/**
 *+------------------------------------------------------------------------+
 *| Licensed Materials - Property of IBM
 *| BI and PM: prmt
 *| (C) Copyright IBM Corp. 2002, 2011
 *|
 *| US Government Users Restricted Rights - Use, duplication or
 *| disclosure restricted by GSA ADP Schedule Contract with IBM Corp.
 *|
 *+------------------------------------------------------------------------+
*/

/**
* This file provides methods setting text direction for various HTML control
* (dynamic input fields, static labels ...)
* 
*/
var PRMT_BidiUtils =
{

	// Bidi constants
	BIDI_TXTDIR_CONTEXTUAL : "auto",
	BIDI_TXTDIR_RTL : "rtl",
 	BIDI_TXTDIR_LTR : "ltr",
 	BIDI_CHAR_LRE : "\u202A", 
 	BIDI_CHAR_RLE : "\u202B",
 	BIDI_CHAR_PDF : "\u202C",
 	BIDI_CHAR_LRM : "\u200E",
 	BIDI_CHAR_RLM : "\u200F",
 	VK_SHIFT : 0x10,
	VK_END : 0x23,
	VK_HOME : 0x24,
	VK_LEFT : 0x25,
	VK_RIGHT : 0x27, 
 	
	/** 
	* It fixes the direction (using the CSS style direction) of the INPUT element depending on the setting and the 
	* input value.  If input.value is a right to left language (like Arabic, Hebrew), then change the input style to right to left.
	* txtAlignPref is for future use in case the user prefers a fixed alignnment (not depending on text direction)
	*/ 
	fixInputDirection : function(inputElement, txtDir, txtAlignPref){	
		if (inputElement !== null && (inputElement.tagName == 'INPUT' || inputElement.tagName == 'TEXTAREA')) {
			inputElement.style.direction = PRMT_BidiUtils.getTextDirection(inputElement.value, txtDir);
		}
	},

	/** 
	* This function enforces the text direction of a given string by adding LRE/RLE PDF header and footer
	*/
	enforceBidiDirection : function(stringValue, txtDir){
		var finalDir = PRMT_BidiUtils.getTextDirection(stringValue, txtDir);	
		var finalValue = stringValue;
		if (finalDir == "ltr") {
			finalValue = PRMT_BidiUtils.BIDI_CHAR_LRE + finalValue + PRMT_BidiUtils.BIDI_CHAR_PDF;
		} else if (finalDir == "rtl") {
			finalValue = PRMT_BidiUtils.BIDI_CHAR_RLE + finalValue + PRMT_BidiUtils.BIDI_CHAR_PDF;
		}
		return finalValue;
	},

	/** 
	* Returns the text direction of a given string depending on the setting and the string text
	*/
	getTextDirection : function(val, txtDir){	
		var finalDir = txtDir;
		if (txtDir == PRMT_BidiUtils.BIDI_TXTDIR_CONTEXTUAL){
			finalDir =((PRMT_BidiUtils.isRTLString(val))? PRMT_BidiUtils.BIDI_TXTDIR_RTL : PRMT_BidiUtils.BIDI_TXTDIR_LTR);
		}
		return finalDir;
	},

	/** 
	* Detect the direction (RTL || LTR ) of a string
	* The first strong character of the string determines the direction of the string
	* 
	*/
	isRTLString : function(stringValue){
		var result = false;
		for (var i = 0; i < stringValue.length; i++) {
         		if (PRMT_BidiUtils.isRTLChar(stringValue.charCodeAt(i))) {
             			result = true;
             			break
             		}
         		else if(PRMT_BidiUtils.isLatinChar(stringValue.charCodeAt(i))) {
        	 		break;
        	 	}       
     		}
     		return result;
	},

	/** 
	* Determines if the passed character c is a RTL (Hebrew or Arabic) char
	*/
	isRTLChar : function(c){
		var result = false;
    		if ((c >= 0x05d0 && c <= 0x05ff) ||
    		(c >= 0x0600 && c <= 0x065f) ||
    		(c >= 0x066a && c <= 0x06ef) ||
    		(c >= 0x06fa && c <= 0x07ff) ||
    		(c >= 0xfb1d && c <= 0xfdff) ||
    		(c >= 0xfe70 && c <= 0xfefc)) {
    			result = true;
    		}
    		return result;
	},
	
	/** 
	* Determines if the passed character c is a Latin char
	*/
	isLatinChar : function(c){
    		return (((c > 64 && c < 91)||(c > 96 && c < 123))? true : false);
	},
	
	/** 
	* Search for the first ancestor element(including the element itself) to have a defined direction
	*/
	lookupDirection : function(elem){
		var lookupDir = null;		
		while ( (lookupDir != PRMT_BidiUtils.BIDI_TXTDIR_LTR) && (lookupDir != PRMT_BidiUtils.BIDI_TXTDIR_RTL) &&  elem && elem.parentNode ) {
			elem = elem.parentNode;
			lookupDir = ( (elem.style && elem.style.direction) ? elem.style.direction : elem.dir);
		}
		return lookupDir;
	},
	
	/** 
	* Determines if a string contains a RTL char
	*/
	containsRTLChar : function(stringValue){
		var result = false;
		for (var i = 0; i < stringValue.length; i++) {
         		if (PRMT_BidiUtils.isRTLChar(stringValue.charCodeAt(i))) {
             			result = true;
             			break
             		}         		     
     		}
     		return result;
	},
	
