import { Utils } from "./utils"

type MenuOption = {
	id: string,
	name: string,
	isOn?: boolean,
	icon?: "checked" | "sortUp" | "sortDown" | undefined,
	type?: "separator" | "color" | "submenu" | "switch" | undefined
}

// Menu is a pop-over context menu system
class Menu {
	static shared = new Menu()

	options: MenuOption[] = []
	readonly subMenuOptions: Map<string, MenuOption[]> = new Map()
	onMenuClicked?: (optionId: string, type?: string) => void
	onMenuToggled?: (optionId: string, isOn: boolean) => void

	private menu?: HTMLElement
	private subMenu?: Menu
	private onBodyClick: any
	private onBodyKeyDown: any

	get view() { return this.menu }

	get isVisible() {
		return (this.menu !== undefined)
	}

	createMenuElement() {
		const menu = Utils.htmlToElement(`<div class="menu noselect"></div>`)
		const menuElement = menu.appendChild(Utils.htmlToElement(`<div class="menu-options"></div>`))
		this.appendMenuOptions(menuElement)

		return menu
	}

	appendMenuOptions(menuElement: HTMLElement) {
		for (const option of this.options) {
			if (option.type === "separator") {
				const optionElement = menuElement.appendChild(Utils.htmlToElement(`<div class="menu-separator"></div>`))
			}
			else {
				const optionElement = menuElement.appendChild(Utils.htmlToElement(`<div class="menu-option"></div>`))
				optionElement.id = option.id
				const nameElement = optionElement.appendChild(Utils.htmlToElement(`<div class="menu-name"></div>`))
				nameElement.innerText = option.name
				if (option.type === "submenu") {
					optionElement.appendChild(Utils.htmlToElement(`<div class="imageSubmenuTriangle" style="float: right;"></div>`))
					optionElement.onmouseenter = (e) => {
						// Calculate offset taking window scroll into account
						const bodyRect = document.body.getBoundingClientRect()
						const rect = optionElement.getBoundingClientRect()
						this.showSubMenu(rect.right - bodyRect.left, rect.top - bodyRect.top, option.id)
					}
				} else {

					if (option.icon) {
						let iconName: string
						switch (option.icon) {
							case "checked": { iconName = "imageMenuCheck"; break }
							case "sortUp": { iconName = "imageMenuSortUp"; break }
							case "sortDown": { iconName = "imageMenuSortDown"; break }
							default: { Utils.assertFailure(`Unsupported menu icon: ${option.icon}`) }
						}
						if (iconName) {
							optionElement.appendChild(Utils.htmlToElement(`<div class="${iconName}" style="float: right;"></div>`))
						}
					}

					optionElement.onmouseenter = () => {
						this.hideSubMenu()
					}
					optionElement.onclick = (e) => {
						if (this.onMenuClicked) {
							this.onMenuClicked(option.id, option.type)
						}
						this.hide()
						e.stopPropagation()
						return false
					}
				}

				if (option.type === "color") {
					const colorbox = optionElement.insertBefore(Utils.htmlToElement(`<div class="menu-colorbox"></div>`), optionElement.firstChild)
					colorbox.classList.add(option.id)			// id is the css class name for the color
				} else if (option.type === "switch") {
					const className = option.isOn ? "octo-switch on" : "octo-switch"
					const switchElement = optionElement.appendChild(Utils.htmlToElement(`<div class="${className}"></div>`))
					switchElement.appendChild(Utils.htmlToElement(`<div class="octo-switch-inner"></div>`))
					switchElement.onclick = (e) => {
						const isOn = switchElement.classList.contains("on")
						if (isOn) {
							switchElement.classList.remove("on")
						} else {
							switchElement.classList.add("on")
						}

						if (this.onMenuToggled) {
							this.onMenuToggled(option.id, !isOn)
						}
						e.stopPropagation()
						return false
					}
					optionElement.onclick = null
				}
			}
		}
	}

	showAtElement(element: HTMLElement) {
		const bodyRect = document.body.getBoundingClientRect()
		const rect = element.getBoundingClientRect()
		// Show at bottom-left of element
		this.showAt(rect.left - bodyRect.left, rect.bottom - bodyRect.top)
	}

	showAt(pageX: number, pageY: number) {
		if (this.menu) { this.hide() }
		this.menu = this.createMenuElement()
		this.menu.style.left = `${pageX}px`
		this.menu.style.top = `${pageY}px`

		document.body.appendChild(this.menu)

		this.onBodyClick = (e: MouseEvent) => {
			console.log(`onBodyClick`)
			this.hide()
		}

		this.onBodyKeyDown = (e: KeyboardEvent) => {
			console.log(`onBodyKeyDown, target: ${e.target}`)
			// Ignore keydown events on other elements
			if (e.target !== document.body) { return }
			if (e.keyCode === 27) {
				// ESC
				this.hide()
				e.stopPropagation()
			}
		}

		setTimeout(() => {
			document.body.addEventListener("click", this.onBodyClick)
			document.body.addEventListener("keydown", this.onBodyKeyDown)
		}, 20)
	}

	hide() {
		if (!this.menu) { return }

		this.hideSubMenu()

		document.body.removeChild(this.menu)
		this.menu = undefined

		document.body.removeEventListener("click", this.onBodyClick)
		this.onBodyClick = undefined

		document.body.removeEventListener("keydown", this.onBodyKeyDown)
		this.onBodyKeyDown = undefined
	}

	hideSubMenu() {
		if (this.subMenu) {
			this.subMenu.hide()
			this.subMenu = undefined
		}
	}

	private showSubMenu(pageX: number, pageY: number, id: string) {
		console.log(`showSubMenu: ${id}`)
		const options: MenuOption[] = this.subMenuOptions.get(id) || []

		if (this.subMenu) {
			if (this.subMenu.options === options) {
				// Already showing the sub menu
				return
			}

			this.subMenu.hide()
		}

		this.subMenu = new Menu()

		this.subMenu.onMenuClicked = (optionId: string, type?: string) => {
			const subMenuId = `${id}-${optionId}`
			if (this.onMenuClicked) {
				this.onMenuClicked(subMenuId, type)
			}
			this.hide()
		}

		this.subMenu.options = options
		this.subMenu.showAt(pageX, pageY)
	}
}

export { Menu, MenuOption }