"use client";

import { useEffect, useRef } from "react";

interface Particle {
  x: number;
  y: number;
  vx: number;
  vy: number;
  size: number;
  opacity: number;
}

export function ParticleBg() {
  const canvasRef = useRef<HTMLCanvasElement>(null);

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

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

    let animationId: number;
    const particles: Particle[] = [];
    const particleCount = 60;

    const resize = () => {
      canvas.width = window.innerWidth;
      canvas.height = window.innerHeight;
    };

    const createParticle = (): Particle => ({
      x: Math.random() * canvas.width,
      y: Math.random() * canvas.height,
      vx: (Math.random() - 0.5) * 0.3,
      vy: (Math.random() - 0.5) * 0.3,
      size: Math.random() * 1.5 + 0.5,
      opacity: Math.random() * 0.3 + 0.1,
    });

    const init = () => {
      resize();
      particles.length = 0;
      for (let i = 0; i < particleCount; i++) {
        particles.push(createParticle());
      }
    };

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

      for (const p of particles) {
        p.x += p.vx;
        p.y += p.vy;

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

        ctx.beginPath();
        ctx.arc(p.x, p.y, p.size, 0, Math.PI * 2);
        ctx.fillStyle = `rgba(0, 240, 255, ${p.opacity})`;
        ctx.fill();
      }

      // Draw connections
      for (let i = 0; i < particles.length; i++) {
        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 dist = Math.sqrt(dx * dx + dy * dy);

          if (dist < 150) {
            ctx.beginPath();
            ctx.moveTo(particles[i].x, particles[i].y);
            ctx.lineTo(particles[j].x, particles[j].y);
            ctx.strokeStyle = `rgba(0, 240, 255, ${0.05 * (1 - dist / 150)})`;
            ctx.lineWidth = 0.5;
            ctx.stroke();
          }
        }
      }

      animationId = requestAnimationFrame(animate);
    };

    init();
    animate();
    window.addEventListener("resize", resize);

    return () => {
      cancelAnimationFrame(animationId);
      window.removeEventListener("resize", resize);
    };
  }, []);

  return (
    <canvas
      ref={canvasRef}
      className="pointer-events-none fixed inset-0 z-0"
      style={{ opacity: 0.6 }}
    />
  );
}
