import { useCallback, useEffect, useMemo, useState } from 'react'
import { api, SmartInfo, StorageDevice } from './api'
import { fmtBytes, fmtRate } from './fmt'
import TaskOutput from './TaskOutput'
import { askText, Btn, Loading, Meter, Spinner, toast } from './ui'
import { useRefreshMs } from './prefs'
import { Sensor, useSensorStream } from './sensors'

const pct = (v: number) => `${Math.round(v)}%`
const KIND: Record<string, string> = { nvme: 'NVMe', ssd: 'SSD', hdd: 'HDD', usb: 'USB', emmc: 'eMMC', sd: 'SD', other: 'disk' }
const hours = (h: number) => (h >= 24 * 365 ? `${(h / 8760).toFixed(1)} y` : h >= 48 ? `${Math.round(h / 24)} d` : `${h} h`)
const ago = (ms: number) => { const s = (Date.now() - ms) / 1000; return s < 3600 ? `${Math.round(s / 60)}m ago` : s < 86400 ? `${Math.round(s / 3600)}h ago` : `${Math.round(s / 86400)}d ago` }


// ---- SMART panel ----
function SmartPanel({ dev, rotational }: { dev: string; rotational: boolean }) {
  const [s, setS] = useState<SmartInfo | null>(null)
  const [err, setErr] = useState('')
  const load = useCallback(async (force = false) => {
    setS(null)
    try { setS(await api.smart(dev, force)); setErr('') } catch (e) { setErr(e instanceof Error ? e.message : 'failed') }
  }, [dev])
  useEffect(() => { load() }, [load])

  if (err) return <div className="error">{err}</div>
  if (!s) return <Loading label="Reading health…" />
  if (!s.available) return <div className="notice">smartmontools isn't installed, so there's no SMART data. Install it from the button above.</div>
  if (s.standby) return <div className="notice">Disk is spun down; SMART wasn't read so it stays asleep. <Btn className="btn" onClick={() => load(true)}>Wake and read</Btn></div>
  if (s.error) return <div className="notice">{s.error}</div>
  const ok = s.passed === true && s.warnings.length === 0
  return (
    <div className="smart">
      <div className="props">
        <div><span className="k">Health</span><span className={ok ? 'good' : 'warn-text'}>{s.passed === null ? 'unknown' : s.passed ? 'PASSED' : 'FAILED'}{s.warnings.length > 0 && ` · ${s.warnings.length} warning${s.warnings.length > 1 ? 's' : ''}`}</span></div>
        {s.temp > 0 && <div><span className="k">Temperature</span><span>{s.temp}°C</span></div>}
        {s.power_on_hours > 0 && <div><span className="k">Powered on</span><span>{hours(s.power_on_hours)} · {s.power_cycles} cycles</span></div>}
        {s.firmware && <div><span className="k">Firmware</span><span className="mono">{s.firmware}</span></div>}
        {s.serial && <div><span className="k">Serial</span><span className="mono">{s.serial}</span></div>}
        {s.self_test && <div><span className="k">Self-test</span><span>{s.self_test}{s.self_test_remaining ? ` (${s.self_test_remaining}% left)` : ''}</span></div>}
        <div><span className="k">Read</span><span className="muted">{ago(s.fetched_at)} <button className="link" onClick={() => load(true)}>refresh</button></span></div>
      </div>
      {s.warnings.length > 0 && <div className="notice attn">{s.warnings.join(' · ')}</div>}
      {s.mmc && (
        <div className="props">
          <div><span className="k">Wear</span><span>{[['A', s.mmc.life_a], ['B', s.mmc.life_b]].filter(([, v]) => v).map(([k, v]) => `type ${k} ${v === 11 ? 'past rated life' : `${(v as number) * 10 - 10}–${(v as number) * 10}% used`}`).join(' · ') || 'not reported'}</span></div>
          <div><span className="k">Reserve</span><span>{['not reported', 'normal', 'warning — 80% of spare blocks used', 'urgent — 90% of spare blocks used'][s.mmc.pre_eol] ?? s.mmc.pre_eol}</span></div>
        </div>
      )}
      {s.nvme && (
        <div className="props">
          <div><span className="k">Endurance</span><span>{s.nvme.percentage_used}% used · spare {s.nvme.available_spare}% (threshold {s.nvme.spare_threshold}%)</span></div>
          <div><span className="k">Written</span><span>{fmtBytes(s.nvme.data_written_bytes)} · read {fmtBytes(s.nvme.data_read_bytes)}</span></div>
          <div><span className="k">Errors</span><span>{s.nvme.media_errors} media · {s.nvme.error_log_entries} logged · {s.nvme.unsafe_shutdowns} unsafe shutdowns</span></div>
        </div>
      )}
      {s.attrs.length > 0 && (
        <div className="attrs-wrap">
        <table className="attrs">
          <thead><tr><th>ID</th><th>Attribute</th><th>Raw</th><th>Value</th><th>Worst</th><th>Thresh</th></tr></thead>
          <tbody>
            {s.attrs.map((a) => (
              <tr key={a.id} className={a.warn ? 'warn' : ''}>
                <td className="num">{a.id}</td><td>{a.name.replace(/_/g, ' ')}{a.failed && <span className="badge bad">{a.failed}</span>}</td>
                <td className="num raw">{a.raw}</td><td className="num">{a.value}</td><td className="num">{a.worst}</td><td className="num">{a.thresh}</td>
              </tr>
            ))}
          </tbody>
        </table>
        </div>
      )}
      {!s.self_test_supported && <div className="muted small">Self-tests: {s.self_test_note || 'not available on this drive'}.</div>}
      {s.self_test_supported && <div className="svc-actions">
        <Btn className="btn" confirm={`Start a short self-test on ${dev}?`} onClick={async () => { if (await api.smartTest(dev, 'short').then(() => true, (e) => { toast(String(e.message ?? e), 'err'); return false })) { toast('short test started'); load(true) } }}>Short test</Btn>
        <Btn className="btn" confirm={`Start a long self-test on ${dev}? ${rotational ? 'This can take hours on a spinning disk.' : ''}`} onClick={async () => { if (await api.smartTest(dev, 'long').then(() => true, (e) => { toast(String(e.message ?? e), 'err'); return false })) { toast('long test started'); load(true) } }}>Long test</Btn>
      </div>}
    </div>
  )
}