	/** 
	* This function determines if there is a RTL char between the index i and previous in the buffer
	*/
	isCharBeforeRTLChar : function(buffer, i, previous) {
    		var result = false;
		var prevChar;
    		while (i > 0 && i != previous) {    
                        prevChar = buffer.charCodeAt(i-1);      
        		if(PRMT_BidiUtils.isRTLChar(prevChar)) {
            			result = true;
				break;
            		}
       	 		else if(PRMT_BidiUtils.isLatinChar(prevChar)) {
           			break;
           		}
			i--;
    		}   
		return result;      
	},
 
	
	/** 
	* This function determines the positions where we should insert the LRM marker for correct display 
	* of the structured text (STT)
	*/   
	parseSTT : function(str, ce_type){    
    		var i,i1;
    		var delimiters;
    		var previous = -1;
    		var segmentsPointers = [];
    		var sp_len = 0;    
    
   		if(ce_type == "FILEPATH"){ 
	   		delimiters = "/\\:."; 
	   		for (i = 0; i < str.length; i++) {
		   		if ((delimiters.indexOf(str.charAt(i)) >= 0) && PRMT_BidiUtils.isCharBeforeRTLChar(str,i,previous)){
					previous = i;    
					segmentsPointers[sp_len] = i;
					sp_len++;
				}
			}	   
		}
				
    		return segmentsPointers;
	}, 

	/** 
	* This function inserts the LRM char at the positions returned by the previous method
	*/
	insertMarkers : function(str, ce_type) {
    		var segmentsPointers = PRMT_BidiUtils.parseSTT(str, ce_type); 
    		var buf = str;
    		shift = 0;                                                
    		var n;
		var marker = PRMT_BidiUtils.BIDI_CHAR_LRM;
    		for (var i = 0; i< segmentsPointers.length; i++) {
        		n = segmentsPointers[i];
        		if(n != null){
            			preStr = buf.substring(0, n + shift);
            			postStr = buf.substring(n + shift, buf.length);
            			buf = preStr + marker + postStr;
            			shift++;
    		    	}                                  
    		}
    		return buf;        
	},
	
	/** 
	* This function inserts the LRM markers in the fake input when the focus is on the true input
	*/
	onFileFocus : function(inputFile, id, ce_type) {
		var fakeObj = document.getElementById(id);
		fakeObj.value = PRMT_BidiUtils.insertMarkers(inputFile.value, ce_type);
	},

	/** 
	* This function inserts the LRM markers in the fake input when the true input has changed
	*/
	onFileChange : function(inputFile, id, ce_type) {
		var fakeObj = document.getElementById(id);
		fakeObj.value = PRMT_BidiUtils.insertMarkers(inputFile.value, ce_type);
  		fakeObj.focus();
	},

	/** 
	* This function reacts on inserting chars in the fake input
	*/
	onFakeKeyDown : function(event, id) {	
		event = (event) ? event : ((window.event) ? window.event : "");
  		var kCode = event.keyCode;
  		if (event.altKey || event.ctrlKey || kCode == PRMT_BidiUtils.VK_SHIFT) {
  			return true;
  		}
  		else if (!(kCode == PRMT_BidiUtils.VK_HOME || kCode == PRMT_BidiUtils.VK_END || kCode == PRMT_BidiUtils.VK_LEFT || kCode == PRMT_BidiUtils.VK_RIGHT)) {
  			PRMT_BidiUtils.focusElement(id);  			
			return false; 
  		}
  		else {
  			return true;
  		}
	},

	/** 
	* This function focuses on the element whose id is given in parameter
	*/
	focusElement : function(id) {
		var elem = document.getElementById(id);
		elem.focus();	
        	return false;
        },
        
        /** 
	* This function handles the copy operation
	* Basically we should remove the LRM markers from the text contained in the clipboard
	*/
	processCopy : function (obj){
    		var text = "";	
		try{
			if  ( window.navigator.appName == "Microsoft Internet Explorer" ) {
				var w = obj.document.parentWindow;
				var e = w.event;
        			var range = obj.document.selection.createRange();
        			text = range.text;
			}
			else {
        			text = obj.document.getSelection();
        		}
			var textToClipboard = PRMT_BidiUtils.removeMarkers(text);		
			if (window.clipboardData) {
				window.clipboardData.setData("Text", textToClipboard);
				e.returnValue = false;
			}
	 	}
	 	catch(e)
	 	{
	 		var v_sMsg = "";
			if ( e && e.name )
			{
				v_sMsg += e.name + "\n";
			}
			if ( e && e.message )
			{
				v_sMsg += e.message;
			}
			if ( v_sMsg )
			{
				alert( v_sMsg );
			}
	 	}      	
	},
	
	/** 
	* This function removes all the Bidi markers in a string
	*/
	removeMarkers : function (str){
		var result = str.replace(/\u200E/g,"");
		result = result.replace(/\u200F/g,"");
		result = result.replace(/\u202A/g,"");
		result = result.replace(/\u202B/g,"");	
		return result.replace(/\u202C/g,""); 
	},
	
	/** 
	* This function formats a structured text of type FILEPATH
	*/
	formatFilePath : function (str){
		var result = PRMT_BidiUtils.insertMarkers(str, 'FILEPATH');			
		return PRMT_BidiUtils.enforceBidiDirection(result, PRMT_BidiUtils.BIDI_TXTDIR_LTR); 
	}  
};