content-script.js

'use strict';

const DEBUG = false;

const VERSIONS = {
    FEB18: 'FEB18',
    JUL19: 'JUL19',
    OCT19: 'OCT19'
};

var images = new Object();

function toI18n(str) {
    return str.replace(/__MSG_(\w+)__/g, function (match, v1) {
        return v1 ? chrome.i18n.getMessage(v1) : '';
    });
}


function localiseObject(obj, tag) {
    var msg = toI18n(tag);
    if (msg != tag) obj.innerHTML = msg;
}


// Finds the div which contains all required elements
function getContainer(node) {
    var container, version;
    [
        ['.irc_c[style*="visibility: visible;"][style*="transform: translate3d(0px, 0px, 0px);"]', VERSIONS.FEB18],
        ['.irc_c[data-ved]', VERSIONS.JUL19],
        ['.tvh9oe', VERSIONS.OCT19]
    ].forEach(element => {
        if (node.closest(element[0])) {
            [container, version] = [node.closest(element[0]), element[1]];
        }
    });
    return [container, version];
}


// Finds and deletes all extension related elements.
function clearExtElements(container) {
    // Remove previously generated elements
    var oldExtensionElements = container.querySelectorAll('.vi_ext_addon');
    for (var element of oldExtensionElements) {
        element.remove();
    }
}


// Returns the image URL
function findImageURL(container, version) {

    var image = null;

    switch (version) {
        case VERSIONS.FEB18:
            image = container.querySelector('img[src]#irc_mi, img[alt^="Image result"][src]:not([src^="https://encrypted-tbn"]).irc_mut, img[src].irc_mi');
            break;
        case VERSIONS.JUL19:
            var iframe = container.querySelector('iframe.irc_ifr');
            if (!iframe)
                return findImageURL(container, VERSIONS.FEB18);
            image = iframe.contentDocument.querySelector('img#irc_mi');
            break;
        case VERSIONS.OCT19:
            image = container.querySelector('img[src].n3VNCb, img[src].r48jcc');
            if (image.src in images) {
                return images[image.src];
            }
    }

    // Override url for images using base64 embeds
    if (image === null || image.src === '' || image.src.startsWith('data')) {
        var thumbnail = document.querySelector('img[name="' + container.dataset.itemId + '"]');
        if (thumbnail === null) {
            // If no thumbnail found, try getting image from URL
            var url = new URL(window.location);
            var imgLink = url.searchParams.get('imgurl');
            if (imgLink) {
                return imgLink;
            }
        } else {
            var meta = thumbnail.closest('.rg_bx').querySelector('.rg_meta');
            var metadata = JSON.parse(meta.innerHTML);
            return metadata.ou;
        }
    }

    // If the above doesn't work, use the link in related images to find it
    if (image === null || image.src === '' || image.src.startsWith('data')) {
        var target_image = container.querySelector('img.target_image');
        if (target_image) {
            var link = target_image.closest('a');
            if (link) {
                // Some extensions replace google image links with their original links
                if (link.href.match(/^[a-z]+:\/\/(?:www\.)?google\.[^/]*\/imgres\?/)) {
                    var link_url = new URL(link.href);
                    var new_imgLink = link_url.searchParams.get('imgurl');
                    if (new_imgLink) {
                        return new_imgLink;
                    }
                } else {
                    return link.href;
                }
            }
        }
    }

    if (image) {
        return image.src;
    }

}

function addViewImageButton(container, imageURL, version) {

    // get the visit buttonm
    var visitButton;
    switch (version) {
        case VERSIONS.FEB18:
            visitButton = container.querySelector('td > a.irc_vpl[href]').parentElement;
            break;
        case VERSIONS.JUL19:
            visitButton = container.querySelector('a.irc_hol[href]');
            break;
        case VERSIONS.OCT19:
            visitButton = container.querySelector('.ZsbmCf[href], a.J2oL9c, a.jAklOc, a.uZ49bd');
            break;
    }

    // Create the view image button
    var viewImageButton = visitButton.cloneNode(true);
    viewImageButton.classList.add('vi_ext_addon');

