Added aws-lti-middleware directory containing code for AWS LTI middle…

…ware

aws-lti-middleware/calculateSemester.js

@@ -0,0 +1,66 @@
+const { SESSION_SYSTEM } = require('@common/global-config')
+
+const calculateSemester = (ms) => {
+    const date = new Date(ms)
+    const semesters = [
+        {
+            name: "Fall",
+            start: 70,
+            end: 100
+        },
+        {
+            name: "Spring",
+            start: 0,
+            end: 45
+        },
+        {
+            name: "Summer",
+            start: 45,
+            end: 70
+        }
+    ]
+    const quarters = [
+        {
+            name: "Fall",
+            start: 75,
+            end: 100
+        },
+        {
+            name: "Winter",
+            start: 0,
+            end: 30
+        },
+        {
+            name: "Spring",
+            start: 30,
+            end: 55
+        },
+        {
+            name: "Summer",
+            start: 55,
+            end: 75
+        }
+    ]
+
+    const currentYear = date.getUTCFullYear()
+    const nextYear = date.getUTCFullYear() + 1
+
+    const _baseline = new Date(0)
+    _baseline.setUTCFullYear(currentYear)
+    const baseline = _baseline.getTime()
+
+    const _eoy = new Date(0)
+    _eoy.setUTCFullYear(nextYear)
+    const eoy = _eoy.getTime()
+
+    const progress = (ms - baseline) / (eoy - baseline) * 100
+
+    const session = (SESSION_SYSTEM === "SEMESTER" ? semesters : quarters)
+        .find(({ start, end }) => progress >= start && progress < end);
+
+    return `${session.name} ${currentYear}`
+}
+
+module.exports = {
+    calculateSemester
+}