var fileList = [];
var observer2 = null;
var numDone = 0;
var delay = 100; //milliseconds
var UploadState = {
        QUEUED: 'queued',
        REQUESTING: 'requesting',
        UPLOADING: 'uploading',
        UPLOADED: 'uploaded',
        HASHED: 'hashed',
        FINISHED: 'finished',
        FAILED: 'failed'
}

//true indicates direct upload is being used, but cancel may set it back to false at which point direct upload functions should not do further work
var directUploadEnabled = false;

var directUploadReport = true;

//How many files have started being processed but aren't yet being uploaded
var filesInProgress = 0;
//The # of the current file being processed (total number of files for which upload has at least started)
var curFile = 0;
//The number of upload ids that have been assigned in the files table
var getUpId = (function() {
        var counter = -1;
        return function() { counter += 1; return counter }
})();
//How many files are completely done
var finishFile = (function() {
        var counter = 0;
        return function() { counter += 1; return counter }
})();


function setupDirectUpload(enabled) {
        if (enabled) {
                directUploadEnabled = true;
                //An indicator as to which version is being used - should keep updated.
                console.log('Dataverse Direct Upload for v5.0');
                $('.ui-fileupload-upload').hide();
                $('.ui-fileupload-cancel').hide();
                //Catch files entered via upload dialog box. Since this 'select' widget is replaced by PF, we need to add a listener again when it is replaced
                var fileInput = document.getElementById('datasetForm:fileUpload_input');
                if (fileInput !== null) {
                        fileInput.addEventListener('change', function(event) {
                                fileList = [];
                                for (var i = 0; i < fileInput.files.length; i++) {
                                        queueFileForDirectUpload(fileInput.files[i]);
                                }
                        }, { once: false });
                }
                //Add support for drag and drop. Since the fileUploadForm is not replaced by PF, catching changes with a mutationobserver isn't needed
                var fileDropWidget = document.getElementById('datasetForm:fileUpload');
                fileDropWidget.addEventListener('drop', function(event) {
                        fileList = [];
                        for (var i = 0; i < event.dataTransfer.files.length; i++) {
                                queueFileForDirectUpload(event.dataTransfer.files[i]);
                        }
                }, { once: false });

                var config = { childList: true };
                var callback = function(mutations) {
                        mutations.forEach(function(mutation) {
                                for (i = 0; i < mutation.addedNodes.length; i++) {
                                        //Add a listener on any replacement file 'select' widget
                                        if (mutation.addedNodes[i].id == 'datasetForm:fileUpload_input') {
                                                fileInput = mutation.addedNodes[i];
                                                mutation.addedNodes[i].addEventListener('change', function(event) {
                                                        for (var j = 0; j < mutation.addedNodes[i].files.length; j++) {
                                                                queueFileForDirectUpload(mutation.addedNodes[i].files[j]);
                                                        }
                                                }, { once: false });
                                        }
                                }
                        });
                };
                if (observer2 != null) {
                        observer2.disconnect();
                }
                observer2 = new MutationObserver(callback);
                observer2.observe(document.getElementById('datasetForm:fileUpload'), config);
        } //else ?
}

function sleep(ms) {
        return new Promise(resolve => setTimeout(resolve, ms));
}

async function cancelDatasetCreate() {
        //Page is going away - don't upload any more files, finish reporting current uploads, and then call cancelCreateCommand to clean up temp files
        if (directUploadEnabled) {
                fileList = [];
                directUploadEnabled = false;
                directUploadReport = false;
                while (curFile != numDone) {
                        $("#cancelCreate").prop('onclick', null).text("Cancel In Progress...").prop('disabled', true);
                        $("#datasetForm\\:save").prop('disabled', true);
                        await sleep(1000);
                }
                cancelCreateCommand();
        } else {
                cancelCreateCommand();
        }
}


async function cancelDatasetEdit() {
        //Don't upload any more files and don't send any more file entries to Dataverse, report any direct upload files that didn't get handled
        if (directUploadEnabled) {
                fileList = [];
                directUploadEnabled = false;
                directUploadReport = false;
                        while (curFile != numDone) {
                        $("#doneFilesButtonnop").prop('onclick', null).text("Cancel In Progress...").prop('disabled', true);
                        await sleep(1000);
                }
                cancelEditCommand();
        } else {
                cancelEditCommand();
        }
}


var inDataverseCall = false;

