// Network: how this machine reaches the internet, and how fast the line actually is.
//
// The speed test runs on the machine in the switcher, not in this browser — so it measures
// that machine's line, and it keeps running if the phone is locked or the tab is closed. What
// is drawn here is what the daemon reports about a test it is running itself.
import { useCallback, useEffect, useMemo, useState } from 'react'
import { api, Iface, NetworkInfo, SpeedResult, SpeedRun } from './api'
import { Sensor, fmtValue, useSensorStream } from './sensors'
import { fmtBytes } from './fmt'
import { Btn, Loading, toast } from './ui'
import { useRefreshMs } from './prefs'
import Sparkline from './Sparkline'

// Docker's per-network bridges, and the veth ends inside them, are real interfaces and
// nobody wants to read nineteen of them. They fold away unless asked for.
const scenery = (f: Iface) =>
  !f.default && (/^br-[0-9a-f]{12}$/.test(f.name) || /^(veth|docker)/.test(f.name) || f.kind === 'loopback')

const KIND: Record<string, string> = { ethernet: 'wired', wifi: 'Wi-Fi', bridge: 'bridge', bond: 'bond', loopback: 'loopback', virtual: 'virtual', vlan: 'VLAN', wlan: 'Wi-Fi', wireguard: 'VPN tunnel', none: 'tunnel' }

// A WireGuard interface is listed here because it is an interface and carries traffic, but
// everything about it that is worth knowing — who is on it, when they last spoke — belongs to
// the VPN tab, and is only there.
const isTunnel = (f: Iface) => f.kind === 'wireguard' || /^(wg|tun|tap)[0-9]/.test(f.name)
const goVPN = () => window.dispatchEvent(new CustomEvent('hamlab:view', { detail: 'vpn' }))

// Where the bytes came from. The usual source is anycast and its edge is the interesting
// part; a fallback source is somewhere fixed, and then *which* one is the interesting part,
// because a mirror far away reads low and the figure should not pretend otherwise.
const where = (r: SpeedResult) =>
  r.source && r.source !== 'cloudflare' ? ` from ${r.source}` : r.colo ? ` via ${r.colo}` : ''

// A round number of megabits, which is how a line is sold and how it should be read.
const mbps = (v: number) => (v >= 100 ? v.toFixed(0) : v.toFixed(1))
const ago = (iso: string) => {
  const s = Math.max(0, (Date.now() - new Date(iso).getTime()) / 1000)
  if (s < 60) return 'just now'
  if (s < 3600) return `${Math.floor(s / 60)} min ago`
  if (s < 86400) return `${Math.floor(s / 3600)} h ago`
  return `${Math.floor(s / 86400)} d ago`
}

// The four figures a speed test produces, big enough to read from across the room.
function Figures({ r, live }: { r?: SpeedResult; live?: SpeedRun }) {
  const running = !!live?.running
  const phase = live?.phase
  const downNow = running && phase === 'download' ? live!.mbps : undefined
  const upNow = running && phase === 'upload' ? live!.mbps : undefined
  return (
    <div className="speedgrid">
      <Figure label="Download" unit="Mbps" value={downNow ?? r?.down_mbps} live={downNow !== undefined} waiting={running && phase === 'latency'} />
      <Figure label="Upload" unit="Mbps" value={upNow ?? r?.up_mbps} live={upNow !== undefined} waiting={running && phase !== 'upload'} />
      <Figure label="Latency" unit="ms" value={r?.latency_ms} waiting={running && phase === 'latency'} />
      <Figure label="Jitter" unit="ms" value={r?.jitter_ms} waiting={running && phase === 'latency'} />
    </div>
  )
}

function Figure({ label, unit, value, live, waiting }: { label: string; unit: string; value?: number; live?: boolean; waiting?: boolean }) {
  return (
    <div className={'speedfig' + (live ? ' live' : '')}>
      <div className="label">{label}</div>
      <div className="big">{value === undefined || value === null ? (waiting ? '·' : '—') : mbps(value)}<i>{unit}</i></div>
    </div>
  )
}

