feat: implement file existence check and improve file upload handling

src/lib/storage/storage.adapter.ts

@@ -2,6 +2,7 @@ import { StorageProvider } from '@/lib/storage/storage.interface';
 import { TypedResult, wrap } from '@/utils/types/results';
 import {
     DeleteObjectCommand,
+    HeadObjectCommand,
     ObjectCannedACL,
     PutObjectCommand,
     S3Client,
@@ -36,6 +37,9 @@ export class S3StorageAdapter implements StorageProvider {
     readonly put: (
         ...args: Parameters<StorageProvider['put']>
     ) => Promise<TypedResult<string>>;
+    readonly exists: (
+        ...args: Parameters<StorageProvider['exists']>
+    ) => Promise<boolean>;
     readonly delete: (
         ...args: Parameters<StorageProvider['delete']>
     ) => Promise<TypedResult<void>>;
@@ -58,6 +62,7 @@ export class S3StorageAdapter implements StorageProvider {
         this.get = wrap(this._get.bind(this));
         this.put = wrap(this._put.bind(this));
         this.delete = wrap(this._delete.bind(this));
+        this.exists = this._exists.bind(this);
     }
 
     private async _get(key: string): Promise<string> {
@@ -75,6 +80,20 @@ export class S3StorageAdapter implements StorageProvider {
         return await getSignedUrl(this.s3Client, command, { expiresIn: 3600 });
     }
 
+    private async _exists(key: string): Promise<boolean> {
+        try {
+            await this.s3Client.send(
+                new HeadObjectCommand({
+                    Bucket: this.bucketName,
+                    Key: key,
+                })
+            );
+            return true;
+        } catch {
+            return false;
+        }
+    }
+
     private async _delete(key: string): Promise<void> {
         await this.s3Client.send(
             new DeleteObjectCommand({