From 898fa80556ddd2ddcf5837b98c15c5b8cc933f37 Mon Sep 17 00:00:00 2001
From: Dan Ghost <daniel.ghost@kineo.com>
Date: Mon, 3 Apr 2023 14:10:23 +0100
Subject: [PATCH] Bug: score logic (#267)

---
 js/scorm/wrapper.js | 28 ++++++++++++++++++++++------
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/js/scorm/wrapper.js b/js/scorm/wrapper.js
index d948cb3e..dc275ff7 100644
--- a/js/scorm/wrapper.js
+++ b/js/scorm/wrapper.js
@@ -212,18 +212,34 @@ class ScormWrapper {
     return this.getValue(this.isSCORM2004() ? 'cmi.score.raw' : 'cmi.core.score.raw');
   }
 
-  setScore(score, minScore = 0, maxScore = 100) {
+  setScore(score, minScore = 0, maxScore = 100, isPercentageBased = true) {
     if (this.isSCORM2004()) {
+      // `raw`, `min`, `max` sum absolute values assigned to questions
       this.setValue('cmi.score.raw', score);
       this.setValue('cmi.score.min', minScore);
       this.setValue('cmi.score.max', maxScore);
-
-      const range = maxScore - minScore;
-      const scaledScore = ((score - minScore) / range).toFixed(7);
-      this.setValue('cmi.score.scaled', scaledScore);
+      // range split into negative/positive ranges (rather than minScore-maxScore) depending on score
+      const range = (score < 0) ? Math.abs(minScore) : maxScore;
+      // `scaled` converted to -1-1 range to indicate negative/positive weighting now that negative values can be assigned to questions
+      const scaledScore = score / range;
+      this.setValue('cmi.score.scaled', scaledScore.toFixed(7));
       return;
     }
-    // SCORM 1.2
+    if (isPercentageBased) {
+      // convert values to 0-100 range
+      // negative scores are capped to 0 due to SCORM 1.2 limitations
+      score = (score < 0) ? 0 : Math.round((score / maxScore) * 100);
+      minScore = 0;
+      maxScore = 100;
+    } else {
+      const validate = (attribute, value) => {
+        const isValid = value >= 0 && score <= 100;
+        if (!isValid) this.logger.warn(`${attribute} must be between 0-100.`);
+      }
+      validate('cmi.core.score.raw', score);
+      validate('cmi.core.score.min', minScore);
+      validate('cmi.core.score.max', maxScore);
+    }
     this.setValue('cmi.core.score.raw', score);
     if (this.isSupported('cmi.core.score.min')) this.setValue('cmi.core.score.min', minScore);
     if (this.isSupported('cmi.core.score.max')) this.setValue('cmi.core.score.max', maxScore);