'use strict';

document.addEventListener('DOMContentLoaded', () => {

  const prefersReducedMotion = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

  // ─── Particles ───────────────────────────────────────────
  if (!prefersReducedMotion) {
    const canvas = document.getElementById('particles-canvas');
    const ctx = canvas.getContext('2d');
    let particles = [];
    let animId;
    let mouseX = -1000;
    let mouseY = -1000;

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

    function createParticles(count) {
      particles = [];
      for (let i = 0; i < count; i++) {
        particles.push({
          x: Math.random() * canvas.width,
          y: Math.random() * canvas.height,
          vx: (Math.random() - 0.5) * 0.8,
          vy: (Math.random() - 0.5) * 0.8,
          size: Math.random() * 2.5 + 0.5,
          opacity: Math.random() * 0.5 + 0.2,
        });
      }
    }

    function drawParticles() {
      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;

        const dx = p.x - mouseX;
        const dy = p.y - mouseY;
        const dist = Math.sqrt(dx * dx + dy * dy);
        if (dist < 120) {
          p.vx += dx * 0.0005;
          p.vy += dy * 0.0005;
          const maxSpeed = 2;
          const speed = Math.sqrt(p.vx * p.vx + p.vy * p.vy);
          if (speed > maxSpeed) {
            p.vx = (p.vx / speed) * maxSpeed;
            p.vy = (p.vy / speed) * maxSpeed;
          }
        }

        ctx.beginPath();
        ctx.arc(p.x, p.y, p.size, 0, Math.PI * 2);
        ctx.fillStyle = `rgba(124, 58, 237, ${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(6, 182, 212, ${0.12 * (1 - dist / 150)})`;
            ctx.lineWidth = 0.8;
            ctx.stroke();
          }
        }
      }

      animId = requestAnimationFrame(drawParticles);
    }

    function initParticles() {
      resizeCanvas();
      const count = Math.min(Math.floor((canvas.width * canvas.height) / 12000), 120);
      createParticles(count);
      drawParticles();
    }

    window.addEventListener('resize', () => {
      resizeCanvas();
      createParticles(Math.min(Math.floor((canvas.width * canvas.height) / 12000), 120));
    });

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

    document.addEventListener('touchmove', (e) => {
      const touch = e.touches[0];
      mouseX = touch.clientX;
      mouseY = touch.clientY;
    });

    initParticles();
  }

  // ─── Typewriter ─────────────────────────────────────────
  const typewriterEl = document.querySelector('.typewriter');
  if (typewriterEl) {
    const text = typewriterEl.dataset.text || '';
    const speed = 60;
    let charIndex = 0;
    let isDeleting = false;
    const cursor = document.createElement('span');
    cursor.className = 'cursor';
    cursor.setAttribute('aria-hidden', 'true');
    typewriterEl.appendChild(cursor);

    // clear initial content
    typewriterEl.childNodes.forEach((node, i) => {
      if (node.nodeType === Node.TEXT_NODE) node.textContent = '';
    });

    function typeStep() {
      if (!isDeleting) {
        if (charIndex < text.length) {
          typewriterEl.textContent = text.slice(0, charIndex + 1);
          typewriterEl.appendChild(cursor);
          charIndex++;
          setTimeout(typeStep, speed);
        } else {
          if (!prefersReducedMotion) {
            setTimeout(() => { isDeleting = true; typeStep(); }, 3000);
          }
        }
      } else {
        if (charIndex > 0) {
          charIndex--;
          typewriterEl.textContent = text.slice(0, charIndex);
          typewriterEl.appendChild(cursor);
          setTimeout(typeStep, speed * 0.6);
        } else {
          isDeleting = false;
          setTimeout(typeStep, 1000);
        }
      }
    }

    typeStep();
  }

  // ─── Navbar scroll effect ───────────────────────────────
  const navbar = document.querySelector('.navbar');
  let lastScroll = 0;

  function handleNavScroll() {
    const currentScroll = window.scrollY;
    if (currentScroll > 50) {
      navbar.classList.add('scrolled');
    } else {
      navbar.classList.remove('scrolled');
    }
    lastScroll = currentScroll;
  }

  window.addEventListener('scroll', handleNavScroll, { passive: true });

