/**
 *
 * Determine an element’s location on the screen once it has been scrolled into view.
 *
 * <example>
    :getLocationInView.js
    it('should get the location of one or multiple elements in view', function () {
        browser.url('http://github.com');

        var location = browser.getLocationInView('.octicon-mark-github');
        console.log(location); // outputs: { x: 150, y: 20 }

        var xLocation = browser.getLocationInView('.octicon-mark-github', 'x')
        console.log(xLocation); // outputs: 150

        var yLocation = browser.getLocationInView('.octicon-mark-github', 'y')
        console.log(yLocation); // outputs: 20
    });
 * </example>
 *
 * @alias browser.getLocationInView
 * @param {String} selector    element with requested position offset
 * @return {Object|Object[]}  The X and Y coordinates for the element on the page (`{x:number, y:number}`)
 *
 * @uses protocol/elements, protocol/elementIdLocationInView
 * @type property
 *
 */

import { CommandError } from '../utils/ErrorHandler'

let getLocationInView = function (selector, prop) {
    return this.elements(selector).then((res) => {
        /**
         * throw NoSuchElement error if no element was found
         */
        if (!res.value || res.value.length === 0) {
            throw new CommandError(7, selector || this.lastResult.selector)
        }

        let elementIdLocationInViewCommands = []
        for (let elem of res.value) {
            elementIdLocationInViewCommands.push(this.elementIdLocationInView(elem.ELEMENT))
        }

        return Promise.all(elementIdLocationInViewCommands)
    }).then((locations) => {
        /**
         * result already unwrapped when command was reran
         */
        if (!Array.isArray(locations)) {
            return locations
        }

        locations = locations.map((location) => {
            if (typeof prop === 'string' && prop.match(/(x|y)/)) {
                return location.value[prop]
            }

            return {
                x: location.value.x,
                y: location.value.y
            }
        })

        return locations.length === 1 ? locations[0] : locations
    })
}

export default getLocationInView