feat: remove appwrite and add nextjs backend

backend/src/file/guard/fileDownload.guard.ts

@@ -0,0 +1,23 @@
+import { CanActivate, ExecutionContext, Injectable } from "@nestjs/common";
+import { Reflector } from "@nestjs/core";
+import { Request } from "express";
+import { FileService } from "src/file/file.service";
+import { PrismaService } from "src/prisma/prisma.service";
+
+@Injectable()
+export class FileDownloadGuard implements CanActivate {
+  constructor(
+    private reflector: Reflector,
+    private fileService: FileService,
+    private prisma: PrismaService
+  ) {}
+
+  async canActivate(context: ExecutionContext) {
+    const request: Request = context.switchToHttp().getRequest();
+
+    const token = request.query.token as string;
+    const { shareId, fileId } = request.params;
+
+    return this.fileService.verifyFileDownloadToken(shareId, fileId, token);
+  }
+}