# osmo_gsm_tester: specifics for running an iperf3 client and server
#
# Copyright (C) 2018 by sysmocom - s.f.m.c. GmbH
#
# Author: Pau Espin Pedrol <pespin@sysmocom.de>
#
# 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 3 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.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import os
import json

from ..core import log, util, config, process, remote
from . import pcap_recorder, run_node

def iperf3_result_to_json(log_obj, data):
    try:
        # Drop non-interesting self-generated output before json:
        if not data.startswith('{\n'):
            data = "{\n" + data.split("\n{\n")[1]
        # Sometimes iperf3 provides 2 dictionaries, the 2nd one being an error about being interrupted (by us).
        # json parser doesn't support (raises exception) parsing several dictionaries at a time (not a valid json object).
        # We are only interested in the first dictionary, the regular results one:
        data = data.split("\n}")[0] + "\n}"
        j = json.loads(data)
        return j
    except Exception as e:
        log_obj.log('failed parsing iperf3 output: "%s"' % data)
        raise e


class IPerf3Server(log.Origin):

    DEFAULT_SRV_PORT = 5003
    LOGFILE = 'iperf3_srv.json'
    REMOTE_DIR = '/tmp'

    def __init__(self, suite_run, ip_address):
        super().__init__(log.C_RUN, 'iperf3-srv_%s' % ip_address.get('addr'))
        self.run_dir = None
        self.process = None
        self._run_node = None
        self.suite_run = suite_run
        self.ip_address = ip_address
        self._port = IPerf3Server.DEFAULT_SRV_PORT
        self.log_file = None
        self.rem_host = None
        self.remote_log_file = None
        self.log_copied = False
        self.logfile_supported = False # some older versions of iperf doesn't support --logfile arg

    def cleanup(self):
        if self.process is None:
            return
        if self.runs_locally() or not self.logfile_supported:
            return
        # copy back files (may not exist, for instance if there was an early error of process):
        try:
            self.rem_host.scpfrom('scp-back-log', self.remote_log_file, self.log_file)
        except Exception as e:
            self.log(repr(e))

    def runs_locally(self):
        locally = not self._run_node or self._run_node.is_local()
        return locally

    def start(self):
        self.log('Starting iperf3-srv')
        self.log_copied = False
        self.run_dir = util.Dir(self.suite_run.get_test_run_dir().new_dir(self.name()))
        self.log_file = self.run_dir.new_file(IPerf3Server.LOGFILE)
        if self.runs_locally():
            self.start_locally()
        else:
            self.start_remotely()

    def start_remotely(self):
        self.rem_host = remote.RemoteHost(self.run_dir, self._run_node.ssh_user(), self._run_node.ssh_addr())
        remote_prefix_dir = util.Dir(IPerf3Server.REMOTE_DIR)
        remote_run_dir = util.Dir(remote_prefix_dir.child('srv-' + str(self)))
        self.remote_log_file = remote_run_dir.child(IPerf3Server.LOGFILE)

        self.rem_host.recreate_remote_dir(remote_run_dir)

        args = ('iperf3', '-s', '-B', self.addr(),
                '-p', str(self._port), '-J')
        if self.logfile_supported:
            args += ('--logfile', self.remote_log_file,)

        self.process = self.rem_host.RemoteProcess(self.name(), args)
        self.suite_run.remember_to_stop(self.process)
        self.process.launch()

    def start_locally(self):
        pcap_recorder.PcapRecorder(self.suite_run, self.run_dir.new_dir('pcap'), None,
                                   'host %s and port not 22' % self.addr())

        args = ('iperf3', '-s', '-B', self.addr(),
                '-p', str(self._port), '-J')
        if self.logfile_supported:
            args += ('--logfile', os.path.abspath(self.log_file),)

        self.process = process.Process(self.name(), self.run_dir, args, env={})
        self.suite_run.remember_to_stop(self.process)
        self.process.launch()

    def set_run_node(self, run_node):
        self._run_node = run_node

    def set_port(self, port):
        self._port = port

    def stop(self):
        self.suite_run.stop_process(self.process)

    def get_results(self):
        if self.logfile_supported:
            if not self.runs_locally() and not self.log_copied:
                self.rem_host.scpfrom('scp-back-log', self.remote_log_file, self.log_file)
                self.log_copied = True
            with open(self.log_file) as f:
                return iperf3_result_to_json(self, f.read())
        else:
            return iperf3_result_to_json(self, self.process.get_stdout())

    def addr(self):
        return self.ip_address.get('addr')

    def port(self):
        return self._port

    def __str__(self):
        return "%s:%u" %(self.addr(), self.port())

    def running(self):
        return not self.process.terminated()

    def create_client(self):
        return IPerf3Client(self.suite_run, self)

class IPerf3Client(log.Origin):

