import { FormEvent, useCallback, useEffect, useState } from 'react'
import { api, MachineStatus, Me } from './api'
import { Btn, Loading, askYes, toast } from './ui'
import { LIST_FLOOR, useRefreshMs } from './prefs'
import { ACCENTS, accentFor, getAccents, setAccents } from './accents'

const fmtUptime = (s: number) => { const d = Math.floor(s / 86400), h = Math.floor((s % 86400) / 3600), m = Math.floor((s % 3600) / 60); return d > 0 ? `${d}d ${h}h` : h > 0 ? `${h}h ${m}m` : `${m}m` }
const ago = (iso?: string) => { if (!iso) return 'never'; const s = (Date.now() - Date.parse(iso)) / 1000; return s < 90 ? 'just now' : s < 3600 ? `${Math.round(s / 60)}m ago` : s < 86400 ? `${Math.round(s / 3600)}h ago` : `${Math.round(s / 86400)}d ago` }
const shortFp = (fp?: string) => (fp ? fp.split(':').slice(0, 6).join(':') + '…' : '')

export default function Machines({ hub, onChanged, onOpen }: { hub: Me; onChanged: () => void; onOpen: (name: string) => void }) {
  const [list, setList] = useState<MachineStatus[] | null>(null)
  const [fp, setFp] = useState<string | undefined>()
  const [err, setErr] = useState('')
  const [name, setName] = useState('')
  const [url, setUrl] = useState('https://')
  const [user, setUser] = useState('')
  const [pw, setPw] = useState('')
  const [adding, setAdding] = useState(false)
  const [addErr, setAddErr] = useState('')
  const norm = (v?: string) => (v ?? '').replace(/^v/, '').replace(/-dirty$/, '')
  const outdated = (m: MachineStatus) => m.online && norm(m.version) !== norm(hub.version)

  const load = useCallback(async () => {
    try { const r = await api.machines(); setList(r.nodes); setFp(r.fingerprint); setErr('') } catch (e) { setErr(e instanceof Error ? e.message : 'failed'); setList([]) }
  }, [])
  const rate = useRefreshMs(LIST_FLOOR)
  useEffect(() => { load(); const t = setInterval(load, rate); return () => clearInterval(t) }, [load, rate])

  async function add(e: FormEvent) {
    e.preventDefault()
    setAdding(true); setAddErr('')
    try {
      const st = await api.addMachine(name.trim().toLowerCase(), url.trim(), user.trim(), pw)
      toast(`${st.name} added${st.online ? ` · ${st.host} v${st.version}` : ' (offline)'}`)
      setName(''); setUrl('https://'); setUser(''); setPw('')
      await load(); onChanged()
    } catch (e) { setAddErr(e instanceof Error ? e.message : 'failed') }
    finally { setAdding(false) }
  }
  async function update(m: MachineStatus) {
    if (!await askYes(`Update ${m.name} to ${norm(hub.version)}? Its Ham Lab restarts; open terminals there are lost.`)) return
    try { const r = await api.updateMachine(m.name); toast(`${m.name} updated to ${r.version}, restarting`); setTimeout(load, 4000) }
    catch (e) {
      const msg = e instanceof Error ? e.message : 'failed'
      if (msg.startsWith('busy:') && await askYes(`${m.name} is ${msg.slice(6)}\n\nForce the update anyway?`)) {
        try { const r = await api.updateMachine(m.name, true); toast(`${m.name} updated to ${r.version}, restarting`); setTimeout(load, 4000) } catch (e2) { toast(`${m.name}: ${e2 instanceof Error ? e2.message : 'failed'}`, 'err') }
      } else toast(`${m.name}: ${msg}`, 'err')
    }
  }
  async function updateAll() {
    const n = list?.filter(outdated).length ?? 0
    if (!await askYes(`Update ${n} machine${n === 1 ? '' : 's'} to ${norm(hub.version)}?`)) return
    try {
      let res = await api.updateAllMachines()
      const busy = res.filter((r) => !r.ok && (r.error ?? '').startsWith('busy:'))
      if (busy.length && await askYes(`${busy.map((r) => r.name).join(', ')}: ${busy[0].error?.slice(6)}\n\nForce those too?`)) res = res.map((r) => r).concat(await api.updateAllMachines(true))
      for (const r of res) toast(r.ok ? `${r.name} → ${r.version}` : `${r.name}: ${r.error}`, r.ok ? 'ok' : 'err')
      setTimeout(load, 4000)
    } catch (e) { toast(e instanceof Error ? e.message : 'failed', 'err') }
  }
  async function remove(m: MachineStatus) {
    if (!await askYes(`Remove ${m.name}? Its access token will be revoked. Nothing on ${m.name} itself is changed.`)) return
    try { await api.removeMachine(m.name); toast(`${m.name} removed`); await load(); onChanged() } catch (e) { toast(e instanceof Error ? e.message : 'failed', 'err') }
  }

  if (!list) return <div className="dash">{err ? <div className="error">{err}</div> : <Loading label="Loading machines…" />}</div>
  return (
    <div className="dash machines">
      <div className="dash-bar"><h2 className="section">This host</h2></div>
      <section className="card">
        <div className="sub-head"><span className="dot ok" /><span className="dname" style={{ color: accentFor(hub.host) }}>{hub.host}</span><span className="badge">hub</span><span className="spacer" /><span className="num muted">v{hub.version.replace(/^v/, '')} · up {fmtUptime(hub.uptime)}</span></div>
        <div className="muted small">{fp ? <>Certificate <span className="mono">{fp}</span></> : 'Serving plain HTTP (behind a reverse proxy). Set "tls": "auto" in config.json for a self-signed certificate if another hub should manage this host.'}</div>
        <Swatches name={hub.host} />
      </section>

