import "./common.js";
//#region js/about-history.js
function setActiveNav() {
	const pageNav = document.querySelector("[data-nav]")?.getAttribute("data-nav");
	if (!pageNav) return;
	document.querySelectorAll(".site-header__nav a").forEach((link) => {
		const active = link.textContent.trim().startsWith(pageNav);
		link.classList.toggle("is-active", active);
	});
}

function getHeaderOffset() {
	const header = document.querySelector(".site-header");
	const h = header ? header.offsetHeight : 88;
	const isMobile = window.matchMedia("(max-width: 992px)").matches;
	if (isMobile) {
		const years = document.querySelector(".ah-nav__years");
		const yearsH = years ? years.offsetHeight : 60;
		return h + yearsH + 12;
	}
	return h + 24;
}

function initHistorySpy() {
	const root = document.querySelector("[data-ah-spy]");
	if (!root) return;
	const navItems = Array.from(root.querySelectorAll(".ah-nav__item[data-year]"));
	const blocks = Array.from(root.querySelectorAll(".ah-block[data-year]"));
	const yearsWrap = root.querySelector(".ah-nav__years");
	const rail = root.querySelector(".ah-nav__rail");
	const indicator = root.querySelector(".ah-nav__indicator");
	if (!navItems.length || !blocks.length) return;

	let activeYear = navItems[0].dataset.year;
	let clicking = false;

	const syncRailHeight = () => {
		if (!yearsWrap || !rail) return;
		rail.style.height = `${yearsWrap.offsetHeight}px`;
	};

	const updateLine = (item) => {
		if (!indicator || !item || !yearsWrap) return;
		syncRailHeight();
		const itemRect = item.getBoundingClientRect();
		const yearsRect = yearsWrap.getBoundingClientRect();
		// 原点固定在顶部，线条延伸到当前高亮年份底部
		const height = Math.max(itemRect.bottom - yearsRect.top, 8);
		indicator.style.height = `${height}px`;
		indicator.style.transform = "";
	};

	const updateLineSoon = (item) => {
		updateLine(item);
		requestAnimationFrame(() => updateLine(item));
		window.setTimeout(() => updateLine(item), 320);
	};

	const setActive = (year) => {
		if (!year || year === activeYear) {
			const current = navItems.find((el) => el.dataset.year === activeYear);
			updateLineSoon(current);
			return;
		}
		activeYear = year;
		navItems.forEach((el) => {
			el.classList.toggle("is-active", el.dataset.year === year);
		});
		const current = navItems.find((el) => el.dataset.year === year);
		updateLineSoon(current);
		if (current && current.closest(".ah-nav__years") && window.matchMedia("(max-width: 992px)").matches) {
			current.scrollIntoView({
				inline: "center",
				block: "nearest",
				behavior: "smooth"
			});
		}
	};

	const scrollToYear = (year) => {
		const target = blocks.find((el) => el.dataset.year === year);
		if (!target) return;
		clicking = true;
		setActive(year);
		const top = window.scrollY + target.getBoundingClientRect().top - getHeaderOffset();
		const done = () => {
			clicking = false;
		};
		if (window.lenis) {
			window.lenis.scrollTo(top, {
				duration: 1,
				onComplete: done
			});
		} else {
			window.scrollTo({
				top,
				behavior: "smooth"
			});
			window.setTimeout(done, 800);
		}
	};

	navItems.forEach((item) => {
		item.addEventListener("click", (event) => {
			event.preventDefault();
			scrollToYear(item.dataset.year);
		});
	});

	const io = new IntersectionObserver((entries) => {
		if (clicking) return;
		const visible = entries.filter((e) => e.isIntersecting).sort((a, b) => b.intersectionRatio - a.intersectionRatio);
		if (!visible.length) return;
		const year = visible[0].target.getAttribute("data-year");
		if (year) setActive(year);
	}, {
		root: null,
		rootMargin: `-${getHeaderOffset()}px 0px -45% 0px`,
		threshold: [0.05, 0.2, 0.4, 0.6]
	});

	blocks.forEach((block) => io.observe(block));

	const onScrollFallback = () => {
		if (clicking) return;
		const offset = getHeaderOffset() + 8;
		let current = blocks[0]?.dataset.year;
		for (const block of blocks) {
			if (block.getBoundingClientRect().top <= offset) current = block.dataset.year;
		}
		if (current) setActive(current);
	};

	if (window.lenis) window.lenis.on("scroll", onScrollFallback);
	else window.addEventListener("scroll", onScrollFallback, { passive: true });

	setActive(activeYear);
	window.addEventListener("resize", () => {
		const current = navItems.find((el) => el.dataset.year === activeYear);
		updateLineSoon(current);
	});

	const hashYear = (location.hash || "").replace(/^#year-/, "");
	if (hashYear && blocks.some((el) => el.dataset.year === hashYear)) {
		requestAnimationFrame(() => scrollToYear(hashYear));
	}
}

setActiveNav();
initHistorySpy();
//#endregion