feat(api): user authentication

src/users/users.service.ts

@@ -0,0 +1,42 @@
+import { Injectable, NotFoundException } from "@nestjs/common";
+import { CreateOrUpdateDto } from "./dto/create-or-update.dto";
+import { User } from "./user.entity";
+import { UserRepository } from "./user.repository";
+
+@Injectable()
+export class UsersService {
+  constructor(private readonly userRepository: UserRepository) {}
+
+  async findById(id: string): Promise<User> {
+    const user = await this.userRepository.findOne(id);
+
+    if (!user) {
+      throw new NotFoundException("UserNotFound");
+    }
+
+    return user;
+  }
+
+  async createOrUpdate(data: CreateOrUpdateDto): Promise<User> {
+    let user = await this.userRepository.findOne({
+      where: { spotify: { id: data.spotify.id } }
+    });
+
+    if (!user) {
+      user = this.userRepository.create({
+        spotify: {
+          id: data.spotify.id
+        }
+      });
+    }
+
+    user.spotify.accessToken = data.spotify.accessToken;
+    user.spotify.refreshToken = data.spotify.refreshToken;
+    user.displayName = data.displayName;
+    user.photo = data.photo;
+
+    await this.userRepository.save(user);
+
+    return user;
+  }
+}