function rememberGallerySelection(id_gallery) {}

function getGallerySelectedIndex(id_gallery) {}

function request(url, data, handler, errorHandler) {
    var xhr = new XMLHttpRequest();
    var url = url;
    xhr.open("POST", url, true);
    xhr.setRequestHeader("Content-Type", "application/json");
    xhr.onreadystatechange = function () {
        if (xhr.readyState === 4) {
            if (xhr.status === 200) {
                try {
                    var js = JSON.parse(xhr.responseText);
                    handler(js)
                } catch (error) {
                    console.error(error);
                    errorHandler()
                }
            } else{
                errorHandler()
            }
        }
    };
    var js = JSON.stringify(data);
    xhr.send(js);
}

function pad2(x) {
    return x<10 ? '0'+x : x
}

function formatTime(secs) {
    if(secs > 3600) return pad2(Math.floor(secs/60/60)) + ":" + pad2(Math.floor(secs/60)%60) + ":" + pad2(Math.floor(secs)%60)
    else if(secs > 60) return pad2(Math.floor(secs/60)) + ":" + pad2(Math.floor(secs)%60)
    else return Math.floor(secs) + "s"
}

function setTitle(progress) {
    var title = 'Stable Diffusion'
    if(opts.show_progress_in_title && progress) title = '[' + progress.trim() + '] ' + title;
    if(document.title != title) document.title =  title;
}

function randomId() {
    return "task(" + Math.random().toString(36).slice(2, 7) + Math.random().toString(36).slice(2, 7) + Math.random().toString(36).slice(2, 7)+")"
}

// starts sending progress requests to "/internal/progress" uri, creating progressbar above progressbarContainer element and
// preview inside gallery element. Cleans up all created stuff when the task is over and calls atEnd.
// calls onProgress every time there is a progress update
function requestProgress(id_task, progressbarContainer, gallery, atEnd = null, onProgress = null, once = false) {
    var hasStarted = false
    var dateStart = new Date()
    var prevProgress = null
    var parentProgressbar = progressbarContainer.parentNode
    var parentGallery = gallery ? gallery.parentNode : null
    var divProgress = document.createElement('div')
    divProgress.className='progressDiv'
    divProgress.id = 'progressbar'
    divProgress.style.display = opts.show_progressbar ? "block" : "none"
    var divInner = document.createElement('div')
    divInner.className='progress'
    divProgress.appendChild(divInner)
    parentProgressbar.insertBefore(divProgress, progressbarContainer)
    localStorage.setItem('task', id_task);
    console.debug('task active:', id_task)
    if (parentGallery) {
        var livePreview = document.createElement('div')
        livePreview.className='livePreview'
        parentGallery.insertBefore(livePreview, gallery)
    }

    var removeProgressBar = function() {
        console.debug('task end:   ', id_task)
        localStorage.removeItem('task');
        setTitle("")
        if (divProgress) parentProgressbar.removeChild(divProgress)
        if (parentGallery) parentGallery.removeChild(livePreview)
        if (atEnd) atEnd()
    }

    var fun = function(id_task, id_live_preview){
      request("./internal/progress", {"id_task": id_task, "id_live_preview": id_live_preview}, function(res){
          var elapsedFromStart = (new Date() - dateStart) / 1000
            if (res.completed) {
                removeProgressBar()
                return
            }
            var rect = progressbarContainer.getBoundingClientRect()
            if (rect.width) divProgress.style.width = rect.width + "px";
            progressText = ""
            divInner.style.width = ((res.progress || 0) * 100.0) + '%'
            divInner.style.background = res.progress ? "" : "transparent"
            if (res.progress > 0) progressText = ((res.progress || 0) * 100.0).toFixed(0) + '%'
            if (res.eta) progressText += " ETA: " + formatTime(res.eta)
            setTitle(progressText)
            if (res.textinfo && res.textinfo.indexOf("\n") == -1) progressText = res.textinfo + " " + progressText
            divInner.textContent = progressText
            hasStarted |= res.active
            if (!res.active && (hasStarted || once)) {
                removeProgressBar()
                return
            }
            if (res.completed) {
              removeProgressBar()
              return
          }
          if (elapsedFromStart > 30 && !res.queued && res.progress == prevProgress) {
                removeProgressBar()
                return
            }
            if (res.live_preview && gallery) {
                var rect = gallery.getBoundingClientRect()
                if(rect.width){
                    livePreview.style.width = rect.width + "px"
                    livePreview.style.height = rect.height + "px"
                }
                var img = new Image();
                img.onload = function() {
                    livePreview.appendChild(img)
                    if (livePreview.childElementCount > 2) livePreview.removeChild(livePreview.firstElementChild)
                }
                img.src = res.live_preview;
            }
            if (onProgress) onProgress(res)
            setTimeout(() => fun(id_task, res.id_live_preview), opts.live_preview_refresh_period || 250)
        }, function() {
            removeProgressBar()
        })
    }
    fun(id_task, 0)
}