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

import psutil

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

parser = argparse.ArgumentParser(description='Check network interface bandwidth utilization.')
parser.add_argument('--bandwidth', type=float, required=True, help='Bandwidth speed in Mbps. Used to calculate percentage.')
parser.add_argument('--critical', type=int, default=75, help='Critical if percent of bandwidth usage is greater than or equal to this.')
parser.add_argument('--warn', type=int, default=50, help='Warning if percent of bandwidth usage is greater than or equal to this.')
parser.add_argument('--max', type=int, default=None, help='Set the max value the bandwidth can be. Useful for graphs and whatever.')
parser.add_argument('--ignore', default=None, help='Interface names to ignore.')
args = parser.parse_args()

ignore_interfaces = args.ignore.split(',') if args.ignore else []

def main():
    data = []
    warn_value = (args.bandwidth * args.warn / 100)
    crit_value = (args.bandwidth * args.critical / 100)

    # Get network interface statistics
    net_io_counters = psutil.net_io_counters(pernic=True)

    # Calculate bandwidth utilization for each interface
    for interface, stats in net_io_counters.items():
        if interface in ignore_interfaces:
            continue
        # Get the number of bytes sent and received
        bytes_sent = stats.bytes_sent
        bytes_recv = stats.bytes_recv

        # Wait for 1 second
        psutil.cpu_percent(interval=1)

        # Get the number of bytes sent and received after 1 second
        new_stats = psutil.net_io_counters(pernic=True)[interface]
        new_bytes_sent = new_stats.bytes_sent
        new_bytes_recv = new_stats.bytes_recv

        # Calculate the bandwidth utilization in bits per second
        bandwidth_utilization = (8 * (new_bytes_sent - bytes_sent + new_bytes_recv - bytes_recv)) / (1 * 1000 * 1000)
        data.append([interface, bandwidth_utilization, 'none'])

    exit_code = nagios.OK
    critical = []
    warn = []
    ok = []
    perf_data = []
    for i in range(len(data)):
        interface = data[i][0]
        bandwidth_utilization = data[i][1]
        if bandwidth_utilization >= crit_value:
            critical.append(interface)
            state = 'critical'
            exit_code = nagios.CRITICAL
        elif bandwidth_utilization >= warn_value:
            warn.append(interface)
            state = 'warning'
            if exit_code < nagios.WARNING:
                exit_code = nagios.WARNING
        else:
            ok.append(interface)
            state = 'ok'
        data[i][2] = f'[{state.upper()}]'
        perf_data.append(f'{interface}={round(bandwidth_utilization, 2)}MB;{warn_value};{crit_value};{f"0;{args.max};" if args.max else ""} ')

    if len(ok):
        print(f'OK: {", ".join(ok)}')
    if len(warn):
        print(f'WARNING: {", ".join(warn)}')
    if len(critical):
        print(f'CRITICAL: {", ".join(critical)}')

    data = [(x[0], f'{round(x[1], 2)} Mbps', x[2]) for x in data]
    data.insert(0, ('Interface', 'Bandwidth', 'State'))
    print(list_to_markdown_table(data, 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)