Initial implementation of QuestionHandler

QuestionHandler used to help figure out which question to ask next to the user when a student is filling out their profile.

classes/QuestionHandler.php

@@ -0,0 +1,180 @@
+<?php
+/**
+ * Created by PhpStorm.
+ * User: Jacob
+ * Date: 3/20/2018
+ * Time: 8:51 PM
+ */
+
+class QuestionHandler
+{
+    /**
+     * Returns the most recently answered question from a user which could also be answered again based on
+     * question dependencies.
+     *
+     * @param Student $student
+     * @return Question
+     */
+    public static function getCurrentQuestion(Student $student)
+    {
+        $aq = $student->getAnsweredQuestions();
+        if (!is_null($aq) and count($aq) > 0) {
+            $answered = array_reverse(array_map(function ($o) {
+                $o->getQuestion();
+            }, $aq));
+            foreach ($answered as $item) {
+                if (self::checkQuestionDependency($student, $item)) {
+                    return $item;
+                }
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Returns the next question a user can answer given question dependencies.
+     *
+     * @param Student $student
+     * @return Question|null
+     */
+    public static function getNextQuestion(Student $student)
+    {
+        $unanswered = self::getUnansweredQuestions($student);
+        foreach ($unanswered as $question) {
+            if (self::checkQuestionDependency($student, $question)) {
+                return $question;
+            }
+        }
+        return null;
+    }
+
+    /**
+     * @param Student $student
+     * @param int $n
+     * @return Question|null
+     */
+    public static function getNthQuestion(Student $student, int $n)
+    {
+        if ($n < count($student->getAnsweredQuestions())) {
+            return $student->getAnsweredQuestions()[$n]->getQuestion();
+        } else {
+            return self::getUnansweredQuestions($student)[$n];
+        }
+    }
+
+    /**
+     * Returns the second most recently answered question from a user which could also be answered again based on
+     * question dependencies.
+     *
+     * @param Student $student
+     * @return Question|null
+     */
+    public static function getPreviousQuestion(Student $student)
+    {
+        $aq = $student->getAnsweredQuestions();
+        if (!is_null($aq) and count($aq) > 0) {
+            $answered = array_reverse(array_map(function ($o) {
+                $o->getQuestion();
+            }, $aq));
+            foreach (array_slice($answered,1) as $item) {
+                if (self::checkQuestionDependency($student, $item)) {
+                    return $item;
+                }
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Returns an array of questions that have yet to be answered by the
+     *
+     * @param Student $student
+     * @return Question[]
+     */
+    public static function getUnansweredQuestions(Student $student)
+    {
+        $dbc = new DatabaseConnection();
+        $params = ["i", $student->getPkID()];
+        $questionIDs = $dbc->query("select multiple", "SELECT pkquestionid FROM tblquestions 
+                                                                    WHERE pkquestionid NOT IN 
+                                                                    (SELECT fkquestionid FROM tblprofileanswers
+                                                                      WHERE fkuserid = ?)", $params);
+        $output = [];
+        if ($questionIDs) {
+            try {
+                foreach ($questionIDs as $questionID) {
+                    $output[] = new QuestionMC($questionID);
+                }
+            } catch (Exception | Error $e) {
+                return [];
+            }
+        }
+        return $output;
+    }
+
+    /**
+     * Checks to see if the given question has been answered by the user
+     *
+     * @param Student $student
+     * @param Question $question
+     * @return bool
+     */
+    public static function isQuestionAnswered(Student $student, Question $question): bool
+    {
+        $aq = $student->getAnsweredQuestions();
+        if (!is_null($aq) and count($aq) > 0) {
+            $answered = array_reverse(array_map(function ($o) {
+                $o->getQuestion();
+            }, $aq));
+            return in_array($question, $answered, true);
+        }
+        return false;
+    }
+
+    /**
+     * @param Student $student
+     * @param Question $question
+     * @param $answer
+     * @param int $importance
+     */
+    public static function saveAnswer(Student $student, Question $question, $answer, int $importance): void
+    {
+        $student->addAnsweredQuestion(new QuestionAnswered($student, $question, $answer, $importance));
+        $student->updateToDatabase();
+    }
+
+    /**
+     * Checks to see if the specified question can be asked to the given student based on the dependencies of the
+     * given question and what questions the student has already answered.
+     *
+     * Will not always return true if the question has already been answered by the student. For example, if a student
+     * answers a child question, then changes the answer to the parent question, and then decides to try to answer
+     * the child question again.
+     *
+     * @param Student $student
+     * @param Question $question
+     * @return bool
+     */
+    private static function checkQuestionDependency(Student $student, Question $question): bool
+    {
+        if (empty($question->getDependencies())) {
+            return true;
+        } else {
+            $haystack = $student->getAnsweredQuestions();
+            for ($i = 0; $i < count($haystack); $i++) {
+                $haystack[$i] = $haystack[$i]->getQuestion()->getPkID();
+            }
+            foreach ($question->getDependencies() as $dependency) {
+                if ($index = array_search($dependency->getParentID(), $haystack, true)) {
+                    $studentAnswer = $student->getAnsweredQuestions()[$index];
+                    if ($dependency->getRequiredAnswer() !== $studentAnswer->getAnswer()) {
+                        return false;
+                    }
+                } else {
+                    return false;
+                }
+            }
+            return true;
+        }
+    }
+}

classes/entities/Question.php

@@ -80,9 +80,9 @@ public function getQuestionText(): string
 
     /**
      * @param Dependency $dependency
-     * @return bool
+     * @return bool|int
      */
-    private function addDependency(Dependency $dependency): bool
+    private function addDependency(Dependency $dependency)
     {
         return array_push($this->dependencies, $dependency);
     }

classes/entities/QuestionAnswered.php

@@ -60,7 +60,7 @@ public function __construct2(Question $question, Student &$student)
      * @param int $importance
      * @throws Exception
      */
-    public function __construct3(Question $question, Student &$student, $answer, int $importance)
+    public function __construct4(Question $question, Student &$student, $answer, int $importance)
     {
         $result = [
             $this->setQuestion($question),

classes/entities/Student.php

@@ -261,9 +261,6 @@ public function updateToDatabase(): bool
                 $result = $dbc->query("update", "UPDATE tbleduprofile SET nact=?, hadap=?, ngpa=?, nsat=?, 
 							  dtentry=?, ncollegelength=?, fkmajorid=?, fkmajor1=?, fkmajor2=?, fkmajor3=?, 
 							  nhouseincome=?, isgender=? WHERE fkuserid=?", $params);
-                $this->inDatabase = $result;
-                $this->synced = $result;
-                return (bool)$result;
             } else {
                 $dbc = new DatabaseConnection();
                 $preferredMajors = $this->getPreferredMajors();
@@ -295,10 +292,19 @@ public function updateToDatabase(): bool
                                                         fkmajor2, fkmajor3, ngpa, nact, nsat, hadap, nhouseincome, 
                                                         dtentry, ncollegelength, isgender) VALUES 
                                                         (?,?,?,?,?,?,?,?,?,?,?,?,?)", $params);
-                $this->inDatabase = $result;
-                $this->synced = $result;
-                return (bool)$result;
             }
+            $this->inDatabase = $result;
+
+            if(!is_null($this->getAnsweredQuestions())) {
+                foreach($this->getAnsweredQuestions() as $answeredQuestion) {
+                    $answeredQuestion->removeFromDatabase();
+                    $result = ($result and $answeredQuestion->updateToDatabase());
+                }
+            }
+
+            $this->inDatabase = $result;
+            $this->synced = $result;
+            return (bool)$result;
         } else {
             return false;
         }