FirestoreとDartでRole管理

role.dart

import 'package:firebase_core/firebase_core.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'dart:math' as math;

void main() async {
  await Firebase.initializeApp(
    options: const FirebaseOptions(
        apiKey: "",
        authDomain: "",
        projectId: "",
        storageBucket: "",
        messagingSenderId: "",
        appId: "",
        measurementId: ""),
  );

  final roomRole = Role(id: "1", name: "room1", roles: {
    "user1": ["write"],
    "user2": ["read"],
    "user3": ["write"],
  });

  final roomRole2 = Role(id: "2", name: "room2", roles: {
    "user1": ["read"],
    "user2": ["write"],
    "user3": ["read", "write"],
    "user4": ["read", "write"],
  });

  print("> room1　に write　権限があるのは以下のユーザーです");
  print(roomRole.userIds("write"));

  await save(roomRole);
  await save(roomRole2);

  await printRole("user1", "read");

  print("> room1 に user1 の read 権限を付与します\n");
  await addRole(roleId: roomRole.id, userId: "user1", roles: ["read"]);

  await printRole("user1", "read");

  print("> room1 から user1 の read 権限を剥奪します\n");
  await removeRole(roleId: roomRole.id, userId: "user1", roles: ["read"]);

  await printRole("user1", "read");
}

// 実行例
// > room1　に write　権限があるのは以下のユーザーです
// (user1, user3)
// > user1 が read 権限を持つのは以下の部屋です
// (room2)

// > room1 に user1 の read 権限を付与します

// > user1 が read 権限を持つのは以下の部屋です
// (room1, room2)

// > room1 から user1 の read 権限を剥奪します

// > user1 が read 権限を持つのは以下の部屋です
// (room2)

Future<void> printRole(String userId, String role) async {
  print("> $userId が $role 権限を持つのは以下の部屋です");
  final names = await findRoom(userId, role);
  print(names);
  print("");
}

Future<void> save(Role role) async {
  await FirebaseFirestore.instance
      .collection("room_roles")
      .doc(role.id)
      .set(role.toJson());
}

Future<Iterable<String>> findRoom(String userId, String role) async {
  final query = FirebaseFirestore.instance
      .collection("room_roles")
      .where("roles.$userId", arrayContains: role);
  final snapshot = await query.get();

  return snapshot.docs.map((e) => e.data()["name"]);
}

Future<void> addRole({
  required String roleId,
  required String userId,
  required List<String> roles,
}) async {
  await FirebaseFirestore.instance
      .collection("room_roles")
      .doc(roleId)
      .update({"roles.$userId": FieldValue.arrayUnion(roles)});
}

Future<void> removeRole({
  required String roleId,
  required String userId,
  required List<String> roles,
}) async {
  await FirebaseFirestore.instance
      .collection("room_roles")
      .doc(roleId)
      .update({"roles.$userId": FieldValue.arrayRemove(roles)});
}

class Role {
  final String id;
  final String name;
  final Map<String, List<String>> roles;

  Role({
    required this.id,
    required this.name,
    required this.roles,
  });

  Map<String, dynamic> toJson() {
    return {
      "id": id,
      "roles": roles,
      "name": name,
    };
  }

  Iterable<String> userIds(String role) {
    return roles.entries.where((r) => r.value.contains(role)).map((r) => r.key);
  }
}