import { useEffect, useRef, useState } from 'react';

export default function ParticleNetwork() {
  const canvasRef = useRef<HTMLCanvasElement>(null);
  const [isMobile, setIsMobile] = useState(false);

  useEffect(() => {
    const isMobileDevice = ('ontouchstart' in window) || (navigator.maxTouchPoints > 0) || window.innerWidth < 768;
    setIsMobile(isMobileDevice);
    if (isMobileDevice) return;

    const canvas = canvasRef.current;
    if (!canvas) return;

    const ctx = canvas.getContext('2d');
    if (!ctx) return;

    let animationFrameId: number;
    let particles: Particle[] = [];
    
    const particleCount = 40;
    const connectionDistance = 180;
    const mouseRadius = 120;

    const mouse = {
      x: -1000,
      y: -1000,
    };

    class Particle {
      x: number;
      y: number;
      vx: number;
      vy: number;
      size: number;

      constructor(width: number, height: number) {
        this.x = Math.random() * width;
        this.y = Math.random() * height;
        this.vx = (Math.random() - 0.5) * 0.3;
        this.vy = (Math.random() - 0.5) * 0.3;
        this.size = Math.random() * 2 + 1;
      }

      update(width: number, height: number) {
        this.x += this.vx;
        this.y += this.vy;

        if (this.x < 0 || this.x > width) this.vx *= -1;
        if (this.y < 0 || this.y > height) this.vy *= -1;

        // Interaction with mouse
        const dx = mouse.x - this.x;
        const dy = mouse.y - this.y;
        const distance = Math.sqrt(dx * dx + dy * dy);

        if (distance < mouseRadius) {
          const force = (mouseRadius - distance) / mouseRadius;
          this.x -= dx * force * 0.02;
          this.y -= dy * force * 0.02;
        }
      }

      draw() {
        if (!ctx) return;
        ctx.beginPath();
        ctx.arc(this.x, this.y, this.size, 0, Math.PI * 2);
        ctx.fillStyle = 'rgba(255, 255, 255, 0.15)';
        ctx.fill();
      }
    }

    const init = () => {
      canvas.width = window.innerWidth;
      canvas.height = window.innerHeight;
      particles = [];
      for (let i = 0; i < particleCount; i++) {
        particles.push(new Particle(canvas.width, canvas.height));
      }
    };

    const animate = () => {
      ctx.clearRect(0, 0, canvas.width, canvas.height);

      for (let i = 0; i < particles.length; i++) {
        particles[i].update(canvas.width, canvas.height);
        particles[i].draw();

        for (let j = i + 1; j < particles.length; j++) {
          const dx = particles[i].x - particles[j].x;
          const dy = particles[i].y - particles[j].y;
          const distance = Math.sqrt(dx * dx + dy * dy);

          if (distance < connectionDistance) {
            ctx.beginPath();
            ctx.moveTo(particles[i].x, particles[i].y);
            ctx.lineTo(particles[j].x, particles[j].y);
            ctx.strokeStyle = `rgba(255, 255, 255, ${0.1 * (1 - distance / connectionDistance)})`;
            ctx.lineWidth = 0.5;
            ctx.stroke();
          }
        }
      }

      animationFrameId = requestAnimationFrame(animate);
    };

    const handleMouseMove = (e: MouseEvent) => {
      mouse.x = e.clientX;
      mouse.y = e.clientY;
    };

    let resizeTimeout: NodeJS.Timeout;
    const handleResize = () => {
      clearTimeout(resizeTimeout);
      resizeTimeout = setTimeout(() => {
        init();
      }, 150);
    };

    window.addEventListener('mousemove', handleMouseMove);
    window.addEventListener('resize', handleResize);

    init();
    animate();

    return () => {
      window.removeEventListener('mousemove', handleMouseMove);
      window.removeEventListener('resize', handleResize);
      clearTimeout(resizeTimeout);
      cancelAnimationFrame(animationFrameId);
    };
  }, []);

  if (isMobile) return null;

  return (
    <canvas
      ref={canvasRef}
      className="fixed inset-0 w-full h-full pointer-events-none z-0"
      style={{ opacity: 0.8 }}
    />
  );
}