/*******************************************************************************
	BI Interactive Learning Strategies
	Contact:	Kevin Heald		kevin.heald@biworldwide.com
	Date:		11.04.2004
	Standard:	SCORM 1.2
	
	Revisions Made:	
	*	Cleaned up programming structure
	*	Modified debug variable to be more specific to the API.
	*	Added a variable to toggle API messages.
	*	Removed the new String(""); assignment from LMS function calls and replaced
		with an empty string (""). The new String() method creates a string object
		not a string which caused errors in the SCORM Test Suite.
			This:		var emptyString = new String("");
						var initResult = api.LMSInitialize(emptyString);
					
			Changed To:	var initResult = api.LMSInitialize("");
*******************************************************************************/

/*******************************************************************************
**  
**	Concurrent Technologies Corporation (CTC) grants you ("Licensee") a non-
**	exclusive, royalty free, license to use, modify and redistribute this
**	software in source and binary code form, provided that i) this copyright
**	notice and license appear on all copies of the software; and ii) Licensee does
**	not utilize the software in a manner which is disparaging to CTC.
**
**	This software is provided "AS IS," without a warranty of any kind.  ALL
**	EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
**	IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-
**	INFRINGEMENT, ARE HEREBY EXCLUDED.  CTC AND ITS LICENSORS SHALL NOT BE LIABLE
**	FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
**	DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES.  IN NO EVENT WILL CTC  OR ITS
**	LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
**	INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
**	CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
**	OR INABILITY TO USE SOFTWARE, EVEN IF CTC  HAS BEEN ADVISED OF THE POSSIBILITY
**	OF SUCH DAMAGES.
**
*******************************************************************************/

/*******************************************************************************
**	This file is part of the ADL Sample API Implementation intended to provide
**	an elementary example of the concepts presented in the ADL Shareable
**	Courseware Object Reference Model (SCORM).
**
**	The purpose in wrapping the calls to the API is to (1) provide a 
**	consistent means of finding the LMS API implementation within the window
**	hierarchy and (2) to validate that the data being exchanged via the
**	API conforms to the defined CMI data types.
** 
**	This is just one possible example for implementing the API guidelines for
**	runtime communication between an LMS and executable content components. 
**	There are several other possible implementations.
**
**	Usage:	Executable course content can call the API Wrapper 
**			functions as follows:
**
**	javascript:
**		var result = LMSInitialize();
**		if (result != true) {
**			//handle error
**		}
**		
**	authorware:
**		result := ReadURL("javascript:apiWrapper.LMSInitialize()", 100)
** 
******************************************************************************************/

var API_Debug = false;  // set this to false to turn debugging off
var API_Message = false; // toggle for displaying API messages

// Define exception/error codes
var _NoError = 0;
var _GeneralException = 101; 
var _InvalidArgumentError = 201;
var _NotInitialized = 301;
var _NotImplementedError = 401;


// local variable definitions
var apiHandle = null;

/******************************************************************************************
**
**	Function: LMSInitialize()
**	Inputs:	None
**	Return:	CMIBoolean true if the initialization was successful, or
**			CMIBoolean false if the initialization failed.
**
**	Description:
**	Initialize communication with LMS by calling the LMSInitialize 
**	function which will be implemented by the LMS, if the LMS is 
**	compliant with the SCORM.
**
******************************************************************************************/
function LMSInitialize() {
	var api = getAPIHandle();
	if (api == null) {
		if (API_Message) {
			alert("Unable to locate the LMS's API Implementation.\nLMSInitialize was not successful.");
		}
		return false;
	}

	// call the LMSInitialize function that should be implemented by the API
	var initResult = api.LMSInitialize("");
	if (initResult.toString() != "1") {
		// LMSInitialize did not complete successfully.
		/*	Note:	An assumption is made that if LMSInitialize returns a non-true
					value, then and only then, an error was raised.	*/

		/*	Note:	Each function could define its own error handler, but we'll 
					just implement a generic one in this example.	*/
		var err = ErrorHandler();
	}
	return initResult;
}

/******************************************************************************************
**
**	Function LMSFinish()
**	Inputs:	None
**	Return:	None
**
**	Description:
**	Close communication with LMS by calling the LMSFinish 
**	function which will be implemented by the LMS, if the LMS is 
**	compliant with the SCORM.
**
******************************************************************************************/
function LMSFinish() {
	var api = getAPIHandle();
	if (api == null) {
		if (API_Message) {
			alert("Unable to locate the LMS's API Implementation.\nLMSFinish was not successful.");
		}
	} else {
		// call the LMSFinish function that should be implemented by the API
		api.LMSFinish("");
		var err = ErrorHandler();
	}
	return;
}

