// ─── Scroll reveal ─────────────────────────────────────────
const reveals = document.querySelectorAll('.reveal');
const observer = new IntersectionObserver((entries) => {
    entries.forEach(e => {
        if (e.isIntersecting) {
            e.target.classList.add('visible');
            observer.unobserve(e.target);
        }
    });
}, {threshold: 0.1, rootMargin: '0px 0px -40px 0px'});
reveals.forEach(el => observer.observe(el));

// ─── Active nav link on scroll ──────────────────────────────
const sections = document.querySelectorAll('section[id]');
const navLinks = document.querySelectorAll('.nav-links a');
window.addEventListener('scroll', () => {
    let current = '';
    sections.forEach(s => {
        if (window.scrollY >= s.offsetTop - 120) current = s.id;
    });
    navLinks.forEach(a => {
        a.style.color = a.getAttribute('href') === `#${current}` ? 'var(--mauve)' : '';
    });
});

// ─── Project filters ──────────────────────────────────────────────
const filterChips = document.querySelectorAll('.filter-chip');
const projectCards = document.querySelectorAll('#project-grid .project-card');
const seeMoreButton = document.querySelector('#projects-see-more');
const DEFAULT_VISIBLE_PROJECTS = 9;

if (filterChips.length > 0 && projectCards.length > 0) {
    let selectedFilter = 'all';
    let isExpanded = false;
    const interactiveSelector = 'a, button, input, textarea, select, summary, [role="button"]';

    const goToCardHref = (card, event) => {
        const href = card.dataset.href;
        if (!href) {
            return;
        }

        const openInNewTab = event.metaKey || event.ctrlKey || event.button === 1;
        if (openInNewTab) {
            window.open(href, '_blank', 'noopener');
            return;
        }

        globalThis.location.href = href;
    };

    const applyFilter = () => {
        const visibleCards = [];

        projectCards.forEach(card => {
            const tech = (card.dataset.tech || '').split(/\s+/).filter(Boolean);
            const shouldShow = selectedFilter === 'all' || tech.includes(selectedFilter);
            card.classList.toggle('is-hidden', !shouldShow);

            if (shouldShow) {
                card.classList.remove('is-collapsed');
                visibleCards.push(card);
            }
        });

        if (!isExpanded) {
            visibleCards.slice(DEFAULT_VISIBLE_PROJECTS).forEach(card => {
                card.classList.add('is-collapsed');
            });
        }

        if (seeMoreButton) {
            const canExpand = visibleCards.length > DEFAULT_VISIBLE_PROJECTS;
            seeMoreButton.hidden = !canExpand;
            seeMoreButton.setAttribute('aria-expanded', canExpand && isExpanded ? 'true' : 'false');
            seeMoreButton.textContent = isExpanded ? 'See less' : 'See more';
        }
    };

    filterChips.forEach(chip => {
        chip.addEventListener('click', () => {
            selectedFilter = chip.dataset.filter || 'all';
            isExpanded = false;

            filterChips.forEach(other => {
                other.classList.toggle('active', other === chip);
            });

            applyFilter();
        });
    });

    if (seeMoreButton) {
        seeMoreButton.addEventListener('click', () => {
            isExpanded = !isExpanded;
            applyFilter();
        });
    }

    projectCards.forEach(card => {
        if (!card.dataset.href) {
            return;
        }

        card.setAttribute('role', 'link');
        card.setAttribute('tabindex', '0');

        card.addEventListener('click', event => {
            const target = event.target;
            if (!(target instanceof Element)) {
                return;
            }

            // Let inline links and other controls inside the card handle their own clicks.
            if (target.closest(interactiveSelector) && target.closest(interactiveSelector) !== card) {
                return;
            }

            goToCardHref(card, event);
        });

        card.addEventListener('keydown', event => {
            if (event.key !== 'Enter' && event.key !== ' ') {
                return;
            }

            const target = event.target;
            if (!(target instanceof Element)) {
                return;
            }

            if (target.closest(interactiveSelector) && target.closest(interactiveSelector) !== card) {
                return;
            }

            event.preventDefault();
            goToCardHref(card, event);
        });
    });

    applyFilter();
}