#!/usr/bin/env python3
import argparse
import sys
import time
import traceback

import numpy as np
import requests
from urllib3.exceptions import InsecureRequestWarning

import checker.nagios as nagios
from checker.markdown import list_to_markdown_table
from checker.units import filesize


def main():
    parser = argparse.ArgumentParser(description='Check OPNsense network traffic for a host.')
    parser.add_argument('--opnsense', required=True, help='OPNsense hostname or IP address.')
    parser.add_argument('--key', required=True, help='OPNsense API key.')
    parser.add_argument('--secret', required=True, help='OPNsense API secret.')
    parser.add_argument('--interface', required=True,
                        help='Interface to check (e.g., lan). Can be something like "lan,wan"')
    parser.add_argument('--host', required=True, help='Address of the host to check.')
    parser.add_argument('--duration', default=10, type=int, help='How many seconds to gather statistics.')
    parser.add_argument('--fail-empty', action='store_true',
                        help='If the API did not return any data, fail with UNKNOWN. Otherwise, assume that there was no traffic.')
    args = parser.parse_args()

    check_result = {}
    interface_names = {}

    requests.packages.urllib3.disable_warnings(category=InsecureRequestWarning)

    # Map interface names to their internal names
    interfaces_mapping = requests.get(f'https://{args.opnsense}/api/diagnostics/traffic/interface',
                                      headers={'Accept': 'application/json'}, auth=(args.key, args.secret),
                                      verify=False, timeout=10)
    if interfaces_mapping.status_code != 200:
        print(
            f'UNKNOWN: unable to query OPNsense API for interface mappings: {interfaces_mapping.status_code}\n{interfaces_mapping.text}')
        sys.exit(nagios.UNKNOWN)
    interfaces_mapping = interfaces_mapping.json()['interfaces']
    interfaces_to_check = set(args.interface.split(','))
    for name, interface in interfaces_mapping.items():
        if interface['name'] in interfaces_to_check:
            interfaces_to_check.remove(interface['name'])
            interface_names[interface['name']] = name

    if not len(interface_names.keys()):
        print(f'UNKNOWN: did not find any valid interface names! Double-check the name.')
        sys.exit(nagios.UNKNOWN)

    for name, interface in interface_names.items():
        # Fetch the data
        # TODO: account for network delays for the check duration
        traffic_data = []
        for _ in range(args.duration):
            response = requests.get(f'https://{args.opnsense}/api/diagnostics/traffic/top/{interface}',
                                    headers={'Accept': 'application/json'}, auth=(args.key, args.secret), verify=False,
                                    timeout=10)
            if response.status_code != 200:
                print(f'UNKNOWN: unable to query OPNsense API for {interface}: {response.status_code}\n{response.text}')
                sys.exit(nagios.UNKNOWN)
            for item in response.json().get(interface, {}).get('records', False):
                if item['address'] == args.host:
                    traffic_data.append(item)
            time.sleep(1)

        if not len(traffic_data) and args.fail_empty:
            print('UNKNOWN: Interface or host not found in OPNsense API response. Raw response:')
            print(traffic_data)
            sys.exit(nagios.UNKNOWN)
        elif not len(traffic_data):
            check_result[name] = {
                'rate_in': 0,
                'rate_out': 0,
                'cumulative_in': 0,
                'cumulative_out': 0,
                'connections': 0
            }
        else:
            try:
                check_result[name] = {
                    'rate_in': np.average([x['rate_bits_in'] for x in traffic_data]),
                    'rate_out': np.average([x['rate_bits_out'] for x in traffic_data]),
                    'cumulative_in': np.average([x['cumulative_bytes_in'] for x in traffic_data]),
                    'cumulative_out': np.average([x['cumulative_bytes_out'] for x in traffic_data]),
                    'connections': int(np.average([len(x['details']) for x in traffic_data]))
                }
            except Exception as e:
                print(f'UNKNOWN: Failed to parse traffic data: "{e}"')
                print(traceback.format_exc())
                print('')
                print('Raw data:')
                print(traffic_data)
                sys.exit(nagios.UNKNOWN)

    # TODO: figure out status
    print('OK: no metrics defined.')
    warn_value = 0
    crit_value = 0

    exit_code = nagios.OK
    critical = []
    warn = []
    ok = []
    perf_data = []

    for name, data in check_result.items():
        # TODO: figure out status
        if -1 >= crit_value:
            critical.append(name)
            status = '[CRITICAL]'
            exit_code = nagios.CRITICAL
        elif -1 >= warn_value:
            warn.append(name)
            status = '[WARNING]'
            exit_code = nagios.WARNING
        else:
            ok.append(name)
            status = '[OK]'

        perf_data.append(f'\'{name}_rate_in\'={int(data["rate_in"])}B;{warn_value};{crit_value};0;')
        perf_data.append(f'\'{name}_rate_out\'={int(data["rate_out"])}B;{warn_value};{crit_value};0;')
        perf_data.append(f'\'{name}_cumulative_in\'={int(data["cumulative_in"])}B;{warn_value};{crit_value};0;')
        perf_data.append(f'\'{name}_cumulative_out\'={int(data["cumulative_out"])}B;{warn_value};{crit_value};0;')
        perf_data.append(f'\'{name}_connections\'={int(data["connections"])}B;{warn_value};{crit_value};0;')

        output_table = [
            ('Host', 'Interface', 'Rate In', 'Rate Out', 'Cumulative In', 'Cumulative Out', 'Connections', 'Status'),
            (args.host, name, filesize(data['rate_in']), filesize(data['rate_out']), filesize(data['cumulative_in']),
             filesize(data['cumulative_out']), data['connections'], status)
        ]
        print(list_to_markdown_table(output_table, align='left', seperator='!', borders=False))

    print(f'| {" ".join(perf_data)}')
    sys.exit(exit_code)


if __name__ == "__main__":
    try:
        main()
    except Exception as e:
        print(f'UNKNOWN: exception "{e}"')
        print(traceback.format_exc())
        sys.exit(nagios.UNKNOWN)