---
const labelOpen = "사이드바 접기";
const labelClosed = "사이드바 펼치기";
---

<button
	type="button"
	class="sidebar-toggle"
	data-sidebar-toggle
	data-label-open={labelOpen}
	data-label-closed={labelClosed}
	aria-pressed="false"
>
	<span class="toggle-icon" aria-hidden="true">⟫</span>
</button>

<script>
	const root = document.documentElement;
	const toggleBtn = document.querySelector("[data-sidebar-toggle]");
	const collapsedClass = "sidebar-collapsed";
	const storageKey = "cel:sidebar-collapsed";

	const getDefaultCollapsed = () => {
		const width = window.innerWidth;
		if (width < 800) return true;
		if (width < 1000) return true;
		return false;
	};

	let savedState = null;

	const applyState = (isCollapsed, { persist = true } = {}) => {
		root.classList.toggle(collapsedClass, isCollapsed);

		if (!toggleBtn) return;
		const label = isCollapsed ? toggleBtn.dataset.labelClosed ?? "사이드바 펼치기" : toggleBtn.dataset.labelOpen ?? "사이드바 접기";
		const icon = toggleBtn.querySelector(".toggle-icon");

		toggleBtn.setAttribute("aria-pressed", isCollapsed ? "true" : "false");
		toggleBtn.setAttribute("aria-label", label);
		if (icon) icon.textContent = isCollapsed ? "⟫" : "⟪";
		if (persist) {
			savedState = isCollapsed ? "1" : "0";
			try {
				window.sessionStorage.setItem(storageKey, isCollapsed ? "1" : "0");
			} catch (error) {
				console.warn("Failed to persist sidebar toggle state", error);
			}
		}
	};

	const getToggleTop = () => {
		const header = document.querySelector("header.header") ?? document.querySelector("header");
		const headerRect = header?.getBoundingClientRect();
		if (headerRect) return headerRect.bottom + 14;
		return 22;
	};

	const setTogglePosition = () => {
		if (!toggleBtn) return;
		const isCollapsed = root.classList.contains(collapsedClass);
		const sidebarPane = document.getElementById("starlight__sidebar");
		const rect = sidebarPane?.getBoundingClientRect();
		const sidebarWidth = parseFloat(getComputedStyle(root).getPropertyValue("--sl-sidebar-width") || "0") || 0;

		const fallbackLeft = sidebarWidth > 0 ? sidebarWidth : 12;
		const anchorLeft = rect && rect.width > 0 ? rect.right : fallbackLeft;
		const top = Math.max(12, getToggleTop());

		toggleBtn.style.left = `${anchorLeft}px`;
		toggleBtn.style.top = `${top}px`;
		toggleBtn.style.transform = "translate(-90%, 0)";
	};

	if (toggleBtn) {
		document.body.appendChild(toggleBtn);

		try {
			savedState = window.sessionStorage.getItem(storageKey);
		} catch (error) {
			console.warn("Failed to read sidebar toggle state", error);
		}

		const resolveState = () => {
			const width = window.innerWidth;
			if (width < 800) return true;
			if (savedState !== null) return savedState === "1";
			return getDefaultCollapsed();
		};

		const initialCollapsed = resolveState();

		applyState(initialCollapsed, { persist: savedState !== null });
		setTogglePosition();

		toggleBtn.addEventListener("click", () => {
			const nextState = !root.classList.contains(collapsedClass);
			applyState(nextState, { persist: true });
			setTogglePosition();
		});

		window.addEventListener("resize", () => {
			window.requestAnimationFrame(() => {
				const nextState = resolveState();
				const shouldPersist = savedState !== null && window.innerWidth >= 800;
				applyState(nextState, { persist: shouldPersist });
				setTogglePosition();
			});
		});
	}
</script>

<style>
	@layer starlight.core {
		.sidebar-toggle {
			position: fixed;
			top: auto;
			left: 12px;
			transform: translate(-90%);
			z-index: calc(var(--sl-z-index-navbar) + 8);
			display: none;
			align-items: center;
			justify-content: center;
			width: 30px;
			height: 40px;
			padding: 0;
			background: var(--sl-color-bg-sidebar);
			border: 1px solid var(--sl-color-hairline);
			border-right: 0;
			border-radius: 0;
			color: color-mix(in srgb, var(--sl-color-hairline-shade) 85%, var(--sl-color-text) 15%);
			font-size: 0.95rem;
			font-weight: 600;
			cursor: pointer;
			transition: transform 0.15s ease, background-color 0.2s ease, border-color 0.2s ease;
		}

		.sidebar-toggle:hover {
			transform: translate(-90%, -1px);
			background: var(--sl-color-bg);
			border-color: var(--sl-color-hairline-shade);
		}

		.sidebar-toggle::before {
			content: "";
			position: absolute;
			top: 0;
			left: auto;
			right: 0;
			width: 1px;
			height: 100%;
			background: var(--sl-color-hairline);
		}

		.sidebar-toggle:hover::before {
			background: var(--sl-color-hairline-shade);
		}

		@media (min-width: 50rem) {
			.sidebar-toggle {
				display: inline-flex;
			}

			:global(.sidebar-collapsed [data-has-sidebar]) {
				--sl-content-inline-start: 0 !important;
			}

			:global(.sidebar-collapsed nav.sidebar) {
				transform: translateX(-100%);
				visibility: hidden;
				pointer-events: none;
				width: 0;
				border: 0;
			}

			:global(.sidebar-collapsed .sidebar-pane) {
				display: none;
			}

			:global(.sidebar-collapsed .main-frame) {
				padding-inline-start: 0 !important;
			}

			:global(.sidebar-collapsed .main-pane) {
				width: 100% !important;
				max-width: 100% !important;
			}
		}
	}
</style>