// Visual effects: particles, cursor, matrix rain, etc.
import { DOM } from './dom.js';

// Particle class for managing individual particles
class Particle {
  constructor(x, y) {
    this.x = x;
    this.y = y;
    this.size = Math.random() * 3 + 1;
    this.speedY = Math.random() * 1 + 0.5;
    this.speedX = (Math.random() - 0.5) * 0.5;
    this.opacity = 1;
  }

  update() {
    this.y += this.speedY;
    this.x += this.speedX;
    this.opacity -= 0.01;
  }

  draw(ctx) {
    ctx.fillStyle = `rgba(0, 122, 204, ${this.opacity})`;
    ctx.beginPath();
    ctx.arc(this.x, this.y, this.size, 0, Math.PI * 2);
    ctx.fill();
  }
}

// Add mouse trail effect with falling particles
export function addMouseTrail() {
  const canvas = document.createElement('canvas');
  const ctx = canvas.getContext('2d');
  document.body.appendChild(canvas);

  canvas.style.position = 'fixed';
  canvas.style.top = '0';
  canvas.style.left = '0';
  canvas.style.pointerEvents = 'none';
  canvas.style.zIndex = '1000';

  function resizeCanvas() {
    canvas.width = window.innerWidth;
    canvas.height = window.innerHeight;
  }

  window.addEventListener('resize', resizeCanvas);
  resizeCanvas();

  let particles = [];
  let mouseX = 0;
  let mouseY = 0;

  document.addEventListener('mousemove', (e) => {
    mouseX = e.clientX;
    mouseY = e.clientY;

    if (Math.random() > 0.5) {
      particles.push(new Particle(mouseX, mouseY));
    }
  });

  function animate() {
    ctx.clearRect(0, 0, canvas.width, canvas.height);

    particles = particles.filter((particle) => {
      particle.update();
      particle.draw(ctx);
      return (
        particle.opacity > 0 &&
        particle.y < canvas.height &&
        particle.x > 0 &&
        particle.x < canvas.width
      );
    });

    requestAnimationFrame(animate);
  }

  animate();
}

// Matrix Rain Effect
export function addMatrixRain() {
  const canvas = document.createElement('canvas');
  const ctx = canvas.getContext('2d');

  canvas.style.position = 'fixed';
  canvas.style.top = '0';
  canvas.style.left = '0';
  canvas.style.width = '100%';
  canvas.style.height = '100%';
  canvas.style.pointerEvents = 'none';
  canvas.style.zIndex = '-1';
  canvas.style.opacity = '0.1';

  document.body.appendChild(canvas);

  canvas.width = window.innerWidth;
  canvas.height = window.innerHeight;

  const matrix = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ123456789@#$%^&*()*&^%+-/~{[|`]}';
  const matrixArray = matrix.split('');

  const font_size = 10;
  const columns = canvas.width / font_size;

  const drops = [];
  for (let x = 0; x < columns; x++) {
    drops[x] = 1;
  }

  function drawMatrix() {
    ctx.fillStyle = 'rgba(0, 0, 0, 0.04)';
    ctx.fillRect(0, 0, canvas.width, canvas.height);

    ctx.fillStyle = '#007acc';
    ctx.font = font_size + 'px arial';

    for (let i = 0; i < drops.length; i++) {
      const text = matrixArray[Math.floor(Math.random() * matrixArray.length)];
      ctx.fillText(text, i * font_size, drops[i] * font_size);

      if (drops[i] * font_size > canvas.height && Math.random() > 0.975) {
        drops[i] = 0;
      }
      drops[i]++;
    }
  }

  setInterval(drawMatrix, 35);

  window.addEventListener('resize', () => {
    canvas.width = window.innerWidth;
    canvas.height = window.innerHeight;
  });
}

