add file upload service

src/infrastructure/file-upload-service/file-upload.service.ts

@@ -0,0 +1,45 @@
+import { Injectable } from '@nestjs/common'
+import { v4 as uuid } from 'uuid'
+import { PrismaService } from '../../prisma.service'
+import { S3Client, PutObjectCommand } from '@aws-sdk/client-s3'
+
+@Injectable()
+export class FileUploadService {
+  constructor(private prismaService: PrismaService) {}
+
+  async uploadFile(dataBuffer: Buffer, fileName: string) {
+    const key = `${uuid()}-${fileName}`
+    const bucketName = process.env.AWS_BUCKET_NAME
+    const region = 'eu-central-1'
+    const s3 = new S3Client({
+      region,
+      credentials: {
+        accessKeyId: process.env.AWS_S3_ACCESS_KEY,
+        secretAccessKey: process.env.AWS_S3_SECRET_ACCESS_KEY,
+      },
+    })
+    const encodeFileName = encodeURIComponent(key)
+
+    const fileUrl = `https://${bucketName}.s3.${region}.amazonaws.com/${encodeFileName}`
+
+    const fileStorageInDB = {
+      fileName,
+      fileUrl,
+      key,
+    }
+
+    const putCommand = new PutObjectCommand({
+      Bucket: bucketName,
+      Body: dataBuffer,
+      Key: key,
+      ContentDisposition: 'inline',
+      ContentType: `image/${fileName.split('.').at(-1)}`,
+    })
+
+    await s3.send(putCommand)
+
+    return this.prismaService.fileEntity.create({
+      data: fileStorageInDB,
+    })
+  }
+}