// DeselectLargest.jsx
//
// Copyright 2009 Dmitriy Mayorov <dmitrym@dimview.org>
// All Rights Reserved
//
/** 
  @fileoverview Deselect the largest file among two or more selected.
  @class Compare sizes of selected files and deselect the largest one.
 
  <h4>Usage</h4>
  <ol>
  <li> In Bridge, select thumbnails
  <li> Right click in Windows, Ctrl-click in Mac OS to invoke context menu
  <li> Choose "Deselect Largest"
  <li> You can then delete the files that remain selected, keeping only the largest.
  </ol>
 
  <h4>Description</h4>
  
  <p>Sharper files contain more information.   All other things being equal, corresponding JPEG
  or CR2 files are bigger.  The snippet uses this observation to identify the sharpest file 
  among selected.

  <p>Script location
  <ul>
    <li>Windows: %APPDATA%\Adobe\Bridge CS3\Startup Scripts\</li> 
    <li>Mac OS X: ~/Library/Application Support/Adobe/Bridge CS3/Startup Scripts/</li>
  </ul>
 
  @constructor Constructor
 */
function DeselectLargest() 
{
  // Any class variables should be commented as such

  /**
    The context in which this snippet can run.
    @type String
  */
  this.requiredContext = "\tNeed to be running in context of Bridge\n";	

  /**
    The unique identifier for the new menu item command
    @type String
  */
  this.menuID = "idDeselectLargest";
}

/**
 Functional part of this snippet.
 @return True if the snippet ran as expected, false otherwise
 @type boolean
*/
DeselectLargest.prototype.run = function() 
{
  var retval = true;
  var uid = 1; // Static counter that is incremented at each run.  Used in prefix to avoid filename conflicts.
  
  if (!this.canRun()) {
	  retval = false;	
	  return retval;
  }

  var cntCommand = new MenuElement("command", "Deselect Largest", "at the end of Thumbnail", this.menuID);

  // What to do when the menu item is selected
  cntCommand.onSelect = function(m) 
  {
    var prefix = 'deselect-largest-' + uid; uid++;
	 
	  // Get the selected Thumbnail objects, only accept these file types
    var thumbs = app.document.getSelection("crw, cr2, jpg");
		
    if (thumbs.length > 1) {
		  var largest_index = 0;
		  var largest_size = 0;
			
			// This might take a while, do it in the background
		  var op = new ProgressOperator("progress", thumbs);

      op.start = function()
		  {
			  op.procStat = "notStarted";
			  op.opStat = "incomplete";
			  app.operationChanged(this);
			  op.procStat = "inProgress";
			  app.operationChanged(this);
			  op.percComp = 1;
			  for (var i = 0; i < thumbs.length; i++) {
			    if (thumbs[i].spec instanceof File) {  // Ignore folders
				    op.percComp = 100 * i / thumbs.length;
				    app.operationChanged(this);
				    if (largest_size < thumbs[i].spec.length) {
                      largest_index = i;
				      largest_size = thumbs[i].spec.length;
				    }
			      }
				}
        op.percComp = 100;
			  op.opStat = "succeeded";
			  op.procStat = "completed";
			  app.operationChanged(this);
	      app.document.deselect(thumbs[largest_index]);
			  return;
		  }

		  op.stop = function() { return; }	
		  op.getConflictInfo = function() { return "unknown"; }
		  op.getOperationStatus = function() { return op.opStat; }
		  op.getPercentageComplete = function() { return op.percComp; }
  		op.getProcessingStatus = function() { return op.procStat; }
		  op.getProgressMessage = function() { return "Identifying and deselecting the largest file"; }
		  op.getType = function() { return "progress"; }
		  op.getUIPolicy = function() { return true; }
		  op.resume = function() { return false; }
		  op.resolveConflict = function() { }

      app.enqueueOperation(op);
		
	  } else {
		  retval = false;
	  }
  };

  // When to display the menu item
  cntCommand.onDisplay = function()
  {
	try {
      cntCommand.text = "Deselect Largest";
      if (app.document.selections.length > 1 && !app.document.selections[0].container) {
        cntCommand.enabled = true;
	  } else {
		cntCommand.enabled = false;
	  }		
	}
	catch (error) { $.writeln(error); }
  };

  return retval;
}

/**
 Determines whether snippet can be run given current context.  The snippet 
 fails if these preconditions are not met:
 <ul>
 <li> A condition - such as Must run in Bridge
 </ul>
 @return True if this snippet can run, false otherwise
 @type Boolean
*/
DeselectLargest.prototype.canRun = function()
{
  if (BridgeTalk.appName == "bridge") { 
    return true;
  }
  $.writeln("ERROR:: Cannot run DeselectLargest");
  $.writeln(this.requiredContext);
  return false;
}

/**
 "main program": construct an anonymous instance and run it
  as long as we are not unit-testing this snippet.
*/
if (typeof(SelectLargest_unitTest ) == "undefined") {
  new DeselectLargest().run();
}