working on markdown quiz experience

Management/Models/Local/LocalQuizQuestion.cs

@@ -1,3 +1,4 @@
+using System.Security.Cryptography;
 using System.Text.RegularExpressions;
 
 namespace LocalModels;
@@ -36,21 +37,47 @@ public record LocalQuizQuestion
   }
 
   private static readonly string[] validFirstAnswerDelimiters = new string[] { "*a)", "a)", "[ ]", "[*]" };
-  public static LocalQuizQuestion ParseMarkdown(string input)
+
+  public static LocalQuizQuestion ParseMarkdown(string input, int questionIndex)
   {
-    var lines = input.Split(Environment.NewLine);
+    var lines = input.Trim().Split(Environment.NewLine);
     var firstLineIsPoints = lines.First().Contains("points: ", StringComparison.CurrentCultureIgnoreCase);
-    int points = firstLineIsPoints ? int.Parse(lines.First().Split(": ")[1]) : 1;
+
+    var textHasPoints = lines.Length > 0
+      && lines.First().Contains(": ")
+      && lines.First().Split(": ").Length > 1
+      && int.TryParse(lines.First().Split(": ")[1], out _);
+
+    int points = firstLineIsPoints && textHasPoints ? int.Parse(lines.First().Split(": ")[1]) : 1;
 
     var linesWithoutPoints = firstLineIsPoints ? lines[1..] : lines;
 
     var linesWithoutAnswers = linesWithoutPoints
-      .TakeWhile(line => !validFirstAnswerDelimiters.Any(prefix => line.TrimStart().StartsWith(prefix)))
+      .TakeWhile(
+        (line, index) =>
+          !validFirstAnswerDelimiters.Any(prefix => line.TrimStart().StartsWith(prefix))
+      )
       .ToArray();
-    var description = string.Join(Environment.NewLine, linesWithoutAnswers);
 
 
-    var (answers, questionType) = getAnswers(linesWithoutPoints);
+    var questionType = getQuestionType(linesWithoutPoints, questionIndex);
+
+    var questionTypesWithoutAnswers = new string[] { "essay", "short answer", "short_answer" };
+    var descriptionLines = questionTypesWithoutAnswers.Contains(questionType.ToLower())
+      ? linesWithoutAnswers
+        .TakeWhile(
+          (line, index) => index != linesWithoutPoints.Length && !questionTypesWithoutAnswers.Contains(line.ToLower())
+        )
+        .ToArray()
+      : linesWithoutAnswers;
+    var description = string.Join(Environment.NewLine, descriptionLines);
+
+
+
+    var typesWithAnswers = new string[] { "multiple_choice", "multiple_answers" };
+    var answers = typesWithAnswers.Contains(questionType)
+      ? getAnswers(linesWithoutPoints, questionIndex)
+      : [];
 
     return new LocalQuizQuestion()
     {
@@ -61,55 +88,79 @@ public record LocalQuizQuestion
     };
   }
 
-  private static (LocalQuizQuestionAnswer[], string questionType) getAnswers(string[] linesWithoutPoints)
+  private static string getQuestionType(string[] linesWithoutPoints, int questionIndex)
+  {
+
+    if (linesWithoutPoints.Length == 0)
+      return "";
+    if (linesWithoutPoints[^1].Equals("essay", StringComparison.CurrentCultureIgnoreCase))
+      return "essay";
+    if (linesWithoutPoints[^1].Equals("short answer", StringComparison.CurrentCultureIgnoreCase))
+      return "short_answer";
+    if (linesWithoutPoints[^1].Equals("short_answer", StringComparison.CurrentCultureIgnoreCase))
+      return "short_answer";
+
+    var answerLines = getAnswersGroupedByLines(linesWithoutPoints, questionIndex);
+    var isMultipleChoice =
+      answerLines.First().StartsWith("a)")
+      || answerLines.First().StartsWith("*a)");
+    if (isMultipleChoice)
+      return "multiple_choice";
+
+    var isMultipleAnswer =
+      answerLines.First().StartsWith("[ ]")
+      || answerLines.First().StartsWith("[*]");
+
+    if (isMultipleAnswer)
+      return "multiple_answers";
+
+    return "";
+  }
+
+  private static List<string> getAnswersGroupedByLines(string[] linesWithoutPoints, int questionIndex)
   {
     var indexOfAnswerStart = linesWithoutPoints
       .ToList()
       .FindIndex(
         l => validFirstAnswerDelimiters.Any(prefix => l.TrimStart().StartsWith(prefix))
       );
+    if (indexOfAnswerStart == -1)
+    {
+      var debugLine = linesWithoutPoints.FirstOrDefault(l => l.Trim().Length > 0);
+      throw new QuizMarkdownParseException($"question {questionIndex + 1}: no answers when detecting question type on {debugLine}");
+    }
+
     var answerLinesRaw = linesWithoutPoints[indexOfAnswerStart..];
 
     var answerStartPattern = @"^(\*?[a-z]\))|\[\s*\]|\[\*\]";
     var answerLines = answerLinesRaw.Aggregate(new List<string>(), (acc, line) =>
     {
-      if (!Regex.IsMatch(line, answerStartPattern))
+      var isNewAnswer = Regex.IsMatch(line, answerStartPattern);
+      if (isNewAnswer)
       {
-        if (acc.Count != 0) // Append to the previous line if there is one
-        {
-          int lastIndex = acc.Count - 1;
-          acc[lastIndex] += Environment.NewLine + line;
-        }
-        else
-        {
-          acc.Add(line);
-        }
+        acc.Add(line);
+        return acc;
       }
+
+      if (acc.Count != 0) // Append to the previous line if there is one
+        acc[^1] += Environment.NewLine + line;
       else
-      {
-        acc.Add(line); // Add as a new line if it matches the pattern
-      }
+        acc.Add(line);
 
       return acc;
     });
+    return answerLines;
+  }
 
-    var answers = answerLines.Select(LocalQuizQuestionAnswer.ParseMarkdown).ToArray();
+  private static LocalQuizQuestionAnswer[] getAnswers(string[] linesWithoutPoints, int questionIndex)
+  {
+    var answerLines = getAnswersGroupedByLines(linesWithoutPoints, questionIndex);
 
-    var isMultipleChoice =
-      answerLines.First().StartsWith("a)")
-      || answerLines.First().StartsWith("*a)");
+    var answers = answerLines
+      .Select((a, i) => LocalQuizQuestionAnswer.ParseMarkdown(a))
+      .ToArray();
 
-    var isMultipleAnswer =
-      answerLines.First().StartsWith("[ ]")
-      || answerLines.First().StartsWith("[*]");
-
-    var questionType = isMultipleChoice
-      ? "multiple_choice"
-      : isMultipleAnswer
-        ? "multiple_answers"
-        : "";
-
-    return (answers, questionType);
+    return answers;
   }
 }