/// <summary>
/// Adds or updates a users answer. Creates new user if they're not in the cache,
/// otherwise update answer. returns the number of questions answered.
/// </summary>
public int AddOrUpdate(Answer updateAnswer)
{
List<CacheAnswer> listAnswers;
// Check for new user
if(!_answerCache.TryGetValue(updateAnswer.ProfileId, out listAnswers))
{
listAnswers = new List<CacheAnswer>();
_answerCache.Add(updateAnswer.ProfileId, listAnswers);
}
//Check if updating or adding new answer
for(int i=0; i < listAnswers.Count; i++)
{
var a = listAnswers[i];
if(a.QuestionId==updateAnswer.QuestionId)
{
a.ChoiceBit = updateAnswer.ChoiceBit();
a.ChoiceAccept = updateAnswer.ChoiceAccept;
a.ChoiceWeight = updateAnswer.ChoiceWeight;
a.LastAnswered = DateTime.Now;
//copy back to list since structs are passed by value
listAnswers[i] = a;
//found and updated answer, done
return listAnswers.Count;
}
}
//Got here: New answer
listAnswers.Add(new CacheAnswer
{
QuestionId = updateAnswer.QuestionId,
ChoiceBit = updateAnswer.ChoiceBit(),
ChoiceAccept = updateAnswer.ChoiceAccept,
ChoiceWeight = updateAnswer.ChoiceWeight,
LastAnswered = DateTime.Now
});
return listAnswers.Count;
}
/// <summary>
/// Makes sure an answer is valid by meeting the following requirements. Returns true
/// if answer is valid, false if not. Has side effect of modifiying passed in Answer.
///
/// - Answer isn't skipped (ChoiceIndex is not 0 or null)
/// - Set Irrelevant values: If ChoiceWeight = 0 then all bits set to 1 on ChoiceAccept
/// - ChoiceWeight must be 0, 1, 2, or 3
/// - ChoiceAccept can't be 0
///
/// </summary>
public bool ValidateAnswer(Answer ans)
{
if (ans.ChoiceIndex == null || ans.ChoiceIndex == 0) return false;
//Irrelevant
if (ans.ChoiceWeight == 0)
{
// user chose irrelevant, mark all answers as acceptable
ans.ChoiceAccept = 0xFF;
}
if (ans.ChoiceWeight != 0 &&
ans.ChoiceWeight != 1 &&
ans.ChoiceWeight != 2 &&
ans.ChoiceWeight != 3)
{
return false;
}
if (ans.ChoiceAccept == 0) return false;
return true;
}
/// <summary>
///
/// Updates/Adds a users answer in the database. Called by AnswerQuestion which already
/// validated the answer so we don't have to here.
///
/// </summary>
protected async Task AnswerDbAsync(Answer ans)
{
var db = new OkbDbContext();
var dbAns = await db.Answers.FindAsync(ans.ProfileId, ans.QuestionId);
//Are we updating a question or adding a new one?
if (dbAns == null)
{
//new answer
ans.LastAnswered = DateTime.Now;
db.Answers.Add(ans);
}
else
{
//update answer
dbAns.ChoiceIndex = ans.ChoiceIndex;
dbAns.ChoiceWeight = ans.ChoiceWeight;
dbAns.ChoiceAccept = ans.ChoiceAccept;
dbAns.LastAnswered = DateTime.Now;
}
await db.SaveChangesAsync();
}
/// <summary>
/// Simulations answering one question to see how fast we can insert answers into the DB.
/// Should be called in a loop and given a Random object.
/// </summary>
public void SimulateAnsweringQuestion(Random rand)
{
var db = new OkbDbContext();
var ans = new Answer
{
ProfileId = rand.Next(2, 200000),
QuestionId = (short)rand.Next(201, 1243),
ChoiceIndex = 1,
ChoiceWeight = 1,
ChoiceAccept = 1,
LastAnswered = DateTime.Now
};
try
{
db.Answers.Add(ans);
db.SaveChanges();
}
catch (Exception)
{
throw;
}
}
/// <summary>
/// Returns true if the other answer matches my requirements
/// </summary>
public bool IsMatch(Answer otherAnswer)
{
return (otherAnswer.ChoiceBit() & ChoiceAccept) != 0;
}
private static void ChoicePart2(TagBuilder tag, Answer answer, Answer compareAnswer, int index)
{
AcceptableChoice(tag, index, answer.ChoiceAccept);
if (compareAnswer != null)
{
//we both answered this question - add comparison classes
if (compareAnswer.ChoiceIndex == index) MatchChoice(tag, index, answer.ChoiceAccept);
}
}
private static void ChosenChoice(TagBuilder tag, int index, Answer answer)
{
if (index != answer.ChoiceIndex)
{
tag.AddCssClass("question-choice-fade");
}
else
{
tag.AddCssClass("question-choice-bold");
}
}
public static HtmlString ShowAnswersMe(this HtmlHelper htmlHelper, Answer answer, IList<string> choices)
{
var html = "";
for (int i = 1; i <= choices.Count; i++)
{
var tag = new TagBuilder("li");
tag.AddCssClass(answer.ChoiceIndex == i ? "question-choice-check" : "question-choice-bullet");
tag.AddCssClass(answer.IsMatch(i) ? "question-choice-green" : "question-choice-strike");
tag.InnerHtml = choices[i - 1];
html += tag.ToString();
}
return new HtmlString(html);
}
///////////////////////////////////////////////////////////////////////////////////////
public static HtmlString ShowAnswer(this HtmlHelper htmlHelper, Answer answer, Answer otherAnswer, IList<string> choices)
{
if (answer.ChoiceIndex == null || otherAnswer.ChoiceIndex == null)
{
return new HtmlString("INVALID ANSWER");
}
var tag = new TagBuilder("span");
tag.AddCssClass(otherAnswer.IsMatch(answer) ? "question-choice-green" : "question-choice-red");
tag.InnerHtml = choices[((int)answer.ChoiceIndex - 1) % choices.Count];
return new HtmlString(tag.ToString());
}
/// <summary>
/// Answers a question by adding it to the db. Will update if answer exists, otherwise adds a new
/// answer. The controller will take care of updating answer in cache. Validation peformed by the caller.
