import { getCacheFor } from './responsive-desktop-menu'

const getItemWidthsFrom = (container) =>
	[...container.querySelectorAll('[data-items] > [data-id]')]
		.filter((el) => el.dataset.id.indexOf('menu') === -1)
		.reduce((sum, el) => {
			let style = window.getComputedStyle(el)

			return (
				sum +
				el.getBoundingClientRect().width +
				parseInt(style.getPropertyValue('margin-left')) +
				parseInt(style.getPropertyValue('margin-right'))
			)
		}, 0)

const getTotalItemsWidthFor = (nav) => {
	let navStyle = window.getComputedStyle(nav)

	return (
		getCacheFor(nav.__id).itemsWidth.reduce((sum, n) => sum + n, 0) +
		(parseInt(navStyle.getPropertyValue('margin-left')) +
			parseInt(navStyle.getPropertyValue('margin-right')))
	)
}

/**
 * 1. Nav is in side with NO items in middle
 * 2. Nav is in middle
 * 3. Nav is either:
 *   a. Secondary
 *   b. Side, but with middle
 */
const computeAvailableSpaceFor = (nav) => {
	let baseContainer = nav.closest('[class*="ct-container"]')
	const baseContainerStyle = window.getComputedStyle(baseContainer)

	let baseWidth = baseContainer.getBoundingClientRect().width

	baseWidth -=
		parseInt(baseContainerStyle.getPropertyValue('padding-left')) +
		parseInt(baseContainerStyle.getPropertyValue('padding-right'))

	// side | middle | secondary
	// TODO: compute sides
	let closestColumn = nav.closest('[data-column]').dataset.column

	let navSide =
		closestColumn === 'start' || closestColumn === 'end'
			? 'side'
			: closestColumn === 'middle'
				? 'middle'
				: 'secondary'

	let hasMiddle = baseContainer.querySelector('[data-column="middle"]')

	// Case 1
	if (navSide === 'side' && !hasMiddle) {
		let allNavs = baseContainer.querySelectorAll('[data-id*="menu"]')

		let containerWidth = baseWidth - getItemWidthsFrom(baseContainer)

		if (allNavs.length > 1) {
			const totalItemsWidth = getTotalItemsWidthFor(nav)

			const totalItemsWidthFromAllNavs = [...allNavs].reduce(
				(total, nav) => total + getTotalItemsWidthFor(nav),
				0
			)

			containerWidth *=
				(100 * totalItemsWidth) / totalItemsWidthFromAllNavs / 100
		}

		return containerWidth
	}

	if (navSide === 'middle') {
		return (
			baseWidth -
			Math.max(
				baseContainer.querySelector('[data-column="start"]')
					? getItemWidthsFrom(
							baseContainer.querySelector('[data-column="start"]')
						)
					: 0,
				baseContainer.querySelector('[data-column="end"]')
					? getItemWidthsFrom(
							baseContainer.querySelector('[data-column="end"]')
						)
					: 0
			) *
				2
		)
	}

	return (
		(baseWidth -
			(baseContainer.querySelector('[data-column="middle"]')
				? getItemWidthsFrom(
						baseContainer.querySelector('[data-column="middle"]')
					)
				: 0)) /
			2 -
		getItemWidthsFrom(nav.closest('[data-column]'))
	)
}

export const getItemsDistribution = (nav) => {
	let containerWidth = computeAvailableSpaceFor(nav)

	let baseContainer = nav.closest('[class*="ct-container"]')

	let navStyle = window.getComputedStyle(nav)

	const totalItemsWidth = getTotalItemsWidthFor(nav)

	const navSideMargins =
		parseInt(navStyle.getPropertyValue('margin-left')) +
		parseInt(navStyle.getPropertyValue('margin-right'))

	const hasAnyOverlap = totalItemsWidth > containerWidth - navSideMargins

	if (!hasAnyOverlap) {
		return {
			fit: getCacheFor(nav.__id).children,
			notFit: [],
		}
	}

	let allNavs = baseContainer.querySelectorAll('[data-id*="menu"]')

	const itemsWidth = getCacheFor(nav.__id).itemsWidth

	const availableSpaceForItems = containerWidth - navSideMargins

	const moreItemWidth = getCacheFor(nav.__id).moreItemWidth

	const itemsWithWidths = getCacheFor(nav.__id)
		.children.map((el, index) => {
			return {
				el,
				width: itemsWidth[index],
			}
		})
		.reduce((result, item) => {
			if (result.length === 0) {
				return [item]
			}

			return [
				...result,
				{
					...item,
					width: item.width + result[result.length - 1].width,
				},
			]
		}, [])

	let itemsThatFit = itemsWithWidths.filter((itemWithWidth) => {
		return itemWithWidth.width + moreItemWidth < availableSpaceForItems
	})

	// Special case: if no items fit, but the first item is smaller than the more item, show it
	// This prevents showing only the "More" item with no siblings.
	if (
		itemsThatFit.length === 0 &&
		itemsWithWidths.length > 0 &&
		itemsWithWidths[0].width < moreItemWidth
	) {
		itemsThatFit = [itemsWithWidths[0]]
	}

	const elsThatFit = itemsThatFit.map(({ el }) => el)

	return {
		fit: elsThatFit,
		notFit: getCacheFor(nav.__id).children.filter((el) => {
			return !elsThatFit.includes(el)
		}),
	}
}