():
  print 'How many seconds to capture per snapshot (enter for 60)?'
  sample_count = raw_input().strip()
  if len(sample_count) > 0 and int(sample_count) > 0:
    sample_count = int(sample_count)
  else:
    print 'Defaulting to 60 samples.'
    sample_count = 60

  snapshots = []
  while True:
    snapshot = GrabCpuSamples(sample_count)
    if snapshot == None:
      break
    snapshots.append(snapshot)

  if len(snapshots) == 0:
    print 'no samples captured'
    return -1

  pyplot.title('CPU usage')

  for s in snapshots:
    pyplot.plot(s.samples, label=s.Text(), linewidth=2)

  pyplot.legend()

  pyplot.show()
  return 0

if __name__ == '__main__':
  sys.exit(main())