Momento/memento-note/components/brainstorm/ghost-cursor.tsx

'use client'

import React, { useEffect, useRef } from 'react'

interface GhostCursorProps {
  isActive: boolean
  containerRef: React.RefObject<HTMLDivElement | null>
  targetId?: string | null
}

export function GhostCursor({ isActive, containerRef, targetId }: GhostCursorProps) {
  const elRef = useRef<HTMLDivElement>(null)
  const rafRef = useRef<number | null>(null)
  const posRef = useRef<{ x: number; y: number; visible: boolean }>({ x: 0, y: 0, visible: false })
  const targetIdRef = useRef(targetId)
  targetIdRef.current = targetId
  const isActiveRef = useRef(isActive)
  isActiveRef.current = isActive

  useEffect(() => {
    if (!isActive) {
      posRef.current.visible = false
      if (elRef.current) elRef.current.style.opacity = '0'
      if (rafRef.current) cancelAnimationFrame(rafRef.current)
      return
    }

    let lastMove = 0
    const MOVE_INTERVAL = 120

    const tick = () => {
      if (!isActiveRef.current) return

      const now = performance.now()
      if (now - lastMove < MOVE_INTERVAL) {
        rafRef.current = requestAnimationFrame(tick)
        return
      }
      lastMove = now

      const container = containerRef.current
      if (!container) { rafRef.current = requestAnimationFrame(tick); return }
      const containerRect = container.getBoundingClientRect()
      if (containerRect.width === 0 || containerRect.height === 0) { rafRef.current = requestAnimationFrame(tick); return }

      const currentTargetId = targetIdRef.current
      let tx: number | null = null
      let ty: number | null = null

      if (currentTargetId) {
        const nodeElement = container.querySelector(`[data-id="${currentTargetId}"]`) as HTMLElement | null
        if (nodeElement) {
          const nodeRect = nodeElement.getBoundingClientRect()
          tx = nodeRect.left - containerRect.left + nodeRect.width / 2
          ty = nodeRect.top - containerRect.top + nodeRect.height / 2
        }
      }

      if (tx === null || ty === null) {
        if (posRef.current.visible) {
          posRef.current.visible = false
          if (elRef.current) elRef.current.style.opacity = '0'
        }
        rafRef.current = requestAnimationFrame(tick)
        return
      }

      const pos = posRef.current
      const speed = 0.15
      const newX = pos.x + (tx - pos.x) * speed
      const newY = pos.y + (ty - pos.y) * speed

      if (!pos.visible) {
        pos.x = tx
        pos.y = ty
        pos.visible = true
        if (elRef.current) {
          elRef.current.style.opacity = '1'
          elRef.current.style.transform = `translate(${tx}px, ${ty}px)`
        }
      } else {
        pos.x = isNaN(newX) ? tx : newX
        pos.y = isNaN(newY) ? ty : newY
        if (elRef.current) {
          elRef.current.style.transform = `translate(${pos.x}px, ${pos.y}px)`
        }
      }

      rafRef.current = requestAnimationFrame(tick)
    }

    rafRef.current = requestAnimationFrame(tick)

    return () => {
      if (rafRef.current) cancelAnimationFrame(rafRef.current)
    }
  }, [isActive, containerRef])

  return (
    <div
      ref={elRef}
      className="absolute pointer-events-none z-50"
      style={{
        left: 0,
        top: 0,
        opacity: 0,
        transition: 'opacity 0.4s ease, transform 0.15s ease-out',
      }}
    >
      <div className="relative">
        <svg width="16" height="16" viewBox="0 0 16 16" fill="none">
          <path d="M0 0L16 6L8 8L6 16L0 0Z" fill="#a78bfa" />
        </svg>
        <div className="absolute -top-1 -right-1 w-3 h-3">
          <span className="relative inline-flex rounded-full h-3 w-3 bg-violet-500" />
        </div>
        <div className="mt-3 ml-3 px-2 py-0.5 rounded-full text-[10px] font-bold text-white whitespace-nowrap shadow-lg bg-gradient-to-r from-violet-500 to-purple-600">
          AI
        </div>
      </div>
    </div>
  )
}