// Smooth scroll for navigation links
function getHeaderHeight() {
    const header = document.querySelector('header');
    return header ? header.offsetHeight : 80;
}

function smoothScrollToSection(hash) {
    const target = document.querySelector(hash);
    if (!target) return;

    // Recalculate header height at the moment of scrolling
    const headerHeight = getHeaderHeight();

    // Use getBoundingClientRect for robust position calc across layouts
    const targetTopRelative = target.getBoundingClientRect().top;
    const absoluteTargetTop = window.scrollY + targetTopRelative;

    // Exact offset: align section start just below the header bottom
    const top = Math.max(absoluteTargetTop - headerHeight, 0);

    window.scrollTo({ top, behavior: 'smooth' });
}

function updateURLHash(hash) {
    // Update URL hash without triggering scroll
    if (hash && hash !== '#') {
        history.pushState(null, null, hash);
    }
}

function scrollToTop() {
    // Remove hash from URL and scroll to top
    history.pushState(null, null, window.location.pathname);
    window.scrollTo({ top: 0, behavior: 'smooth' });
}

document.querySelectorAll('nav a[href^="#"]').forEach(anchor => {
    anchor.addEventListener('click', function (e) {
        e.preventDefault();

        // If mobile menu is open, close it first so header height is correct
        const siteNavEl = document.getElementById('site-nav');
        const menuBtn = document.getElementById('menu-toggle');
        const wasOpen = siteNavEl && siteNavEl.classList.contains('open');
        if (wasOpen) {
            siteNavEl.classList.remove('open');
            if (menuBtn) menuBtn.setAttribute('aria-expanded', 'false');
            // Wait for next frame so layout updates and header height is correct
            requestAnimationFrame(() => {
                smoothScrollToSection(this.getAttribute('href'));
                updateURLHash(this.getAttribute('href'));
            });
        } else {
            smoothScrollToSection(this.getAttribute('href'));
            updateURLHash(this.getAttribute('href'));
        }
    });
});

// Add active class to navigation based on scroll position
const sections = document.querySelectorAll('section[id]');
const navLinks = document.querySelectorAll('nav a');

function setActiveNav() {
    let current = '';
    const headerHeight = getHeaderHeight();
    
    sections.forEach(section => {
        const sectionTop = section.offsetTop;
        const sectionHeight = section.clientHeight;
        // Account for fixed header in active link detection
        if (window.scrollY + headerHeight + 30 >= sectionTop && window.scrollY < sectionTop + sectionHeight) {
            current = section.getAttribute('id');
        }
    });
    
    navLinks.forEach(link => {
        link.classList.remove('active');
        if (link.getAttribute('href') === `#${current}`) {
            link.classList.add('active');
        }
    });
}

window.addEventListener('scroll', setActiveNav);
window.addEventListener('load', setActiveNav);

// Adjust on resize (header height can change)
window.addEventListener('resize', () => {
    // Re-run active link calculation to keep alignment correct
    setActiveNav();
});

// Handle direct hash navigation (e.g., page load with #section)
window.addEventListener('load', () => {
    if (location.hash) {
        // Use the same precise scroll logic on initial load
        smoothScrollToSection(location.hash);
    }
});

// Lightbox for screenshots (desktop only behavior)
const lightbox = document.getElementById('lightbox');
const lightboxImg = document.getElementById('lightbox-image');
const lightboxCaption = document.getElementById('lightbox-caption');

function openLightbox(src, caption) {
    if (!lightbox) return;
    lightboxImg.src = src;
    lightboxCaption.textContent = caption || '';
    lightbox.setAttribute('aria-hidden', 'false');
    document.body.style.overflow = 'hidden';
}

function closeLightbox() {
    if (!lightbox) return;
    lightbox.setAttribute('aria-hidden', 'true');
    lightboxImg.src = '';
    document.body.style.overflow = '';
}

// Delegate clicks on screenshots
document.addEventListener('click', (e) => {
    const img = e.target.closest('.screenshot img');
    if (img) {
        // Only open overlay on wider screens
        if (window.innerWidth >= 768) {
            openLightbox(img.src, img.alt || img.nextElementSibling?.textContent || '');
            e.preventDefault();
        }
    }

    if (e.target.matches('[data-close]')) {
        closeLightbox();
    }
});

// Close on ESC
window.addEventListener('keydown', (e) => {
    if (e.key === 'Escape') closeLightbox();
});

// Mobile burger menu
const menuToggle = document.getElementById('menu-toggle');
const siteNav = document.getElementById('site-nav');
if (menuToggle && siteNav) {
    menuToggle.addEventListener('click', () => {
        const isOpen = siteNav.classList.toggle('open');
        menuToggle.setAttribute('aria-expanded', isOpen ? 'true' : 'false');
    });

    // Close menu after navigating
    siteNav.querySelectorAll('a').forEach(link => {
        link.addEventListener('click', () => {
            if (siteNav.classList.contains('open')) {
                siteNav.classList.remove('open');
                menuToggle.setAttribute('aria-expanded', 'false');
            }
        });
    });
}

// Handle SPORE title click to scroll to top and remove hash
const sporeTitle = document.querySelector('.brand h1');
if (sporeTitle) {
    sporeTitle.addEventListener('click', scrollToTop);
    sporeTitle.style.cursor = 'pointer';
}