# btcdata

Bitcoin data backend — Clojure Kit application. Fetches BTC prices from Binance WebSocket and Kraken HTTP, stores in PostgreSQL, exposes a JSON API with WebSocket price stream.

## Build & Development Commands

- `make run` — Start dev server on port 4100
- `make repl` — Start nREPL
- `make test` — Run tests
- `make uberjar` — Build production JAR
- `docker compose up -d` — Start btcdata container

## Docker

Docker runs alongside local dev on different ports and databases:

| | Local dev      | Docker         |
|--|----------------|----------------|
| **Port** | localhost:4100 | localhost:4101 |
| **Database** | btcprice | btcprod |

## REPL Commands

```clojure
(dev-prep!)   ;; Prepare dev system
(go)          ;; Start system
(reset)       ;; Reload code & restart
(halt)        ;; Stop system
(reset-db)    ;; Drop & re-migrate database
(migrate)     ;; Run pending migrations
(rollback)    ;; Rollback last migration
(query-fn)    ;; Get database query function
```

## Architecture

- **Framework:** Kit (Integrant-based)
- **Server:** Undertow
- **Routing:** Reitit
- **Database:** PostgreSQL + conman + Migratus
- **Port:** 4100 (env: BTCDATA_PORT)
- **CORS:** Configured via CORS_ORIGIN env var

## API Endpoints

- `GET /api/health` — Health check
- `GET /api/price/ws` — WebSocket endpoint for live HTML price fragments (HTMX-compatible)
- `GET /api/price/latest` — Latest price as JSON

## Source Layout

```
src/clj/pmagnus/btcdata/
├── core.clj              # App entry point
├── config.clj            # System config loader
├── ws/
│   └── binance.clj       # Binance WebSocket client
├── kraken/
│   ├── ohlc.clj          # Hourly OHLC poller
│   └── ohlc_daily.clj    # Daily OHLC poller
└── web/
    ├── handler.clj       # Ring handler + routes
    ├── controllers/
    │   └── health.clj    # Health check
    ├── middleware/
    │   ├── core.clj      # Base middleware + CORS
    │   ├── exception.clj # Exception handling
    │   └── formats.clj   # Content negotiation
    └── routes/
        ├── api.clj       # /api routes (JSON + WebSocket)
        └── utils.clj     # Route utilities
```