#!/usr/bin/env pmpython
#
# Copyright (c) 2013-2016,2018 Red Hat.
# Copyright (c) 1995-2002 Silicon Graphics, Inc.  All Rights Reserved.
#
# 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.
#
# pylint: disable=bare-except,missing-docstring,unnecessary-lambda,too-few-public-methods

# get python3-compatible incremental line printing
from __future__ import print_function

import sys
from pcp import pmapi
import cpmapi as c_api


class sampler(object):
    def __init__(self, fg):
        self.fg = fg
        self.load1 = fg.extend_item('kernel.all.load', instance='1 minute')
        self.load15 = fg.extend_item('kernel.all.load', instance='15 minute')
        self.cpu_user = fg.extend_indom('kernel.percpu.cpu.user', scale='second/second')
        self.cpu_sys = fg.extend_indom('kernel.percpu.cpu.sys', scale='second/second')
        self.freemem = fg.extend_item('mem.freemem', scale='Mbyte', mtype=c_api.PM_TYPE_DOUBLE)
        self.dkiops = fg.extend_item('disk.all.total', scale='count/second')
        self.timestamp = fg.extend_timestamp()
        self.ncpu = fg.extend_item('hinv.ncpu')

    def get_sample(self):
        self.fg.fetch()

        # compute overall cpu utilization; identify peak
        self.cpu_util = 0
        self.peak_cpu_util = -1
        self.peak_cpu = 0
        for (ucode, _, uvalue), (scode, _, svalue) in zip(self.cpu_user(), self.cpu_sys()):
            assert ucode == scode	# indoms should match
            try:
                util = uvalue() + svalue()
                # small errors are possible, so clip the utilization at 1.0
                util = min(util, 1.0)
            except:
                # suspect PM_ERR_AGAIN from first-step rate-calculation
                util = 0

            self.cpu_util += util
            if util > self.peak_cpu_util:
                self.peak_cpu_util = util
                self.peak_cpu = ucode

        self.cpu_util /= self.ncpu()

class pmclient_fg(object):
    def option_override(self, opt):
        if opt == 'p':
            return 1
        return 0

    def option(self, opt, optarg, index):
        if opt == 'p':
            self.pause = True

    def __init__(self, argv):
        self.pause = False

        opts = pmapi.pmOptions()
        opts.pmSetShortOptions('A:a:D:gh:n:O:p:S:s:T:t:VZ:z?P') # PMAPI_OPTIONS + 'P'
        opts.pmSetOptionFlags(c_api.PM_OPTFLAG_STDOUT_TZ)
        opts.pmSetLongOptionText('Reporting options')
        opts.pmSetLongOption('pause', 0, 'p', '', 'pause between updates for archive replay')
        opts.pmSetLongOptionArchive()
        opts.pmSetLongOptionHost()
        opts.pmSetOptionCallback(lambda opt, optarg, index: self.option(opt, optarg, index))
        opts.pmSetOverrideCallback(lambda opt: self.option_override(opt))
        # .... etc; the python pmOptions should have a function for the PMAPI_OPTIONS common set
        self.opts = opts

        c_api.pmGetOptionsFromList(argv)
        self.typed = opts.pmGetOptionContext()
        if self.typed == c_api.PM_CONTEXT_ARCHIVE:
            target = opts.pmGetOptionArchives()[0]
        elif self.typed == c_api.PM_CONTEXT_HOST:
            if self.pause:
                raise pmapi.pmUsageErr
            target = opts.pmGetOptionHosts()[0]
        else:
            self.typed = c_api.PM_CONTEXT_HOST
            target = 'local:'

        self.fg = pmapi.fetchgroup(self.typed, target)
        self.ctx = self.fg.get_context()

        # for other pmOptions related to archive time offsets, etc.:
        # opts.pmSetContextOptions(ctx, ....) ?

        self.host = self.ctx.pmGetContextHostName()


    def run(self):
        info = sampler(self.fg)
        if self.opts.pmGetOptionSamples():
            samples = self.opts.pmGetOptionSamples()
        else:
            samples = -1

        if self.opts.pmGetOptionInterval():
            interval = self.opts.pmGetOptionInterval()
        else:
            interval = pmapi.timeval(5, 0)

        if self.typed == c_api.PM_CONTEXT_ARCHIVE:
            info.get_sample() # fetch the separate early ncpu record
        info.get_sample() # fetch other rate metrics

        lines = 0
        while True:
            if samples >= 0:
                if samples == 0:
                    break
                samples -= 1

            if lines % 15 == 0:
                if self.typed == c_api.PM_CONTEXT_ARCHIVE:
                    print('Archive: %s, ' % self.opts.pmGetOptionArchives()[0], end='')
                print('Host: %s, %d cpu(s), %s' % (self.host, info.ncpu(), info.timestamp()))

                # - report format
                #  CPU  Busy    Busy  Free Mem   Disk     Load Average
                # Util   CPU    Util  (Mbytes)   IOPS    1 Min  15 Min
                #X.XXX   XXX   X.XXX XXXXX.XXX XXXXXX  XXXX.XX XXXX.XX

                print('  CPU', end='')
                if info.ncpu() > 1:
                    print('  Busy    Busy', end='')
                print('  Free Mem   Disk     Load Average')
                print(' Util', end='')
                if info.ncpu() > 1:
                    print('   CPU    Util', end='')
                print('  (Mbytes)   IOPS    1 Min  15 Min')

            if self.typed != c_api.PM_CONTEXT_ARCHIVE or self.pause:
                self.ctx.pmtimevalSleep(interval)

            info.get_sample()
            print('%5.2f' % info.cpu_util, end='')
            if info.ncpu() > 1:
                print('   %3d   %5.2f' % (info.peak_cpu, info.peak_cpu_util), end='')
            print(' %9.3f' % info.freemem(), end='')
            print(' %6d' % info.dkiops(), end='')
            print('  %7.2f %7.2f' % (info.load1(), info.load15()))
            lines += 1

if __name__ == '__main__':
    try:
        pmclient = pmclient_fg(sys.argv)
        pmclient.run()
    except pmapi.pmErr as error:
        sys.stderr.write('%s: %s\n' % (error.progname(), error.message()))
    except KeyboardInterrupt:
        sys.exit(0)