(function() {
  'use strict';

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

  // Header scroll effect
  const header = document.querySelector('.header');
  let ticking = false;

  function updateHeader() {
    const scrollY = window.scrollY;
    if (scrollY > 50) {
      header.style.boxShadow = '0 2px 16px rgba(10, 22, 40, 0.1)';
    } else {
      header.style.boxShadow = 'none';
    }
    ticking = false;
  }

  window.addEventListener('scroll', function() {
    if (!ticking) {
      requestAnimationFrame(updateHeader);
      ticking = true;
    }
  }, { passive: true });

  // Form handling with validation
  const form = document.getElementById('contactForm');
  const formSuccess = document.getElementById('formSuccess');

  function validateField(field) {
    const value = field.value.trim();
    let isValid = true;

    if (field.hasAttribute('required') && !value) {
      isValid = false;
    }

    if (field.type === 'tel' && value) {
      // Israeli phone number validation (basic)
      const phonePattern = /^0[0-9]{8,9}$/;
      const cleanPhone = value.replace(/[-\s]/g, '');
      isValid = phonePattern.test(cleanPhone);
    }

    if (isValid) {
      field.classList.remove('invalid');
      field.removeAttribute('aria-invalid');
    } else {
      field.classList.add('invalid');
      field.setAttribute('aria-invalid', 'true');
    }

    return isValid;
  }

  if (form) {
    const nameField = form.querySelector('#name');
    const phoneField = form.querySelector('#phone');

    // Validate on blur
    [nameField, phoneField].forEach(function(field) {
      if (field) {
        field.addEventListener('blur', function() {
          validateField(this);
        });

        // Clear error on input
        field.addEventListener('input', function() {
          if (this.classList.contains('invalid')) {
            validateField(this);
          }
        });
      }
    });

    form.addEventListener('submit', function(e) {
      e.preventDefault();
      
      // Validate all required fields
      let isFormValid = true;
      
      if (nameField && !validateField(nameField)) {
        isFormValid = false;
      }
      
      if (phoneField && !validateField(phoneField)) {
        isFormValid = false;
      }

      if (!isFormValid) {
        // Focus first invalid field
        const firstInvalid = form.querySelector('.invalid');
        if (firstInvalid) {
          firstInvalid.focus();
        }
        return;
      }
      
      const submitBtn = form.querySelector('.form-submit');
      const originalText = submitBtn.textContent;
      submitBtn.textContent = 'שולח...';
      submitBtn.disabled = true;
      submitBtn.setAttribute('aria-busy', 'true');
      
      // Simulate submission
      setTimeout(function() {
        submitBtn.textContent = originalText;
        submitBtn.disabled = false;
        submitBtn.removeAttribute('aria-busy');
        formSuccess.hidden = false;
        formSuccess.setAttribute('role', 'alert');
        form.reset();
        
        // Clear any validation states
        form.querySelectorAll('.invalid').forEach(function(el) {
          el.classList.remove('invalid');
          el.removeAttribute('aria-invalid');
        });
        
        setTimeout(function() {
          formSuccess.hidden = true;
        }, 6000);
      }, 1200);
    });
  }

  // Smooth scroll for anchor links
  document.querySelectorAll('a[href^="#"]').forEach(function(anchor) {
    anchor.addEventListener('click', function(e) {
      const href = this.getAttribute('href');
      if (href === '#') return;
      
      const target = document.querySelector(href);
      if (target) {
        e.preventDefault();
        target.scrollIntoView({
          behavior: prefersReducedMotion ? 'auto' : 'smooth',
          block: 'start'
        });
        target.focus({ preventScroll: true });
      }
    });
  });

})();