#!/usr/bin/python

import psutil as ps
import collections

####################################################################################
Metrics = collections.namedtuple("Metrics", ["name", "value"])

class Collection (object):
    class Group (object):
        class Metric (object):
            name = "unknown"
            collector_function = 0
            collector_function_arguments = {}
            collector_function_result_attr = ""

            @classmethod
            def harvest(cls):
                query = cls.collector_function.im_func(**cls.collector_function_arguments)
                if ((isinstance(query, list)) or (isinstance(query, dict))):
                    return Metrics(cls.name,
                                query[cls.collector_function_result_attr])
                elif (isinstance(query,tuple)):
                    return Metrics(cls.name,
                                query.__getattribute__(cls.collector_function_result_attr))
                else:
                    return Metrics(cls.name,
                                query)

####################################################################################

class std (Collection):

    class cpu (Collection.Group):

        class usage (Collection.Group.Metric):
            name = "cpu.usage"
            collector_function = ps.cpu_percent
            collector_function_arguments = {
                'interval': 0.0,
            }

    class memory (Collection.Group):

        class usage(Collection.Group.Metric):
            name = "memory.usage"
            collector_function = ps.virtmem_usage
            collector_function_result_attr = "percent"

    class swap (Collection.Group):

        class usage(Collection.Group.Metric):
            name = "swap.usage"
            collector_function = ps.swap_memory
            collector_function_result_attr = "percent"

    class user (Collection.Group):

        class count (Collection.Group.Metric):
            name = "user.count"
            @classmethod
            def harvest(cls):
                return Metrics(cls.name, len(ps.get_users()))

    class network (Collection.Group):

        class packages_sent (Collection.Group.Metric):
            name = "network.packages_sent"
            collector_function = ps.network_io_counters
            collector_function_result_attr = "packets_sent"

        class packages_received (Collection.Group.Metric):
            name = "network.packages_received"
            collector_function = ps.network_io_counters
            collector_function_result_attr = "packets_recv"

        class bytes_sent (Collection.Group.Metric):
             name = "network.bytes_sent"
             collector_function = ps.network_io_counters
             collector_function_result_attr = "bytes_sent"

        class bytes_received(Collection.Group.Metric):
            name = "network.bytes_received"
            collector_function = ps.network_io_counters
            collector_function_result_attr = "bytes_recv"

    class system (Collection.Group):

        class boot_time (Collection.Group.Metric):
            name = "system.boot_time"
            collector_function = ps.get_boot_time