// ==UserScript==
// @author       @shitchell
// @namespace    https://github.com/shitchell
// @license      wtfpl
// @name         adblockblockblock
// @version      0.0.1
// @description  Remove anti-adblock
// @include      *://*
// @grant        none
// @run-at       document-start
// @downloadURL none
// ==/UserScript==

// This script is under active development. I will update this with more class names
// used by modals I come across used to block the page. Warning: this script MIGHT
// break some pages. It basically searches for any elements which contain a certain
// string in their class names and then follows their parent tree up to see if that
// matching element or any of its parents have a z-index > 50. I might increase that
// z-index if 50 is too low and accidentally removes intentional, desired elements,
// and I might have to implement more sophisticated logic than the above if it ends
// up destroying many elements we'd rather keep. Please drop a comment with the link
// to any page this breaks (although hopefully that number is tiny to nil)!

var DEBUG = false;
var VERIFIED_ELEMENTS = [];

function debug(...message) {
    if (DEBUG) {
        let timestamp = new Date().toISOString().replace(/T/, ' ').replace(/\..+/, '');
        let prefix = `[adblockblockblock] ${timestamp} --`;
        console.log(prefix, ...message);
    }
}

function removeAdblockblock() {
    'use strict';
    debug("Removing adblockblock...");

    //
    /// Search for the following common classes used by modals that block the page
    ////
    let pageBlockerClasses = [
        'overlay' // this definitely needs to be updated with more classes........
    ];
    debug("Searching for page blockers...", pageBlockerClasses);
    for (const pageBlockerClass of pageBlockerClasses) {
        // Get all elements that contain the class name
        let blockerCandidateElements = document.querySelectorAll(`*[class*="${pageBlockerClass}"]`);
        debug(`Found ${blockerCandidateElements.length} elements with class name containing "${pageBlockerClass}"`, blockerCandidateElements);

        // Loop through the elements and their parents to see if they are blocking the page
        for (let blockerCandidateElement of blockerCandidateElements) {
            debug(`Checking element "${blockerCandidateElement.tagName}" with class "${blockerCandidateElement.className}"`, blockerCandidateElement);

            // Store the original element so that we can cache/skip it if we've already verified it
            const originalBlockerCandidateElement = blockerCandidateElement;
            let blockerCandidateVerified = true;
            
            // Check if we've already verified this element
            if (VERIFIED_ELEMENTS.includes(originalBlockerCandidateElement)) {
                debug(`Element "${blockerCandidateElement.tagName}" with class "${blockerCandidateElement.className}" has already been verified`, blockerCandidateElement);
                continue;
            }

            // Check the z-index and position of the element and its parents
            while (blockerCandidateElement) {
                if (
                    blockerCandidateElement.tagName === 'BODY'
                    || blockerCandidateElement.tagName === 'HTML') {
                    // If we get to the top, the element is not blocking the page
                    break;
                }

                // Check the z-index and position
                let computedStyle = window.getComputedStyle(blockerCandidateElement);
                let position = computedStyle.getPropertyValue('position');
                let zIndex = computedStyle.getPropertyValue('z-index');
                if (
                    (position === 'fixed' || position === 'absolute' || position === 'sticky')
                    && zIndex !== 'auto' && zIndex > 50
                ) {
                    // If the element has a position and z-index that would block the page, remove it
                    debug(`Removing element "${blockerCandidateElement.tagName}" with class "${blockerCandidateElement.className}"`, blockerCandidateElement);
                    blockerCandidateElement.remove();
                    blockerCandidateVerified = false;
                    break;
                }

                // Move on up the DOM tree
                blockerCandidateElement = blockerCandidateElement.parentElement;
            }

            // Cache the element if it was verified
            if (blockerCandidateVerified) {
                debug(`Element "${originalBlockerCandidateElement.tagName}" with class "${originalBlockerCandidateElement.className}" has been verified`, originalBlockerCandidateElement);
                VERIFIED_ELEMENTS.push(originalBlockerCandidateElement);
            }
        }
    }

    //
    /// Double check the html, body, and content elements to ensure content is not hidden
    ////
    let overflowHiddenElements = document.querySelectorAll('html, body, #content, #main, main, section');
    for (const overflowHiddenElement of overflowHiddenElements) {
        let computedStyle = window.getComputedStyle(overflowHiddenElement);
        let overflow = computedStyle.getPropertyValue('overflow');
        debug(`Overflow of element "${overflowHiddenElement.tagName}" with class "${overflowHiddenElement.className}" is "${overflow}"`, overflowHiddenElement);
        if (overflow.indexOf('hidden') !== -1) {
            debug("Setting overflow to 'initial !important'...", overflowHiddenElement);
            overflowHiddenElement.style.overflow = 'initial !important';
        }
    }
}

(function() {
    'use strict';

    // Remove the adblockblock
    removeAdblockblock();

    // Remove the adblockblock if the page changes
    let observer = new MutationObserver(removeAdblockblock);
    observer.observe(document, { childList: true, subtree: true });
})();