litecloud/instructions.md

Project Prompt: Secure File Hosting Platform (Nextcloud-like)

Overview

Build a full-stack web application that mimics the core features of Nextcloud with secure file upload, download, and sharing functionality. The stack should be:

• Frontend: Flutter Web
• Backend: Rust (Axum framework)
• Database: PostgreSQL
• Storage: Encrypted file storage on local disk
• Deployment: Docker (two-container setup: web + db)

Required Features

Core Features

• Users can upload and download files
• Files are encrypted at rest using AES-256 (server-side encryption)
• Users can generate public shareable links to download files
• File upload limits per user (configurable)
• Support for shared folders among users (with permissions)
• Serve Flutter web UI and backend API from the same container

Authentication and User Management

• User registration and login using email + password
• Passwords must be securely hashed using Argon2 or bcrypt
• JWT-based session handling for API authentication
• Role-based permission system:
  • Owner, editor, viewer roles for shared folders
  • Users can only access files and folders they own or are shared with them

File Handling

• Store files in /data directory, encrypted using a per-file key
• Save metadata and encryption keys in PostgreSQL (keys encrypted with a master key)
• Expose REST endpoints:
  • POST /api/upload
  • GET /api/download/:id
  • POST /api/share
  • GET /api/shared/:token
• Limit file uploads per user (configurable max size)
• Maintain a file tree (directories, nested folders)

Infrastructure

• Use Docker Compose to define:
  • web: Rust backend and Flutter frontend in a single container
  • db: PostgreSQL container
• Only expose one public port (80), used by the web container
• Use Docker volume for persistent file storage (./data)

Project Structure

project-root/
├── docker-compose.yml
├── Dockerfile (multi-stage for Flutter + Rust)
├── backend/         # Rust API
├── frontend/        # Flutter Web app
├── data/            # Mounted volume for encrypted files

Libraries and Tools

• Rust Backend:

  • axum for HTTP server
  • tokio for async runtime
  • sqlx for PostgreSQL
  • jsonwebtoken for JWT
  • argon2 or bcrypt for password hashing
  • aes-gcm or ring for file encryption
  • uuid for file and share link identifiers
  • dotenvy to manage environment variables

• Flutter Frontend:

  • File upload UI
  • Folder navigation
  • Login/Register screens
  • Share file dialog with permission settings

Goals

Generate:

• Docker Compose config and Dockerfile
• Flutter web UI skeleton with login/upload functionality
• Rust backend with user authentication, file handling, and share APIs
• PostgreSQL schema with users, files, shares, and permissions