#!/usr/bin/python

##
## Copyright (c) 2010-2020 Intel Corporation
##
## Licensed under the Apache License, Version 2.0 (the "License");
## you may not use this file except in compliance with the License.
## You may obtain a copy of the License at
##
##     http://www.apache.org/licenses/LICENSE-2.0
##
## Unless required by applicable law or agreed to in writing, software
## distributed under the License is distributed on an "AS IS" BASIS,
## WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
## See the License for the specific language governing permissions and
## limitations under the License.
##

from rapid_log import RapidLog 
from prox_ctrl import prox_ctrl
from rapid_machine import RapidMachine
from math import ceil, log2


class RandomPortBits(object):
    """
    Class to generate PROX bitmaps for random bit generation
    in source & dst UPD ports to emulate mutiple flows
    """
    @staticmethod
    def get_bitmap(flow_number):
        number_of_random_bits = ceil(log2(flow_number))
        if number_of_random_bits > 30:
            raise Exception("Not able to support that many flows")
            # throw exeption since we need the first bit to be 1
            # Otherwise, the randomization could results in all 0's
            # and that might be an invalid UDP port and result in 
            # packets begin discarded
        src_number_of_random_bits = number_of_random_bits // 2
        dst_number_of_random_bits = number_of_random_bits - src_number_of_random_bits
        src_port_bitmap = '1000000000000000'.replace ('0','X',src_number_of_random_bits)
        dst_port_bitmap = '1000000000000000'.replace ('0','X',dst_number_of_random_bits)
        return [src_port_bitmap, dst_port_bitmap]

class RapidGeneratorMachine(RapidMachine):
    """
    Class to deal with rapid configuration files
    """
    def get_cores(self):
        return (self.machine_params['gencores'] + self.machine_params['latcores'])

    def generate_lua(self, vim):
        appendix = 'gencores="%s"\n'% ','.join(map(str, self.machine_params['gencores']))
        appendix = appendix + 'latcores="%s"\n'% ','.join(map(str, self.machine_params['latcores']))
        if 'gw_vm' in self.machine_params.keys():
            for index, gw_ip in enumerate(self.machine_params['gw_ips'], start = 1):
                appendix = appendix + 'gw_ip{}="{}"\n'.format(index, gw_ip)
                appendix = appendix + 'gw_hex_ip{}="{}"\n'.format(index, self.ip2hex(gw_ip))
        if 'bucket_size_exp' in self.machine_params.keys():
            self.bucket_size_exp = self.machine_params['bucket_size_exp']
        else:
            self.bucket_size_exp = 11
        appendix = appendix + 'bucket_size_exp="{}"\n'.format(self.bucket_size_exp)
        if 'heartbeat' in self.machine_params.keys():
            appendix = appendix + 'heartbeat="%s"\n'% self.machine_params['heartbeat']
        else:
            appendix = appendix + 'heartbeat="60"\n'
        super().generate_lua(vim, appendix)

    def start_prox(self):
        # Start the generator with the -e option so that the cores don't
        # start automatically
        super().start_prox('-e')

    def set_generator_speed(self, speed):
        # The assumption is that we only use task 0 for generating
        # We should check the gen.cfg file to make sure there is only task=0
        speed_per_gen_core = speed / len(self.machine_params['gencores']) 
        self.socket.speed(speed_per_gen_core, self.machine_params['gencores'])

    def set_udp_packet_size(self, size):
        # We should check the gen.cfg to make sure we only send UDP packets
        # Frame size is PROX pkt size + 4 bytes CRC
        # PROX "pkt_size" i.e.  14-bytes L2 frame header + VLAN 4 bytes header + IP packet size
        self.socket.set_size(self.machine_params['gencores'], 0, size)
        # 18 is the difference between the frame size and IP size = size of (MAC addresses, ethertype and FCS)
        self.socket.set_value(self.machine_params['gencores'], 0, 16, size-18, 2)
        # 38 is the difference between the frame size and UDP size = 18 + size of IP header (=20)
        self.socket.set_value(self.machine_params['gencores'], 0, 38, size-38, 2)

    def set_flows(self, number_of_flows):
        source_port,destination_port = RandomPortBits.get_bitmap(number_of_flows)
        self.socket.set_random(self.machine_params['gencores'],0,34,source_port,2)
        self.socket.set_random(self.machine_params['gencores'],0,36,destination_port,2)

    def start_gen_cores(self):
        self.socket.start(self.machine_params['gencores'])

    def stop_gen_cores(self):
        self.socket.stop(self.machine_params['gencores'])

    def start_latency_cores(self):
        self.socket.start(self.machine_params['latcores'])

    def stop_latency_cores(self):
        self.socket.stop(self.machine_params['latcores'])

    def lat_stats(self):
        # Checking all tasks in the cfg file. In this way, we can have more
        # latency tasks on the same core
        return (self.socket.lat_stats(self.machine_params['latcores'],
                self.all_tasks_for_this_cfg))