(async(window, document)=>{
    // https://gist.github.com/hagb4rd/6843803a6674fe1b9ead6f1e60f14f15#file-queue-download-images-js
    // -----------

    // queue() returns a promise returning function. 'tasks' is an array of higher order functions that return 'promise returning'/'async' functions [()=>async(){ }]. 
    // the purpose of that wrapping  is not to start resolving the promise immediately, but being able to map parameters for the task.  
    //'concurrent' is the max. number of tasks to be executed in parallel.
    function queue(tasks, concurrent) {
        return function() {
            var result = new Array(tasks.length);
            var running = 0;
            var pending = tasks.length;
            var cursor = 0;
        
            function next(onDone, onError) {
                if (cursor < tasks.length && running < concurrent) {
                let index = cursor;
                ++cursor;
                ++running;
        
                function save(v) {
                result[index] = v;
                --running;
                --pending;
                if (pending === 0)
                    onDone(result);
                else
                    next(onDone, onError);
                return v;
                }
        
                //execute task/resolve promise, and save result
                tasks[index]().then(save, save);
                //load next task
                next(onDone, onError);
            }
            }
            return new Promise(function(resolve, reject) {
            next(function(result) {
                resolve(result);
            }, reject);
            });
        }
    }
    
window.urlcreate=(u=`https://content4.coedcherry.com/watch-my-gf/184395/91122_#.jpg`,n=1,m=20)=>[...(new Array(m-n+1)).keys()].map(x=>(x+n)).map(x=>{ var pad=u.match(/#+/)[0].length; return u.replace(`#`.repeat(pad), String(x).padStart(pad, '0'));})

window.loadImage=(u)=>new Promise((resolve,reject)=>{var i=new Image(); i.onload=(e)=>resolve(i); i.onerror=(e)=>{var a=document.createElement('a');a.target='imageview';a.href=u; a.innerText=u;resolve(a)}; i.src=u; });

window.findImageLinks=(extensions=['.jpg','.png','.jpeg','.gif','.tif','.wbem'])=>[...document.querySelectorAll('a')].map(a=>a.href).filter(href=>extensions.some(ext=>ext==href.slice(-ext.length)));

window.prepend=(elem)=>(document.body||document.rootElement).prepend(elem);

window.loadImages=(list)=>(document.documentElement.innerHTML=``,list.map(u=>()=>(console.log(u), loadImage(u)).then(x=>prepend(x))).reduce((prev,next)=>prev.then(next),Promise.resolve()))

window.linkedImages=(d)=>{
        d=d||window.document;
        var xs=d.querySelectorAll("[href$=\".jpg\"],[href$=\".png\"]")
        var is=[...xs].map(x=>x.href);
        return is;
    }
window.embedImages=(minW=250,minH=250)=>[...document.querySelectorAll('img')].filter(({width, height})=>(width>=minW && height>=minH));

window.dataUrlFromCanvas=(img)=>new Promise((resolve,reject) => {
        if(img instanceof Image) {
            try {
		var n=document.createElement("CANVAS");
                n.height=img.height;
                n.width=img.width;
                n.getContext("2d").drawImage(img,0,0);
                var dataUrl=n.toDataURL("image/jpeg");
                return resolve(dataUrl);
            } catch(err) {
                reject(err.message);
            }    
        } else {
            var e=new Image();
            e.crossOrigin='Anonymous';
            var n=document.createElement("CANVAS");        
            e.addEventListener("error", (e)=>reject(e.message));
            e.addEventListener("load", () => {
                try {
                    n.height=e.height;
                    n.width=e.width;
                    n.getContext("2d").drawImage(e,0,0);
                    var dataUrl=n.toDataURL("image/jpeg");
                    resolve(dataUrl);
                } catch(err) {
                    reject(err.message);
                }
            });
            e.src = img.src ? img.src : img;
        }
    })

window.dataUrlByFileReader = (url) => new Promise((resolve, reject) => {
        var xhr = new XMLHttpRequest();
        xhr.responseType = 'blob';
        xhr.onerror=(e)=>reject(e);
        xhr.onload = function () {
            var reader = new FileReader();
            reader.onerror = function(e) {
                reject(e.message)
            }
            reader.onloadend = function () {
            resolve(reader.result);
            }
            reader.readAsDataURL(xhr.response);
        };
        xhr.open('GET', url);
        xhr.send();
    })

window.readAsDataUrl=async(img)=>{
        var dataUrl;
        try {
            dataUrl=await dataUrlFromCanvas(img);
            return dataUrl;
        } catch(err) {
            conole.log(err);
        }
        try {
            dataUrl=await dataUrlFromCanvas(`https://jslave.herokuapp.com/proxy/?url=${img}`);
            return dataUrl;
        } catch(err) {
            conole.log(err);
        }
        try {
            dataUrl=await dataUrlFromCanvas(`https://jslave2.herokuapp.com/proxy/?url=${img}`);
            return dataUrl;
        } catch(err) {
            conole.log(err);
        }
        try {
            dataUrl=await dataUrlByFileReader(img);
            return dataUrl;
        } catch(err) {
            console.log(err);
        }
        try {
            dataUrl=await dataUrlByFileReader(`https://jslave.herokuapp.com/proxy/?url=${img}`);
            return dataUrl;
        } catch(err) {
            console.log(err);
        }
        try {
            dataUrl=await dataUrlByFileReader(`https://jslave2.herokuapp.com/proxy/?url=${img}`);
            return dataUrl;
        } catch(err) {
            console.log(err);
        }
        throw Error('could not resolve create dataUrl');
    };

window.download=async(image,name)=>{
        try {
            var a=document.createElement('a');
            var dataUrl=await readAsDataUrl(image);
            a.href=dataUrl;
            a.setAttribute('download', name);
            a.style.display='none';
            (document.body || document.documentElement).appendChild(a);
            console.log('dowload:'+name);
            console.log(image);
            a.click();      
        } catch (err) {
            console.log(err, [image, name]);
        }
        return [image, name]
    }
window.downloadText=async(txt,name)=>{
        try {
            var rndName=()=>Date.now()+(Math.random()*100000|0)+'.txt'
            name=name||rndName();
            var a=document.createElement('a');
            var dataUrl=`data:text/plain;charset=utf-8,${encodeURIComponent(txt)}`;
            a.href=dataUrl;
            a.setAttribute('download', name);
            a.style.display='none';
            (document.body || document.documentElement).appendChild(a);
            console.log(`downloading: ${name}`);
            console.log(`--------------`);
            console.log(txt);
            a.click();      
        } catch (err) {
            console.log(err, [txt, name]);
        }
        return [txt, name]
    }
window.downloadLinkedImages=()=>{
    return [...linkedImages()].map((url)=>{
            var name=`${location.host}${location.pathname.replace(/\//g,'.')}.${url.split(/\//).pop()}`;
            return ()=>download(url,name)
        })
    };
window.downloadImages=(w=250,h=250)=>embedImages(w,h).map((i)=>{
    var url=new URL(i.src); 
    var name=[url.host].concat(i.alt?i.alt.match(/\w+/g):[]).concat(url.pathname.match(/[^/\?]+/g)).filter(x=>!!x).join('-');
    return ()=>download(i.src,name); 
    });

downloadText(findImageLinks().join('\n'));
    
})(window, window.document)

//Bookmarklet