class fileUpload {
        constructor(file) {
                this.file = file;
                this.state = UploadState.QUEUED;
        }
        async startRequestForDirectUploadUrl() {
                this.state=UploadState.REQUESTING;
                //Wait for each call to finish and update the DOM
                while (inDataverseCall === true) {
                        await sleep(delay);
                }
                inDataverseCall = true;
                //storageId is not the location - has a : separator and no path elements from dataset
                //(String uploadComponentId, String fullStorageIdentifier, String fileName, String contentType, String checksumType, String checksumValue)
                requestDirectUploadUrls([{ name: 'fileSize', value: this.file.size }]);
        }

        async doUpload() {
                this.state = UploadState.UPLOADING;
                var thisFile = curFile-1;
                //This appears to be the earliest point when the file table has been populated, and, since we don't know how many table entries have had ids added already, we check
                var filerows = $('.ui-fileupload-files .ui-fileupload-row');
                //Add an id attribute to each entry so we can later match progress and errors with the right entry
                for (i = 0; i < filerows.length; i++) {
                        var upid = filerows[i].getAttribute('upid');
                        if (typeof upid === "undefined" || upid === null || upid === '') {
                                var newUpId = getUpId();
                                filerows[i].setAttribute('upid', newUpId);
                        }
                }
                //Get the list of files to upload
                var files = $('.ui-fileupload-files');
                //Find the corresponding row (assumes that the file order and the order of rows is the same)
                var fileNode = files.find("[upid='" + thisFile + "']");
                //Decrement number queued for processing
                filesInProgress = filesInProgress - 1;
                var progBar = fileNode.find('.ui-fileupload-progress');
                var cancelButton = fileNode.find('.ui-fileupload-cancel');
                 var cancelled=false;
                  $(cancelButton).click(function() {cancelled=true});
                progBar.html('');
                progBar.append($('<progress/>').attr('class', 'ui-progressbar ui-widget ui-widget-content ui-corner-all'));
                if(this.urls.hasOwnProperty("url")) {
                $.ajax({
                        url: this.urls.url,
                        headers: { "x-amz-tagging": "dv-state=temp" },
                        type: 'PUT',
                        data: this.file,
                        context:this,
                        cache: false,
                        processData: false,
                        success: function() {
                                //ToDo - cancelling abandons the file. It is marked as temp so can be cleaned up later, but would be good to remove now (requires either sending a presigned delete URL or adding a callback to delete only a temp file
                                if(!cancelled) {
                                    this.reportUpload();
                                }
                        },
                        error: function(jqXHR, textStatus, errorThrown) {
                                console.log('Failure: ' + jqXHR.status);
                                console.log('Failure: ' + errorThrown);
                                uploadFailure(jqXHR, thisFile);
                        },
                        xhr: function() {
                                var myXhr = $.ajaxSettings.xhr();
                                if (myXhr.upload) {
                                        myXhr.upload.addEventListener('progress', function(e) {
                                                if (e.lengthComputable) {
                                                        var doublelength = 2 * e.total;
                                                        progBar.children('progress').attr({
                                                                value: e.loaded,
                                                                max: doublelength
                                                        });
                                                }
                                        });
                                }
                                return myXhr;
                        }
                });
                } else {
                  var loaded=[];
                  this.etags=[];
                  this.numEtags=0;
                  var doublelength = 2* this.file.size;
                  var partSize= this.urls.partSize;
                  var started=0;
                  console.log('Num parts: ' + Object.keys(this.urls.urls).length);
                  loaded[thisFile]=[];
                  for (const [key, value] of Object.entries(this.urls.urls)) {
                    if(!directUploadEnabled || cancelled) {
                      //Direct upload has been cancelled - quit uploading new parts and abort this mp upload
                      //once the parts in progress are done
                      while((started-this.numEtags)>0) {
                        await sleep(delay);
                      }
                      this.cancelMPUpload();
                      directUploadFinished();
                      break;
                    }
                    started=started+1;
                    //Don't queue more than 10 parts at a time
                    while((started-this.numEtags)>10) {
                      await sleep(delay);
                    }
                    if(typeof this.etags[key] == 'undefined' || this.etags[key]==-1) {
                       this.etags[key]=-1;
                       var size = Math.min(partSize, this.file.size-(key-1)*partSize);
                       var offset=(key-1)*partSize;
                       var blob=this.file.slice(offset, offset + size);
                       $.ajax({
                        url: value,
  //                      headers: { "x-amz-tagging": "dv-state=temp" },
                        type: 'PUT',
                        data: blob,
                        context:this,
                        cache: false,
                        processData: false,
                        success: function(data, status, response) {
                                console.log('Successful upload of part ' + key + ' of ' + Object.keys(this.urls.urls).length);
                                //The header has quotes around the eTag
                                this.etags[key]=response.getResponseHeader('ETag').replace(/["]+/g, '');
                                this.numEtags = this.numEtags+1;
                                if(this.numEtags == Object.keys(this.urls.urls).length) {
                                  this.multipartComplete();
                                }
                        },
                        error: function(jqXHR, textStatus, errorThrown) {
                                console.log('Failure: ' + jqXHR.status);
                                console.log('Failure: ' + errorThrown);
                                console.log(thisFile + ' : part' + key);
                                this.numEtags = this.numEtags+1;
                                this.etags[key]=-1;
                                if(this.numEtags == Object.keys(this.urls.urls).length) {
                                  this.multipartComplete();
                                }
                        },
                        xhr: function() {
                                var myXhr = $.ajaxSettings.xhr();
                                if (myXhr.upload) {
                                        myXhr.upload.addEventListener('progress', function(e) {
                                                if (e.lengthComputable) {
                                                        loaded[thisFile][key-1]=e.loaded;
                                                        var total=0;
                                                        for(let val of loaded[thisFile].values()) {
                                                          //if parts with lower keys haven't reported yet, there could be undefined values in the array = skip those
                                                          if(typeof val !== 'undefined') {
                                                            total = total+val;
                                                          }
                                                        }
                                                        progBar.children('progress').attr({
                                                                value: total ,
                                                                max: doublelength
                                                        });
                                                }
                                        });
                                }
                                return myXhr;
                        }
                });
              }
            }
          }
        }

