/**
 * Convert a single file-input element into a 'multiple' input list
 *
 * Usage:
 *
 *   1. Create a file input element (no name)
 *      eg. <input type="file" id="first_file_element">
 *
 *   2. Create a DIV for the output to be written to
 *      eg. <div id="files_list"></div>
 *
 *   3. Instantiate a MultiSelector object, passing in the DIV and an (optional) maximum number of files
 *      eg. var multi_selector = new MultiSelector( document.getElementById( 'files_list' ), 3 );
 *
 *   4. Add the first element
 *      eg. multi_selector.addElement( document.getElementById( 'first_file_element' ) );
 *
 *   5. That's it.
 *
 *   You might (will) want to play around with the addListRow() method to make the output prettier.
 *
 *   You might also want to change the line 
 *       element.name = 'file_' + this.count;
 *   ...to a naming convention that makes more sense to you.
 * 
 * Licence:
 *   Use this however/wherever you like, just don't blame me if it breaks anything.
 *
 * Credit:
 *   If you're nice, you'll leave this bit:
 *  
 *   Class by Stickman -- http://www.the-stickman.com
 *      with thanks to:
 *      [for Safari fixes]
 *         Luis Torrefranca -- http://www.law.pitt.edu
 *         and
 *         Shawn Parker & John Pennypacker -- http://www.fuzzycoconut.com
 *      [for duplicate name bug]
 *         'neal'
 */
function MultiSelector( elNames, list_target, par_target, max ){

    // Meno input-ov:
    this.elNames = elNames;

    // Where to write the list
    this.list_target = list_target;
    // Cely paragraf, kam sa pridava list:
    this.par_target = par_target;
    // How many elements?
    this.count = 0;
    // How many elements?
    this.id = 0;
    // Is there a maximum?
    if( max ){
        this.max = max;
    } else {
        this.max = -1;
    };
    
    /**
     * Add a new file input element
     */
    this.addElement = function( element ){

        // Make sure it's a file input element
        if( element.tagName == 'INPUT' && element.type == 'file' ){

            // Element name -- what number am I?
            //element.name = 'file_' + this.id++;
	    element.name = this.elNames + '[]';

            // Add reference to this object
            element.multi_selector = this;

            // What to do when a file is selected
            element.onchange = function(){

    	        par_target.style.display = 'block';	

                // New file input
                var new_element = document.createElement( 'input' );
                new_element.type = 'file';
                new_element.className=element.className;
                new_element.size=element.size;

                // Add new element
                this.parentNode.insertBefore( new_element, this );

                // Apply 'update' to element
                this.multi_selector.addElement( new_element );

                // Update list
                this.multi_selector.addListRow( this );

                // Hide this: we can't use display:none because Safari doesn't like it
                this.style.position = 'absolute';
                this.style.left = '-1000px';

            };
            // If we've reached maximum number, disable input element
            if( this.max != -1 && this.count >= this.max ){
                element.disabled = true;
            };

            // File element counter
            this.count++;
            // Most recent element
            this.current_element = element;
            element.focus();
        } else {
            // This can only be applied to file input elements!
            alert( 'Error: not a file input element' );
        };

    };

    /**
     * Add a new row to the list of files
     */
    this.addListRow = function( element ){
        // 
	statusWinNeeded = true;

        // Row div
        var new_row = document.createElement( 'div' );

	// Image:
        var new_row_image = document.createElement( 'img' );
        new_row_image.src = 'scripts/images/delete.gif';
	new_row_image.alt = 'Zrušiť pridanie súboru';
	new_row_image.title = new_row_image.alt;
	new_row_image.style.cursor = 'pointer';

        // References
        new_row.element = element;

        // Delete function
        new_row_image.onclick= function(){

            // Remove element from form
            this.parentNode.element.parentNode.removeChild( this.parentNode.element );

            // Remove this row from the list
            this.parentNode.parentNode.removeChild( this.parentNode );

            // Decrement counter
            this.parentNode.element.multi_selector.count--;

	    if (this.parentNode.element.multi_selector.count == 1)
  	        par_target.style.display = 'none';	


            // Re-enable input element (if it's disabled)
            this.parentNode.element.multi_selector.current_element.disabled = false;

            // Appease Safari
            //    without it Safari wants to reload the browser window
            //    which nixes your already queued uploads
            return false;
        };

        // Set row value
        new_row.innerHTML = element.value;

        new_row.insertBefore( new_row_image, new_row.firstChild );

        // Add it to the list
        this.list_target.appendChild( new_row );
        
    };

};