/**
 * Unchecker - Simple extension letting you uncheck all checkboxes on a page
 * Copyright (c) Ad5001 2021
 * 
 * This Source Code Form is subject to the terms of the Mozilla Public License, 
 * v. 2.0. If a copy of the MPL was not distributed with this file, You can 
 * obtain one at http://mozilla.org/MPL/2.0/.
 **/

const UNCHK_SCRIPT = `
function disable_checkboxes(element){
    document.body.querySelectorAll('input[type="checkbox"]').forEach(function(el){
        el.checked = false
    })
}
disable_checkboxes(document.body)
document.body.querySelectorAll('iframe').forEach(function(el){disable_checkboxes(el.contentDocument || el.contentWindow.document)})
`
const CHK_SCRIPT = `
function check_checkboxes(element){
    document.body.querySelectorAll('input[type="checkbox"]').forEach(function(el){
        el.checked = true
    })
}
check_checkboxes(document.body)
document.body.querySelectorAll('iframe').forEach(function(el){check_checkboxes(el.contentDocument || el.contentWindow.document)})
`
const TITLE_APPLY = "Uncheck all checkboxes";
const TITLE_REMOVE = "Check all checkboxes";
const APPLICABLE_PROTOCOLS = ["http:", "https:"];
const MENU_CONTEXTS = ["editable", "image", "link", "page"];

/**
 * Toggle Script: based on the current title, insert or remove the Script.
 * Update the page action's title and icon, aswell as the context menu item to reflect its state.
 **/
function toggleScript(tab) {

    function gotTitle(title) {
        if (title === TITLE_APPLY) {
            browser.browserAction.setIcon({tabId: tab.id, path: "icons/off.svg"});
            browser.browserAction.setTitle({tabId: tab.id, title: TITLE_REMOVE});
            browser.menus.remove("unchecker-main").then(function() {
                browser.menus.create({
                    id: "unchecker-main",
                    title: TITLE_REMOVE,
                    icons: {
                        "16": "icons/off.svg"
                    },
                    contexts: MENU_CONTEXTS,
                    onclick(info,tab) { toggleScript(tab) } 
                });
            }, function(){})
            browser.tabs.executeScript({
                code: UNCHK_SCRIPT
            });
        } else {
            browser.browserAction.setIcon({tabId: tab.id, path: "icons/on.svg"});
            browser.browserAction.setTitle({tabId: tab.id, title: TITLE_APPLY});
            browser.menus.remove("unchecker-main").then(function() {
                browser.menus.create({
                    id: "unchecker-main",
                    title: TITLE_APPLY,
                    icons: {
                        "16": "icons/on.svg"
                    },
                    contexts: MENU_CONTEXTS,
                    onclick(info,tab) { toggleScript(tab) } 
                });
            }, function(){})
            browser.tabs.executeScript({
                code: CHK_SCRIPT
            });
        }
    }

    var gettingTitle = browser.browserAction.getTitle({tabId: tab.id});
    gettingTitle.then(gotTitle);
}

/**
 * Returns true only if the URL's protocol is in APPLICABLE_PROTOCOLS.
 **/
function protocolIsApplicable(url) {
    let anchor =  document.createElement('a');
    anchor.href = url;
    return APPLICABLE_PROTOCOLS.includes(anchor.protocol);
}

/**
 * Initialize the page action: set icon and title, then show.
 * Only operates on tabs whose URL's protocol is applicable.
 **/
function initializebrowserAction(tab, createMenu) {
    if(protocolIsApplicable(tab.url)) {
        browser.browserAction.setIcon({tabId: tab.id, path: "icons/on.svg"});
        browser.browserAction.setTitle({tabId: tab.id, title: TITLE_APPLY});
        browser.browserAction.show(tab.id);
    }
    if(createMenu) {
        browser.menus.remove("unchecker-main").then(function() {
            browser.menus.create({
                id: "unchecker-main",
                title: TITLE_APPLY,
                icons: {
                    "16": "icons/on.svg"
                },
                contexts: MENU_CONTEXTS,
                onclick(info,tab) { toggleScript(tab) } 
            });
        }, function(){})
    }
}

/**
 * When first loaded, initialize the page action for all tabs.
 **/
browser.menus.create({
    id: "unchecker-main",
    title: TITLE_APPLY,
    icons: {
        "16": "icons/on.svg"
    },
    contexts: MENU_CONTEXTS,
    onclick(info,tab) { toggleScript(tab) } 
});
let gettingAllTabs = browser.tabs.query({});
gettingAllTabs.then((tabs) => {
    for (let tab of tabs) {
        initializebrowserAction(tab, false);
    }
});

/**
 * Each time a tab is updated, reset the page action for that tab.
 **/
browser.tabs.onUpdated.addListener((id, changeInfo, tab) => {
    initializebrowserAction(tab, true);
});

/** 
 * Toggle Script when the page action is clicked.
 **/
browser.browserAction.onClicked.addListener(toggleScript);