Split data layer into btcdata service

Remove DB, Binance WebSocket, and Kraken pollers from btcprice.
UI now uses vanilla EventSource connecting to btcdata for live
price updates. btcprice is now a pure UI service with no database.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CLAUDE.md

@@ -1,15 +1,14 @@
 # btcprice
 
-Bitcoin price tracker - Clojure Kit web application.
+Bitcoin price tracker UI — Clojure Kit web application. Serves the HTML/HTMX/Tailwind UI. Connects to btcdata for live price data via SSE.
 
 ## Build & Development Commands
 
-- `make run` — Start dev server on port 3000
+- `make run` — Start dev server on port 4000
-- `make repl` — Start nREPL on port 7888
+- `make repl` — Start nREPL
 - `make test` — Run tests
 - `make tailwind` — Watch Tailwind CSS for changes
 - `make uberjar` — Build production JAR
-- `docker compose up -d` — Start PostgreSQL
 
 ## REPL Commands
 
@@ -18,10 +17,6 @@ Bitcoin price tracker - Clojure Kit web application.
 (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
@@ -29,9 +24,10 @@ Bitcoin price tracker - Clojure Kit web application.
 - **Framework:** Kit (Integrant-based)
 - **Server:** Undertow
 - **Routing:** Reitit
-- **Templates:** Hiccup + HTMX
+- **Templates:** Hiccup + vanilla JS EventSource
 - **Styling:** Tailwind CSS v4
-- **Database:** PostgreSQL + conman + Migratus
+- **Data backend:** btcdata (separate service at BTCDATA_URL, default http://localhost:4100)
+- **No database** — all data comes from btcdata
 
 ## Source Layout
 
@@ -50,6 +46,6 @@ src/clj/pmagnus/btcprice/
     │   └── formats.clj   # Content negotiation
     └── routes/
         ├── api.clj       # /api routes (JSON)
-        ├── ui.clj        # UI routes (HTML)
+        ├── ui.clj        # UI routes (HTML + EventSource)
         └── utils.clj     # Route utilities
 ```

Dockerfile

@@ -23,6 +23,6 @@ COPY --from=build /build/target/btcprice-standalone.jar /btcprice/btcprice-stand
 
 EXPOSE 4040
 ENV PORT=4040
-ENV JDBC_URL=jdbc:postgresql://postgres:5432/btcprod
+ENV BTCDATA_URL=http://btcdata:4100
 
 CMD ["java", "-jar", "/btcprice/btcprice-standalone.jar"]

deps.edn

@@ -1,7 +1,5 @@
 {:paths ["src/clj" "resources"]
  :deps {org.clojure/clojure                  {:mvn/version "1.12.3"}
-        org.clojure/data.json                {:mvn/version "2.5.1"}
-
         ;; Kit
         io.github.kit-clj/kit-core           {:mvn/version "1.0.6"}
 
@@ -27,12 +25,7 @@
 
         ;; Serialization
         metosin/muuntaja                     {:mvn/version "0.6.11"}
-        luminus-transit/luminus-transit       {:mvn/version "0.1.6"}
+        luminus-transit/luminus-transit       {:mvn/version "0.1.6"}}
-
-        ;; Database
-        io.github.kit-clj/kit-postgres       {:mvn/version "1.0.7"}
-        io.github.kit-clj/kit-sql-conman     {:mvn/version "1.10.5"}
-        io.github.kit-clj/kit-sql-migratus   {:mvn/version "1.0.5"}}
 
  :aliases
  {:build {:deps {io.github.clojure/tools.build {:mvn/version "0.10.9"}}

docker-compose.yml

@@ -1,10 +1,22 @@
 services:
+  btcdata:
+    build: ../btcdata
+    restart: unless-stopped
+    ports:
+      - "4100:4100"
+    environment:
+      BTCDATA_PORT: "4100"
+      JDBC_URL: "jdbc:postgresql://postgres:5432/btcprod?user=postgres&password=ratata,123"
+      CORS_ORIGIN: "http://localhost:4040"
+    extra_hosts:
+      - "postgres:host-gateway"
+
   app:
     build: .
