import Poppable from './poppable.js'
import Popup from './popup.js'
import { Elements } from './utils.js'

/** A Popup Menu that shows text labels in a vertical row.
 */
export default class PopupMenu extends Popup {
    /**
     * The constructor.
     * @constructor
     * @param {DOM Element} parent - The DOM parent element.
     * @param {Object} commands - A dict object with command label strings as keys
     *                            and command functions as values.
     * @param {string} fontSize - Describes the font size as CSS value
     * @param {number || string} padding - Describes the padding as CSS value
     * @param {number || string} notchSize - Describes the size of the notch (callout) as CSS value
     * @param {string} highlightColor  - The color of highlighted menu items as CSS value
     * @param {string} backgroundColor  - The color of the background as CSS value
     * @param {string} normalColor  - The color of normal menu items as CSS value
     * @param {DOM Element} keepWithin  - The container to stay within
     * @param {boolean} autoClose  - Autoclose the menu after selecting an item
     */
    constructor({
        parent = null,
        commands = null,
        fontSize = '1em',
        fontFamily = 'Arial',
        padding = 16,
        zIndex = 1,
        spacing = '0px',
        switchPos = false,
        notchSize = 10,
        maxWidth = 800,
        backgroundColor = '#EEE',
        normalColor = '#444',
        highlightColor = 'black',
        notchPosition = 'bottomLeft',
        keepWithin = null,
        autoClose = true
    } = {}) {
        super({
            parent,
            fontSize,
            fontFamily,
            padding,
            notchSize,
            notchPosition,
            backgroundColor,
            keepWithin,
            normalColor,
            autoClose
        })
        this.commands = commands
        this.zIndex = zIndex
        this.switchPos = switchPos
        this.spacing = spacing
        this.highlightColor = highlightColor
    }

    /** Setup menu with a dictionary of command labels and command functions.
     * @param {Object} commands - A dict object with command label strings as keys
     *                            and command functions as values.
     * @return {PopupMenu} this
     */
    setup(commands) {
        this.commands = commands
        this.items = {}
        this.element = document.createElement('div')
        this.element.style.zIndex = this.zIndex
        Elements.addClass(this.element, 'unselectable')
        this.notch = document.createElement('div')
        Elements.setStyle(this.notch, this.notchStyle())
        for (let key in commands) {
            let item = document.createElement('div')
            this.element.appendChild(item)
            item.innerHTML = key
            item.style.paddingBottom = item.style.paddingTop = this.spacing
            Elements.setStyle(item, {
                color: this.normalColor,
                cursor: 'default'
            })
            Elements.addClass(item, 'unselectable')
            Elements.addClass(item, 'popupMenuItem')
            this.items[key] = item
            item.onclick = event => {
                this.perform(event, key)
            }
            item.ontap = event => {
                this.perform(event, key)
            }
            item.onmouseover = event => {
                this.over(event, key)
            }
            item.onmouseout = event => {
                this.out(event, key)
            }
        }

        this.element.appendChild(this.notch)
        this.parent.appendChild(this.element)
        this.insertedNode = this.element
        Elements.setStyle(this.element, this.defaultStyle())
        this.layout()
        return this
    }

    /** Execute a menu command.
     * @param {object} event - The trigger event.
     * @param {string} key - The selected key.
     */
    perform(event, key) {
        let func = this.commands[key]
        if (this.autoClose) {
            this.close()
        }
        setTimeout((event, key) => {
            func(event, key)
        }, 20, event, key)
    }

    /** Update the menu item denoted by key.
     * @param {string} key - The selected key.
     * @param {boolean} highlight - Show the item highlighted.
     */
    update(key, highlight = false) {
        let text = this.items[key]
        text.style.color = highlight ? this.highlightColor : this.normalColor
    }

    /** Mouse over handöer.
     * @param {Event} event - The mouse event.
     * @param {boolean} key - The selected key.
     */
    over(event, key) {
        for (let k in this.items) {
            this.update(k, k == key)
        }
    }

    /** Mouse out handöer.
     * @param {Event} event - The mouse event.
     * @param {boolean} key - The selected key.
     */
    out(event, key) {
        this.update(key)
    }

    /** Shows the PopupMenu with the given commands at the specified point.
     * @param {Object} commands - A dict object with command label strings as keys
     *                            and command functions as values.
     * @param {Point} point - The position as x, y coordinates {px}.
     * @return {PopupMenu} this
     */
    showAt(commands, point) {
        this.show(commands)
        this.placeAt(point)
        return this
    }

    /** Convenient static methods to show and reuse a PopupMenu implemented
     * as a class variable.
     * @param {Object} commands - A dict object with command label strings as keys
     *                            and command functions as values.
     * @param {Point} point - The position as x, y coordinates {px}.
     * @param {string} fontSize - Describes the font size as CSS value
     * @param {number || string} padding - Describes the padding as CSS value
     * @param {number || string} notchSize - Describes the size of the notch (callout) as CSS value
     * @param {string} highlightColor  - The color of highlighted menu items as CSS value
     * @param {string} backgroundColor  - The color of the background as CSS value
     * @param {string} normalColor  - The color of normal menu items as CSS value
     * @param {boolean} autoClose  - Autoclose the menu after selecting an item
     */
    static open(
        commands,
        point,
        {
            parent = null,
            context = window,
            fontSize = '1em',
            fontFamily = 'Arial',
            padding = 16,
            zIndex = 1,
            spacing = '0px',
            switchPos = false,
            notchSize = 10,
            maxWidth = 800,
            keepWithin = null,
            backgroundColor = '#EEE',
            normalColor = '#444',
            autoClose = true
        } = {}
    ) {
        let registered = Poppable.get(context)
        if (registered) {
            this.closePopup()
            return
        }
        console.log('open', point)
        let notchPosition = point.y < 50 && switchPos ? 'topCenter' : 'bottomCenter'
        let popup = new PopupMenu({
            parent,
            fontSize,
            padding,
            zIndex,
            spacing,
            switchPos,
            notchSize,
            notchPosition,
            maxWidth,
            backgroundColor,
            normalColor,
            notchPosition,
            keepWithin,
            autoClose
        })
        popup.showAt(commands, point)
        popup.register(context)
        popup.closeEventListener = e => {
            if (this.eventOutside(e)) this.closePopup(context)
        }
        if (autoClose) {
            context.addEventListener('mousedown', popup.closeEventListener, true)
            context.addEventListener('touchstart', popup.closeEventListener, true)
            context.addEventListener('pointerdown', popup.closeEventListener, true)
        }
    }

    static eventOutside(e) {
        return !Elements.hasClass(e.target, 'popupMenuItem')
    }

    /** Convenient static methods to close the PopupMenu implemented
     * as a class variable.
     */
    static closePopup(context = window) {
        let registered = Poppable.get(context)
        if (registered) {
            registered.close()
            context.removeEventListener('mousedown', registered.closeEventListener)
            context.removeEventListener('touchstart', registered.closeEventListener)
            context.removeEventListener('pointerdown', registered.closeEventListener)
        }
    }
}