// Custom Cursor
export function addCustomCursor() {
  const cursor = document.createElement('div');
  cursor.className = 'custom-cursor';
  document.body.appendChild(cursor);

  const trail = document.createElement('div');
  trail.className = 'custom-cursor-trail';
  document.body.appendChild(trail);

  let mouseX = 0,
    mouseY = 0;
  let trailX = 0,
    trailY = 0;

  document.addEventListener('mousemove', (e) => {
    mouseX = e.clientX;
    mouseY = e.clientY;

    cursor.style.left = mouseX - 10 + 'px';
    cursor.style.top = mouseY - 10 + 'px';
  });

  function animateTrail() {
    trailX += (mouseX - trailX) * 0.1;
    trailY += (mouseY - trailY) * 0.1;

    trail.style.left = trailX - 4 + 'px';
    trail.style.top = trailY - 4 + 'px';

    requestAnimationFrame(animateTrail);
  }
  animateTrail();

  const interactiveElements = DOM.getAll('a, button, .avatar, .brand-name');

  interactiveElements.forEach((el) => {
    el.addEventListener('mouseenter', () => {
      cursor.style.transform = 'scale(2)';
      cursor.style.background =
        'radial-gradient(circle, rgba(255, 107, 107, 0.8) 0%, rgba(255, 107, 107, 0.4) 50%, transparent 100%)';
    });

    el.addEventListener('mouseleave', () => {
      cursor.style.transform = 'scale(1)';
      cursor.style.background =
        'radial-gradient(circle, rgba(0, 122, 204, 0.8) 0%, rgba(0, 122, 204, 0.4) 50%, transparent 100%)';
    });
  });
}

// Interactive Background
export function addInteractiveBackground() {
  const canvas = document.createElement('canvas');
  canvas.style.position = 'fixed';
  canvas.style.top = '0';
  canvas.style.left = '0';
  canvas.style.width = '100%';
  canvas.style.height = '100%';
  canvas.style.pointerEvents = 'none';
  canvas.style.zIndex = '-2';
  canvas.style.opacity = '0.3';

  document.body.appendChild(canvas);

  const ctx = canvas.getContext('2d');
  canvas.width = window.innerWidth;
  canvas.height = window.innerHeight;

  const particles = [];
  const particleCount = 50;

  class BgParticle {
    constructor() {
      this.x = Math.random() * canvas.width;
      this.y = Math.random() * canvas.height;
      this.vx = (Math.random() - 0.5) * 2;
      this.vy = (Math.random() - 0.5) * 2;
      this.size = Math.random() * 3 + 1;
      this.opacity = Math.random() * 0.5 + 0.2;
    }

    update() {
      this.x += this.vx;
      this.y += this.vy;

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

    draw() {
      ctx.beginPath();
      ctx.arc(this.x, this.y, this.size, 0, Math.PI * 2);
      ctx.fillStyle = `rgba(0, 122, 204, ${this.opacity})`;
      ctx.fill();
    }
  }

  for (let i = 0; i < particleCount; i++) {
    particles.push(new BgParticle());
  }

  function animate() {
    ctx.clearRect(0, 0, canvas.width, canvas.height);

    particles.forEach((particle) => {
      particle.update();
      particle.draw();
    });

    // Draw connections
    particles.forEach((particle, i) => {
      particles.slice(i + 1).forEach((otherParticle) => {
        const dx = particle.x - otherParticle.x;
        const dy = particle.y - otherParticle.y;
        const distance = Math.sqrt(dx * dx + dy * dy);

        if (distance < 100) {
          ctx.beginPath();
          ctx.moveTo(particle.x, particle.y);
          ctx.lineTo(otherParticle.x, otherParticle.y);
          ctx.strokeStyle = `rgba(0, 122, 204, ${0.1 * (1 - distance / 100)})`;
          ctx.lineWidth = 1;
          ctx.stroke();
        }
      });
    });

    requestAnimationFrame(animate);
  }

  animate();

  window.addEventListener('resize', () => {
    canvas.width = window.innerWidth;
    canvas.height = window.innerHeight;
  });
}