PC friendly instagram

pc-friendly-instagram.user.js

// ==UserScript==
// @name           pc-friendly-instagram
// @namespace      https://gist.github.com/justdanpo
// @version        0.7
// @description    pc-friendly-instagram
// @author         den_po
// @include        https://*.instagram.com/*
// @run-at         document-start
// @grant          none
// ==/UserScript==

(function () {
    const ua = navigator.userAgent += " Instagram"
    let loaderFound = false
    let cfgFound = false
    let oldReq = undefined

    document.documentElement.setAttribute('onreset', "navigator.__defineGetter__('userAgent', function(){ return '" + ua.replace(/'/g, "\'") + "' });")
    document.documentElement.dispatchEvent(new CustomEvent('reset'))
    document.documentElement.removeAttribute('onreset')

    new MutationObserver((mutations, observer) => mutations.forEach(mutation => mutation.addedNodes.forEach(itm => {
        if (itm.tagName == "SECTION") {
            //expand feed width
            itm.querySelectorAll("main > section").forEach(s => { s.style.maxWidth = "calc(100vh - 120px)" })

            //limit preview size
            itm.querySelectorAll("div > button > span.createSpriteExpand").forEach(expandButton => {
                expandButton.parentNode.parentNode.style.width = expandButton.parentNode.parentNode.style.height = "calc(100vh - 100px)"
                itm.style.display = "table"
            })

            //move buttons to top
            itm.querySelectorAll('nav > div > div > div:nth-of-type(2)').forEach(buttons => {
                buttons.style.left = "50px"
                buttons.style.top = "0"
                buttons.style.bottom = "auto"
                buttons.style.zIndex = "20"
                buttons.style.width = "200px"
            })

            //add permanent "feed" link
            itm.querySelectorAll('svg[aria-label="Posts"]').forEach(postsGrid => {
                const link = postsGrid.closest("a")
                const originalFeedLink = link.nextSibling

                let newLink = document.createElement("a")
                newLink.href = link.href += "feed/"
                newLink.innerHTML = '<span class="glyphsSpritePhoto_list__outline__24__grey_5" aria-label="Feed"></span>'
                newLink.className = originalFeedLink.className
                newLink.onclick = (e) => { e.preventDefault(); originalFeedLink.click() }

                originalFeedLink.style.display = "none"
                link.parentNode.insertBefore(newLink, link.nextSibling)

                new MutationObserver((mutations, observer) => mutations.forEach(mutation => {
                    if (newLink.className != mutation.target.className) newLink.className = mutation.target.className
                })).observe(originalFeedLink, { attributes: true })
            })

            //search input
            itm.querySelectorAll('input[placeholder="Search"]').forEach(searchInput => {
                searchInput.style.marginLeft = "250px"
            })
        }
        else if (itm.tagName == "SCRIPT" && !loaderFound) {

            let match = /Requiring module.*?\.(\w+)=function/g.exec(itm.innerHTML)
            if (match && match.length > 1) {
                loaderFound = true

                function myReq(fn, idx, dependencies) {
                    return oldReq(
                        (g, r, i, a, m, e, d) => {
                            let retValue = fn(g, r, i, a, m, e, d)

                            if (!cfgFound && m && m.hasOwnProperty("exports") && m.exports && m.exports.hasOwnProperty("feed-sidebar-threshold-min")) {
                                cfgFound = true
                                window._hookedConfig = m.exports
                                window._hookedConfig["feed-sidebar-threshold-min"].value = 99999
                            }
                            return retValue
                        }
                        , idx, dependencies)
                }

                window.__defineGetter__(match[1], function () { return myReq })
                window.__defineSetter__(match[1], function (newVal) { oldReq = newVal })
            }
        }

        if (itm && itm.querySelectorAll) {
            itm.querySelectorAll('video').forEach(video => {
                video.controls = "controls"
            })

            itm.querySelectorAll('img').forEach(img => {
                let decoding = img.attributes.getNamedItem("decoding")
                if (decoding && decoding.value == "auto") {
                    //get image context menu back
                    if (img.parentNode.nextSibling && img.parentNode.nextSibling.children.length == 0) img.parentNode.nextSibling.style.display = "none"

                    //improve image quality
                    img.sizes = "1080px"
                    new MutationObserver((mutations, observer) => mutations.forEach(mutation => { img.sizes = "1080px" })).observe(img, { attributes: true, attributeFilter: ['srcset'] })
                }
            })

            //remove annoying "login to continue" popup
            if (itm.tagName == "DIV" && itm.querySelector('.coreSpriteLoggedOutWordmark')) {
                itm.parentNode.removeChild(itm)
                document.body.style.overflow = "auto"
                let bo = new MutationObserver((mutations, observer) => mutations.forEach(mutation => { document.body.style.overflow = "auto" }))
                bo.observe(document.body, { attributes: true, attributeFilter: ['style'] })
                setTimeout(() => bo.disconnect(), 1000)
            }
        }
    }))).observe(document, { childList: true, subtree: true })
})()

What exactly does this script do?

It's outdated and doesn't work now. It allowed to upload images (which wasn't available at that time) and displayed images in a higher resolution.