From 78233cf2810e6053d38de90e92b7a1b0f2b26e19 Mon Sep 17 00:00:00 2001
From: Frode Petterson <frode.andre.petterson@gmail.com>
Date: Mon, 17 Jul 2017 16:09:44 +0200
Subject: [PATCH] Improve sort of matching type tasks

Will order by correct/wrong and group matches on same row
HFP-1250
---
 type-processors/matching-processor.class.php | 174 +++++++++++++++----
 1 file changed, 138 insertions(+), 36 deletions(-)

diff --git a/type-processors/matching-processor.class.php b/type-processors/matching-processor.class.php
index 9d950d1..4f03a35 100644
--- a/type-processors/matching-processor.class.php
+++ b/type-processors/matching-processor.class.php
@@ -172,6 +172,113 @@ function generateRows($mappedCRP, $mappedResponse, $dropzones, $draggables) {
     return $html;
   }
 
+  /**
+   * Sort handler for comparing result rows
+   *
+   * @param stdClass $a
+   * @param stdClass $b
+   * @return int
+   */
+  private static function rowcmp($a, $b) {
+    if ($a->isCorrect && $b->isCorrect || !$a->isCorrect && !$b->isCorrect) {
+      return strcmp($a->response, $b->response);
+    }
+    if ($a->isCorrect && !$b->isCorrect) {
+      return -1;
+    }
+    if (!$a->isCorrect && $b->isCorrect) {
+      return 1;
+    }
+  }
+
+  /**
+   * Creates the inital set of rows needed when generating the table HTML
+   *
+   * @param array $draggables
+   * @param array $crp
+   * @param array $response
+   * @return array
+   */
+  private static function createUserAnswerRows(&$draggables, &$crp, &$response) {
+    // Create list with all rows to display
+    $rows = array();
+    foreach ($response as $key => $answer) {
+
+      $row = (object) array(
+        'isCorrect' => in_array($answer, $crp),
+        'crp' => '',
+      );
+
+      // Locate response label
+      foreach ($draggables as $draggable) {
+        if ($draggable->id === $answer) {
+          $row->response = $draggable->value;
+          break;
+        }
+      }
+
+      $rows[] = $row;
+    }
+
+    // Sort rows
+    usort($rows, array('MatchingProcessor', 'rowcmp'));
+    return $rows;
+  }
+
+  /**
+   * Creates a list of soluton labels.
+   *
+   * @param array $draggables
+   * @param array $crp
+   * @return array
+   */
+  private static function createSolutionRows(&$draggables, &$crp) {
+    // Create list of solution labels
+    $solutions = array();
+    foreach ($crp as $pattern) {
+      $solutions[] = $draggables[$pattern]->value;
+    }
+    sort($solutions);
+    return $solutions;
+  }
+
+  /**
+   * Puts the solutions labels into the approperiate rows.
+   *
+   * @param array $rows
+   * @param array $solutions
+   */
+  private static function addSolutionsToRows(&$rows, &$solutions) {
+    // Add solution labels to rows
+    foreach ($rows as $key => &$row) {
+      if (empty($solutions)) {
+        break; // All solutions have been added
+      }
+
+      if ($row->isCorrect) {
+        // Add solution if hasn't been added yet
+        $index = array_search($row->response, $solutions);
+        if ($index !== FALSE) {
+          $row->crp = $solutions[$index];
+          unset($solutions[$index]); // Prevent adding multiple times
+        }
+      }
+      else {
+        // Add the next solution
+        $row->crp = array_shift($solutions);
+      }
+    }
+
+    // In case we still have some solutions left, add extra rows for them
+    foreach ($solutions as $solution) {
+      $rows[] = (object) array(
+        'isCorrect' => FALSE,
+        'crp' => $solution,
+        'response' => '',
+      );
+    }
+  }
+
   /**
    * Generate row for a single dropzone and populate it with correct answers and
    * user answers
@@ -184,59 +291,54 @@ function generateRows($mappedCRP, $mappedResponse, $dropzones, $draggables) {
    * @return string Drop zone rows element
    */
   function generateDropzoneRows($dropzone, $draggables, $crp, $response) {
-    $dzRows = sizeof($crp) > sizeof($response) ? sizeof($crp) : sizeof($response);
-
-    // Skip row if no correct or user answers
-    if ($dzRows <= 0) {
-      return '';
+    if (!count($response) && !count($crp)) {
+      return ''; // Skip if no correct or user answers
     }
 
-    $rows = '';
+    // Get rows needed to display user answers
+    $rows = self::createUserAnswerRows($draggables, $crp, $response);
+
+    // Get correct solutions labels for the task
+    $solutions = self::createSolutionRows($draggables, $crp);
+
+    // Merges the solutions into the correct rows
+    self::addSolutionsToRows($rows, $solutions);
+
+    // Ready to generate the HTML
+    $rowsHtml = '';
     $lastCellInRow = 'h5p-matching-last-cell-in-row';
+    $numRows = count($rows);
 
-    for ($i = 0; $i < $dzRows; $i++) {
-      $row = '';
-      $tdClass = $i >= $dzRows - 1 ? $lastCellInRow : '';
+    foreach ($rows as $key => &$row) {
+      $rowHtml = '';
+      $tdClass = ($key >= $numRows - 1 ? $lastCellInRow : '');
 
-      if ($i === 0) {
-        // Add drop zone
-        $row .=
+      if ($key === 0) {
+        // Print Drop Zone
+        $rowHtml .=
           '<th class="' . 'h5p-matching-dropzone ' . $lastCellInRow . '"' .
-            ' rowspan="' . $dzRows . '"' .
+            ' rowspan="' . $numRows . '"' .
           '>' .
             $dropzone->value .
           '</th>';
       }
 
       // Add correct response pattern
-      $crpCellContent = isset($crp[$i]) ? $draggables[$crp[$i]]->value : '';
-      $row .= '<td class="' . $tdClass . '">' .
-                $crpCellContent .
+      $rowHtml .= '<td class="' . $tdClass . '">' .
+                $row->crp .
               '</td>';
 
-
-      // Add user response
-      $isCorrectClass = '';
-      $responseCellContent = '';
-      if (isset($response[$i])) {
-        $isCorrectClass = isset($response[$i]) && in_array($response[$i], $crp) ?
-          'h5p-matching-draggable-correct' : 'h5p-matching-draggable-wrong';
-        foreach ($draggables as $draggable) {
-          if ($draggable->id === $response[$i]) {
-            $responseCellContent = $draggable->value;
-            break;
-          }
-        }
-      }
-
-      $classes = $tdClass . (sizeof($isCorrectClass) ? ' ' : '') . $isCorrectClass;
-      $row .= '<td class="' . $classes . '">' .
-                $responseCellContent .
+      // Add user reponse
+      $correctClass = ($row->isCorrect ? 'h5p-matching-draggable-correct' : 'h5p-matching-draggable-wrong');
+      $classes = $tdClass . ($tdClass !== '' && $correctClass !== '' ?  ' ' : '') . ($row->response !== '' ? $correctClass : '');
+      $rowHtml .= '<td class="' . $classes . '">' .
+                $row->response .
               '</td>';
 
-      $rows .= '<tr>' . $row . '</tr>';
+      $rowsHtml .= '<tr>' . $rowHtml . '</tr>';
     }
-    return $rows;
+
+    return $rowsHtml;
   }
 
   /**