        //All of the multipart part uploads have succeeded or failed. Here we decide whether to finish, retry, or cancel/abort 
        multipartComplete() {
          console.log('reporting file ' + this.file.name);
          var allGood=true;
          //Safety check - verify that all eTags were set
          for(val in this.etags.values()) {
            if (val==-1) {
              allGood=false;
              break;
            }
          }
          if(!allGood) {
            if(this.alreadyRetried) {
              console.log('Error after retrying ' + this.file.name);
              uploadFailure(jqXHR, thisFile);
              this.cancelMPUpload();
            } else {
              this.alreadyRetried=true;
              this.doUpload();
            }
          } else {
            this.finishMPUpload();
          }
        }
        
        reportUpload() {
                this.state = UploadState.UPLOADED;
                console.log('S3 Upload complete for ' + this.file.name + ' : ' + this.storageId);
                if (directUploadReport) {
                        getMD5(this.file, prog => {
                                var current = 1 + prog;
                                $('progress').attr({
                                        value: current,
                                        max: 2
                                });
                        }).then(md5 => {
                                this.handleDirectUpload(md5);
                        }, err => console.error(err));
                }
                else {
                        console.log("Abandoned: " + this.storageId);
                }
        }
        async cancelMPUpload() {
               $.ajax({
                        url: this.urls.abort,
                        type: 'DELETE',
                        context:this,
                        cache: false,
                        processData: false,
                        success: function() {
                          console.log('Successfully cancelled upload of ' + this.file.name);
                        },
                        error: function(jqXHR, textStatus, errorThrown) {
                                console.log('Failure: ' + jqXHR.status);
                                console.log('Failure: ' + errorThrown);

                        }
            });
         }
        async finishMPUpload() {
          var eTagsObject={};
          for(var i=1;i<=this.numEtags;i++) {
             eTagsObject[i]=this.etags[i];
          }
               $.ajax({
                        url: this.urls.complete,
                        type: 'PUT',
                        context:this,
                        data: JSON.stringify(eTagsObject),
                        cache: false,
                        processData: false,
                        success: function() {
                          console.log('Successfully completed upload of ' + this.file.name);
                          this.reportUpload();
                        },
                        error: function(jqXHR, textStatus, errorThrown) {
                                console.log('Failure: ' + jqXHR.status);
                                console.log('Failure: ' + errorThrown);