      <div className="dash-bar"><h2 className="section">Managed machines · {list.length}</h2><span className="spacer" />{list.some(outdated) && <Btn className="btn on" onClick={updateAll}>Update {list.filter(outdated).length} outdated</Btn>}</div>
      {err && <div className="error">{err}</div>}
      {list.length === 0 && <div className="notice">No machines yet. Install Ham Lab on another host, set its password, then add it below.</div>}
      <div className="cards">
        {list.map((m) => (
          <section className="card" key={m.name}>
            <div className="sub-head">
              <span className={'dot ' + (m.online ? 'ok' : 'bad')} />
              <span className="dname" style={{ color: accentFor(m.name) }}>{m.host || m.name}</span>
              <span className="muted small mono">{m.url}</span>
              <span className="spacer" />
              {m.reboot_needed && <span className="badge" title="reboot required">⟳</span>}
              {outdated(m) && <span className="badge bad" title={`running ${norm(m.version)}, hub has ${norm(hub.version)}`}>outdated</span>}
            </div>
            <div className="props">
              <div><span className="k">Status</span><span className={m.online ? 'good' : 'warn-text'}>{m.online ? 'online' : m.error || 'offline'}</span></div>
              {/* the name it was added under is its identity here: it is what Remove, Update and the URL use */}
              <div><span className="k">Added as</span><span className="mono">{m.name}{m.host && m.host !== m.name ? ' · renamed itself since' : ''}</span></div>
              {m.version && <div><span className="k">Version</span><span>v{m.version.replace(/^v/, '')}</span></div>}
              {m.online && <div><span className="k">Load</span><span>{m.load} · up {fmtUptime(m.uptime ?? 0)}</span></div>}
              <div><span className="k">Seen</span><span>{ago(m.last_seen)}</span></div>
              {m.fingerprint && <div><span className="k">Cert</span><span className="mono" title={m.fingerprint}>{shortFp(m.fingerprint)}</span></div>}
              <div><span className="k">Added</span><span>{new Date(m.added).toLocaleDateString()}</span></div>
            </div>
            <Swatches name={m.name} />
            <div className="svc-actions">
              <button className="btn on" disabled={!m.online} onClick={() => onOpen(m.name)}>Open</button>
              {outdated(m) && <Btn className="btn" onClick={() => update(m)}>Update</Btn>}
              <Btn className="btn danger" onClick={() => remove(m)}>Remove</Btn>
            </div>
          </section>
        ))}
      </div>

      <div className="dash-bar"><h2 className="section">Add a machine</h2></div>
      <form className="card addform" onSubmit={add}>
        <label>Name <input value={name} onChange={(e) => setName(e.target.value)} placeholder="grid" pattern="[a-z0-9][a-z0-9_\-]*" title="lower-case letters, digits, - and _" required /></label>
        <label>Address <input value={url} onChange={(e) => setUrl(e.target.value)} placeholder="https://10.0.0.214:8100" required /></label>
        <label>A user on it <input value={user} onChange={(e) => setUser(e.target.value)} placeholder="core" autoComplete="off" spellCheck={false} autoCapitalize="off" /></label>
        <label>Their password <input type="password" value={pw} onChange={(e) => setPw(e.target.value)} autoComplete="off" required /></label>
        {addErr && <div className="error">{addErr}</div>}
        <div className="svc-actions">
          <button className="btn on" disabled={adding || !name || !pw}>{adding ? 'Pairing…' : 'Add machine'}</button>
          <span className="muted small">The password is used once to obtain an access token and is not stored. The user may be left blank on a machine with a single account. The machine's certificate is pinned on first contact.</span>
        </div>
      </form>
    </div>
  )
}

// The colour a machine wears in the header stripe and the switcher: ten to tap, or any other.
export function Swatches({ name }: { name: string }) {
  const [, bump] = useState(0)
  const cur = accentFor(name)
  const pick = (c: string) => { setAccents({ ...getAccents(), [name]: c }); bump((n) => n + 1) }
  return (
    <div className="swatches" title={`${name}'s colour — it marks the header whenever you are on this machine`}>
      {ACCENTS.map((c) => <button key={c} className={'swatch' + (c.toLowerCase() === cur.toLowerCase() ? ' on' : '')} style={{ background: c }} aria-label={c} onClick={() => pick(c)} />)}
      <input type="color" value={cur} onChange={(e) => pick(e.target.value)} aria-label="another colour" />
    </div>
  )
}