(function (){ 
_.defaults(Exercises, { 
khanExercisesUrlBase: "/khan-exercises/",
getCurrentFramework: function (userExerciseOverride){ 
return (userExerciseOverride || userExercise).exerciseModel.fileName? "khan-exercises": "perseus"; 
} 
}
); 
_.extend(Exercises, { 
guessLog: undefined,
userActivityLog: undefined}
); 
var PerseusBridge = Exercises.PerseusBridge, localMode = Exercises.localMode, originalCheckAnswerText, userExercise, problemNum, answeredCorrectly, hintsAreFree, attempts, numHints, hintsUsed, lastAttemptOrHint; 
$(Exercises).bind("problemTemplateRendered", problemTemplateRendered).bind("newProblem", newProblem).bind("hintUsed", hintUsed).bind("readyForNextProblem", readyForNextProblem).bind("warning", warning).bind("upcomingExercise", upcomingExercise).bind("gotoNextProblem", gotoNextProblem).bind("updateUserExercise", updateUserExercise).bind("clearExistingProblem", clearExistingProblem); 
function problemTemplateRendered(){ 
$("#issue-throbber").attr("src", Exercises.khanExercisesUrlBase + "css/images/throbber.gif"); 
$("#positive-reinforcement").hide(); 
if (localMode) { 
$("#positive-reinforcement > img").attr("src", Exercises.khanExercisesUrlBase + "images/face-smiley.png"); 
} 
originalCheckAnswerText = $("#check-answer-button").val(); 
$("#check-answer-button").click(handleCheckAnswer); 
$("#answerform").submit(handleCheckAnswer); 
$("#skip-question-button").click({ 
skipped: true }
, handleCheckAnswer); 
$("#hint").click(handleHint); 
$("#next-question-button").click(function (){ 
$(Exercises).trigger("gotoNextProblem"); 
$(this).attr("disabled", true ).addClass("buttonDisabled"); 
} 
); 
$("#positive-reinforcement").click(function (){ 
$("#next-question-button").click(); 
} 
); 
$("#warning-bar-close a").click(function (e){ 
e.preventDefault(); 
$("#warning-bar").fadeOut("slow"); 
} 
); 
$("#scratchpad-show").click(function (e){ 
e.preventDefault(); 
Khan.scratchpad.toggle(); 
if (!localMode && userExercise.user) { 
window.localStorage["scratchpad:" + userExercise.user] = Khan.scratchpad.isVisible(); 
} 
} 
); 
$(PerseusBridge).trigger("problemTemplateRendered"); 
$(Khan).trigger("problemTemplateRendered"); 
} 
function newProblem(e, data){ 
Exercises.guessLog = [] ; 
Exercises.userActivityLog = [] ; 
answeredCorrectly = false , hintsAreFree = false , attempts = 0; 
numHints = data.numHints; 
hintsUsed = 0; 
lastAttemptOrHint = new Date().getTime(); 
$("#hint").attr("disabled", numHints === 0); 
} 
function handleCheckAnswer(e){ 
var framework = Exercises.getCurrentFramework(); 
var skipped = e.data && e.data.skipped; 
var score; 
if (framework === "perseus") { 
score = PerseusBridge.scoreInput(); 
} 
 else if (framework === "khan-exercises") { 
score = Khan.scoreInput(); 
} 
if (score.empty && !skipped) { 
return false ; 
} 
var curTime = new Date().getTime(); 
var timeTaken = Math.round((curTime - lastAttemptOrHint) / 1000); 
lastAttemptOrHint = curTime; 
Exercises.guessLog.push(score.guess); 
Exercises.userActivityLog.push([score.correct? "correct-activity": "incorrect-activity", JSON.stringify(score.guess), timeTaken] ); 
if (score.correct) { 
answeredCorrectly = true ; 
$(Exercises).trigger("problemDone"); 
} 
if (Exercises.assessmentMode) { 
disableCheckAnswer(); 
} 
 else if (score.correct) { 
$("#check-answer-button").hide(); 
$("#check-answer-results > p").hide(); 
_AN_Call_show("show", $("#next-question-button").removeAttr("disabled").removeClass("buttonDisabled")).focus(); 
_AN_Call_show("show", $("#positive-reinforcement")); 
} 
 else { 
$("#check-answer-button").parent().effect("shake", { 
times: 3,
distance: 5}
, 480).val("Try Again"); 
