added semester filter

backend/src/main/java/edu/gcc/hallmonitor/Filter.java

@@ -43,6 +43,7 @@ static void registerFilterType(
     static void init() {
         Days.init();
         Department.init();
+        Semester.init();
         NumCredits.init();
         ProfName.init();
         Time.init();

backend/src/main/java/edu/gcc/hallmonitor/Semester.java

@@ -0,0 +1,39 @@
+package edu.gcc.hallmonitor;
+
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+
+public record Semester(String semester) implements Filter {
+
+    @Override
+    public boolean filter(Course course) {
+        return course.semester().equals(semester);
+    }
+
+    @Override
+    public JsonNode toJSON() {
+        ObjectNode root = Main.MAPPER.createObjectNode();
+        root.put("type", "semester");
+        root.put("value", semester);
+        return root;
+    }
+
+    private static Filter deserialize(JsonNode value) {
+        return new Semester(value.asText());
+    }
+
+    private static Set<String> possibleValues(List<Course> courses) {
+        return courses.stream()
+                .map(Course::semester)
+                .collect(Collectors.toSet());
+    }
+
+    public static void init() {
+        Filter.registerFilterType("semester", Semester::deserialize, Semester::possibleValues);
+    }
+}
+

backend/src/test/java/edu/gcc/hallmonitor/SemesterTest.java

@@ -0,0 +1,44 @@
+package edu.gcc.hallmonitor;
+
+import java.time.LocalTime;
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class SemesterTest {
+    @Test
+    public void testSemesterFilter() {
+        Course fall = emptyWithSemester("2023_Fall");
+        Course spring = emptyWithSemester("2024_Spring");
+
+        Semester filter = new Semester("2023_Fall");
+
+        assertEquals(true, filter.filter(fall));
+        assertEquals(false, filter.filter(spring));
+    }
+
+    private static Course emptyWithSemester(String semester) {
+        return new Course(
+            "",
+            List.of(""),
+            "",
+            0,
+            ' ',
+            "",
+            0,
+            semester,
+            List.of(new CourseTime(
+                "M",
+                LocalTime.of(0, 0),
+                LocalTime.of(0, 0)
+            )),
+            false,
+            false,
+            0,
+            0
+        );
+    }
+}
+

frontend/src/SearchPage.tsx

@@ -22,6 +22,8 @@ interface Course {
 export default function SearchPage() {
   const courses_per_page = 10;
   const [query, setQuery] = useState('');
+  const [semester, setSemester] = useState('ALL');
+  const [semesters, setSemesters] = useState<string[]>([]);
   const [department, setDepartment] = useState('ALL');
   const [professor, setProfessor] = useState('ALL');
   const [courses, setCourses] = useState<Course[]>([]);
@@ -70,7 +72,7 @@ export default function SearchPage() {
     }
 
     search();
-  }, [department, professor, days, credits, timeStart, timeEnd]);
+  }, [semester, department, professor, days, credits, timeStart, timeEnd]);
 
 
   //Toggles a course in the user's schedule and syncs with the backend.
@@ -137,6 +139,12 @@ export default function SearchPage() {
 
   // updating all the filters
 
+  const updateSem = async (event: React.ChangeEvent<HTMLSelectElement>) => {
+      const updated = event.target.value;
+      await updateFilter('semester', semester, updated);
+      setSemester(updated);
+    };
+
   const updateDept = async (event: React.ChangeEvent<HTMLSelectElement>) => {
     const updated = event.target.value;
     await updateFilter('department', department, updated);
@@ -179,6 +187,8 @@ export default function SearchPage() {
     };
     const updateFilters = async () => {
       // Update:
+      // Semesters
+      setSemesters(await getValues('semester'));
       // Departments
       setDepartments(await getValues('department'));
       // Professors
@@ -215,6 +225,9 @@ export default function SearchPage() {
       const resp = await fetch('/search/filter');
       for (const filter of await resp.json()) {
         switch (filter.type) {
+          case "semester":
+            setSemester(filter.value);
+            break;
           case "department":
             setDepartment(filter.value);
             break;
@@ -276,6 +289,7 @@ export default function SearchPage() {
     });
 
     setDepartment('ALL');
+    setSemester('ALL');
     setProfessor('ALL');
     setDays(new Set());
     setCredits('ALL');
@@ -306,6 +320,13 @@ export default function SearchPage() {
       <div className="sidebar">
         <h3>Filters</h3>
 
+        <h4> Semester </h4>
+
+        <select value={semester} onChange={updateSem}>
+          <option value="ALL">All Semesters</option>
+          {semesters.map(sem => <option key={sem} value={sem}>{sem}</option>)}
+        </select>
+
         <h4> Department & Professor</h4>
 
         <select value={department} onChange={updateDept}>