Serve level_kinds from server, use for both validation and UI

main.go

@@ -29,6 +29,11 @@ var schema string
 var (
 	htmlTemplates *template.Template
 	jsTemplates   *texttemplate.Template
+	levelKinds    = map[string][]string{
+		"student": {"prefer", "prefer_not"},
+		"parent":  {"must_not"},
+		"admin":   {"must", "prefer", "prefer_not", "must_not"},
+	}
 )
 
 func main() {
@@ -452,7 +457,7 @@ func handleTripMe(db *sql.DB) http.HandlerFunc {
 			students = []studentInfo{}
 		}
 		w.Header().Set("Content-Type", "application/json")
-		json.NewEncoder(w).Encode(map[string]any{"role": role, "students": students})
+		json.NewEncoder(w).Encode(map[string]any{"role": role, "students": students, "level_kinds": levelKinds})
 	}
 }
 
@@ -893,22 +898,15 @@ func handleCreateConstraint(db *sql.DB) http.HandlerFunc {
 			http.Error(w, "students must be different", http.StatusBadRequest)
 			return
 		}
-		switch body.Level {
-		case "student":
-			if body.Kind != "prefer" && body.Kind != "prefer_not" {
-				http.Error(w, "students may only use prefer or prefer not", http.StatusBadRequest)
-				return
-			}
-		case "parent":
-			if body.Kind != "must_not" {
-				http.Error(w, "parents may only use must not", http.StatusBadRequest)
-				return
-			}
-		case "admin":
-		default:
+		validKinds := levelKinds[body.Level]
+		if validKinds == nil {
 			http.Error(w, "invalid level", http.StatusBadRequest)
 			return
 		}
+		if !slices.Contains(validKinds, body.Kind) {
+			http.Error(w, "invalid kind for level", http.StatusBadRequest)
+			return
+		}
 		if role != "admin" {
 			if body.Level != role {
 				http.Error(w, "forbidden", http.StatusForbidden)

static/trip.js

@@ -411,11 +411,7 @@ async function loadStudents() {
 
         const addRow = document.createElement('div');
         addRow.className = 'constraint-add';
-        const levelKinds = {
-            student: ['prefer', 'prefer_not'],
-            parent: ['must_not'],
-            admin: ['must', 'prefer', 'prefer_not', 'must_not']
-        };
+        const levelKinds = me.level_kinds;
         const levelSelect = document.createElement('wa-select');
         levelSelect.size = 'small';
         for (const level of ['student', 'parent', 'admin']) {
@@ -618,9 +614,7 @@ async function renderMemberView(me) {
         ? { '': 'OK to room with', prefer: 'Would like to room with', prefer_not: 'Would prefer not to room with' }
         : { '': 'OK to room with', must_not: 'Not OK to room with' };
 
-    const kindOptions = me.role === 'student'
-        ? ['', 'prefer', 'prefer_not']
-        : ['', 'must_not'];
+    const kindOptions = ['', ...me.level_kinds[me.role]];
 
     const pendingSelects = [];