A production-ready Android + Go backend application for finding student train discounts across UK train operators.
trainstudent/
├── android/ # Android app (Kotlin + Jetpack Compose)
│ ├── app/
│ │ ├── build.gradle.kts # Dependencies: Compose, Hilt, Room, Retrofit
│ │ └── src/main/
│ │ ├── AndroidManifest.xml # Permissions, activities
│ │ └── java/com/trainstudent/
│ │ ├── TrainStudentApp.kt # @HiltAndroidApp
│ │ ├── di/
│ │ │ ├── AppModule.kt # Room, Voice handlers
│ │ │ └── NetworkModule.kt # Retrofit, OkHttp
│ │ ├── model/
│ │ │ ├── BookingPlan.kt # NetCost, BookingAction
│ │ │ ├── TrainService.kt # Live train data
│ │ │ ├── TravelIntent.kt # ParsedStation, ParsedDateTime
│ │ │ └── UserProfile.kt # Railcard, verification
│ │ ├── network/
│ │ │ └── TrainStudentApi.kt # Retrofit interface
│ │ ├── repository/
│ │ │ └── TrainStudentRepository.kt
│ │ ├── data/
│ │ │ └── VoiceMetricsDatabase.kt # Room DB for metrics
│ │ ├── voice/
│ │ │ ├── VoiceInputHandler.kt # Interface
│ │ │ ├── SpeechRecognizerHandler.kt # Android STT
│ │ │ ├── CactusLlmHandler.kt # Cactus 7B/13B
│ │ │ ├── CactusModelDownloader.kt # DownloadManager
│ │ │ ├── DownloadCompleteReceiver.kt
│ │ │ ├── StationMatcher.kt # Fuzzy + Soundex
│ │ │ ├── TimeParser.kt # NLU time parsing
│ │ │ └── VoiceMetricsCollector.kt
│ │ └── ui/
│ │ ├── MainActivity.kt # Navigation host
│ │ ├── theme/
│ │ │ ├── Theme.kt
│ │ │ └── Type.kt
│ │ ├── save/
│ │ │ ├── SaveMoneyScreen.kt
│ │ │ └── SaveMoneyViewModel.kt
│ │ ├── live/
│ │ │ ├── LiveTrainsScreen.kt
│ │ │ └── LiveTrainsViewModel.kt
│ │ ├── offers/
│ │ │ ├── OffersScreen.kt
│ │ │ └── OffersViewModel.kt
│ │ └── components/
│ │ ├── AnimatedInputChip.kt
│ │ ├── BookingPlanCard.kt
│ │ ├── TimePickerBottomSheet.kt
│ │ ├── StationPickerDialog.kt
│ │ └── SettingsBottomSheet.kt
│ ├── build.gradle.kts # Root project config
│ ├── settings.gradle.kts
│ └── gradle/wrapper/
│ └── gradle-wrapper.properties
│
├── backend/ # Go backend (Fiber)
│ ├── main.go # Server entry, routes
│ ├── go.mod # Module definition
│ ├── handlers/
│ │ ├── discount.go # POST /api/search
│ │ ├── codes.go # POST /api/codes/northern
│ │ ├── grandcentral.go # POST /api/codes/grandcentral
│ │ ├── offers.go # GET /api/offers
│ │ ├── avanti.go # POST /api/avanti/search
│ │ └── live_trains.go # GET /api/trains/live
│ ├── services/
│ │ ├── northern/
│ │ │ └── code_generator.go # Salesforce Aura flow
│ │ ├── avanti/
│ │ │ └── avanti_client.go # Token scraper + UNiDAYS search
│ │ ├── grandcentral/
│ │ │ └── student_discount.go # .ac.uk email verification
│ │ └── gmail/
│ │ └── oauth_poller.go # Gmail API code extraction
│ └── convex/
│ ├── schema.ts # Convex tables
│ └── queries.ts # Convex functions
│
└── README.md # This file
- Dual Provider Support: Switch between Android SpeechRecognizer and Cactus LLM (7B/13B models)
- Live Correction: Tappable chips for accent tolerance with 300ms debounce
- Metrics Collection: Room DB tracks latency, correction count, battery drain
-
Northern Railway (50% Discount)
- Salesforce Aura flow submission
- Gmail API polling for code extraction
- Code expires at 23:59 same day
-
Avanti West Coast (UNiDAYS)
- Server-rendered token extraction (clientstamp/noncestamp)
/TravelSolution/NewSearchwithPromotionCode: "UNIDAYS"
-
Grand Central (Student Discount)
- .ac.uk email validation
- Multipart form submission to atreemosurvey.com
- 96dp Mic Button with pulsing animation ring
- AnimatedInputChip with infinite transition (1→1.05 scale)
- Material 3 TimePicker/DatePicker bottom sheet with quick select chips
- BookingPlanCard with CHEAPEST badge and proof chips
cd android
./gradlew assembleDebugcd backend
go mod tidy
go run main.goThe server runs on http://localhost:8080
| Method | Endpoint | Description |
|---|---|---|
| POST | /api/search |
Search discounts for route |
| POST | /api/codes/northern |
Generate Northern 50% code |
| POST | /api/codes/grandcentral |
Submit Grand Central student form |
| POST | /api/avanti/search |
Search Avanti with UNiDAYS |
| GET | /api/offers |
List available offers |
| GET | /api/trains/live |
Get live departures |
- Kotlin 1.9.22
- Jetpack Compose (BOM 2024.01.00)
- Hilt 2.50 (DI)
- Room 2.6.1 (Local DB)
- Retrofit 2.9 + OkHttp 4.12
- kotlinx-serialization 1.6.3
- kotlinx-datetime 0.5.0
- Cactus LLM SDK
- Go 1.21
- Fiber v2.52.0
- Google Gmail API
- Convex (optional persistence)
MIT