     restart: unless-stopped
     ports:
       - "4040:4040"
     environment:
-      JDBC_URL: "jdbc:postgresql://postgres:5432/btcprod?user=postgres&password=ratata,123"
+      BTCDATA_URL: "http://btcdata:4100"
-    extra_hosts:
+    depends_on:
-      - "postgres:host-gateway"
+      - btcdata

env/dev/clj/user.clj

@@ -1,6 +1,5 @@
 (ns user
   (:require
-   [clojure.tools.logging :as log]
    [integrant.core :as ig]
    [integrant.repl :refer [go halt reset reset-all set-prep!]]
    [integrant.repl.state :as state]
@@ -19,30 +18,6 @@
      (-> (config/system-config {:profile :test})
          (ig/expand)))))
 
-(defn reset-db []
-  (let [sys (or @pmagnus.btcprice.core/system
-                integrant.repl.state/system)]
-    (when-let [mig (:db.sql/migrations sys)]
-      (migratus.core/reset mig)
-      (log/info "Database reset complete"))))
-
-(defn rollback []
-  (let [sys (or @pmagnus.btcprice.core/system
-                integrant.repl.state/system)]
-    (when-let [mig (:db.sql/migrations sys)]
-      (migratus.core/rollback mig))))
-
-(defn migrate []
-  (let [sys (or @pmagnus.btcprice.core/system
-                integrant.repl.state/system)]
-    (when-let [mig (:db.sql/migrations sys)]
-      (migratus.core/migrate mig))))
-
-(defn query-fn []
-  (let [sys (or @pmagnus.btcprice.core/system
-                integrant.repl.state/system)]
-    (:db.sql/query-fn sys)))
-
 (comment
   (dev-prep!)
   (go)

resources/migrations/20260217000000-create-binance-price.down.sql

@@ -1 +0,0 @@
-DROP TABLE binance_price;

resources/migrations/20260217000000-create-binance-price.up.sql

@@ -1,5 +0,0 @@
-CREATE TABLE binance_price (
-  id          BIGSERIAL PRIMARY KEY,
-  price       NUMERIC(18,8) NOT NULL,
-  recorded_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
-);

resources/migrations/20260218000000-create-kraken-hour.down.sql

@@ -1 +0,0 @@
-DROP TABLE kraken_hour;

resources/migrations/20260218000000-create-kraken-hour.up.sql

@@ -1,11 +0,0 @@
-CREATE TABLE kraken_hour (
-  ts          BIGINT         NOT NULL PRIMARY KEY,
-  open        NUMERIC(18,8)  NOT NULL,
-  high        NUMERIC(18,8)  NOT NULL,
-  low         NUMERIC(18,8)  NOT NULL,
-  close       NUMERIC(18,8)  NOT NULL,
-  vwap        NUMERIC(18,8)  NOT NULL,
-  volume      NUMERIC(24,8)  NOT NULL,
-  trade_count INTEGER        NOT NULL,
-  created_at  TIMESTAMPTZ    NOT NULL DEFAULT NOW()
-);

resources/migrations/20260218100000-create-kraken-day.down.sql

@@ -1 +0,0 @@
-DROP TABLE kraken_day;

resources/migrations/20260218100000-create-kraken-day.up.sql

@@ -1,11 +0,0 @@
-CREATE TABLE kraken_day (
-  ts          BIGINT         NOT NULL PRIMARY KEY,
-  open        NUMERIC(18,8)  NOT NULL,
-  high        NUMERIC(18,8)  NOT NULL,
-  low         NUMERIC(18,8)  NOT NULL,
-  close       NUMERIC(18,8)  NOT NULL,
-  vwap        NUMERIC(18,8)  NOT NULL,
-  volume      NUMERIC(24,8)  NOT NULL,
-  trade_count INTEGER        NOT NULL,
-  created_at  TIMESTAMPTZ    NOT NULL DEFAULT NOW()
-);

resources/migrations/placeholder.txt

@@ -1 +0,0 @@
-Migration files go here.