/******************************************************************************************
**
**	Function LMSGetValue(name) 
**	Inputs:	name - string representing the cmi data model defined category or 
**				   element (e.g. cmi.core.student_id)
**	Return:	The value presently assigned by the LMS to the cmi data model 
**			element defined by the element or category identified by the name
**			input value.
**
**	Description:	
**	Wraps the call to the LMS LMSGetValue method
**
******************************************************************************************/
function LMSGetValue(name) {
	var api = getAPIHandle();
	if (api == null) {
		if (API_Message) {
			alert("Unable to locate the LMS's API Implementation.\nLMSGetValue was not successful.");
		}
		return null;
	} else {
		var value = api.LMSGetValue(name);
		var err = ErrorHandler();
		/*	if an error was encountered, then return null, 
			else return the retrieved value	*/
		if (err != _NoError) {
			return null;
		} else {
			return value.toString();
		}
	}
}

/******************************************************************************************
**
**	Function LMSSetValue(name, value) 
**	Inputs:	name - string representing the cmi data model defined category or element
**			value - the value that the named element or category will be assigned
**	Return:	None
**
**	Description:
**	Wraps the call to the LMS LMSSetValue method
**
******************************************************************************************/
function LMSSetValue(name, value) {
	var api = getAPIHandle();
	if (api == null) {
		if (API_Message) {
			alert("Unable to locate the LMS's API Implementation.\nLMSSetValue was not successful.");
		}
	} else {
		api.LMSSetValue(name, value);
		var err = ErrorHandler();
	}
	return;
}

/******************************************************************************************
**
**	Function LMSCommit() 
**	Inputs:	None
**	Return:	None
**
**	Description:
**	Call the LMSCommit function which will be implemented by the LMS, 
**	if the LMS is compliant with the SCORM.
**
******************************************************************************************/
function LMSCommit() {
	var api = getAPIHandle();
	if (api == null) {
		if (API_Message) {
			alert("Unable to locate the LMS's API Implementation.\nLMSCommit was not successful.");
		}
	} else {
		// call the LMSCommit function that should be implemented by the API
		api.LMSCommit("");
		var err = ErrorHandler();
	}
	return;
}

/******************************************************************************************
**
**	Function LMSGetLastError() 
**	Inputs:	None
**	Return:	The error code (integer format) that was set by the last LMS function call
**
**	Description:
**	Call the LMSGetLastError function which will be implemented by the LMS, 
**	if the LMS is compliant with the SCORM.
**
******************************************************************************************/
function LMSGetLastError() {
	var api = getAPIHandle();
	if (api == null) {
		if (API_Message) {
			alert("Unable to locate the LMS's API Implementation.\nLMSGetLastError was not successful.");
		}
		//since we can't get the error code from the LMS, return a general error
		return _GeneralError;
	}
	return api.LMSGetLastError().toString();
}

/******************************************************************************************
**
**	Function LMSGetErrorString(errorCode)
**	Inputs:	errorCode - Error Code(integer format)
**	Return:	The textual description that corresponds to the input error code 
**
**	Description:
**	Call the LMSGetErrorString function which will be implemented by the LMS, 
**	if the LMS is compliant with the SCORM.
**
******************************************************************************************/
function LMSGetErrorString(errorCode) {
	var api = getAPIHandle();
	if (api == null) {
		if (API_Message) {
			alert("Unable to locate the LMS's API Implementation.\nLMSGetErrorString was not successful.");
		}
	}
	return api.LMSGetErrorString(errorCode).toString();
} 

/******************************************************************************************
**
**	Function LMSGetDiagnostic(errorCode) 
**	Inputs:	errorCode - Error Code(integer format), or null
**	Return:	The vendor specific textual description that corresponds to the input error code 
**
**	Description:
**	Call the LMSGetDiagnostic function which will be implemented by the LMS, 
**	if the LMS is compliant with the SCORM.
**
******************************************************************************************/
function LMSGetDiagnostic(errorCode) {
	var api = getAPIHandle();
	if (api == null) {
		if (API_Message) {
			alert("Unable to locate the LMS's API Implementation.\nLMSGetDiagnostic was not successful.");
		}
	}
	return api.LMSGetDiagnostic(errorCode).toString();
}

/*******************************************************************************
**
**	Function LMSIsInitialized() 
**	Inputs:	none
**	Return:	true if the LMS API is currently initialized, otherwise false 
**
**	Description:
**	Determines if the LMS API is currently initialized or not.
**
*******************************************************************************/
function LMSIsInitialized() {
	/*	there is no direct method for determining if the LMS API is initialized
		for example an LMSIsInitialized function defined on the API so we'll try
		a simple LMSGetValue and trap for the LMS Not Initialized Error	*/
   
	var api = getAPIHandle();
	if (api == null) {
		if (API_Message) {
			alert("Unable to locate the LMS's API Implementation.\nLMSIsInitialized() failed.");
		}
		// no choice but to return false.
		return false;
	} else {
		var value = api.LMSGetValue("cmi.core.student_name");
		var errCode = api.LMSGetLastError().toString();
		if (errCode == _NotInitialized) {
			return false;
		} else {
			return true;
		}
	}
}

/******************************************************************************************
**	APIWrapper Private function implementations
**	Note:	This is javascript so there is no way to really prevent someone 
**			from calling the other methods in this file, but they are really 
**			intended to be private methods.  Only the methods above
**			are intended to be called directly by the learning 
**			content components.
******************************************************************************************/

