// The graphical console of a VM: spice-html5 (vendored, loaded on demand) drawing the SPICE
// stream that Ham Lab bridges from Incus into a canvas. Used for installers from an ISO, and
// anything else with a screen rather than a serial line.
import { useEffect, useRef, useState } from 'react'
import { wsURLPath } from './api'
import { Btn, useEscape } from './ui'
// No spice.css: upstream's stylesheet is for its own demo page and sets body, *, button and
// canvas for the whole document. Imported here it restyled every button in Ham Lab. The
// console is styled by the .vga rules in styles.css.

type Spice = typeof import('./vendor/spice-html5/src/main.js')

export default function VgaConsole({ name, onClose }: { name: string; onClose: () => void }) {
  const [state, setState] = useState<'loading' | 'connecting' | 'connected' | 'error'>('loading')
  const [err, setErr] = useState('')
  const [fit, setFit] = useState(true)
  const [size, setSize] = useState('')
  const conn = useRef<InstanceType<Spice['SpiceMainConn']> | null>(null)
  const mod = useRef<Spice | null>(null)
  const area = useRef<HTMLDivElement>(null)
  const screen = useRef<HTMLDivElement>(null)
  useEscape(onClose)

  useEffect(() => {
    let dead = false
    import('./vendor/spice-html5/src/main.js').then((m) => {
      if (dead) return
      mod.current = m
      setState('connecting')
      try {
        conn.current = new m.SpiceMainConn({
          uri: wsURLPath(`/api/virt/instances/${encodeURIComponent(name)}/vga`),
          screen_id: 'spice-screen', message_id: 'spice-message',
          onerror: (e) => { setState('error'); setErr(e instanceof Error ? e.message : (e as Event & { reason?: string })?.reason || 'the console closed') },
          onsuccess: () => setState('connected'),
          onagent: () => { try { m.handle_resize() } catch { /* no agent in the guest yet */ } },
        })
      } catch (e) { setState('error'); setErr(String(e)) }
    }).catch((e) => { setState('error'); setErr('could not load the SPICE viewer: ' + String(e)) })
    return () => { dead = true; try { conn.current?.stop() } catch { /* already gone */ } conn.current = null }
  }, [name])

  // The guest draws at its own resolution; scale the canvas to the pane unless asked not to.
  useEffect(() => {
    const a = area.current, s = screen.current
    if (!a || !s) return
    const apply = () => {
      const c = s.querySelector('canvas')
      if (!c) return
      setSize(`${c.width}×${c.height}`)
      c.tabIndex = 1
      if (!fit) { s.style.transform = ''; s.style.width = ''; s.style.height = ''; return }
      const k = Math.min(1, (a.clientWidth - 8) / c.width, (a.clientHeight - 8) / c.height)
      s.style.transformOrigin = 'top left'
      s.style.transform = `scale(${k})`
      s.style.width = `${c.width}px`; s.style.height = `${c.height}px`
    }
    apply()
    const ro = new ResizeObserver(apply); ro.observe(a)
    const mo = new MutationObserver(apply); mo.observe(s, { childList: true, attributes: true, subtree: true, attributeFilter: ['width', 'height'] })
    return () => { ro.disconnect(); mo.disconnect() }
  }, [fit, state])

  const cad = () => { if (conn.current && mod.current) mod.current.sendCtrlAltDel(conn.current) }
  const focus = () => screen.current?.querySelector('canvas')?.focus()
  return (
    <div className="modal-back vga-back" onClick={onClose}>
      <div className="vga" onClick={(e) => e.stopPropagation()}>
        <div className="logs-bar vga-bar">
          <span className={'dot ' + (state === 'connected' ? 'ok' : state === 'error' ? 'bad' : 'warn')} />
          <span className="dname">{name}</span>
          <span className="muted small">{state === 'connected' ? `VGA · ${size || 'waiting for the first frame'}` : state === 'error' ? err : state === 'loading' ? 'loading the viewer…' : 'connecting…'}</span>
          <span className="spacer" />
          <Btn className="btn" disabled={state !== 'connected'} onClick={cad} title="send Ctrl+Alt+Del to the guest">Ctrl+Alt+Del</Btn>
          <button className={'btn' + (fit ? ' on' : '')} onClick={() => setFit(!fit)} title="scale the screen to this window, or show it pixel for pixel">Fit</button>
          <button className="btn" onClick={onClose}>Close</button>
        </div>
        <div className="vga-area" ref={area} onClick={focus}>
          <div id="spice-area"><div id="spice-screen" ref={screen} /></div>
          <div id="spice-message" className="spice-message vga-msg" />
        </div>
        <div className="muted small vga-hint">Click the screen to type into it. Keys go to the guest while it has focus; Escape with focus elsewhere closes this.</div>
      </div>
    </div>
  )
}