  // ─── Hamburger menu ─────────────────────────────────────
  const hamburger = document.querySelector('.hamburger');
  const navLinks = document.querySelector('.nav-links');

  function toggleMenu() {
    const isOpen = navLinks.classList.toggle('open');
    hamburger.classList.toggle('active');
    hamburger.setAttribute('aria-expanded', isOpen);
    document.body.style.overflow = isOpen ? 'hidden' : '';
  }

  if (hamburger) {
    hamburger.addEventListener('click', toggleMenu);
  }

  // close menu on link click
  document.querySelectorAll('.nav-links a').forEach(link => {
    link.addEventListener('click', () => {
      if (navLinks.classList.contains('open')) {
        toggleMenu();
      }
    });
  });

  // close menu on escape
  document.addEventListener('keydown', (e) => {
    if (e.key === 'Escape' && navLinks.classList.contains('open')) {
      toggleMenu();
    }
  });

  // ─── Active nav link ────────────────────────────────────
  const sections = document.querySelectorAll('section[id]');
  const navAnchors = document.querySelectorAll('.nav-links a');

  function updateActiveLink() {
    let current = '';
    sections.forEach(section => {
      const top = section.offsetTop - 120;
      if (window.scrollY >= top) {
        current = section.getAttribute('id');
      }
    });
    navAnchors.forEach(a => {
      a.classList.toggle('active', a.getAttribute('href') === `#${current}`);
    });
  }

  window.addEventListener('scroll', updateActiveLink, { passive: true });

  // ─── Scroll Reveal (IntersectionObserver) ───────────────
  if (!prefersReducedMotion) {
    const revealObserver = new IntersectionObserver((entries) => {
      entries.forEach(entry => {
        if (entry.isIntersecting) {
          entry.target.classList.add('visible');
        }
      });
    }, { threshold: 0.15, rootMargin: '0px 0px -50px 0px' });

    document.querySelectorAll('.reveal').forEach(el => revealObserver.observe(el));
  } else {
    document.querySelectorAll('.reveal').forEach(el => el.classList.add('visible'));
  }

  // ─── Counter Animation ──────────────────────────────────
  const counters = document.querySelectorAll('.stat-number');

  function animateCounter(el) {
    const target = parseInt(el.dataset.target, 10);
    const suffix = el.dataset.suffix || '';
    const duration = 2000;
    const startTime = performance.now();

    function update(currentTime) {
      const elapsed = currentTime - startTime;
      const progress = Math.min(elapsed / duration, 1);
      const eased = 1 - Math.pow(1 - progress, 3);
      const current = Math.floor(eased * target);
      el.textContent = current + suffix;
      if (progress < 1) {
        requestAnimationFrame(update);
      } else {
        el.textContent = target + suffix;
      }
    }

    requestAnimationFrame(update);
  }

  if (!prefersReducedMotion) {
    const counterObserver = new IntersectionObserver((entries) => {
      entries.forEach(entry => {
        if (entry.isIntersecting) {
          const counter = entry.target;
          animateCounter(counter);
          counterObserver.unobserve(counter);
        }
      });
    }, { threshold: 0.5 });

    counters.forEach(c => counterObserver.observe(c));
  } else {
    counters.forEach(c => {
      c.textContent = c.dataset.target + (c.dataset.suffix || '');
    });
  }

  // ─── Service cards staggered reveal ─────────────────────
  if (!prefersReducedMotion) {
    const cardObserver = new IntersectionObserver((entries) => {
      entries.forEach(entry => {
        if (entry.isIntersecting) {
          const delay = parseInt(entry.target.dataset.delay || '0', 10);
          setTimeout(() => {
            entry.target.classList.add('visible');
          }, delay);
          cardObserver.unobserve(entry.target);
        }
      });
    }, { threshold: 0.2 });

    document.querySelectorAll('.service-card.reveal, .stat-item.reveal, .proyecto-card.reveal').forEach(
      el => cardObserver.observe(el)
    );
  }

  // ─── Smooth scroll for anchor links (fallback) ──────────
  document.querySelectorAll('a[href^="#"]').forEach(anchor => {
    anchor.addEventListener('click', (e) => {
      const targetId = anchor.getAttribute('href');
      if (targetId === '#') return;
      const target = document.querySelector(targetId);
      if (target) {
        e.preventDefault();
        target.scrollIntoView({ behavior: 'smooth', block: 'start' });
      }
    });
  });
});