feat: changed backend-pg to backend

backend/src/lib/casl/index.ts

@@ -0,0 +1,44 @@
+import { buildMongoQueryMatcher, MongoAbility } from "@casl/ability";
+import { FieldCondition, FieldInstruction, JsInterpreter } from "@ucast/mongo2js";
+import picomatch from "picomatch";
+
+const $glob: FieldInstruction<string> = {
+  type: "field",
+  validate(instruction, value) {
+    if (typeof value !== "string") {
+      throw new Error(`"${instruction.name}" expects value to be a string`);
+    }
+  }
+};
+
+const glob: JsInterpreter<FieldCondition<string>> = (node, object, context) => {
+  const secretPath = context.get(object, node.field);
+  const permissionSecretGlobPath = node.value;
+  return picomatch.isMatch(secretPath, permissionSecretGlobPath, { strictSlashes: false });
+};
+
+export const conditionsMatcher = buildMongoQueryMatcher({ $glob }, { glob });
+
+/**
+ * Extracts and formats permissions from a CASL Ability object or a raw permission set.
+ */
+const extractPermissions = (ability: MongoAbility) =>
+  ability.rules.map((permission) => `${permission.action}_${permission.subject}`);
+
+/**
+ * Compares two sets of permissions to determine if the first set is at least as privileged as the second set.
+ * The function checks if all permissions in the second set are contained within the first set and if the first set has equal or more permissions.
+ *
+ */
+export const isAtLeastAsPrivileged = (permissions1: MongoAbility, permissions2: MongoAbility) => {
+  const set1 = new Set(extractPermissions(permissions1));
+  const set2 = new Set(extractPermissions(permissions2));
+
+  for (const perm of set2) {
+    if (!set1.has(perm)) {
+      return false;
+    }
+  }
+
+  return set1.size >= set2.size;
+};