export default function Network() {
  const [d, setD] = useState<NetworkInfo | null>(null)
  const [err, setErr] = useState('')
  const [all, setAll] = useState(false)
  const [busy, setBusy] = useState(false)
  const rate = useRefreshMs()
  const load = useCallback(async () => {
    try { setD(await api.network()); setErr('') } catch (e) { setErr(e instanceof Error ? e.message : 'failed') }
  }, [])
  useEffect(() => { load() }, [load])

  const run = d?.run
  const running = !!run?.running
  // While a test is running the state is polled hard, because the needle should move; at rest
  // the page is a read and asks again only now and then.
  useEffect(() => {
    const every = running ? Math.max(400, Math.min(rate, 1000)) : Math.max(5000, rate)
    const t = setInterval(() => {
      if (document.visibilityState !== 'visible') return
      if (running) api.speedtest().then((r) => setD((old) => (old ? { ...old, run: r } : old))).catch(() => {})
      else load()
    }, every)
    return () => clearInterval(t)
  }, [running, rate, load])
  // The run that just ended brings a result and a history entry with it.
  const phase = run?.phase
  useEffect(() => { if (phase === 'done') load() }, [phase, load])

  const live = useSensorStream<{ n: Record<string, Sensor> }>({ n: 'net.*' }, { everyMs: Math.max(1000, rate) })
  const sens = live.data?.n ?? {}
  const rateOf = (name: string, dir: 'rx' | 'tx') => sens[`net.${name.toLowerCase().replace(/[^a-z0-9_-]+/g, '_')}.${dir}`]?.value

  const ifaces = d?.report.ifaces ?? []
  const shown = all ? ifaces : ifaces.filter((f) => !scenery(f))
  const hidden = ifaces.length - shown.length
  const hist = useMemo(() => (d?.history ?? []).filter((r) => !r.error), [d])
  const last = run?.result && !run.result.error ? run.result : hist[hist.length - 1]

  const start = async () => {
    setBusy(true)
    try { const r = await api.startSpeedtest(); setD((old) => (old ? { ...old, run: r } : old)) }
    catch (e) { toast(e instanceof Error ? e.message : 'failed', 'err') }
    finally { setBusy(false) }
  }
  const cancel = async () => {
    try { await api.cancelSpeedtest(); load() } catch (e) { toast(e instanceof Error ? e.message : 'failed', 'err') }
  }

  if (!d) return <div className="dash">{err ? <div className="notice">{err === 'not found' ? "This machine's Ham Lab is older than the Network tab. Update it from Machines." : err}</div> : <Loading label="Reading the network…" />}</div>
  const o = d.outside
  const failed = run?.result?.error

  return (
    <div className="dash net">
      <div className="dash-bar"><h2 className="section">Internet speed</h2><span className="spacer" />
        <span className="muted small">{last ? `measured ${ago(last.at)}` : 'not measured yet'}</span></div>
      <section className="card speedtest">
        <Figures r={last} live={run} />
        {running && (
          <div className="speedbar">
            <div className="meter"><div className="fill" style={{ width: `${Math.round((run!.done || 0) * 100)}%` }} /></div>
            <span className="muted small">{run!.phase === 'latency' ? 'measuring the round trip' : run!.phase === 'download' ? 'pulling down' : 'pushing up'} · {fmtBytes(run!.bytes || 0)} moved</span>
          </div>
        )}
        <div className="svc-actions">
          {running
            ? <><Btn className="btn danger" onClick={cancel}>Stop</Btn><span className="muted small">running on {d.report.host} — it carries on if you close this</span></>
            : <><Btn className="btn on" busy={busy} onClick={start}>Run speed test</Btn>
              <span className="muted small">{last ? `${fmtBytes((last.down_bytes ?? 0) + (last.up_bytes ?? 0))} moved in ${last.took_sec}s${where(last)}` : 'about ten seconds'}</span></>}
        </div>
        {failed && <div className="error">{failed === 'cancelled' ? 'Stopped.' : failed}</div>}
        {!failed && last?.note && <div className="notice">{last.note}</div>}
        <div className="muted small method">{d.method}</div>
      </section>

