import Popper from 'popper.js'

function furthest(el, s) {
	var nodes = []

	while (el.parentNode) {
		if (
			el.parentNode &&
			el.parentNode.matches &&
			el.parentNode.matches(s)
		) {
			nodes.push(el.parentNode)
		}

		el = el.parentNode
	}

	return nodes[nodes.length - 1]
}

const getPreferedPlacementFor = el => {
	const farmost = furthest(el, 'li.menu-item')

	if (!farmost) {
		return 'right'
	}

	return farmost.getBoundingClientRect().left > innerWidth / 2
		? 'left'
		: 'right'
}

export const handleSingleSubmenu = (menu, preferedPlacement = null) => {
	;[...menu.querySelectorAll('[data-submenu]')].map(el => {
		el.removeAttribute('data-submenu')
	})

	setTimeout(
		() =>
			(menu._popper = new Popper(menu.parentNode, menu, {
				modifiers: {
					applyStyle: { enabled: false },

					preventOverflow: {
						enabled: false
					},

					hide: {
						enabled: false
					},

					flip: {
						// enabled: false,
						behavior: ['right', 'left'],
						flipVariationsByContent: true
					},

					setCustomStyle: {
						enabled: true,
						order: 100000000,
						fn: ({
							flipped,
							instance,
							instance: { reference, popper },
							placement,
							styles
						}) => {
							reference.dataset.submenu =
								placement === 'left' ? 'left' : 'right'
						}
					}
				},
				placement: preferedPlacement || getPreferedPlacementFor(menu)
			}))
	)
}

export const handleFirstLevelForMenu = menu => {
	;[...menu.children]
		.filter(
			el =>
				el.classList.contains('menu-item-has-children') ||
				el.classList.contains('page_item_has_children')
		)
		.map(el => el.querySelector('.sub-menu'))
		.map(menu => handleSingleSubmenu(menu, 'right'))
}

const mouseenterHandler = ({ target }) => {
	const menu = target.querySelector('.sub-menu')

	if (menu._timeout_id) {
		clearTimeout(menu._timeout_id)
	}

	;[...menu.children]
		.filter(
			el =>
				el.classList.contains('menu-item-has-children') ||
				el.classList.contains('page_item_has_children')
		)
		.map(el => el.querySelector('.sub-menu'))
		.map(menu => {
			;[...menu.querySelectorAll('[data-submenu]')].map(el => {
				el.removeAttribute('data-submenu')
			})

			setTimeout(
				() =>
					(menu._popper = new Popper(menu.parentNode, menu, {
						modifiers: {
							applyStyle: { enabled: false },

							preventOverflow: {
								enabled: true
							},

							hide: {
								enabled: false
							},

							flip: {
								// enabled: false,
								behavior: ['right', 'left'],
								flipVariations: true,
								flipVariationsByContent: true
							},

							setCustomStyle: {
								enabled: true,
								order: 100000000,
								fn: ({
									flipped,
									instance,
									instance: { reference, popper },
									placement,
									styles
								}) => {
									const {
										left,
										width,
										right
									} = popper.getBoundingClientRect()

									let futurePlacement = placement

									if (placement === 'left') {
										if (
											reference.getBoundingClientRect()
												.left -
												width <
											0
										) {
											futurePlacement = 'right'
										}
									}

									if (placement === 'right') {
										if (
											reference.getBoundingClientRect()
												.right -
												width <
											0
										) {
											futurePlacement = 'left'
										}
									}

									reference.dataset.submenu = futurePlacement
								}
							}
						},
						placement: getPreferedPlacementFor(menu)
					}))
			)
		})

	menu.parentNode.addEventListener(
		'mouseleave',
		() => {
			;[...menu.children]
				.filter(
					el =>
						el.classList.contains('menu-item-has-children') ||
						el.classList.contains('page_item_has_children')
				)
				.map(el => el.querySelector('.sub-menu'))
				.map(menu => {
					if (!menu._popper) return

					menu._popper.destroy()
					menu._popper = null
				})

			menu._timeout_id = setTimeout(() => {
				menu._timeout_id = null
				;[...menu.children]
					.filter(
						el =>
							el.classList.contains('menu-item-has-children') ||
							el.classList.contains('page_item_has_children')
					)
					.map(el => el.removeAttribute('data-submenu'))
			}, 200)
		},
		{ once: true }
	)
}

export const handleUpdate = menu => {
	menu.parentNode.removeEventListener('mouseenter', mouseenterHandler)
	menu.parentNode.addEventListener('mouseenter', mouseenterHandler)
}