#!/usr/bin/env python
"""RDFValue instances related to the statistics collection."""

import math
import threading

from grr.lib import utils
from grr.lib.rdfvalues import client
from grr.lib.rdfvalues import protodict as rdf_protodict
from grr.lib.rdfvalues import structs as rdf_structs
from grr_response_proto import analysis_pb2
from grr_response_proto import jobs_pb2


class StatsHistogramBin(rdf_structs.RDFProtoStruct):
  protobuf = jobs_pb2.StatsHistogramBin


class StatsHistogram(rdf_structs.RDFProtoStruct):
  """Histogram with a user-provided set of bins."""
  protobuf = jobs_pb2.StatsHistogram
  rdf_deps = [
      StatsHistogramBin,
  ]

  @classmethod
  def FromBins(cls, bins):
    res = cls()
    for b in bins:
      res.bins.Append(StatsHistogramBin(range_max_value=b))
    return res

  def RegisterValue(self, value):
    """Puts a given value into an appropriate bin."""
    if self.bins:
      for b in self.bins:
        if b.range_max_value > value:
          b.num += 1
          return

      self.bins[-1].num += 1


class RunningStats(rdf_structs.RDFProtoStruct):
  """Class for collecting running stats: mean, stdev and histogram data."""
  protobuf = jobs_pb2.RunningStats
  rdf_deps = [
      StatsHistogram,
  ]

  def RegisterValue(self, value):
    self.num += 1
    self.sum += value
    self.sum_sq += value**2

    self.histogram.RegisterValue(value)

  @property
  def mean(self):
    if self.num == 0:
      return 0
    else:
      return self.sum / float(self.num)

  @property
  def std(self):
    if self.num == 0:
      return 0
    else:
      return math.sqrt(self.sum_sq / float(self.num) - self.mean**2)


class ClientResourcesStats(rdf_structs.RDFProtoStruct):
  """RDF value representing clients' resources usage statistics for hunts."""
  protobuf = jobs_pb2.ClientResourcesStats
  rdf_deps = [
      client.ClientResources,
      RunningStats,
  ]

  CPU_STATS_BINS = [
      0.1, 0.2, 0.3, 0.4, 0.5, 0.75, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8, 9, 10,
      15, 20
  ]
  NETWORK_STATS_BINS = [
      16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536,
      131072, 262144, 524288, 1048576, 2097152
  ]
  NUM_WORST_PERFORMERS = 10

  def __init__(self, initializer=None, **kwargs):
    super(ClientResourcesStats, self).__init__(
        initializer=initializer, **kwargs)

    self.user_cpu_stats.histogram = StatsHistogram.FromBins(self.CPU_STATS_BINS)
    self.system_cpu_stats.histogram = StatsHistogram.FromBins(
        self.CPU_STATS_BINS)
    self.network_bytes_sent_stats.histogram = StatsHistogram.FromBins(
        self.NETWORK_STATS_BINS)

    self.lock = threading.RLock()

  @utils.Synchronized
  def RegisterResources(self, client_resources):
    """Update stats with info about resources consumed by a single client."""
    self.user_cpu_stats.RegisterValue(client_resources.cpu_usage.user_cpu_time)
    self.system_cpu_stats.RegisterValue(
        client_resources.cpu_usage.system_cpu_time)
    self.network_bytes_sent_stats.RegisterValue(
        client_resources.network_bytes_sent)

    self.worst_performers.Append(client_resources)
    new_worst_performers = sorted(
        self.worst_performers,
        key=lambda s: s.cpu_usage.user_cpu_time + s.cpu_usage.system_cpu_time,
        reverse=True)[:self.NUM_WORST_PERFORMERS]
    self.worst_performers = new_worst_performers


class Sample(rdf_structs.RDFProtoStruct):
  """A Graph sample is a single data point."""
  protobuf = analysis_pb2.Sample


class SampleFloat(rdf_structs.RDFProtoStruct):
  """A Graph float data point."""
  protobuf = analysis_pb2.SampleFloat


class Graph(rdf_structs.RDFProtoStruct):
  """A Graph is a collection of sample points."""
  protobuf = analysis_pb2.Graph
  rdf_deps = [
      Sample,
  ]

  def Append(self, **kwargs):
    self.data.Append(**kwargs)

  def __len__(self):
    return len(self.data)

  def __nonzero__(self):
    return bool(self.data)

  def __getitem__(self, item):
    return Sample(self.data[item])

  def __iter__(self):
    for x in self.data:
      yield Sample(x)


class GraphFloat(Graph):
  """A Graph that stores sample points as floats."""
  protobuf = analysis_pb2.GraphFloat
  rdf_deps = [
      SampleFloat,
  ]

  def __getitem__(self, item):
    return SampleFloat(self.data[item])

  def __iter__(self):
    for x in self.data:
      yield SampleFloat(x)


class GraphSeries(rdf_protodict.RDFValueArray):
  """A sequence of graphs (e.g. evolving over time)."""
  rdf_type = Graph