    // Set the view image button url
    var viewImageLink;
    switch (version) {
        case VERSIONS.FEB18:
            viewImageLink = viewImageButton.querySelector('a');
            break;
        default:
            viewImageLink = viewImageButton;
    }

    viewImageLink.href = imageURL;
    if (version == VERSIONS.OCT19) {
        viewImageLink.removeAttribute('jsaction');
    }

    // Set additional options
    if (options['open-in-new-tab']) {
        viewImageLink.setAttribute('target', '_blank');
    }
    if (options['no-referrer']) {
        viewImageLink.setAttribute('rel', 'noreferrer');
    }

    // Set the view image button text
    var viewImageButtonText;
    switch (version) {
        case VERSIONS.FEB18:
            viewImageButtonText = viewImageButton.querySelector('.Tl8XHc');
            break;
        case VERSIONS.JUL19:
            viewImageButtonText = viewImageButton.querySelector('.irc_ho');
            break;
        case VERSIONS.OCT19:
            viewImageButtonText = viewImageButton.querySelector('.pM4Snf, .KSvtLc, .Pw5kW, .q7UPLe, .K8E1Be, .pFBf7b, span');
            break;
    }

    if (options['manually-set-button-text']) {
        viewImageButtonText.innerText = options['button-text-view-image'];
    } else {
        localiseObject(viewImageButtonText, '__MSG_viewImage__');
    }

    // Remove globe icon if not wanted
    if (!options['show-globe-icon']) {
        switch (version) {
            case VERSIONS.FEB18:
                viewImageButton.querySelector('.RL3J9c').remove();
                break;
            case VERSIONS.JUL19:
                viewImageButton.querySelector('.aDEWOd').remove();
                break;
            case VERSIONS.OCT19:
                viewImageButton.querySelector('.XeEBj.AJkoub').remove();
                break;
        }
    }

    // Place the view image button
    visitButton.parentElement.insertBefore(viewImageButton, visitButton);
    visitButton.parentElement.insertBefore(visitButton, viewImageButton);
}


function addSearchImageButton(container, imageURL, version) {

    var link;
    switch (version) {
        case VERSIONS.FEB18:
            link = container.querySelector('.irc_dsh > a.irc_hol');
            break;
        case VERSIONS.JUL19:
            link = container.querySelector('.irc_ft > a.irc_help');
            break;
        case VERSIONS.OCT19:
            link = container.querySelector('.PvkmDc, .qnLx5b, .zSA7pe');
            break;
    }

    // Create the search by image button
    var searchImageButton = link.cloneNode(true);
    searchImageButton.classList.add('vi_ext_addon');

    // Set the more sizes button text
    var searchImageButtonText;
    switch (version) {
        case VERSIONS.FEB18:
            searchImageButtonText = container.querySelector('.irc_ho');
            break;
        case VERSIONS.JUL19:
            searchImageButtonText = searchImageButton.querySelector('span');
            break;
        case VERSIONS.OCT19:
            searchImageButtonText = searchImageButton;
            break;
    }

    if (options['manually-set-button-text']) {
        searchImageButtonText.innerText = options['button-text-search-by-image'];
    } else {
        localiseObject(searchImageButtonText, '__MSG_searchImage__');
    }

    // Set the search by image button url
    searchImageButton.href = '/uploadbyurl?url=' + encodeURIComponent(imageURL);

    // Set additional options
    if (options['open-search-by-in-new-tab']) {
        searchImageButton.setAttribute('target', '_blank');
    }

    // Place the more sizes button
    link.parentElement.insertBefore(searchImageButton, link);
    link.parentElement.insertBefore(link, searchImageButton);

}


// Adds links to an object
function addLinks(node) {

    if (DEBUG)
        console.log('ViewImage: Trying to add links to node: ', node);

    // Find the container
    var [container, version] = getContainer(node);

    // Return if no container was found
    if (!container) {
        if (DEBUG)
            console.log('ViewImage: Adding links failed, container was not found.');
        return;
    }

    if (DEBUG)
        console.log('ViewImage: Assuming site version: ', version);

    // Clear any old extension elements
    clearExtElements(container);

    // Find the image url
    var imageURL = findImageURL(container, version);