    REMOTE_DIR = '/tmp'
    LOGFILE = 'iperf3_cli.json'

    def __init__(self, suite_run, iperf3srv):
        super().__init__(log.C_RUN, 'iperf3-cli_%s' % iperf3srv.addr())
        self.run_dir = None
        self.process = None
        self._run_node = None
        self.server = iperf3srv
        self.suite_run = suite_run
        self.log_file = None
        self.rem_host = None
        self.remote_log_file = None
        self.log_copied = False
        self.logfile_supported = False # some older versions of iperf doesn't support --logfile arg

    def runs_locally(self):
        locally = not self._run_node or self._run_node.is_local()
        return locally

    def prepare_test_proc(self, downlink=False, netns=None, time_sec=None):
        if time_sec is None:
            values = config.get_defaults('iperf3cli')
            config.overlay(values, self.suite_run.config().get('iperf3cli', {}))
            time_sec_str = values.get('time', time_sec)

            # Convert duration to seconds
            if isinstance(time_sec_str, str) and time_sec_str.endswith('h'):
                time_sec = int(time_sec_str[:-1]) * 3600
            elif isinstance(time_sec_str, str) and time_sec_str.endswith('m'):
                time_sec = int(time_sec_str[:-1]) * 60
            else:
                time_sec = int(time_sec_str)

        assert(time_sec)

        self.log('Preparing iperf3-client connecting to %s:%d (time=%ds)' % (self.server.addr(), self.server.port(), time_sec))
        self.log_copied = False
        self.run_dir = util.Dir(self.suite_run.get_test_run_dir().new_dir(self.name()))
        self.log_file = self.run_dir.new_file(IPerf3Client.LOGFILE)
        if self.runs_locally():
            return self.prepare_test_proc_locally(downlink, netns, time_sec)
        else:
            return self.prepare_test_proc_remotely(downlink, netns, time_sec)

    def prepare_test_proc_remotely(self, downlink, netns, time_sec):
        self.rem_host = remote.RemoteHost(self.run_dir, self._run_node.ssh_user(), self._run_node.ssh_addr())

        remote_prefix_dir = util.Dir(IPerf3Client.REMOTE_DIR)
        remote_run_dir = util.Dir(remote_prefix_dir.child('cli-' + str(self)))
        self.remote_log_file = remote_run_dir.child(IPerf3Client.LOGFILE)

        self.rem_host.recreate_remote_dir(remote_run_dir)

        popen_args = ('iperf3', '-c',  self.server.addr(),
                      '-p', str(self.server.port()), '-J',
                      '-t', str(time_sec))
        if self.logfile_supported:
            popen_args += ('--logfile', self.remote_log_file,)
        if downlink:
            popen_args += ('-R',)

        if netns:
            self.process = self.rem_host.RemoteNetNSProcess(self.name(), netns, popen_args, env={})
        else:
            self.process = self.rem_host.RemoteProcess(self.name(), popen_args, env={})
        return self.process

    def prepare_test_proc_locally(self, downlink, netns, time_sec):
        pcap_recorder.PcapRecorder(self.suite_run, self.run_dir.new_dir('pcap'), None,
                                   'host %s and port not 22' % self.server.addr(), netns)

        popen_args = ('iperf3', '-c',  self.server.addr(),
                      '-p', str(self.server.port()), '-J',
                      '-t', str(time_sec))
        if self.logfile_supported:
            popen_args += ('--logfile', os.path.abspath(self.log_file),)
        if downlink:
            popen_args += ('-R',)

        if netns:
            self.process = process.NetNSProcess(self.name(), self.run_dir, netns, popen_args, env={})
        else:
            self.process = process.Process(self.name(), self.run_dir, popen_args, env={})
        return self.process

    def run_test_sync(self, netns=None):
        self.prepare_test_proc(netns)
        self.process.launch_sync()
        return self.get_results()

    def get_results(self):
        if self.logfile_supported:
            if not self.runs_locally() and not self.log_copied:
                self.rem_host.scpfrom('scp-back-log', self.remote_log_file, self.log_file)
                self.log_copied = True
            with open(self.log_file) as f:
                return iperf3_result_to_json(self, f.read())
        else:
            return iperf3_result_to_json(self, self.process.get_stdout())

    def set_run_node(self, run_node):
        self._run_node = run_node

    def __str__(self):
        # FIXME: somehow differentiate between several clients connected to same server?
        return "%s:%u" %(self.server.addr(), self.server.port())

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