                        }
            });        }

        async handleDirectUpload(md5) {
                this.state = UploadState.HASHED;
                //Wait for each call to finish and update the DOM
                while (inDataverseCall === true) {
                        await sleep(delay);
                }
                inDataverseCall = true;
                //storageId is not the location - has a : separator and no path elements from dataset
                //(String uploadComponentId, String fullStorageIdentifier, String fileName, String contentType, String checksumType, String checksumValue)
                handleExternalUpload([{ name: 'uploadComponentId', value: 'datasetForm:fileUpload' }, { name: 'fullStorageIdentifier', value: this.storageId }, { name: 'fileName', value: this.file.name }, { name: 'contentType', value: this.file.type }, { name: 'checksumType', value: 'MD5' }, { name: 'checksumValue', value: md5 }]);
        }
}

function queueFileForDirectUpload(file) {
        if (fileList.length === 0) { uploadWidgetDropRemoveMsg(); }
        var fUpload = new fileUpload(file);
        fileList.push(fUpload);
        //Fire off the first 4 to start (0,1,2,3)
        if (filesInProgress < 4) {
                filesInProgress = filesInProgress + 1;
                fUpload.startRequestForDirectUploadUrl();
        }
}

async function uploadFileDirectly(urls, storageId, filesize) {
        await sleep(delay);
        inDataverseCall = false;

        if (directUploadEnabled) {
                var upload = null;

                //As long as we have the right file size, we're OK
                for (i = 0; i < fileList.length; i++) {
                        if (fileList[i].file.size == filesize) {
                                upload = fileList.splice(i,i+1)[0];
                                break;
                        }
                }
                upload.urls = JSON.parse(urls);
                upload.storageId = storageId;

                //Increment count of files being processed
                curFile = curFile + 1;
                console.log('Uploading ' + upload.file.name + ' as ' + storageId + ' to ' + urls);

                upload.doUpload();
        }
}




function removeErrors() {
        var errors = document.getElementsByClassName("ui-fileupload-error");
        for (i = errors.length - 1; i >= 0; i--) {
                errors[i].parentNode.removeChild(errors[i]);
        }
}

var observer = null;

function uploadStarted() {
        // If this is not the first upload, remove error messages since
        // the upload of any files that failed will be tried again.
        removeErrors();
        var curId = 0;
        //Find the upload table body
        var files = $('.ui-fileupload-files .ui-fileupload-row');
        //Add an id attribute to each entry so we can later match errors with the right entry
        for (i = 0; i < files.length; i++) {
                files[i].setAttribute('upid', curId);
                curId = curId + 1;
        }
        //Setup an observer to watch for additional rows being added
        var config = { childList: true };
        var callback = function(mutations) {
                //Add an id attribute to all new entries
                mutations.forEach(function(mutation) {
                        for (i = 0; i < mutation.addedNodes.length; i++) {
                                mutation.addedNodes[i].setAttribute('upid', curId);
                                curId = curId + 1;
                        }
                        //Remove existing error messages since adding a new entry appears to cause a retry on previous entries
                        removeErrors();
                });
        };
        //uploadStarted appears to be called only once, but, if not, we should stop any current observer
        if (observer != null) {
                observer.disconnect();
        }
        observer = new MutationObserver(callback);
        observer.observe(files[0].parentElement, config);
}

function uploadFinished(fileupload) {
        if (fileupload.files.length === 0) {
                $('button[id$="AllUploadsFinished"]').trigger('click');
                //stop observer when we're done
                if (observer != null) {
                        observer.disconnect();
                        observer = null;
                }
        }
}

async function directUploadFinished() {

        numDone = finishFile();
        var total = curFile;
        var inProgress = filesInProgress;
        var inList = fileList.length;
        console.log(inList + ' : ' + numDone + ' : ' + total + ' : ' + inProgress);
        if (directUploadEnabled) {
                if (inList === 0) {
                        if (total === numDone) {
                                $('button[id$="AllUploadsFinished"]').trigger('click');
                                //stop observer when we're done
                                if (observer != null) {
                                        observer.disconnect();
                                        observer = null;
                                }
                        }
                } else {
                        if ((inProgress < 4) && (inProgress < inList)) {
                                filesInProgress = filesInProgress + 1;
                                for (i = 0; i < fileList.length; i++) {
                                  if(fileList[i].state==UploadState.QUEUED) {
                                    fileList[i].startRequestForDirectUploadUrl();
                                    break;
                                  }
                                 }
                        }
                }
        }
        await sleep(delay);

        inDataverseCall = false;
}

async function uploadFailure(jqXHR, upid, filename) {
        // This handles HTTP errors (non-20x reponses) such as 0 (no connection at all), 413 (Request too large),
        // and 504 (Gateway timeout) where the upload call to the server fails (the server doesn't receive the request)
        // It notifies the user and provides info about the error (status, statusText)
        // On some browsers, the status is available in an event: window.event.srcElement.status
        // but others, (Firefox) don't support this. The calls below retrieve the status and other info
        // from the call stack instead (arguments to the fail() method that calls onerror() that calls this function

        if (directUploadEnabled) {
                await sleep(delay);
        }
        inDataverseCall = false;

