/**
 * Sticky header behaviour (theme-wide; do not duplicate sticky CSS/scroll JS in header.php).
 *
 * @package Trafium_AI
 */
(function () {
	'use strict';

	var STICKY_CLASS = 'trf-is-sticky';
	var NAV_TARGET_CLASS = 'trf-header-sticky-target';
	var MAX_FULL_BAR_RATIO = 0.22;
	var MAX_FULL_BAR_PX = 112;

	function adminBarOffset() {
		var bar = document.getElementById('wpadminbar');
		if (!bar) {
			return 0;
		}

		return bar.offsetHeight || 0;
	}

	function normalizeMode(raw) {
		if (!raw) {
			return '';
		}

		return String(raw)
			.trim()
			.toLowerCase()
			.replace(/_/g, '-');
	}

	function clearSticky(el) {
		if (!el) {
			return;
		}

		el.classList.remove(STICKY_CLASS);
		if (el.style && el.style.position === 'sticky') {
			el.style.position = '';
		}
		if (el.style && el.style.top) {
			el.style.top = '';
		}
	}

	function applySticky(el) {
		if (!el) {
			return;
		}

		el.classList.add(STICKY_CLASS);
	}

	function findNavRow(header) {
		var explicit = header.querySelector(
			'.trf-header-sticky-target, .trf-header__nav-row, [class*="__nav-row"]'
		);
		if (explicit) {
			return explicit;
		}

		var nav = header.querySelector('nav[aria-label*="Primary" i], nav[aria-label*="primary" i]');
		if (nav) {
			var row = nav.closest('[class*="__nav-row"], [class*="__nav-inner"], [class*="__bar"]');
			return row || nav.parentElement || nav;
		}

		var children = header.children;
		for (var i = children.length - 1; i >= 0; i--) {
			var child = children[i];
			if (child && child.querySelector && child.querySelector('nav')) {
				return child;
			}
		}

		return null;
	}

	function countBands(header) {
		var count = 0;
		var children = header.children;
		for (var i = 0; i < children.length; i++) {
			var node = children[i];
			if (!node || node.nodeType !== 1) {
				continue;
			}
			if (node.tagName === 'SCRIPT' || node.tagName === 'STYLE') {
				continue;
			}
			count++;
		}

		return count;
	}

	function inferMode(header) {
		var bands = countBands(header);
		var height = header.offsetHeight || 0;

		if (bands >= 2 || findNavRow(header) !== header && findNavRow(header) !== null && bands >= 2) {
			return 'nav-only';
		}

		if (height > MAX_FULL_BAR_PX || height > window.innerHeight * MAX_FULL_BAR_RATIO) {
			return findNavRow(header) ? 'nav-only' : 'none';
		}

		if (height <= 96 && bands <= 1) {
			return 'full-bar';
		}

		return 'none';
	}

	function resolveMode(header) {
		var declared = normalizeMode(header.getAttribute('data-trf-sticky'));
		if (declared === 'none' || declared === 'off' || declared === 'false') {
			return 'none';
		}
		if (declared === 'nav-only' || declared === 'nav') {
			return 'nav-only';
		}
		if (declared === 'full-bar' || declared === 'full') {
			return 'full-bar';
		}

		return inferMode(header);
	}

	function initHeaderSticky() {
		var header = document.querySelector(
			'header.trf-site-header, header#site-header, body > header[role="banner"]'
		);
		if (!header) {
			return;
		}

		var mode = resolveMode(header);
		if (mode === 'none') {
			clearSticky(header);
			return;
		}

		document.documentElement.style.setProperty(
			'--trf-admin-bar-offset',
			adminBarOffset() + 'px'
		);

		var navRow = findNavRow(header);
		clearSticky(header);

		if (mode === 'nav-only') {
			if (navRow) {
				applySticky(navRow);
			}

			return;
		}

		var height = header.offsetHeight || 0;
		if (
			height > MAX_FULL_BAR_PX ||
			height > window.innerHeight * MAX_FULL_BAR_RATIO
		) {
			if (navRow) {
				applySticky(navRow);
			}

			return;
		}

		applySticky(header);
	}

	function onReady() {
		initHeaderSticky();
		window.addEventListener('resize', initHeaderSticky, { passive: true });
	}

	if (document.readyState === 'loading') {
		document.addEventListener('DOMContentLoaded', onReady);
	} else {
		onReady();
	}
})();