#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""Ping every collected switch's management IP in parallel.
Zabbix host -> switch latency is the only latency that can be measured without
touching device config, so this is what drives the node latency colouring.
Writes /tmp/latency.tsv  ->  <ip>\\t<avg_ms or empty>
"""
import json
import re
import subprocess
import concurrent.futures as cf
import urllib.request

import l2cfg

TOK = 'd3abb125eb301a021ef80a2847a803a7cd2d0b1d3c8337a14d09db9d571369b5'
API = 'http://192.168.87.20:8080/api_jsonrpc.php'
OUT = '/tmp/latency.tsv'


def call(m, p):
    d = json.dumps({"jsonrpc": "2.0", "method": m, "params": p, "id": 1}).encode()
    q = urllib.request.Request(API, data=d, headers={'Content-Type': 'application/json', 'Authorization': 'Bearer ' + TOK})
    return json.loads(urllib.request.urlopen(q, timeout=60).read().decode())


def ping(ip):
    try:
        r = subprocess.run(['ping', '-c', '3', '-W', '1', '-q', ip],
                           capture_output=True, text=True, timeout=10)
        m = re.search(r'=\s*[\d.]+/([\d.]+)/', r.stdout)
        if m:
            return ip, float(m.group(1))
        m = re.search(r'time=([\d.]+)\s*ms', r.stdout)
        if m:
            return ip, float(m.group(1))
    except Exception:
        pass
    return ip, None


def main():
    hs = l2cfg.hosts(call)
    ips = sorted({i['ip'] for h in hs for i in (h.get('interfaces') or [])
                  if i.get('ip') and i.get('type') == '2'})
    if not ips:
        ips = sorted({i['ip'] for h in hs for i in (h.get('interfaces') or []) if i.get('ip')})
    res = {}
    with cf.ThreadPoolExecutor(max_workers=40) as ex:
        for ip, v in ex.map(ping, ips):
            res[ip] = v
    with open(OUT, 'w', encoding='utf-8') as f:
        for ip in ips:
            v = res.get(ip)
            f.write('%s\t%s\n' % (ip, '' if v is None else '%.3f' % v))
    ok = sum(1 for v in res.values() if v is not None)
    print('latency: %d/%d reachable' % (ok, len(ips)))


if __name__ == '__main__':
    main()