#!/usr/bin/env python
#
# 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 range
import requests
from requests.packages.urllib3.exceptions import InsecureRequestWarning  # type: ignore

requests.packages.urllib3.disable_warnings(InsecureRequestWarning)
import json
import time
import os
from subprocess import call
from sparker import Sparker, MessageType  # type: ignore
import re
from multiprocessing import Pool
import socket
import CLEUCreds  # type: ignore
from cleu.config import Config as C  # type: ignore

CACHE_FILE = "/home/jclarke/cached_devs.dat"
PING_DEVS_FILE = "/home/jclarke/ping-devs.json"

MESSAGES = {
    "BAD": {"msg": "Pinger detected that device %s (IP: %s)%s is no longer reachable", "type": MessageType.BAD},
    "GOOD": {"msg": "Pinger has detected that device %s (IP: %s)%s is now reachable again", "type": MessageType.GOOD},
}

ROOM_NAME = "Device Alarms"

excluded_devices = [r"^VHS-"]

additional_devices = []


def check_prev(dev_dic, prev_devs, pstate="REACHABLE"):
    send_msg = False
    for pd in prev_devs:
        if pd["name"] == dev_dic["name"]:
            if pd["reachability"] != pstate:
                send_msg = True
            break
    return send_msg


def know_device(dev_dic, prev_devs):
    for pd in prev_devs:
        if pd["name"] == dev_dic["name"]:
            return True

    return False


def ping_device(dev):
    global ROOM_NAME, MESSAGES, prev_devs, spark, excluded_devices

    dev_dic = {}

    dev_dic["name"] = dev["Hostname"]
    dev_dic["ip"] = dev["IPAddress"]
    if dev_dic["ip"] == "0.0.0.0":
        return None
    for exc in excluded_devices:
        if re.search(exc, dev_dic["name"]) or re.search(exc, dev_dic["ip"]):
            return None
    # print('Pinging {}'.format(dev_dic['name']))
    msg_tag = "BAD"
    send_msg = True
    if not dev["Reachable"]:
        send_msg = know_device(dev_dic, prev_devs)
    for _ in range(2):
        res = call(["/usr/local/sbin/fping", "-q", "-r0", dev_dic["ip"]])
        if res == 0:
            break

        time.sleep(0.5)
    if res != 0:
        dev_dic["reachability"] = "UNREACHABLE"
        send_msg = check_prev(dev_dic, prev_devs, "UNREACHABLE")
    else:
        dev_dic["reachability"] = "REACHABLE"
        msg_tag = "GOOD"
        send_msg = check_prev(dev_dic, prev_devs)

    if send_msg:
        loc = ""
        if "LocationDetail" in dev:
            loc = " (Location: {})".format(dev["LocationDetail"])
        message = MESSAGES[msg_tag]["msg"] % (dev_dic["name"], dev_dic["ip"], loc)
        spark.post_to_spark(C.WEBEX_TEAM, ROOM_NAME, message, MESSAGES[msg_tag]["type"])

    return dev_dic


def get_devs(p):
    global additional_devices

    url = "http://{}/get/switches/json".format(C.TOOL)

    devices = []
    #    response = requests.request('GET', url)
    code = 200
    #   code = response.status_code
    if code == 200:
        # j = json.loads(response.text)
        j = []

        for dev in additional_devices:
            ip = dev
            try:
                ip = socket.gethostbyname(dev)
            except Exception as e:
                spark.post_to_spark(C.WEBEX_TEAM, ROOM_NAME, "Failed to resolve {}: {}".format(dev, e), MessageType.WARNING)
                continue
            j.append({"Hostname": dev, "IPAddress": ip, "Reachable": True})

        results = [p.apply_async(ping_device, [d]) for d in j]
        for res in results:
            retval = res.get()
            if retval is not None:
                devices.append(retval)

    return devices


if __name__ == "__main__":
    prev_devs = []
    if os.path.exists(CACHE_FILE):
        with open(CACHE_FILE, "r") as fd:
            prev_devs = json.load(fd)

    spark = Sparker(token=CLEUCreds.SPARK_TOKEN)

    try:
        with open(PING_DEVS_FILE, "r") as fd:
            additional_devices = json.load(fd)
    except:
        pass

    pool = Pool(20)
    devs = get_devs(pool)
    with open(CACHE_FILE, "w") as fd:
        json.dump(devs, fd, ensure_ascii=False, indent=4)