if (score.message != null ) { 
_AN_Call_show("show", $("#check-answer-results > p").html(score.message).tmpl()); 
} 
 else { 
$("#check-answer-results > p").hide(); 
} 
if (framework === "perseus") { 
} 
 else if (framework === "khan-exercises") { 
$(Khan).trigger("refocusSolutionInput"); 
} 
} 
if (!hintsAreFree) { 
hintsAreFree = true ; 
$(".hint-box").css("position", "relative").animate({ 
top: -10}
, 250).find(".info-box-header").slideUp(250).end().find("#hint").removeClass("orange").addClass("green"); 
updateHintButtonText(); 
} 
$(Exercises).trigger("checkAnswer", { 
correct: score.correct,
fast: !localMode && userExercise.secondsPerFastProblem >= timeTaken}
); 
if (localMode) { 
return false ; 
} 
var data = buildAttemptData(score.correct, ++attempts, JSON.stringify(score.guess), timeTaken, skipped); 
request("problems/" + problemNum + "/attempt", data).fail(function (xhr){ 
$(Exercises).trigger("attemptError"); 
if (xhr && xhr.readyState === 0) { 
return ; 
} 
$("#problem-and-answer").css("visibility", "hidden"); 
$(Exercises).trigger("warning", "This page is out of date. You need to <a href='" + _.escape(_AN_Read_href("href", _AN_Read_location("location", window))) + "'>refresh</a>, but " + "don't worry, you haven't lost progress. If you think " + "this is a mistake, <a href='http://www.khanacademy.org/" + "reportissue?type=Defect&issue_labels='>tell us</a>."); 
} 
); 
return false ; 
} 
function handleHint(){ 
var framework = Exercises.getCurrentFramework(); 
if (framework === "perseus") { 
$(PerseusBridge).trigger("showHint"); 
} 
 else if (framework === "khan-exercises") { 
$(Khan).trigger("showHint"); 
} 
} 
function hintUsed(){ 
Khan.scratchpad.resize(); 
hintsUsed++ ; 
updateHintButtonText(); 
if (hintsUsed === numHints) { 
$("#hint").attr("disabled", true ); 
$(Exercises).trigger("allHintsUsed"); 
} 
var curTime = new Date().getTime(); 
var timeTaken = Math.round((curTime - lastAttemptOrHint) / 1000); 
lastAttemptOrHint = curTime; 
Exercises.userActivityLog.push(["hint-activity", "0", timeTaken] ); 
if (!localMode && !userExercise.readOnly && !answeredCorrectly) { 
request("problems/" + problemNum + "/hint", buildAttemptData(false , attempts, "hint", timeTaken, false )); 
} 
} 
function updateHintButtonText(){ 
var $hintButton = $("#hint"); 
var hintsLeft = numHints - hintsUsed; 
if (hintsAreFree) { 
$hintButton.val(hintsUsed? "Show next step (" + hintsLeft + " left)": "Show solution"); 
} 
 else { 
$hintButton.val("I'd like another hint (" + (hintsLeft === 1? "1 hint left": hintsLeft + " hints left") + ")"); 
} 
} 
function buildAttemptData(correct, attemptNum, attemptContent, timeTaken, skipped){ 
var framework = Exercises.getCurrentFramework(); 
var data; 
if (framework === "perseus") { 
data = PerseusBridge.getSeedInfo(); 
} 
 else if (framework === "khan-exercises") { 
data = Khan.getSeedInfo(); 
} 
_.extend(data, { 
casing: "camel",
complete: correct? 1: 0,
count_hints: hintsUsed,
time_taken: timeTaken,
attempt_number: attemptNum,
attempt_content: attemptContent,
review_mode: Exercises.reviewMode? 1: 0,
topic_mode: (!Exercises.reviewMode && !Exercises.practiceMode)? 1: 0,
card: JSON.stringify(Exercises.currentCard),
stack_uid: Exercises.completeStack.getUid(),
topic_id: Exercises.topic && Exercises.topic.id,
cards_done: _AN_Read_length("length", Exercises.completeStack),
cards_left: _AN_Read_length("length", Exercises.incompleteStack) - 1,
user_assessment_key: Exercises.userAssessmentKey,
skipped: skipped? 1: 0}
); 
return data; 
} 
var attemptHintQueue = jQuery({ 
}
); 
$(window).unload(function (){ 
if (attemptHintQueue.queue().length) { 
$(Exercises).trigger("attemptError"); 