/******************************************************************************************
**
**	Function ErrorHandler()
**	Inputs:	None
**	Return:	The current value of the LMS Error Code
**
**	Description:
**	Determines if an error was encountered by the previous API call
**	and if so, displays a message to the user.  If the error code
**	has associated text it is displayed.  
**
**	Side Effects:	Displays an alert window with the appropriate error information
**
******************************************************************************************/
function ErrorHandler() {
	var api = getAPIHandle();
	if (api == null) {
		if (API_Message) {
			alert("Unable to locate the LMS's API Implementation.\nCannot determine LMS error code.");
		}
		return;
	}

	//	check for errors caused by or from the LMS
	var errCode = api.LMSGetLastError().toString();
	if (errCode != _NoError) {
		//	an error was encountered so display the error description
		var errDescription = api.LMSGetErrorString(errCode);
		if (API_Debug == true) {
			errDescription += "\n";
			errDescription += api.LMSGetDiagnostic(null);
			/*	by passing null to LMSGetDiagnostic, we get any available diagnostics
				on the previous error.	*/
		}
		if (API_Message) {
			alert(errDescription);
		}
	}
	return errCode;
}

/******************************************************************************************
**
**	Function getAPIHandle()
**	Inputs:	None
**	Return:	value contained by APIHandle
**
**	Description:
**	Returns the handle to API object if it was previously set, 
**	otherwise it returns null
**
******************************************************************************************/
function getAPIHandle() {
	if (apiHandle == null) {
	apiHandle = getAPI();
	} 
	return apiHandle;
}

/******************************************************************************************
**
**	Function findAPI(win)
**	Inputs:	win - a Window Object
**	Return:	If an API object is found, it is returned, otherwise null is returned.
**
**	Description:
**	This function looks for an object named API in the supported window hierarchy, 
** 
******************************************************************************************/
function findAPI(win) {
	/*	Search the window hierarchy for an object named "API"  
		Look in the current window (win) and recursively look in any child frames	*/

	if (API_Debug) {
	alert("win is: " + win.location.href);
	}
   
	if (win.API != null) {
		if (API_Debug) {
			alert("found api in this window");
		}
		return win.API;
	}
   
	if (win.length > 0) {  // does the window have frames?
		if (API_Debug) {
			alert("looking for api in windows frames");
		}
		for (var i = 0; i < win.length; i++) {
			if (API_Debug) {
				alert("looking for api in frames[" + i + "]");
			}
			var theAPI = findAPI(win.frames[i]);
			if (theAPI != null) {
				return theAPI;
			}
		}
	}
   
	if (API_Debug) {
		alert("didn't find api in this window (or its children)");
	}
	return null;
}

/******************************************************************************************
**
**	Function getAPI()
**	Inputs:	none
**	Return:	If an API object is found, it is returned, otherwise null is returned.
**
**	Description:
**	This function looks for an object named API, first in the current window's hierarchy, 
**	and then, if necessary, in the current window's opener window hierarchy (if there is
**	an opener window).
******************************************************************************************/
function getAPI() {
	/*	start at the topmost window - findAPI will recurse down through
		all of the child frames	*/
	var theAPI = findAPI(this.top);
	

	if (theAPI == null) {
		/*	the API wasn't found in the current window's hierarchy.  If the
			current window has an opener (was launched by another window),
			check the opener's window hierarchy.	*/
		if (API_Debug) {
			alert("checking to see if this window has an opener");
			alert("typeof(window.opener) is: " + typeof(window.opener));
		}

		var openerHandle = this.opener;
		if (API_Debug) alert("first openerHandle is " + openerHandle + "\ntypeof(openerHandle) is " + typeof(openerHandle));
		
		//regardless of whether there is an opener, firefox gets object as type!
		var str = "";
		for (var s in openerHandle) str+= s;
		if (API_Debug) {
			//for (var s in openerHandle) str+= "openerHandle."+s+" is " + openerHandle[s] + "\n";
			alert("properties of openerHandle are:\n" + str);
		}
		
		//str has openerHandle property names captured. if it has no properties, it will be empty string
		while (typeof(openerHandle) != "undefined" && str != "" && !openerHandle.closed) {
			if (API_Debug) {
				alert("checking this windows opener");
			}
			if (openerHandle != null) {
				if (API_Debug) {
					alert("this windows opener is NOT null - looking there");
				}
				theAPI = findAPI(openerHandle.top); 
			} else {
				if (API_Debug) {
					alert("this windows opener is null");
					break; //end of the line, no more openers
				}
			}
			//api is found, break out, else look for opener of opener
			if (theAPI != null) { 
				break;
			} else {
				openerHandle = openerHandle.opener;
				str = "";
				for (var s in openerHandle) str+= s;
				if (API_Debug) {
					alert("in while, openerHandle.opener is now openerHandle, typeof(openerHandle) is " + typeof(openerHandle));
					alert("properties of openerHandle are:\n" + str);
				}
			}
		}
	}
	if (API_Debug) {
		alert("returning " + theAPI);
	}
	return theAPI;
}