// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
// See License.txt for license information.

const ytRegex = /(?:http|https):\/\/(?:www\.|m\.)?(?:(?:youtube\.com\/(?:(?:v\/)|(?:(?:watch|embed\/watch)(?:\/|.*v=))|(?:embed\/)|(?:user\/[^/]+\/u\/[0-9]\/)))|(?:youtu\.be\/))([^#&?]*)/;
const imgRegex = /.+\/(.+\.(?:jpg|gif|bmp|png|jpeg))(?:\?.*)?$/i;

export function isValidUrl(url = '') {
    const regex = /^https?:\/\//i;
    return regex.test(url);
}

export function stripTrailingSlashes(url = '') {
    return url.trim().replace(/\/+$/, '');
}

export function removeProtocol(url = '') {
    return url.replace(/(^\w+:|^)\/\//, '');
}

export function extractFirstLink(text) {
    const pattern = /(^|[\s\n]|<br\/?>)((?:https?|ftp):\/\/[-A-Z0-9+\u0026\u2019@#/%?=()~_|!:,.;]*[-A-Z0-9+\u0026@#/%=~()_|])/i;
    let inText = text;

    // strip out code blocks
    inText = inText.replace(/`[^`]*`/g, '');

    // strip out inline markdown images
    inText = inText.replace(/!\[[^\]]*]\([^)]*\)/g, '');

    const match = pattern.exec(inText);
    if (match) {
        return match[0].trim();
    }

    return '';
}

export function isYoutubeLink(link) {
    return link.trim().match(ytRegex);
}

export function isImageLink(link) {
    const match = link.trim().match(imgRegex);
    return Boolean(match && match[1]);
}