import Ember from 'ember';
import {invokeAction} from 'ember-invoke-action';

const {TextField, computed, run} = Ember;

let joinUrlParts = function (url, path) {
    if (path[0] !== '/' && url.slice(-1) !== '/') {
        path = `/${path}`;
    } else if (path[0] === '/' && url.slice(-1) === '/') {
        path = path.slice(1);
    }

    return url + path;
};

let isRelative = function (url) {
    // "protocol://", "//example.com", "scheme:", "#anchor", & invalid paths
    // should all be treated as absolute
    return !url.match(/\s/) && !validator.isURL(url) && !url.match(/^(\/\/|#|[a-zA-Z0-9\-]+:)/);
};

export default TextField.extend({
    classNames: 'gh-input',

    isBaseUrl: computed('baseUrl', 'value', function () {
        return this.get('baseUrl') === this.get('value');
    }),

    didReceiveAttrs() {
        this._super(...arguments);

        let baseUrl = this.get('baseUrl');
        let url = this.get('url');

        // if we have a relative url, create the absolute url to be displayed in the input
        if (isRelative(url)) {
            url = joinUrlParts(baseUrl, url);
        }

        this.set('value', url);
    },

    focusIn(event) {
        this.set('hasFocus', true);

        if (this.get('isBaseUrl')) {
            // position the cursor at the end of the input
            run.next(function (el) {
                let {length} = el.value;

                el.setSelectionRange(length, length);
            }, event.target);
        }
    },

    keyDown(event) {
        // delete the "placeholder" value all at once
        if (this.get('isBaseUrl') && (event.keyCode === 8 || event.keyCode === 46)) {
            this.set('value', '');

            event.preventDefault();
        }

        // CMD-S
        if (event.keyCode === 83 && event.metaKey) {
            this.notifyUrlChanged();
        }
    },

    keyPress(event) {
        invokeAction(this, 'clearErrors');

        // enter key
        if (event.keyCode === 13) {
            this.notifyUrlChanged();
        }

        return true;
    },

    focusOut() {
        this.set('hasFocus', false);

        this.notifyUrlChanged();
    },

    notifyUrlChanged() {
        let url = this.get('value').trim();
        let urlParts = document.createElement('a');
        let baseUrl = this.get('baseUrl');
        let baseUrlParts = document.createElement('a');

        // ensure value property is trimmed
        this.set('value', url);

        // leverage the browser's native URI parsing
        urlParts.href = url;
        baseUrlParts.href = baseUrl;

        // if we have an email address, add the mailto:
        if (validator.isEmail(url)) {
            url = `mailto:${url}`;
            this.set('value', url);
        }

        // if we have a relative url, create the absolute url to be displayed in the input
        if (isRelative(url)) {
            url = joinUrlParts(baseUrl, url);
            this.set('value', url);
        }

        // get our baseUrl relativity checks in order
        let isOnSameHost = urlParts.host === baseUrlParts.host;
        let isAnchorLink = url.match(/^#/);
        let isRelativeToBasePath = urlParts.pathname.indexOf(baseUrlParts.pathname) === 0;

        // if our pathname is only missing a trailing / mark it as relative
        if (`${urlParts.pathname}/` === baseUrlParts.pathname) {
            isRelativeToBasePath = true;
        }

        // if relative to baseUrl, remove the base url before sending to action
        if (!isAnchorLink && isOnSameHost && isRelativeToBasePath) {
            url = url.replace(/^[a-zA-Z0-9\-]+:/, '');
            url = url.replace(/^\/\//, '');
            url = url.replace(baseUrlParts.host, '');
            url = url.replace(baseUrlParts.pathname, '');

            // handle case where url path is same as baseUrl path but missing trailing slash
            if (urlParts.pathname.slice(-1) !== '/') {
                url = url.replace(baseUrlParts.pathname.slice(0, -1), '');
            }

            if (!url.match(/^\//)) {
                url = `/${url}`;
            }

            if (!url.match(/\/$/) && !url.match(/[\.#\?]/)) {
                url = `${url}/`;
            }
        }

        this.sendAction('change', url);
    }
});