restrict filter options to those actually possible with existing query+filter

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

@@ -29,6 +29,8 @@ private static Filter deserialize(JsonNode value) {
     private static Set<String> possibleValues(List<Course> courses) {
         return courses.stream()
                 .map(Course::department)
+                // Don't include ZLOAD "courses"
+                .filter(s -> !s.equals("ZLOAD"))
                 .collect(Collectors.toSet());
     }
 

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

@@ -30,6 +30,12 @@ private static Set<String> possibleValue(List<Course> courses) {
         return courses.stream()
                 .map(Course::professor)
                 .flatMap(List::stream)
+                // Remove the staff entries
+                .filter(s -> !s.contains("Staff, -"))
+                // Remove empty entries
+                .filter(s -> !s.isEmpty())
+                // Strip PhD from names
+                .map(s -> s.replace("PhD", "").trim())
                 .collect(Collectors.toSet());
 
     }

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

@@ -25,7 +25,7 @@ public class Search {
     private List<Course> searchResults;
     private List<Course> matchResults;
 
-    private static List<Course> allCourses;
+    public static List<Course> allCourses;
     private static HashMap<String, Course> courseMap;
 
     static {

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

@@ -3,6 +3,7 @@
 import java.util.stream.Collectors;
 
 import io.javalin.Javalin;
+import java.util.List;
 
 public class SearchController {
     private static Search search = new Search();
@@ -62,5 +63,13 @@ public static void registerRoutes(Javalin app) {
                 search.removeFilter(f);
             }
         });
+
+        app.get("/search/filter-values/{filter-type}", ctx -> {
+            List<Course> courses = search.getMatchResults();
+            if (courses.isEmpty()) {
+                courses = Search.allCourses;
+            }
+            ctx.json(Filter.possibleValues(ctx.pathParam("filter-type"), courses));
+        });
     }
 }

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

@@ -52,7 +52,7 @@ private static Set<String> possibleValues(List<Course> courses) {
                 .flatMap(List::stream)
                 .map(time -> List.of(time.startTime(), time.endTime()))
                 .flatMap(List::stream)
-                .map(time -> time.format(DateTimeFormatter.ofPattern("HH:MM")))
+                .map(time -> time.format(DateTimeFormatter.ofPattern("HH:mm")))
                 .forEach(times::add);
         return times;
     }

frontend/src/SearchPage.tsx

@@ -170,42 +170,30 @@ export default function SearchPage() {
     setTimeEnd(end);
   };
 
-
-
-
-
-
-  // --- LOAD COURSES FOR FILTERS ---
+  // Set the filter options
   useEffect(() => {
-    const fetchCourses = async () => {
-      const res = await fetch('/courses');
-      const items: Course[] = await res.json();
-
-      setDepartments(
-        Array.from(new Set(items.map(c => c.subject).filter(d => d && d !== 'ZLOAD'))).sort()
-      );
-
-      setProfessors(
-        Array.from(
-          new Set(
-            items
-              .flatMap(c => c.faculty || [])
-              .filter(p => p && !p.includes('Staff, -') && p !== '-')
-              .map(p => p.replace(/,?\s*PhD\.?/i, '').trim())
-          )
-        ).sort()
-      );
-
-      setAvailableCredits(
-         Array.from(new Set(items.map(c => c.credits).filter(c => c != null))).map(String).sort()
-       );
-
-      const times = items
-        .flatMap(c => c.times?.map(t => t.start_time) || [])
-        .filter(t => t); // remove empty
-      setAvailableTimes(Array.from(new Set(times)).sort());
+    const getValues = async (t: string) => {
+      const res = await fetch(`/search/filter-values/${t}`);
+      const list = await res.json();
+      return list.sort();
+    };
+    const updateFilters = async () => {
+      // Update:
+      // Departments
+      setDepartments(await getValues('department'));
+      // Professors
+      setProfessors(await getValues('professor'));
+      // availableTimes
+      setAvailableTimes(await getValues('timeRange'));
+      // availableCredits
+      setAvailableCredits(await getValues('credits'));
     };
+    updateFilters();
+    // Only whenever the course list changes
+  }, [courses]);
 
+  // --- LOAD COURSES FOR FILTERS ---
+  useEffect(() => {
     const fetchResults = async() => {
       const res = await fetch("/search/results");
       const items = (await res.json()) as Course[];
@@ -223,8 +211,6 @@ export default function SearchPage() {
 
     fetchQuery();
 
-    fetchCourses();
-
     const setFilters = async () => {
       const resp = await fetch('/search/filter');
       for (const filter of await resp.json()) {