#!/usr/bin/env python3
#
# Copyright (c) 2017-2020  Joe Clarke <jclarke@cisco.com>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.


from builtins import str
from builtins import range
import os
import re
import sys
import time
import json
import paramiko
import CLEUCreds


CACHE_FILE = "/home/jclarke/mac_counts.dat"
CACHE_FILE_TMP = CACHE_FILE + ".tmp"

commands = [
    {
        "command": "show mac address-table count | inc Dynamic Address Count",
        "pattern": r"Dynamic Address Count:\s+(\d+)",
        "metric": "totalMacs",
        "devices": ["core1-l3c", "core2-l3c"],
    },
    {
        "command": "show mac address-table dynamic | inc Total",
        "pattern": r"Total.*: (\d+)",
        "metric": "totalMacs",
        "devicePatterns": [{"pattern": "10.127.0.{}", "range": {"min": 1, "max": 60}}],
    },
    {
        "command": "show ip arp summary | inc IP ARP",
        "pattern": r"(\d+) IP ARP entries",
        "metric": "arpEntries",
        "devicePatterns": [{"pattern": "10.127.0.{}", "range": {"min": 1, "max": 60}}],
    },
]


def send_command(chan, command):
    chan.sendall(command + "\n")
    i = 0
    output = ""
    while i < 10:
        if chan.recv_ready():
            break
        i += 1
        time.sleep(i * 0.5)
    while chan.recv_ready():
        r = chan.recv(131070).decode("utf-8")
        output = output + r

    return output


def get_results(ssh_client, ip, command, pattern, metric):
    response = ""
    try:
        ssh_client.connect(ip, username=CLEUCreds.NET_USER, password=CLEUCreds.NET_PASS, timeout=5, allow_agent=False, look_for_keys=False)
        chan = ssh_client.invoke_shell()
        output = ""
        try:
            send_command(chan, "term length 0")
            send_command(chan, "term width 0")
            output = send_command(chan, command)
        except Exception as ie:
            response = '{}{{idf="{}"}}'.format(metric, ip)
            sys.stderr.write("Failed to get MACs from {}: {}\n".format(ip, ie))
            return response

        m = re.search(pattern, output)
        if m:
            response = '{}{{idf="{}"}} {}'.format(metric, ip, m.group(1))
        else:
            response = '{}{{idf="{}"}} 0'.format(metric, ip)
    except Exception as e:
        ssh_client.close()
        sys.stderr.write("Failed to connect to {}: {}\n".format(ip, e))
        return ""

    ssh_client.close()

    return response


def get_metrics():

    response = []

    ssh_client = paramiko.SSHClient()
    ssh_client.set_missing_host_key_policy(paramiko.AutoAddPolicy())

    for command in commands:
        if "devices" in command:
            for device in command["devices"]:
                response.append(get_results(ssh_client, device, command["command"], command["pattern"], command["metric"]))
        else:
            for pattern in command["devicePatterns"]:
                if "range" in pattern:
                    for i in range(pattern["range"]["min"], pattern["range"]["max"]):
                        response.append(
                            get_results(
                                ssh_client, pattern["pattern"].format(str(i)), command["command"], command["pattern"], command["metric"]
                            )
                        )
                else:
                    for sub in pattern["subs"]:
                        response.append(
                            get_results(
                                ssh_client, pattern["pattern"].format(sub), command["command"], command["pattern"], command["metric"]
                            )
                        )

    return response


if __name__ == "__main__":
    response = get_metrics()

    fd = open(CACHE_FILE_TMP, "w")
    json.dump(response, fd, indent=4)
    fd.close()

    os.rename(CACHE_FILE_TMP, CACHE_FILE)