// ---- device card ----
function DeviceCard({ d, live, forceOpen }: { d: StorageDevice; live?: { read_bps: number; write_bps: number; util_pct: number }; forceOpen: boolean | null }) {
  const [own, setOwn] = useState(false)
  const open = forceOpen ?? own
  const setOpen = (v: boolean) => setOwn(v)
  return (
    <section className="card disk">
      <div className="sub-head">
        <span className="badge">{KIND[d.kind] ?? d.kind}</span>
        <span className="dname">{d.name}</span>
        <span className="model">{[d.vendor, d.model].filter(Boolean).join(' ')}</span>
        <span className="spacer" />
        <span className="num">{fmtBytes(d.size)}{d.temp ? ` · ${d.temp.toFixed(0)}°C` : ''}</span>
      </div>
      {live && <div className="sub-head num muted">read {fmtRate(live.read_bps)} · write {fmtRate(live.write_bps)} · {pct(live.util_pct)} busy</div>}
      <div className="muted small disk-summary">
        {d.serial && <span>S/N {d.serial}</span>}
        {d.namespaces && d.namespaces.length > 1 && <span>{d.namespaces.length} namespaces</span>}
        <span>{d.parts.length} partition{d.parts.length === 1 ? '' : 's'}</span>
        {d.parts.filter((p) => p.mount && p.mount !== '[SWAP]').length > 0 && <span>mounted at {d.parts.filter((p) => p.mount && p.mount !== '[SWAP]').map((p) => p.mount).join(', ')}</span>}
        {d.parts.some((p) => p.mount === '[SWAP]') && <span>swap</span>}
      </div>
      {forceOpen === null && <div className="svc-actions"><button className="btn" onClick={() => setOpen(!open)}>{open ? 'Hide SMART' : 'SMART'}</button></div>}
      {open && <SmartPanel dev={d.name} rotational={d.rotational} />}
    </section>
  )
}

