/**
 * useDeviceTier — lightweight client-side device capability detection.
 *
 * Returns 'desktop' | 'tablet' | 'mobile' based on viewport width,
 * touch capability, and hardware concurrency. The result is computed
 * once on mount and never changes (no resize listener — the 3D scene
 * should not swap LOD tiers mid-session).
 *
 * Also exports a plain `getDeviceTier()` function for non-React contexts.
 */
import { useMemo } from 'react'

/** Compute device tier from current browser globals. */
export function getDeviceTier() {
  if (typeof window === 'undefined') return 'desktop'

  const w = window.innerWidth
  const hasTouch = navigator.maxTouchPoints > 0
  const cores = navigator.hardwareConcurrency || 4

  // Mobile: narrow viewport OR low-core touch device
  if (w <= 600 || (hasTouch && w <= 768)) return 'mobile'

  // Tablet: mid-width touch device (iPad, Android tablet, etc.)
  if (w <= 1024 && hasTouch) return 'tablet'

  // Low-powered desktops with ≤ 2 cores get tablet-tier rendering
  if (cores <= 2) return 'tablet'

  return 'desktop'
}

/** React hook — memoized once per component lifetime. */
export function useDeviceTier() {
  return useMemo(() => getDeviceTier(), [])
}

export default useDeviceTier