/// </summary>
public async Task AnswerAsync(Answer ans)
{
await AnswerDbAsync(ans);
}
/// <summary>
/// Skip the question. Returns the next 2 questions like Answer but they aren't shown
/// asynchronously - make the user wait for skipping questions. Doesn't update the
/// answer cache.
/// </summary>
public async Task<JsonResult> Skip(AnswerViewModel input)
{
var profileId = GetMyProfileId();
var answer = new Answer
{
ProfileId = profileId,
QuestionId = (short)input.QuestionId,
ChoiceIndex = null,
ChoiceAccept = 0,
ChoiceWeight = 0,
};
await _quesRepo.AnswerAsync(answer);
var nextQuestions = _quesRepo.Next2Questions(profileId);
return Json(nextQuestions);
}
/// <summary>
/// Add/Updates a user's answer in the database, and then calls MatchApiClient to
/// update the cache. Responsible for keeping DB and cache in sync so wraps these
/// operations in a transaction.
///
/// - If getNextFlag = true get the next 2 questions and return them as JSON
/// - Otherwise return the user's validated answer
/// - Sets forceRecalculateMatches = true if user answered less than 10 questions (so new users can see results immediately)
///
/// More info about TransactionScope (limitations):
/// https://msdn.microsoft.com/en-us/data/dn456843.aspx
///
/// </summary>
public async Task<JsonResult> Answer(AnswerViewModel input, bool getNextFlag = true)
{
var profileId = GetMyProfileId();
_matchApiClient = GetMatchApiClient();
var answer = new Answer
{
ProfileId = profileId,
QuestionId = (short)input.QuestionId
};
//Convert checkboxes to bit array for Acceptable choices
byte acceptBits = 0;
foreach (var index in input.ChoiceAccept)
{
acceptBits |= (byte)(1 << (index - 1));
}
answer.ChoiceIndex = (byte)input.ChoiceIndex;
answer.ChoiceAccept = acceptBits;
answer.ChoiceWeight = (byte)input.ChoiceImportance;
//We should do some user input validation
if(!_quesRepo.ValidateAnswer(answer))
{
//invalid answer - return not OK
Response.StatusCode = (int)HttpStatusCode.BadRequest;
return Json(null);
}
// Isolation Level: Read Committed
// Timeout : 5 minutes
var options = new TransactionOptions
{
IsolationLevel = IsolationLevel.ReadCommitted,
Timeout = TimeSpan.FromMinutes(5)
};
int count;
//Update DB and Cache in a transaction
//By default if scope.Complete() isn't called the transaction is rolled back.
using (var scope = new TransactionScope(TransactionScopeOption.Required, options, TransactionScopeAsyncFlowOption.Enabled))
{
var t1 = _quesRepo.AnswerAsync(answer);
var t2 = _matchApiClient.AnswerAsync(answer);
//await Task.WhenAll(t1, t2);
await t1;
count = await t2;
scope.Complete();
}
//Update the Activity feed
if(IsOkToAddActivity(OkbConstants.ActivityCategories.AnsweredQuestion))
{
//Get the question text
var ques = _quesRepo.GetQuestion(input.QuestionId);
var choiceText = "";
choiceText = ques.Choices[((int)answer.ChoiceIndex - 1) % ques.Choices.Count];
_feedRepo.AnsweredQuestionActivity(profileId, ques.Text, choiceText);
UpdateActivityLastAdded(OkbConstants.ActivityCategories.AnsweredQuestion);
}
//set forceRecalculateMatches = true if answered less than 10 questions
if (count < 10)
{
Session[OkbConstants.FORCE_RECALCULATE_MATCHES] = true;
}
IList<QuestionModel> nextQuestions = null;
//Get the next questions
if (getNextFlag)
{
nextQuestions = _quesRepo.Next2Questions(profileId);
return Json(nextQuestions);
}
else
{
return Json(answer);
}
}