resources/queries.sql

@@ -1,44 +0,0 @@
--- queries for btcprice
-
--- :name insert-binance-price! :! :n
--- :doc Insert a Binance BTC price
-INSERT INTO binance_price (price) VALUES (:price)
-
--- :name get-latest-binance-price :? :1
--- :doc Get the most recent Binance BTC price
-SELECT price, recorded_at FROM binance_price ORDER BY id DESC LIMIT 1
-
--- :name upsert-kraken-hour! :! :n
--- :doc Upsert a Kraken hourly OHLC candle
-INSERT INTO kraken_hour (ts, open, high, low, close, vwap, volume, trade_count)
-VALUES (:ts, :open, :high, :low, :close, :vwap, :volume, :trade-count)
-ON CONFLICT (ts) DO UPDATE
-SET open = EXCLUDED.open,
-    high = EXCLUDED.high,
-    low  = EXCLUDED.low,
-    close = EXCLUDED.close,
-    vwap  = EXCLUDED.vwap,
-    volume = EXCLUDED.volume,
-    trade_count = EXCLUDED.trade_count
-
--- :name get-latest-kraken-hour :? :1
--- :doc Get the most recent Kraken hourly candle by timestamp
-SELECT ts, open, high, low, close, vwap, volume, trade_count, created_at
-FROM kraken_hour ORDER BY ts DESC LIMIT 1
-
--- :name upsert-kraken-day! :! :n
--- :doc Upsert a Kraken daily OHLC candle
-INSERT INTO kraken_day (ts, open, high, low, close, vwap, volume, trade_count)
-VALUES (:ts, :open, :high, :low, :close, :vwap, :volume, :trade-count)
-ON CONFLICT (ts) DO UPDATE
-SET open = EXCLUDED.open,
-    high = EXCLUDED.high,
-    low  = EXCLUDED.low,
-    close = EXCLUDED.close,
-    vwap  = EXCLUDED.vwap,
-    volume = EXCLUDED.volume,
-    trade_count = EXCLUDED.trade_count
-
--- :name get-latest-kraken-day :? :1
--- :doc Get the most recent Kraken daily candle by timestamp
-SELECT ts FROM kraken_day ORDER BY ts DESC LIMIT 1

resources/system.edn

@@ -32,34 +32,9 @@
  {:routes #ig/ref :router/routes
   :env    #ig/ref :system/env}
 
- :db.sql/connection
- {:jdbc-url #env JDBC_URL}
-
- :db.sql/query-fn
- {:conn        #ig/ref :db.sql/connection
-  :options     {}
-  :filename    "queries.sql"}
-
- :db.sql/migrations
- {:store            :database
-  :db               {:datasource #ig/ref :db.sql/connection}
-  :migrate-on-init? true}
-
  :reitit.routes/api
- {:base-path "/api"
+ {:base-path "/api"}
-  :query-fn  #ig/ref :db.sql/query-fn}
 
  :reitit.routes/ui
  {:base-path   ""
-  :query-fn  #ig/ref :db.sql/query-fn
+  :btcdata-url #or [#env BTCDATA_URL "http://localhost:4100"]}}
-  :binance   #ig/ref :ws/binance}
-
- :ws/binance
- {:query-fn #ig/ref :db.sql/query-fn
-  :uri      "wss://stream.binance.com:9443/ws/btcusdt@trade"}
-
- :kraken/ohlc
- {:query-fn #ig/ref :db.sql/query-fn}
-
- :kraken/ohlc-day
- {:query-fn #ig/ref :db.sql/query-fn}}

src/clj/pmagnus/btcprice/core.clj

@@ -6,19 +6,11 @@
    [pmagnus.btcprice.env :refer [defaults]]
 
    ;; Edges
-   [kit.edge.db.postgres]
-   [kit.edge.db.sql.conman]
-   [kit.edge.db.sql.migratus]
    [kit.edge.server.undertow]
    [pmagnus.btcprice.web.handler]
    ;; Routes
    [pmagnus.btcprice.web.routes.api]
-   [pmagnus.btcprice.web.routes.ui]
+   [pmagnus.btcprice.web.routes.ui])
-   ;; WebSocket clients
-   [pmagnus.btcprice.ws.binance]
-   ;; Pollers
-   [pmagnus.btcprice.kraken.ohlc]
-   [pmagnus.btcprice.kraken.ohlc-daily])
   (:gen-class))
 
 (defonce system (atom nil))

src/clj/pmagnus/btcprice/kraken/ohlc.clj

@@ -1,124 +0,0 @@
-(ns pmagnus.btcprice.kraken.ohlc
-  (:require
-   [clojure.data.json :as json]
-   [clojure.tools.logging :as log]
-   [integrant.core :as ig])
-  (:import
-   [java.net URI]
-   [java.net.http HttpClient HttpRequest HttpResponse$BodyHandlers]))
-
-(def ^:private kraken-ohlc-url
-  "https://api.kraken.com/0/public/OHLC?pair=XBTUSD&interval=60")
-
-(defn- fetch-ohlc
-  "HTTP GET to Kraken OHLC endpoint. Returns parsed JSON result map.
