/*
Contains:
Cookie Functions -- "Night of the Living Cookie" Version (25-Jul-96)
Written by:  Bill Dortch, hIdaho Design <bdortch@hidaho.com>
The following functions are released to the public domain.

Refactored for TWiki by Arthur Clemens 2006.
*/

/**
The preferred way for reading and writing cookies is using getPref and setPref, otherwise the limit of 20 cookies per domain is reached soon. See http://twiki.org/cgi-bin/view/TWiki/TWikiSettingsCookie.
*/

twiki.Pref = {
	
	TWIKI_PREF_COOKIE_NAME:"TWIKIPREF",
	/**
	Separates key-value pairs
	*/
	COOKIE_PREF_SEPARATOR:"|",
	/**
	Separates key from value
	*/
	COOKIE_PREF_VALUE_SEPARATOR:"=",
	/**
	By default expire one year from now.
	*/
	COOKIE_EXPIRY_TIME:365 * 24 * 60 * 60 * 1000,

	/**
	Writes a TWiki preference value. If the TWiki preference of given name already exists, a new value is written. If the preference name is new, a new preference is created.
	Characters '|' and '=' are reserved as separators.
	@param inPrefName : (String) name of the preference to write, for instance 'SHOWATTACHMENTS'
	@param inPrefValue : (String) stringified value to write, for instance '1'
	*/
	setPref:function(inPrefName, inPrefValue) {
		var prefName = twiki.Pref._getSafeString(inPrefName);
		var prefValue = (isNaN(inPrefValue)) ? twiki.Pref._getSafeString(inPrefValue) : inPrefValue;
		var cookieString = twiki.Pref._getPrefCookie();
		var prefs = cookieString.split(twiki.Pref.COOKIE_PREF_SEPARATOR);
		var index = twiki.Pref._getKeyValueLoc(prefs, prefName);
		if (index != -1) {
			// updating this entry is done by removing the existing entry from the array and then pushing the new key-value onto it
			prefs.splice(index, 1);
		}
		// else not found, so don't remove an existing entry
		var keyvalueString = prefName + twiki.Pref.COOKIE_PREF_VALUE_SEPARATOR + prefValue;
		prefs.push(keyvalueString);
		twiki.Pref._writePrefValues(prefs);
	},
	
	/**
	Reads the value of a preference.
	Characters '|' and '=' are reserved as separators.
	@param inPrefName (String): name of the preference to read, for instance 'SHOWATTACHMENTS'
	@return The value of the preference; an empty string when no value is found.
	*/
	getPref:function(inPrefName) {
		var prefName = twiki.Pref._getSafeString(inPrefName);
		return twiki.Pref.getPrefValueFromPrefList(prefName, twiki.Pref.getPrefList());
	},
	
	/**
	Reads the value of a preference from an array of key-value pairs. Use in conjunction with getPrefList() when you want to store the key-value pairs for successive look-ups.
	@param inPrefName (String): name of the preference to read, for instance 'SHOWATTACHMENTS'
	@param inPrefList (Array): list of key-value pairs, retrieved with getPrefList()
	@return The value of the preference; an empty string when no value is found.
	*/
	getPrefValueFromPrefList:function(inPrefName, inPrefList) {
		var keyvalue = twiki.Pref._getKeyValue(inPrefList, inPrefName);
		if (keyvalue != null) return keyvalue[1];
		return '';
	},
	
	/**
	Gets the list of all values set with setPref.
	@return An Array of key-value pair pref values; null if no value has been set before.
	*/
	getPrefList:function() {
		var cookieString = twiki.Pref._getPrefCookie();
		if (!cookieString) return null;
		return cookieString.split(twiki.Pref.COOKIE_PREF_SEPARATOR);
	},
	
	/**
	To write a TWiki preference cookie (TWIKIPREF), use twiki.Pref.setPref.
	
	Retrieves the value of the cookie specified by "name".
	@param inName : (String) identifier name of the cookie
	@return (String) the cookie value; null if no cookie with name inName has been set.
	*/
	getCookie:function(inName) {
		var arg = inName + "=";
		var alen = arg.length;
		var clen = document.cookie.length;
		var i = 0;
		while (i < clen) {
			var j = i + alen;
			if (document.cookie.substring(i, j) == arg) {
				return twiki.Pref._getCookieVal(j);
			}
			i = document.cookie.indexOf(" ", i) + 1;
			if (i == 0) break; 
		}
		return null;
	},
	
