//Open window with progress bar.
//pair upload window and progress window (using UploadID).
function ProgressBar(form){
 //check file sizes.
 
 if (checkFileSize()) {
   alert('Upload size is over limit. Please check selected files.')
   return false;
 };

  
 //ASP script handling progress window
 var ProgressScript
 ProgressScript = 'progress.dat'
 

 //Progress window parameters
 var pp = 'toolbar=no,location=no,directories=no,status=no,menubar=no'
 pp+=',scrollbars=no,resizable=yes,width=350,height=200';
  
 //1. Get unique UploadID
 var UploadID
 UploadID = Math.round(Math.random() * 0x7FFFFFF0)
  
 //2. Add upload ID to form action URL
 var action = form.action;
 if ('' == action) action = ''+document.location;
 action = AddToQuery(action, 'UploadID', UploadID);
 form.action = action

 //3. Open progress window with the same UploadID
 var ProgressURL
 ProgressURL = ProgressScript + '?UploadID=' + UploadID 

 var v = window.open(ProgressURL,'_blank',pp)
 
 return true;
};





//Adds value and its name to querystring
function AddToQuery(q, valname, val){
 if (q.indexOf('?')<0) {
   q += '?'
 } else {
 var pv = q.indexOf(valname+'=');
 if (pv >= 0){
  var amp = q.indexOf('&', pv);
  if (amp<0) {
   q = q.substr(0, pv) 
  } else {
   q = q.substr(0, pv) + q.substr(amp+1) + '&'
  }
 } else {
  if (q.substr(q.length-1)!='?') q += '&'
 };
 };
 q += valname + '=' + val
 return q
};





//Additional function - dynamic form to add new files at a client side.

var nfiles = 3;
//Add two files for upload
//Expand();
function Expand(){
  
  //get an HTML code of a first upload element
  var adh = dfile1.outerHTML;

  //replace '1' to nfiles (2, 3, ...)
  adh = adh.replace(/1/g,++nfiles)
  
  //insert the code of a new element before end of div files
  files.insertAdjacentHTML('BeforeEnd',adh);

  //clear mask and real value of the element nfiles
  //document.getElementById('maskfile'+nfiles).value=''
  return false;
};


//Huge-asp upload preview sample
//http://www.pstruh.cz

function isImage(file){
  //Get a file extension
  var ext = file.substr(file.lastIndexOf('.')).toLowerCase()

  //Check extension to image types.
  
  return '.gif,.jpg,.png,.jpeg,.bmp,'.indexOf(ext+',') >= 0
};

var lastfieldname = ''
var filenamechecked = ''
function preview(n) {
  //get current input preview
  var htmlfile = document.getElementById('fi_image'+n);
  var file = htmlfile.value

  //set the size field.
  var himg = document.getElementById('himg'+n);
  if (file.length>0) himg.src = 'file://' + file;
  else { 
    himg.src = ''; 
    document.getElementById('size'+n).innerHTML='-'
  };
  
  if (file.length<=0) return;

  //or get get preview for one of form field
  //var file = file_upload.SourceFile1.value
  var ipreview = document.getElementById('ipreview'+n);
  
  //do not check the file more than one.
  if (filenamechecked != htmlfile.value) {
    filenamechecked = htmlfile.value
  } else {
    return true;
  };

  if (isImage(file)) {

    //Show preview for the image.
    ipreview.src = 'file://' + file
    //alert(file);
    //alert(ipreview.src);
    ipreview.title = 'fi_image' + file 
    if (ipreview.width != 200) ipreview.width = 200;

    // eval("ImageName"+n).innerHTML = 'Image preview<br>(' + htmlfile.name + ')'
  } else {
    //some default image for preview
    ipreview.src = 'res://shdoclc.dll/warning.gif'

    alert('Please choose some image file (.gif,.jpg,.png,.jpeg,.bmp)');
    
  };
  
  lastfieldname = htmlfile.name
}

function himgLoaded(n){
  checkFileSize();
};


//this function gets a sizes of images,
//write the sizes to HTML form
//counts total size and checks file sizes against a limit
var maxFileSize = 1500000
var FormSizeLimit = 4000000
function checkFileSize() {
  var totalSize = 0;
  var htmlSize;
  var overLimit = false;
  for (j = 1; j <= nfiles; j++) {
    var himg = document.getElementById('himg'+j);
    var size = document.getElementById('size'+j);
    var fileSize = himg.fileSize ;

    fileSize = parseInt(fileSize);
    
    if (fileSize < 0) {
      size.innerHTML = '-';
    } else {
      htmlSize = formatSize(fileSize);
      if ( fileSize>maxFileSize ) {
        htmlSize += ' (over limit, ' + formatSize(maxFileSize) + ' max)'
        size.style.color = 'red';
        overLimit = true;
      } else {
        size.style.color = '';
      };
      size.innerHTML = htmlSize;
      totalSize += fileSize;
    };//if (fileSize < 0) {
  };//for (j = 1; j <= nfiles; j++)


  var htotalSize = document.getElementById('totalSize');
  
  if (totalSize > 0){
    htmlSize = formatSize(totalSize);
  } else {
    htmlSize = '-';
  };
  if (totalSize > FormSizeLimit) {
    htotalSize.style.color = 'red';
    htmlSize += ' (over limit, ' + formatSize(FormSizeLimit) + ' max)'
    overLimit = true;
  } else {
    htmlSize += ' (of ' + formatSize(FormSizeLimit) + ' max)'
  };
  htotalSize.innerHTML = htmlSize
  return overLimit;
};

function formatSize(size) {
  if (size < 0x100000) {// < 1 MB
    return Math.round(size / 0x400)+"&nbsp;kB"; 
  } else { // > 1 MB
    return (Math.round((size / 0x100000)*10)/10)+"&nbsp;MB";
  }
}