-   When `since` is provided, appends &since= to fetch only newer candles."
-  [^HttpClient client since]
-  (let [url     (if since
-                  (str kraken-ohlc-url "&since=" since)
-                  kraken-ohlc-url)
-        request (-> (HttpRequest/newBuilder)
-                    (.uri (URI. url))
-                    (.header "Accept" "application/json")
-                    (.GET)
-                    (.build))
-        resp    (.send client request (HttpResponse$BodyHandlers/ofString))
-        body    (json/read-str (.body resp) :key-fn keyword)]
-    (when-let [errors (seq (:error body))]
-      (throw (ex-info "Kraken API error" {:errors errors})))
-    (:result body)))
-
-(defn- parse-candle
-  "Convert a Kraken OHLC array [ts, open, high, low, close, vwap, volume, count]
-   to a map with bigdec values."
-  [[ts open high low close vwap volume count]]
-  {:ts          (long ts)
-   :open        (bigdec open)
-   :high        (bigdec high)
-   :low         (bigdec low)
-   :close       (bigdec close)
-   :vwap        (bigdec vwap)
-   :volume      (bigdec volume)
-   :trade-count (int count)})
-
-(defn- save-candles!
-  "Upsert each candle into the kraken_hour table."
-  [query-fn candles]
-  (doseq [candle candles]
-    (query-fn :upsert-kraken-hour! candle)))
-
-(defn- seed-since-from-db
-  "Query DB for the latest candle timestamp. Returns it or nil."
-  [query-fn]
-  (some-> (query-fn :get-latest-kraken-hour {})
-          :ts))
-
-(defn- poll!
-  "Fetch OHLC data, drop the last (in-progress) candle, save completed ones.
-   Returns the count of saved candles."
-  [client query-fn since-atom]
-  (let [result   (fetch-ohlc client @since-atom)
-        ;; Kraken returns a map with the pair key and a "last" key
-        last-ts  (:last result)
-        pair-key (first (remove #{:last} (keys result)))
-        raw      (get result pair-key)
-        candles  (map parse-candle (butlast raw))]
-    (when (seq candles)
-      (save-candles! query-fn candles)
-      (when last-ts
-        (reset! since-atom last-ts))
-      (log/info "Fetched" (count candles) "completed Kraken hourly candles"))
-    (count candles)))
-
-(defn- ms-until-next-poll
-  "Milliseconds from now until next HH:01:00 UTC."
-  []
-  (let [now    (java.time.ZonedDateTime/now java.time.ZoneOffset/UTC)
-        next   (-> now
-                   (.truncatedTo java.time.temporal.ChronoUnit/HOURS)
-                   (.plusMinutes 1))
-        target (if (.isAfter now next)
-                 (.plusHours next 1)
-                 next)]
-    (.toMillis (java.time.Duration/between now target))))
-
-(defn- start-poll-loop!
-  "Start a background future that polls Kraken aligned to HH:01:00 UTC.