	/**
	Creates a new cookie or updates an existing cookie.
	@param inName : (String) identifier name of the cookie
	@param inValue : (String) stringified cookie value, for instance '1'
	@param inExpires : (Date) (optional) the expiration data of the cookie; if omitted or null, expires the cookie at the end of the current session
	@param inPath : (String) (optional) the path for which the cookie is valid; if omitted or null, uses the path of the current document
	@param inDomain : (String) (optional) the domain for which the cookie is valid; if omitted or null, uses the domain of the current document
	@param inUsesSecure : (Boolean) (optional) whether cookie transmission requires a secure channel (https)
	@use
	To call setCookie using name, value and path, write:
	<pre>
	twiki.Pref.setCookie ("myCookieName", "myCookieValue", null, "/");
	</pre>	
	To set a secure cookie for path "/myPath", that expires after the current session, write:
	<pre>
	twiki.Pref.setCookie ("myCookieName", "myCookieValue", null, "/myPath", null, true);
	</pre>
	*/
	setCookie:function(inName, inValue, inExpires, inPath, inDomain, inUsesSecure) {
		var cookieString = inName + "=" + escape (inValue) +
			((inExpires) ? "; expires=" + inExpires.toGMTString() : "") +
			((inPath) ? "; path=" + inPath : "") +
			((inDomain) ? "; domain=" + inDomain : "") +
			((inUsesSecure) ? "; secure" : "");
		document.cookie = cookieString;
	},
	
	/**
	Function to delete a cookie. (Sets expiration date to start of epoch)
	@param inName : (String) identifier name of the cookie
	@param inPath : (String) The path for which the cookie is valid. This MUST be the same as the path used to create the cookie, or null/omitted if no path was specified when creating the cookie.
	@param inDomain : (String) The domain for which the cookie is valid. This MUST be the same as the domain used to create the cookie, or null/omitted if no domain was specified when creating the cookie.
	*/
	deleteCookie:function(inName, inPath, inDomain) {
		if (twiki.Pref.getCookie(inName)) {
			document.cookie = inName + "=" + ((inPath) ? "; path=" + inPath : "") + ((inDomain) ? "; domain=" + inDomain : "") + "; expires=Thu, 01-Jan-70 00:00:01 GMT";
		}
	},
	
	/* PRIVILIGED METHODS */
	
	/**
	Finds a key-value pair in an array.
	@param inKeyValues: (Array) the array to iterate
	@param inKey: (String) the key to find in the array
	@return The first occurrence of a key-value pair, where key == inKey; null if none is found.
	*/
	_getKeyValue:function(inKeyValues, inKey) {
		if (!inKeyValues) return null;
		var i = inKeyValues.length;
		while (i--) {
			var keyvalue = inKeyValues[i].split(twiki.Pref.COOKIE_PREF_VALUE_SEPARATOR);
			if (keyvalue[0] == inKey) return keyvalue;	
		}
		return null;
	},
	
	/**
	Finds the location of a key-value pair in an array.
	@param inKeyValues: (Array) the array to iterate
	@param inKey: (String) the key to find in the array
	@return The location of the first occurrence of a key-value tuple, where key == inKey; -1 if none is found.
	*/
	_getKeyValueLoc:function(inKeyValues, inKey) {
		if (!inKeyValues) return null;
		var i = inKeyValues.length;
		while (i--) {
			var keyvalue = inKeyValues[i].split(twiki.Pref.COOKIE_PREF_VALUE_SEPARATOR);
			if (keyvalue[0] == inKey) return i;	
		}
		return -1;
	},
	
	/**
	Writes a cookie with the stringified array values of inValues.
	@param inValues: (Array) an array with key-value tuples
	*/
	_writePrefValues:function(inValues) {
		var cookieString = (inValues != null) ? inValues.join(twiki.Pref.COOKIE_PREF_SEPARATOR) : '';
		var expiryDate = new Date ();
		twiki.Pref._fixCookieDate (expiryDate); // Correct for Mac date bug - call only once for given Date object!
		expiryDate.setTime (expiryDate.getTime() + twiki.Pref.COOKIE_EXPIRY_TIME);
		twiki.Pref.setCookie(twiki.Pref.TWIKI_PREF_COOKIE_NAME, cookieString, expiryDate, '/');
	},
	
	/**
	Gets the TWiki pref cookie; creates a new cookie if it does not exist.
	@return The TWiki pref cookie.
	*/
	_getPrefCookie:function() {
		var cookieString = twiki.Pref.getCookie(twiki.Pref.TWIKI_PREF_COOKIE_NAME);
		if (cookieString == undefined) {
			cookieString = "";
		}
		return cookieString;
	},
	
	/**
	Strips reserved characters '|' and '=' from the input string.
	@return The stripped string.
	*/
	_getSafeString:function(inString) {
		var regex = new RegExp(/[|=]/);
		return inString.replace(regex, "");
	},
	
	/**
	Retrieves the decoded value of a cookie.
	@param inOffset : (Number) location of value in full cookie string.
	*/
	_getCookieVal:function(inOffset) {
		var endstr = document.cookie.indexOf (";", inOffset);
		if (endstr == -1) {
			endstr = document.cookie.length;
		}
		return unescape(document.cookie.substring(inOffset, endstr));
	},
	
	/**
	Function to correct for 2.x Mac date bug.  Call this function to
	fix a date object prior to passing it to setCookie.
	IMPORTANT:  This function should only be called *once* for
	any given date object!  See example at the end of this document.
	*/
	_fixCookieDate:function(inDate) {
		var base = new Date(0);
		var skew = base.getTime(); // dawn of (Unix) time - should be 0
		if (skew > 0) {	// Except on the Mac - ahead of its time
			inDate.setTime(inDate.getTime() - skew);
		}
	}
}