      {hist.length > 1 && (
        <>
          <div className="dash-bar"><h2 className="section">Past tests</h2><span className="spacer" /><span className="muted small">{hist.length} kept</span></div>
          <section className="card">
            <Sparkline height={60} format={(v) => `${mbps(v)} Mbps`}
              series={[{ name: 'down', values: hist.map((r) => r.down_mbps), color: 'var(--s1)' },
                { name: 'up', values: hist.map((r) => r.up_mbps), color: 'var(--s2)' }]} />
            <div className="props" style={{ marginTop: 8 }}>
              {[...hist].reverse().slice(0, 8).map((r) => (
                <div key={r.at}><span className="k">{new Date(r.at).toLocaleString()}</span>
                  <span className="mono">↓ {mbps(r.down_mbps)} · ↑ {mbps(r.up_mbps)} Mbps · {r.latency_ms} ms</span></div>
              ))}
            </div>
          </section>
        </>
      )}

      <div className="dash-bar"><h2 className="section">Out there</h2></div>
      <section className="card">
        <div className="props">
          <div><span className="k">Public address</span><span className="mono">{o.ip || '—'}{o.error ? ` · ${o.error}` : ''}</span></div>
          {o.colo && <div><span className="k">Reached via</span><span>{o.colo}{o.country ? ` · ${o.country}` : ''}</span></div>}
          {d.report.gateway && <div><span className="k">Gateway</span><span className="mono">{d.report.gateway}{d.report.gateway_via ? ` via ${d.report.gateway_via}` : ''}</span></div>}
          {!!d.report.dns?.length && <div><span className="k">DNS</span><span className="mono">{d.report.dns.join(', ')}</span></div>}
          {!!d.report.search?.length && <div><span className="k">Search</span><span className="mono">{d.report.search.join(' ')}</span></div>}
        </div>
      </section>

      <div className="dash-bar"><h2 className="section">Interfaces</h2><span className="spacer" />
        {hidden > 0 && <button className="link" onClick={() => setAll(true)}>show {hidden} more</button>}
        {all && <button className="link" onClick={() => setAll(false)}>hide the scenery</button>}</div>
      {shown.map((f) => {
        const rx = rateOf(f.name, 'rx'), tx = rateOf(f.name, 'tx')
        return (
          <section className="card iface" key={f.name}>
            <div className="sub-head">
              <span className="dname mono">{f.name}</span>
              {f.default && <span className="badge ok" title="the default route leaves by this one">internet</span>}
              <span className="badge">{KIND[f.kind] ?? f.kind}</span>
              {isTunnel(f) && <button className="link" onClick={goVPN} title="who is on this tunnel">peers →</button>}
              {!f.up ? <span className="badge bad">down</span> : !f.carrier && <span className="badge bad">no link</span>}
              <span className="spacer" />
              <span className="muted small mono">{typeof rx === 'number' ? `↓ ${fmtValue(rx, 'B/s')}` : ''} {typeof tx === 'number' ? `↑ ${fmtValue(tx, 'B/s')}` : ''}</span>
            </div>
            <div className="props">
              {f.addrs.length > 0 && <div><span className="k">Address</span><span className="mono">{f.addrs.filter((a) => !a.v6).map((a) => `${a.ip}/${a.prefix}`).join(', ') || '—'}</span></div>}
              {f.addrs.some((a) => a.v6) && <div><span className="k">IPv6</span><span className="mono" title={f.addrs.filter((a) => a.v6).map((a) => `${a.ip}/${a.prefix}`).join('\n')}>{f.addrs.filter((a) => a.v6).length} addresses</span></div>}
              {!!f.speed_mbps && <div><span className="k">Link</span><span>{f.speed_mbps >= 1000 ? `${f.speed_mbps / 1000} Gbps` : `${f.speed_mbps} Mbps`}{f.duplex ? ` ${f.duplex} duplex` : ''}</span></div>}
              {f.signal_dbm !== undefined && <div><span className="k">Signal</span><span>{f.signal_dbm} dBm</span></div>}
              {f.mac && <div><span className="k">MAC</span><span className="mono">{f.mac}</span></div>}
              <div><span className="k">MTU</span><span>{f.mtu}{f.driver ? ` · ${f.driver}` : ''}</span></div>
              <div><span className="k">Moved</span><span className="mono">↓ {fmtBytes(f.rx_total)} · ↑ {fmtBytes(f.tx_total)}</span></div>
            </div>
          </section>
        )
      })}
    </div>
  )
}