        //Retrieve the error number (status) and related explanation (statusText)
        var status = 0;
        var statusText = null;

        // There are various metadata available about which file the error pertains to
        // including the name and size.
        // However, since the table rows created by PrimeFaces only show name and approximate size,
        // these may not uniquely identify the affected file. Therefore, we set a unique upid attribute
        // in uploadStarted (and the MutationObserver there) and look for that here. The files array has
        // only one element and that element includes a description of the row involved, including it's upid.

        var name = null;
        var id = null;
        if(jqXHR=== null) {
          status=1;  //made up
          statusText='Aborting';
        } else if ((typeof jqXHR !== 'undefined')) {
                status = jqXHR.status;
                statusText = jqXHR.statusText;
                id = upid;
                name = filename;
        } else {
                try {
                        name = arguments.callee.caller.caller.arguments[1].files[0].name;
                        id = arguments.callee.caller.caller.arguments[1].files[0].row[0].attributes.upid.value;
                        status = arguments.callee.caller.caller.arguments[1].jqXHR.status;
                        statusText = arguments.callee.caller.caller.arguments[1].jqXHR.statusText;
                } catch {
                        console.log("Unable to determine status for error - assuming network issue");
                }
        }

        //statusText for error 0 is the unhelpful 'error'
        if (status == 0) statusText = 'Network Error';

        //Log the error
        console.log('Upload error:' + name + ' upid=' + id + ', Error ' + status + ': ' + statusText);
        //Find the table
        var rows = $('.ui-fileupload-files .ui-fileupload-row');
        //Create an error element
        var node = document.createElement("TD");
        //Add a class to make finding these errors easy
        node.classList.add('ui-fileupload-error');
        //Add the standard error message class for formatting purposes
        node.classList.add('ui-message-error');
        var textnode = document.createTextNode("Upload unsuccessful (" + status + ": " + statusText + ").");
        node.appendChild(textnode);
        //Add the error message to the correct row
        for (i = 0; i < rows.length; i++) {
                if (rows[i].getAttribute('upid') == id) {
                        //Remove any existing error message/only show last error (have seen two error 0 from one network disconnect)
                        var err = rows[i].getElementsByClassName('ui-fileupload-error');
                        if (err.length != 0) {
                                err[0].remove();
                        }
                        rows[i].appendChild(node);
                        break;
                }
        }
        if (directUploadEnabled) {
                //Mark this file as processed and keep processing further files
                directUploadFinished();
        }
}
//MD5 Hashing functions

function readChunked(file, chunkCallback, endCallback) {
        var fileSize = file.size;
        var chunkSize = 64 * 1024 * 1024; // 64MB
        var offset = 0;

        var reader = new FileReader();
        reader.onload = function() {
                if (reader.error) {
                        endCallback(reader.error || {});
                        return;
                }
                offset += reader.result.length;
                // callback for handling read chunk
                // TODO: handle errors
                chunkCallback(reader.result, offset, fileSize);
                if (offset >= fileSize) {
                        endCallback(null);
                        return;
                }
                readNext();
        };

        reader.onerror = function(err) {
                endCallback(err || {});
        };

        function readNext() {
                var fileSlice = file.slice(offset, offset + chunkSize);
                reader.readAsBinaryString(fileSlice);
        }
        readNext();
}

function getMD5(blob, cbProgress) {
        return new Promise((resolve, reject) => {
                var md5 = CryptoJS.algo.MD5.create();
                readChunked(blob, (chunk, offs, total) => {
                        md5.update(CryptoJS.enc.Latin1.parse(chunk));
                        if (cbProgress) {
                                cbProgress(offs / total);
                        }
                }, err => {
                        if (err) {
                                reject(err);
                        } else {
                                // TODO: Handle errors
                                var hash = md5.finalize();
                                var hashHex = hash.toString(CryptoJS.enc.Hex);
                                resolve(hashHex);
                        }
                });
        });
}