user-role-cluster (#761)

Reviewed-on: #761

migration.sql

@@ -27,7 +27,8 @@ CREATE TABLE IF NOT EXISTS "family" (
 
 CREATE TABLE IF NOT EXISTS "role" (
 	"id" integer NOT NULL PRIMARY KEY AUTOINCREMENT,
-	"name" text NOT NULL UNIQUE
+	"name" text NOT NULL UNIQUE,
+	"cluster" text
 );
 
 CREATE TABLE IF NOT EXISTS "user_role" (
@@ -220,3 +221,20 @@ CREATE TABLE IF NOT EXISTS "distance" (
 	"distance_in_km" integer NOT NULL
 );
 
+
+CREATE TRIGGER IF NOT EXISTS prevent_multiple_roles_same_cluster
+BEFORE INSERT ON user_role
+BEGIN
+    SELECT CASE 
+        WHEN EXISTS (
+            SELECT 1
+            FROM user_role ur
+            JOIN role r1 ON ur.role_id = r1.id
+            JOIN role r2 ON r1."cluster" = r2."cluster"
+            WHERE ur.user_id = NEW.user_id
+            AND r2.id = NEW.role_id
+            AND r1.id != NEW.role_id
+        )
+        THEN RAISE(ABORT, 'User already has a role in this cluster')
+    END;
+END;