!function(w, d) {
    if (!w.HTMLInclude) {
        w.HTMLInclude = function() {
            function isInViewport(element, offset) {
                return element.getBoundingClientRect().top <= (+offset + w.innerHeight)
            }
            function ajax(url, elements) {
                let xhr = new XMLHttpRequest()
                xhr.onreadystatechange = function() {
                    if (xhr.readyState == 4 && xhr.status == 200) {
                        elements.forEach(function(element) {
                            let dataReplace = element.getAttribute("data-replace")
                            let z = xhr.responseText
                            if (dataReplace) {
                                dataReplace.split(",").forEach(function(el) {
                                    let o = el.trim().split(":")
                                    z = z.replace(new RegExp(o[0], "g"), o[1])
                                })
                            }
                            element.outerHTML = z
                            let scripts = new DOMParser().parseFromString(z, 'text/html').querySelectorAll("SCRIPT")
                            let i = 0
                            let j = scripts.length
                            while (i < j) {
                                let newScript = d.createElement("SCRIPT")
                                scripts[i].src ? newScript.src = scripts[i].src : newScript.innerHTML = scripts[i].innerHTML
                                d.head.appendChild(newScript)
                                i++
                            }
                        })
                    }
                }
                xhr.open("GET", url, true)
                xhr.send()
            }
            function lazyLoad(element, offset) {
                w.addEventListener("scroll", function scrollFunc() {
                    if (isInViewport(element, offset)) {
                        w.removeEventListener("scroll", scrollFunc)
                        ajax(element.getAttribute("data-include"), [element])
                    }
                })
            }
            let store = {}
            let dis = d.querySelectorAll('[data-include]:not([data-in])')
            let i = dis.length
            while (i--) {
                let di = dis[i].getAttribute('data-include')
                let laziness = dis[i].getAttribute('data-lazy')
                dis[i].setAttribute("data-in", "")
                if (!laziness || (laziness && isInViewport(dis[i], laziness))) {
                    store[di] = store[di] || []
                    store[di].push(dis[i])
                } else {
                    lazyLoad(dis[i], laziness)
                }
            }
            for (let key in store) {
                ajax(key, store[key])
            }
        }
    }
    w.HTMLInclude()
}(window, document)