} 
} 
); 
function request(method, data){ 
var apiBaseUrl = (Exercises.assessmentMode? "/api/v1/user/assessment/exercises": "/api/v1/user/exercises"); 
var params = { 
url: apiBaseUrl + "/" + userExercise.exerciseModel.name + "/" + method,
type: "POST",
data: data,
dataType: "json"}
; 
var deferred = $.Deferred(); 
attemptHintQueue.queue(function (next){ 
$.ajax(params).then(function (data, textStatus, jqXHR){ 
deferred.resolve(data, textStatus, jqXHR); 
$(Exercises).trigger("updateUserExercise", { 
userExercise: data,
source: "serverResponse"}
); 
} 
, function (jqXHR, textStatus, errorThrown){ 
deferred.reject(jqXHR, textStatus, errorThrown); 
attemptHintQueue.clearQueue(); 
} 
).always(function (){ 
$(Exercises).trigger("apiRequestEnded"); 
next(); 
} 
); 
} 
); 
$(Exercises).trigger("apiRequestStarted"); 
return deferred.promise(); 
} 
function readyForNextProblem(e, data){ 
userExercise = data.userExercise; 
problemNum = userExercise.totalDone + 1; 
$(Exercises).trigger("updateUserExercise", { 
userExercise: userExercise}
); 
var framework = Exercises.getCurrentFramework(); 
if (framework === "perseus") { 
$(PerseusBridge).trigger("readyForNextProblem", data); 
} 
 else if (framework === "khan-exercises") { 
$(Khan).trigger("readyForNextProblem", data); 
} 
} 
function warning(e, message, showClose){ 
$(function (){ 
var warningBar = $("#warning-bar"); 
$("#warning-bar-content").html(message); 
if (showClose) { 
_AN_Call_show("show", warningBar.addClass("warning").children("#warning-bar-close")); 
} 
 else { 
warningBar.addClass("error").children("#warning-bar-close").hide(); 
} 
warningBar.fadeIn("fast"); 
} 
); 
} 
function upcomingExercise(e, data){ 
var framework = Exercises.getCurrentFramework(data.userExercise); 
if (framework === "perseus") { 
$(PerseusBridge).trigger("upcomingExercise", data); 
} 
 else if (framework === "khan-exercises") { 
$(Khan).trigger("upcomingExercise", data); 
} 
} 
function gotoNextProblem(){ 
var framework = Exercises.getCurrentFramework(); 
if (framework === "perseus") { 
} 
 else if (framework === "khan-exercises") { 
$(Khan).trigger("gotoNextProblem"); 
} 
} 
function updateUserExercise(e, data){ 
var framework = Exercises.getCurrentFramework(); 
if (framework === "perseus") { 
} 
 else if (framework === "khan-exercises") { 
$(Khan).trigger("updateUserExercise", data); 
} 
} 
function enableCheckAnswer(){ 
$("#check-answer-button").removeAttr("disabled").removeClass("buttonDisabled").val(originalCheckAnswerText); 
$("#skip-question-button").removeAttr("disabled").removeClass("buttonDisabled"); 
} 
function disableCheckAnswer(){ 
$("#check-answer-button").attr("disabled", "disabled").addClass("buttonDisabled").val("Please wait..."); 
$("#skip-question-button").attr("disabled", "disabled").addClass("buttonDisabled"); 
} 
function clearExistingProblem(){ 
var framework = Exercises.getCurrentFramework(); 
enableCheckAnswer(); 
$("#happy").hide(); 
if (!$("#examples-show").data("show")) { 
$("#examples-show").click(); 
} 
_AN_Call_show("show", $("#check-answer-button")); 
$("#next-question-button").blur().hide(); 
$("#positive-reinforcement").hide(); 
if (framework === "perseus") { 
} 
 else if (framework === "khan-exercises") { 
$(Khan).trigger("cleanupProblem"); 
} 
$("#workarea, #hintsarea, #solutionarea").empty(); 
$("#solutionarea").off(".emptyAnswer"); 
$("#hint").removeClass("green").addClass("orange").val("I'd like a hint").data("buttonText", false ).appendTo("#get-hint-button-container"); 
_AN_Call_show("show", $(".hint-box").css("top", 0).find(".info-box-header")); 
_AN_Call_clear("clear", Khan.scratchpad); 
} 
} 
)();