Amazon Keepa and Sakura Checker Plugin for Amazon Japan

amazon_keepa_sakura_checker.user.js

// ==UserScript==
// @name        Amazon Keepa and Sakura Checker
// @description Amazon Keepa and Sakura Checker Plugin for Amazon Japan
// @author      Maxeo | maxeo.net, Kusaanko
// @license     https://creativecommons.org/licenses/by-sa/4.0/
// @match       https://www.amazon.co.jp/*
// @version     1.3.2
// @namespace   https://greasyfork.org/users/88678
// ==/UserScript==

// Forked from https://greasyfork.org/ja/scripts/26852-amazon-keepa
// Added support for Amazon Japan and fixed problem not to show keepa
// Added support for Sakura Checker https://sakura-checker.jp/

function place() {
    if(window.location.href.match(/https:\/\/www.amazon.*\/(dp\/*|gp\/product\/*)/)) {
        var prod_code;
        if (prod_code = window.location.pathname.match(/^\/gp\/product\/(.*)\/.*$/)) {
            prod_code = prod_code[1]
        }
        else if (prod_code = window.location.pathname.match(/^\/.*\/dp\/(.*)\/.*$/)) {
            prod_code = prod_code[1];
        }
        else if (prod_code = window.location.pathname.match(/^\/dp\/(.*)\/.*$/)) {
            prod_code = prod_code[1];
        }
        else if(prod_code = window.location.pathname.match(/^\/gp\/product\/(.*)\\?.*$/)) {
            prod_code = prod_code[1];
        }
        else if (prod_code = window.location.pathname.match(/^\/.*\/dp\/(.*)\\?.*$/)) {
            prod_code = prod_code[1];
        }
        else if (prod_code = window.location.pathname.match(/^\/dp\/(.*)\\?.*$/)) {
            prod_code = prod_code[1];
        }

        var numl=0;
        switch(document.location.hostname.match('.*\.amazon\.(.*)$')[1]){
            case 'com':
                numl=1;
                break;
            case 'ca':
                numl=6;
                break;
            case 'mx':
                numl=11;
                break;
            case 'uk':
                numl=2;
                break;
            case 'de':
                numl=3;
                break;
            case 'fr':
                numl=4;
                break;
            case 'it':
                numl=8;
                break;
            case 'es':
                numl=9;
                break;
            case 'co.jp':
                numl=5;
                break;
            case 'in':
                numl=10;
                break;
        }

        var target = '#hover-zoom-end';
        if(document.querySelector(target) == null) {
            // Mobile
            target = '#productTitleGroupAnchor';
        }
        appendHtml(document.querySelector(target), '<iframe style="width: 100%; height: 489px; border:0 none;overflow: hidden;" src="https://keepa.com/iframe_addon.html#'+numl+'-0-'+prod_code+'" scrolling="no" id="keepa"></iframe>');
        appendHtml(document.querySelector(target), '<iframe style="width: 100%; height: 600px; border:0 none;overflow: hidden;" src="https://sakura-checker.jp/search/'+prod_code+'/" id="sakura_checker"></iframe>');
    }
}

var preURL = '';
setInterval(function() {
    if(window.location.href != preURL) {
        preURL = window.location.href;
        if(document.querySelector('#keepa') != null) {
            document.querySelector('#keepa').remove();
            document.querySelector('#sakura_checker').remove();
        }
        place();
    }
}, 1000);

function appendHtml(el, str) {
    var div = document.createElement('div');
    div.innerHTML = str;
    while (div.children.length > 0) {
        el.appendChild(div.children[0]);
    }
}