-   When `has-data?` is false, fetches immediately to backfill."
-  [client query-fn since-atom running? has-data?]
-  (future
-    (when-not has-data?
-      (try
-        (poll! client query-fn since-atom)
-        (catch Exception e
-          (log/error e "Kraken OHLC initial poll failed"))))
-    (while @running?
-      (let [wait (ms-until-next-poll)]
-        (log/info "Next Kraken OHLC poll in" (quot wait 60000) "minutes")
-        (Thread/sleep wait)
-        (when @running?
-          (try
-            (poll! client query-fn since-atom)
-            (catch Exception e
-              (log/error e "Kraken OHLC poll failed"))))))))
-
-(defmethod ig/init-key :kraken/ohlc
-  [_ {:keys [query-fn]}]
-  (let [client    (HttpClient/newHttpClient)
-        db-since  (seed-since-from-db query-fn)
-        since     (atom db-since)
-        running?  (atom true)
-        has-data? (some? db-since)
-        fut       (start-poll-loop! client query-fn since running? has-data?)]
-    (if has-data?
-      (log/info "Starting Kraken OHLC poller, next fetch in" (quot (ms-until-next-poll) 60000) "minutes")
-      (log/info "Starting Kraken OHLC poller, fetching immediately (no data)"))
-    {:running? running?
-     :future   fut
-     :since    since}))
-
-(defmethod ig/halt-key! :kraken/ohlc
-  [_ {:keys [running? future]}]
-  (log/info "Stopping Kraken OHLC poller")
-  (reset! running? false)
-  (future-cancel future))

src/clj/pmagnus/btcprice/kraken/ohlc_daily.clj

@@ -1,123 +0,0 @@
-(ns pmagnus.btcprice.kraken.ohlc-daily
-  (:require
-   [clojure.data.json :as json]
-   [clojure.tools.logging :as log]
-   [integrant.core :as ig])
-  (:import
-   [java.net URI]
-   [java.net.http HttpClient HttpRequest HttpResponse$BodyHandlers]))
-
-(def ^:private kraken-ohlc-url
-  "https://api.kraken.com/0/public/OHLC?pair=XBTUSD&interval=1440")
-
-(defn- fetch-ohlc
-  "HTTP GET to Kraken OHLC endpoint (daily). Returns parsed JSON result map.
-   When `since` is provided, appends &since= to fetch only newer candles."
-  [^HttpClient client since]
-  (let [url     (if since
-                  (str kraken-ohlc-url "&since=" since)
-                  kraken-ohlc-url)
-        request (-> (HttpRequest/newBuilder)
-                    (.uri (URI. url))
-                    (.header "Accept" "application/json")
-                    (.GET)
-                    (.build))
-        resp    (.send client request (HttpResponse$BodyHandlers/ofString))
-        body    (json/read-str (.body resp) :key-fn keyword)]
-    (when-let [errors (seq (:error body))]
-      (throw (ex-info "Kraken API error" {:errors errors})))
-    (:result body)))
-
-(defn- parse-candle
-  "Convert a Kraken OHLC array [ts, open, high, low, close, vwap, volume, count]
-   to a map with bigdec values."
-  [[ts open high low close vwap volume count]]
-  {:ts          (long ts)
-   :open        (bigdec open)
-   :high        (bigdec high)
-   :low         (bigdec low)
-   :close       (bigdec close)
-   :vwap        (bigdec vwap)
-   :volume      (bigdec volume)
-   :trade-count (int count)})
-
-(defn- save-candles!
-  "Upsert each candle into the kraken_day table."
-  [query-fn candles]
-  (doseq [candle candles]
-    (query-fn :upsert-kraken-day! candle)))
-
-(defn- seed-since-from-db
-  "Query DB for the latest daily candle timestamp. Returns it or nil."
-  [query-fn]
-  (some-> (query-fn :get-latest-kraken-day {})
-          :ts))
-
-(defn- poll!
-  "Fetch daily OHLC data, drop the last (in-progress) candle, save completed ones.
-   Returns the count of saved candles."
