import { useCallback, useEffect, useRef, useState } from 'react'
import { api, Me, Term } from './api'
import Rail, { Group } from './Rail'
import TerminalPane, { TermHandle } from './TerminalPane'
import KeyBar from './KeyBar'
import Dashboard from './Dashboard'
import Services from './Services'
import Cron from './Cron'
import Updates from './Updates'
import Disks from './Disks'
import Files from './Files'
import Power from './Power'
import { Btn, NetBar, Toasts, toast } from './ui'

// Inline outline icon so it matches the monochrome glyphs in the rail (emoji would be full colour).
const FolderIcon = (
  <svg viewBox="0 0 16 16" width="14" height="14" fill="none" stroke="currentColor" strokeWidth="1.6" strokeLinejoin="round" aria-hidden="true">
    <path d="M1.5 4a1 1 0 0 1 1-1h3.2l1.6 1.6h6.2a1 1 0 0 1 1 1V12a1 1 0 0 1-1 1h-11a1 1 0 0 1-1-1V4z" />
  </svg>
)

const GROUPS: Group[] = [
  { id: 'dashboard', label: 'Dashboard', icon: '◔', page: true },
  { id: 'terminal', label: 'Terminal', icon: '>_' },
  { id: 'services', label: 'Services', icon: '⚙', page: true },
  { id: 'cron', label: 'Cron', icon: '⏱', page: true },
  { id: 'updates', label: 'Updates', icon: '⇪', page: true },
  { id: 'disks', label: 'Disks', icon: '▤', page: true },
  { id: 'files', label: 'Files', icon: FolderIcon, page: true },
]

type View = 'terminal' | 'dashboard' | 'services' | 'cron' | 'updates' | 'disks' | 'files'

function fmtUptime(s: number): string {
  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`
}

export default function Shell({ me, onLoggedOut }: { me: Me; onLoggedOut: () => void }) {
  const [terms, setTerms] = useState<Term[]>([])
  const [active, setActive] = useState<string | null>(null)
  const [view, setView] = useState<View>('dashboard')
  const [drawer, setDrawer] = useState(false)
  const [online, setOnline] = useState(true)
  const [creating, setCreating] = useState(false)
  const handles = useRef<Record<string, TermHandle>>({})

  const reload = useCallback(async () => {
    const list = await api.terminals()
    setTerms(list)
    setActive((a) => (a && list.some((t) => t.id === a) ? a : list[0]?.id ?? null))
  }, [])

  useEffect(() => { reload() }, [reload])

  async function create() {
    setCreating(true)
    try {
      const t = await api.createTerminal()
      await reload()
      setActive(t.id)
      setView('terminal')
      setDrawer(false)
    } catch (e) { toast(`new terminal — ${e instanceof Error ? e.message : 'failed'}`, 'err') }
    finally { setCreating(false) }
  }
  async function rename(t: Term) {
    const name = window.prompt('Rename terminal', t.name)
    if (name && name.trim() && name !== t.name) {
      try { await api.renameTerminal(t.id, name.trim()); await reload() } catch (e) { toast(`rename — ${e instanceof Error ? e.message : 'failed'}`, 'err') }
    }
  }
  async function close(t: Term) {
    if (t.running && !window.confirm(`Close "${t.name}"? The shell will be hung up.`)) return
    try { await api.deleteTerminal(t.id); delete handles.current[t.id]; await reload() }
    catch (e) { toast(`close — ${e instanceof Error ? e.message : 'failed'}`, 'err') }
  }
  async function logout() { await api.logout(); onLoggedOut() }

  // Files → "open in terminal": type into the active shell (creating one if needed) and switch to it.
  async function runInTerminal(cmd: string) {
    let id = active
    if (!id || !terms.some((t) => t.id === id && t.running)) {
      try { const t = await api.createTerminal(); await reload(); id = t.id; setActive(t.id) } catch (e) { toast(`terminal — ${e instanceof Error ? e.message : 'failed'}`, 'err'); return }
    }
    setView('terminal'); setDrawer(false)
    const send = (tries: number) => { const h = handles.current[id!]; if (h) h.input(cmd + '\n'); else if (tries > 0) window.setTimeout(() => send(tries - 1), 100) }
    window.setTimeout(() => send(20), 50)
  }

  const activeTerm = terms.find((t) => t.id === active)
  const termView = view === 'terminal'

  return (
    <div className={'app' + (drawer ? ' drawer-open' : '')}>
      <NetBar />
      <Toasts />
      <header className="header">
        <button className="icon-btn menu" onClick={() => setDrawer(!drawer)} aria-label="menu">☰</button>
        <span className="brand">Ham Lab</span>
        <span className="host">{me.user}@{me.host}</span>
        <span className="spacer" />
        <span className="stat" title="load average">{me.load}</span>
        <span className={'dot ' + (online ? 'ok' : 'bad')} title={online ? 'connected' : 'disconnected'} />
        <Power host={me.host} rebootNeeded={me.reboot_needed} />
        <Btn className="link" onClick={logout}>logout</Btn>
      </header>

      <div className="body">
        <Rail groups={GROUPS} terms={terms} active={active} view={view} creating={creating}
          onSelect={(id) => { setActive(id); setView('terminal'); setDrawer(false) }}
          onView={(id) => { setView(id as View); setDrawer(false) }}
          onNew={create} onRename={rename} onClose={close} />
        <div className="backdrop" onClick={() => setDrawer(false)} />

        <main className="main">
          {view === 'dashboard' && <Dashboard />}
          {view === 'services' && <Services />}
          {view === 'cron' && <Cron />}
          {view === 'updates' && <Updates />}
          {view === 'disks' && <Disks />}
          {view === 'files' && <Files onOpenInTerminal={runInTerminal} />}
          {termView && terms.length === 0 && (
            <div className="center muted">
              <div>No terminals.</div>
              <Btn className="primary" busy={creating} onClick={create}>+ New Terminal</Btn>
            </div>
          )}
          {terms.map((t) => (
            <TerminalPane key={t.id} id={t.id} active={termView && t.id === active}
              register={(h) => { if (h) handles.current[t.id] = h; else delete handles.current[t.id] }}
              onStatus={(ok) => { if (t.id === active) setOnline(ok) }}
              onExit={reload} />
          ))}
        </main>
      </div>

      {termView && activeTerm && <KeyBar send={(s) => handles.current[activeTerm.id]?.input(s)}
        setCtrl={(v) => handles.current[activeTerm.id]?.armCtrl(v)} />}

      <footer className="footer">
        <span>{me.version.startsWith('v') ? me.version : 'v' + me.version}</span>
        <span>up {fmtUptime(me.uptime)}</span>
        <span className="spacer" />
        <span className="muted">{view === 'dashboard' ? 'Dashboard' : view === 'services' ? 'Services' : view === 'cron' ? 'Cron' : view === 'updates' ? 'Updates' : view === 'disks' ? 'Disks' : view === 'files' ? 'Files' : activeTerm ? activeTerm.name : ''}</span>
      </footer>
    </div>
  )
}