    // Return if image was not found
    if (!imageURL) {

        if (DEBUG)
            console.log('ViewImage: Adding links failed, image was not found.');

        return;
    }

    addViewImageButton(container, imageURL, version);
    addSearchImageButton(container, imageURL, version);
}

function parseDataSource(array) {
    var meta = array[31][0][12][2];
    for (var i = 0; i < meta.length; i++) {
        try {
            images[meta[i][1][2][0]] = meta[i][1][3][0];
        } catch (error) {
            if (DEBUG)
                console.log('ViewImage: Skipping image');
        }
    }
}

function parseDataSource1() {
    const start_search = /AF_initDataCallback\({key:\s'ds:1',\sisError:\s{2}false\s,\shash:\s'\d+',\sdata:/;
    const end_search = ', sideChannel: {}});</script>';

    var match = document.documentElement.innerHTML.match(start_search);

    var start_index = match.index + match[0].length;
    var end_index = start_index + document.documentElement.innerHTML.slice(start_index).indexOf(end_search);

    parseDataSource(JSON.parse(document.documentElement.innerHTML.slice(start_index, end_index)));
}

function parseDataSource2() {
    const start_search = /AF_initDataCallback\({key:\s'ds:2',\sisError:\s{2}false\s,\shash:\s'\d+',\sdata:function(){return\s/;
    const end_search = '}});</script>';

    var match = document.documentElement.innerHTML.match(start_search);

    var start_index = match.index + match[0].length;
    var end_index = start_index + document.documentElement.innerHTML.slice(start_index).indexOf(end_search);
    parseDataSource(JSON.parse(document.documentElement.innerHTML.slice(start_index, end_index)));
}

// Check if source holds array of images
try {

    if (document.documentElement.innerHTML.indexOf('key: \'ds:1\'') != -1) {
        if (DEBUG)
            console.log('ViewImage: Attempting to parse data source 1.');
        parseDataSource1();
    } else if (document.documentElement.innerHTML.indexOf('key: \'ds:2\'') != -1) {
        if (DEBUG)
            console.log('ViewImage: Attempting to parse data source 2.');
        parseDataSource2();
    } else {
        throw 'Could not determine data source type.';
    }

    if (DEBUG)
        console.log('ViewImage: Successfully created source images array.');

} catch (error) {
    if (DEBUG) {
        console.log('ViewImage: Failed to create source images array.');
        console.error(error);
    }
}


// Define the mutation observers
var observer = new MutationObserver(function (mutations) {

    if (DEBUG)
        console.log('ViewImage: Mutations detected: ', mutations);

    var node;
    for (var mutation of mutations) {
        if (mutation.addedNodes && mutation.addedNodes.length > 0) {
            for (node of mutation.addedNodes) {
                if (node.classList) {
                    // Check for new image nodes
                    if (['irc_mi', 'irc_mut', 'irc_ris', 'n3VNCb', 'r48jcc'].some(className => node.classList.contains(className))) {
                        addLinks(node);
                    }
                }
            }
        }

        if (mutation.target.classList && mutation.target.classList.contains('n3VNCb', 'r48jcc')) {
            node = mutation.target.closest('.tvh9oe');

            if (!node.hasAttribute('aria-hidden')) {
                addLinks(node);
            }
        }
    }
});

// Get options and start adding links
var options;
chrome.storage.sync.get(['options', 'defaultOptions'], function (storage) {
    options = Object.assign(storage.defaultOptions, storage.options);

    if (DEBUG)
        console.log('ViewImage: Initialising observer...');

    observer.observe(document.body, {
        childList: true,
        subtree: true,
        attributes: true
    });
});


// inject CSS into document
if (DEBUG)
    console.log('ViewImage: Injecting CSS...');

var customStyle = document.createElement('style');
customStyle.innerText = `
.irc_dsh>.irc_hol.vi_ext_addon,
.irc_ft>.irc_help.vi_ext_addon,
.PvkmDc.vi_ext_addon,
.qnLx5b.vi_ext_addon
{
    margin: 0 4pt!important
}

.irc_hol.vi_ext_addon
{
    flex-grow:0!important
}

.zSA7pe[href^="/searchbyimage"] {
    margin-left: 4px;
}

.ZsbmCf.vi_ext_addon{
    flex-grow:0
}`;
document.head.appendChild(customStyle);