// ---- page ----
export default function Disks() {
  const [devs, setDevs] = useState<StorageDevice[] | null>(null)
  const [hasSmart, setHasSmart] = useState(true)
  const [err, setErr] = useState('')
  const [task, setTask] = useState<string | null>(null)
  const [allSmart, setAllSmart] = useState<boolean>(() => localStorage.getItem('hamlab.disks.smart') === '1')
  const rate = useRefreshMs()

  const load = useCallback(async () => {
    try {
      const r = await api.storage()
      setDevs(r.devices); setHasSmart(r.smartctl); setErr('')
    } catch (e) { setErr(e instanceof Error ? e.message : 'failed') }
  }, [])
  useEffect(() => { load() }, [load])
  // Live per-device rates come from the sensor stream, grouped by the kernel name in each sensor's labels.
  const stream = useSensorStream<{ d: Record<string, Sensor> }>({ d: 'disk.*' }, { everyMs: rate })
  const live = useMemo(() => {
    const by: Record<string, { name: string; read_bps: number; write_bps: number; util_pct: number }> = {}
    for (const x of Object.values(stream.data?.d ?? {})) {
      const name = x.labels?.device
      if (!name || typeof x.value !== 'number') continue
      const row = (by[name] ??= { name, read_bps: 0, write_bps: 0, util_pct: 0 })
      if (x.id.endsWith('.read')) row.read_bps = x.value
      else if (x.id.endsWith('.write')) row.write_bps = x.value
      else if (x.id.endsWith('.util')) row.util_pct = x.value
    }
    return { disks: Object.values(by) }
  }, [stream.data])

  if (!devs) return <div className="dash">{err ? <div className="error">{err}</div> : <Loading label="Scanning disks…" />}</div>
  const liveFor = (dev: StorageDevice) => {
    const names = dev.namespaces?.length ? dev.namespaces : [dev.name]
    const rows = (live?.disks ?? []).filter((x) => names.includes(x.name))
    if (rows.length === 0) return undefined
    return { read_bps: rows.reduce((a, x) => a + x.read_bps, 0), write_bps: rows.reduce((a, x) => a + x.write_bps, 0), util_pct: Math.max(...rows.map((x) => x.util_pct)) }
  }

  return (
    <div className="dash disks">
      {err && <div className="error">{err}</div>}
      <div className="dash-bar">
        <h2 className="section">Devices · {devs.length}</h2>
        <span className="spacer" />
        {hasSmart && <button className={'chip' + (allSmart ? ' on' : '')} title="show SMART for every drive" onClick={() => { const v = !allSmart; setAllSmart(v); localStorage.setItem('hamlab.disks.smart', v ? '1' : '0') }}>{allSmart ? 'SMART: all open' : 'SMART: show all'}</button>}
        {!hasSmart && <Btn className="btn" onClick={async () => { try { const t = await api.installPackages(['smartmontools']); setTask(t.id) } catch (e) { toast(e instanceof Error ? e.message : 'failed', 'err') } }}>Install smartmontools</Btn>}
        <Btn className="btn" title="reload" onClick={load}>↻</Btn>
      </div>
      {!hasSmart && <div className="notice">SMART health needs smartmontools on this host. Install it with the button, then reload.</div>}
      {task && <TaskOutput id={task} onDone={(t) => { toast(`${t.title}: ${t.exit_code === 0 ? 'finished' : `exited ${t.exit_code}`}`, t.exit_code === 0 ? 'ok' : 'err'); load() }} />}
      <div className="cards disk-cards">
        {devs.map((d) => <DeviceCard key={d.name} d={d} live={liveFor(d)} forceOpen={allSmart ? true : null} />)}
      </div>

    </div>
  )
}