AU Room Timetable App

Find available rooms at Aarhus University and view their schedules in real-time.

Features

Frontend

• Smart Room Search - Fast, intuitive search with instant results
• Geolocation-Based Recommendations - Automatically shows the 5 nearest buildings based on your location
• Favorites System - Save your frequently used rooms with localStorage persistence
• Interactive Calendar - Date picker with real-time schedule visualization
• Live Availability Status - Real-time occupied/available badges with time estimates
• Fully Responsive - Optimized for mobile, tablet, and desktop
• SEO Optimized - Danish metadata and structured data for better discoverability
• Modern UI - Clean, professional design with Tailwind CSS and shadcn/ui components

Backend

• Custom GWT-RPC Decoder - A from-scratch implementation that reverse-engineers Google Web Toolkit's RPC protocol specifically for AU's timetable API
  • Handles complex serialization formats with history tracking
  • Supports nested objects, arrays, and back-references
  • Transforms proprietary GWT format into clean JSON
  • This was the most challenging and rewarding part of the project!
• Clean Architecture - Standard Go project layout with separation of concerns
  • Handlers (HTTP layer)
  • Services (business logic)
  • Clients (external API communication)
  • Middleware (auth, logging, CORS)
• Structured JSON Logging - Production-ready logging with configurable log levels
• Bearer Token Authentication - Secure communication between frontend and backend
• State Management - Efficient room subscription tracking
• Session Management - Automatic token refresh for AU timetable API
• High Performance - Concurrent request handling with proper timeouts
• Docker Ready - Multi-stage builds for optimized containers

Quick Start

Prerequisites

• Docker & Docker Compose
• OpenSSL (for generating secrets)

Setup

1. Clone the repository

   git clone <your-repo-url>
   cd au-timetable-app

2. Generate secrets and create .env file

   make setup

3. Start the application

   make run

4. Access the application

   • Frontend: http://localhost:5080
   • Backend API: http://localhost:8080

Other Commands

make stop        # Stop all containers
make logs        # View container logs
make http        # Run backend locally (without Docker)
make test        # Run tests

Development

Run backend locally

make http

Run backend in development mode

make http-dev

Run tests

make test

Build production binaries

make build

Project Structure

.
├── backend/
│   ├── cmd/
│   │   ├── api/              # API server entry point
│   │   └── decode/           # CLI tool for decoding GWT-RPC payloads
│   ├── internal/
│   │   ├── handler/          # HTTP handlers
│   │   ├── service/          # Business logic
│   │   ├── client/           # External API clients
│   │   ├── middleware/       # Auth, logging, etc.
│   │   ├── config/           # Configuration management
│   │   └── state/            # Application state
│   ├── pkg/
│   │   ├── gwtrpc/           # GWT-RPC protocol implementation ⭐
│   │   │   ├── decoder/      # Custom decoder (the pride and joy!)
│   │   │   ├── encoder/      # Request encoder
│   │   │   └── parser/       # Response parser
│   │   └── logger/           # Structured JSON logging
│   └── testdata/             # Test fixtures
├── frontend/
│   ├── app/
│   │   ├── schedule/[roomId]/ # Room detail pages
│   │   └── api/              # API proxy routes
│   ├── components/           # Reusable React components
│   └── lib/                  # Utilities and helpers
├── .env.example              # Environment variables template
├── docker-compose.yml
└── Makefile

Technical Highlights

The GWT-RPC Decoder

The crown jewel of this project is the custom GWT-RPC decoder (backend/pkg/gwtrpc/decoder/). GWT-RPC is a proprietary serialization protocol used by Google Web Toolkit, and there are no existing Go implementations.

What makes it special:

• Reverse Engineered Protocol - Built by analyzing network traffic and GWT source code
• Complex Type Handling - Manages nested objects, arrays, maps, and custom types
• History Tracking - Implements GWT's object reference system for deduplication
• Back-Reference Resolution - Handles circular references and object reuse
• Production Tested - Processes real AU timetable data with 100% accuracy

Example usage:

decoder := decoder.NewDecoder(payloadBuffer)
result, err := decoder.Decode()
// Transforms GWT binary format into structured Go data

You can even use it as a standalone CLI tool:

make decode payload.txt

Author

Created by Mikkel Maae Østergaard

Not affiliated with Aarhus Universitet