add room permissions hook

src/app/hooks/useRoomPermissions.ts

@@ -0,0 +1,60 @@
+import { useMemo } from 'react';
+import {
+  IPowerLevels,
+  PowerLevelActions,
+  PowerLevelNotificationsAction,
+  readPowerLevel,
+} from './usePowerLevels';
+
+export type RoomPermissionsAPI = {
+  event: (type: string, userId: string) => boolean;
+  stateEvent: (type: string, userId: string) => boolean;
+  action: (action: PowerLevelActions, userId: string) => boolean;
+  notificationAction: (action: PowerLevelNotificationsAction, userId: string) => boolean;
+};
+
+export const getRoomPermissionsAPI = (
+  creators: Set<string>,
+  powerLevels: IPowerLevels
+): RoomPermissionsAPI => {
+  const api: RoomPermissionsAPI = {
+    event: (type, userId) => {
+      if (creators.has(userId)) return true;
+      const userPower = readPowerLevel.user(powerLevels, userId);
+      const requiredPL = readPowerLevel.event(powerLevels, type);
+      return userPower >= requiredPL;
+    },
+    stateEvent: (type, userId) => {
+      if (creators.has(userId)) return true;
+      const userPower = readPowerLevel.user(powerLevels, userId);
+      const requiredPL = readPowerLevel.state(powerLevels, type);
+      return userPower >= requiredPL;
+    },
+    action: (action, userId) => {
+      if (creators.has(userId)) return true;
+      const userPower = readPowerLevel.user(powerLevels, userId);
+      const requiredPL = readPowerLevel.action(powerLevels, action);
+      return userPower >= requiredPL;
+    },
+    notificationAction: (action, userId) => {
+      if (creators.has(userId)) return true;
+      const userPower = readPowerLevel.user(powerLevels, userId);
+      const requiredPL = readPowerLevel.notification(powerLevels, action);
+      return userPower >= requiredPL;
+    },
+  };
+
+  return api;
+};
+
+export const useRoomPermissions = (
+  creators: Set<string>,
+  powerLevels: IPowerLevels
+): RoomPermissionsAPI => {
+  const api: RoomPermissionsAPI = useMemo(
+    () => getRoomPermissionsAPI(creators, powerLevels),
+    [creators, powerLevels]
+  );
+
+  return api;
+};