"use client";

import { useEffect, useRef, useCallback, useState } from "react";
import Link from "next/link";
import gsap from "gsap";

function useGridSize() {
  const [gridSize, setGridSize] = useState({ cols: 20, rows: 12 });

  useEffect(() => {
    const updateGridSize = () => {
      const width = window.innerWidth;
      if (width < 640) {
        // Mobile
        setGridSize({ cols: 8, rows: 10 });
      } else if (width < 1024) {
        // Tablet
        setGridSize({ cols: 12, rows: 10 });
      } else {
        // Desktop
        setGridSize({ cols: 20, rows: 12 });
      }
    };

    updateGridSize();
    window.addEventListener("resize", updateGridSize);
    return () => window.removeEventListener("resize", updateGridSize);
  }, []);

  return gridSize;
}

function TileGrid() {
  const gridRef = useRef<HTMLDivElement>(null);
  const tilesRef = useRef<(HTMLDivElement | null)[]>([]);
  const { cols, rows } = useGridSize();

  const handleMouseEnter = useCallback((index: number) => {
    const tile = tilesRef.current[index];
    if (tile) {
      gsap.killTweensOf(tile);
      gsap.to(tile, {
        rotateY: 180,
        duration: 0.5,
        ease: "power2.inOut",
        overwrite: true,
      });
    }
  }, []);

  const handleMouseLeave = useCallback((index: number) => {
    const tile = tilesRef.current[index];
    if (tile) {
      gsap.killTweensOf(tile);
      gsap.to(tile, {
        rotateY: 0,
        duration: 0.5,
        ease: "power2.inOut",
        overwrite: true,
      });
    }
  }, []);

  // Reset refs array when grid size changes
  useEffect(() => {
    tilesRef.current = [];
  }, [cols, rows]);

  return (
    <div
      ref={gridRef}
      className="absolute inset-0 grid z-0"
      style={{
        gridTemplateColumns: `repeat(${cols}, 1fr)`,
        gridTemplateRows: `repeat(${rows}, 1fr)`,
      }}
    >
      {Array.from({ length: cols * rows }).map((_, index) => (
        <div
          key={index}
          onMouseEnter={() => handleMouseEnter(index)}
          onMouseLeave={() => handleMouseLeave(index)}
          className="cursor-pointer"
          style={{ perspective: "500px" }}
        >
          <div
            ref={(el) => { tilesRef.current[index] = el; }}
            className="w-full h-full relative"
            style={{ 
              transformStyle: "preserve-3d",
              willChange: "transform",
            }}
          >
            {/* Front - Black */}
            <div
              className="absolute inset-0 bg-black border border-zinc-900"
              style={{ backfaceVisibility: "hidden" }}
            />
            {/* Back - White */}
            <div
              className="absolute inset-0 bg-white"
              style={{
                backfaceVisibility: "hidden",
                transform: "rotateY(180deg)",
              }}
            />
          </div>
        </div>
      ))}
    </div>
  );
}

export default function Hero() {
  const headingRef = useRef<HTMLHeadingElement>(null);
  const contentRef = useRef<HTMLDivElement>(null);

  useEffect(() => {
    // Animate heading on mount
    if (headingRef.current) {
      gsap.fromTo(
        headingRef.current,
        { opacity: 0, y: 50 },
        { opacity: 1, y: 0, duration: 1, ease: "power3.out", delay: 0.3 }
      );
    }

    if (contentRef.current) {
      gsap.fromTo(
        contentRef.current.children,
        { opacity: 0, y: 30 },
        { opacity: 1, y: 0, duration: 0.8, stagger: 0.15, ease: "power3.out", delay: 0.5 }
      );
    }
  }, []);

  return (
    <section className="relative min-h-screen bg-black overflow-hidden pt-28">
      {/* Tile Grid Background */}
      <TileGrid />

      <div className="relative max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 h-full pointer-events-none">
        <div className="flex items-center justify-center min-h-[calc(100vh-12rem)] pb-20">
          {/* Center Content */}
          <div className="text-center relative z-10">
            <div className="inline-flex items-center gap-2 bg-lime-400 text-black px-5 py-2.5 text-xs font-bold tracking-widest rounded-full mb-10 pointer-events-auto">
              <span className="w-2 h-2 bg-black rounded-full animate-pulse" />
              FEBRUARY 2026
            </div>

            <h1
              ref={headingRef}
              className="text-6xl sm:text-7xl lg:text-8xl xl:text-9xl font-black tracking-tighter text-white leading-[0.85] mb-8"
              style={{
                WebkitTextStroke: "2px black",
                paintOrder: "stroke fill",
              }}
            >
              <span className="block">UNLEASH</span>
              <span 
                className="block text-lime-400 drop-shadow-[0_0_30px_rgba(163,230,53,0.5)]"
                style={{
                  WebkitTextStroke: "2px black",
                  paintOrder: "stroke fill",
                }}
              >
                YOUR ART
              </span>
            </h1>

            <div ref={contentRef}>
              <p className="text-zinc-300 text-base sm:text-lg max-w-lg mx-auto mb-10 leading-relaxed font-light drop-shadow-[0_2px_4px_rgba(0,0,0,0.8)]">
                From canvas to screen, showcase your creativity and let your
                artwork speak to the world.
              </p>

              <div className="flex flex-col sm:flex-row gap-4 justify-center pointer-events-auto mb-12">
                <Link
                  href="/register"
                  className="inline-flex items-center justify-center gap-2 bg-lime-400 text-black px-10 py-4 text-sm font-bold tracking-wider hover:bg-lime-300 transition-all hover:scale-105 rounded-full shadow-[0_0_30px_rgba(163,230,53,0.3)]"
                >
                  JOIN COMPETITION
                </Link>
                <Link
                  href="/gallery"
                  className="inline-flex items-center justify-center gap-2 bg-transparent text-white px-10 py-4 text-sm font-bold tracking-wider hover:bg-white/10 transition-all rounded-full border border-zinc-700 hover:border-zinc-500"
                >
                  EXPLORE GALLERY
                </Link>
              </div>

              {/* Scroll Indicator */}
              <div className="flex flex-col items-center gap-2">
                <span className="text-lime-400 text-[10px] tracking-[0.3em] uppercase drop-shadow-[0_0_10px_rgba(163,230,53,0.8)]">Scroll</span>
                <div className="w-px h-8 bg-gradient-to-b from-lime-400 to-transparent shadow-[0_0_10px_rgba(163,230,53,0.5)]" />
              </div>
            </div>
          </div>
        </div>
      </div>

      {/* Bottom Marquee */}
      <div className="absolute bottom-0 left-0 right-0 bg-lime-400 text-black py-3 overflow-hidden z-10">
        <div className="animate-marquee-slow whitespace-nowrap flex items-center">
          {Array(8)
            .fill(null)
            .map((_, i) => (
              <div key={i} className="flex items-center">
                <span className="text-xl sm:text-2xl font-black tracking-tight mx-6 uppercase">
                  ArtSplash
                </span>
                <span className="text-black/40 mx-4">✦</span>
                <span className="text-xl sm:text-2xl font-black tracking-tight mx-6 uppercase text-black/60">
                  SJEC
                </span>
                <span className="text-black/40 mx-4">✦</span>
                <span className="text-xl sm:text-2xl font-black tracking-tight mx-6 uppercase">
                  2026
                </span>
                <span className="text-black/40 mx-4">✦</span>
              </div>
            ))}
        </div>
      </div>
    </section>
  );
}