"use client"

import type { MotionProps } from "motion/react"
import type { CSSProperties, ElementType, JSX } from "react"

import { cn } from "@/lib/utils"
import { motion } from "motion/react"
import { memo, useMemo } from "react"

type MotionHTMLProps = MotionProps & Record<string, unknown>

// Cache motion components at module level to avoid creating during render
const motionComponentCache = new Map<
  keyof JSX.IntrinsicElements,
  React.ComponentType<MotionHTMLProps>
>()

const getMotionComponent = (element: keyof JSX.IntrinsicElements) => {
  let component = motionComponentCache.get(element)
  if (!component) {
    component = motion.create(element)
    motionComponentCache.set(element, component)
  }
  return component
}

export interface TextShimmerProps {
  children: string
  as?: ElementType
  className?: string
  duration?: number
  spread?: number
}

const ShimmerComponent = ({
  children,
  as: Component = "p",
  className,
  duration = 2,
  spread = 2,
}: TextShimmerProps) => {
  const MotionComponent = useMemo(
    () => getMotionComponent(Component as keyof JSX.IntrinsicElements),
    [Component]
  )

  const dynamicSpread = useMemo(
    () => (children?.length ?? 0) * spread,
    [children, spread]
  )

  return (
    // eslint-disable-next-line react-hooks/static-components -- component is cached at module level via motionComponentCache
    <MotionComponent
      animate={{ backgroundPosition: "0% center" }}
      className={cn(
        "relative inline-block bg-[length:250%_100%,auto] bg-clip-text text-transparent",
        "[--bg:linear-gradient(90deg,#0000_calc(50%-var(--spread)),var(--color-background),#0000_calc(50%+var(--spread)))] [background-repeat:no-repeat,padding-box]",
        className
      )}
      initial={{ backgroundPosition: "100% center" }}
      style={
        {
          "--spread": `${dynamicSpread}px`,
          backgroundImage:
            "var(--bg), linear-gradient(var(--color-muted-foreground), var(--color-muted-foreground))",
        } as CSSProperties
      }
      transition={{
        duration,
        ease: "linear",
        repeat: Number.POSITIVE_INFINITY,
      }}
    >
      {children}
    </MotionComponent>
  )
}

export const Shimmer = memo(ShimmerComponent)