-  [client query-fn since-atom]
-  (let [result   (fetch-ohlc client @since-atom)
-        last-ts  (:last result)
-        pair-key (first (remove #{:last} (keys result)))
-        raw      (get result pair-key)
-        candles  (map parse-candle (butlast raw))]
-    (when (seq candles)
-      (save-candles! query-fn candles)
-      (when last-ts
-        (reset! since-atom last-ts))
-      (log/info "Fetched" (count candles) "completed Kraken daily candles"))
-    (count candles)))
-
-(defn- ms-until-next-daily-poll
-  "Milliseconds from now until next 00:01:00 UTC."
-  []
-  (let [now    (java.time.ZonedDateTime/now java.time.ZoneOffset/UTC)
-        next   (-> now
-                   (.truncatedTo java.time.temporal.ChronoUnit/DAYS)
-                   (.plusMinutes 1))
-        target (if (.isAfter now next)
-                 (.plusDays next 1)
-                 next)]
-    (.toMillis (java.time.Duration/between now target))))
-
-(defn- start-poll-loop!
-  "Start a background future that polls Kraken daily OHLC aligned to 00:01:00 UTC.
-   When `has-data?` is false, fetches immediately to backfill."
-  [client query-fn since-atom running? has-data?]
-  (future
-    (when-not has-data?
-      (try
-        (poll! client query-fn since-atom)
-        (catch Exception e
-          (log/error e "Kraken daily OHLC initial poll failed"))))
-    (while @running?
-      (let [wait (ms-until-next-daily-poll)]
-        (log/info "Next Kraken daily OHLC poll in" (quot wait 60000) "minutes")
-        (Thread/sleep wait)
-        (when @running?
-          (try
-            (poll! client query-fn since-atom)
-            (catch Exception e
-              (log/error e "Kraken daily OHLC poll failed"))))))))
-
-(defmethod ig/init-key :kraken/ohlc-day
-  [_ {:keys [query-fn]}]
-  (let [client    (HttpClient/newHttpClient)
-        db-since  (seed-since-from-db query-fn)
-        since     (atom db-since)
-        running?  (atom true)
-        has-data? (some? db-since)
-        fut       (start-poll-loop! client query-fn since running? has-data?)]
-    (if has-data?
-      (log/info "Starting Kraken daily OHLC poller, next fetch in" (quot (ms-until-next-daily-poll) 60000) "minutes")
-      (log/info "Starting Kraken daily OHLC poller, fetching immediately (no data)"))
-    {:running? running?
-     :future   fut
-     :since    since}))
-
-(defmethod ig/halt-key! :kraken/ohlc-day
-  [_ {:keys [running? future]}]
-  (log/info "Stopping Kraken daily OHLC poller")
-  (reset! running? false)
-  (future-cancel future))

src/clj/pmagnus/btcprice/web/htmx.clj

@@ -17,9 +17,7 @@
                    [:meta {:name "apple-mobile-web-app-capable" :content "yes"}]
                    [:meta {:name "apple-mobile-web-app-status-bar-style" :content "black-translucent"}]
                    [:title (or (:title opts#) "BTC Price")]
-                   [:link {:rel "stylesheet" :href "/css/output.css"}]
+                   [:link {:rel "stylesheet" :href "/css/output.css"}]]
-                   [:script {:src "https://unpkg.com/htmx.org@2.0.8"}]
-                   [:script {:src "https://unpkg.com/htmx-ext-sse@2.2.2/sse.js"}]]
                   [:body
                    [:div.mx-auto.max-w-lg.px-4.py-6
                     ~@content]]]))}))

src/clj/pmagnus/btcprice/web/routes/api.clj

@@ -8,8 +8,7 @@
    [reitit.ring.coercion :as coercion]
    [reitit.ring.middleware.muuntaja :as muuntaja]
    [reitit.ring.middleware.parameters :as parameters]
-   [reitit.swagger :as swagger]
+   [reitit.swagger :as swagger]))
-   [reitit.swagger-ui :as swagger-ui]))
 
 (defn- api-routes [_opts]
   [["/swagger.json"

src/clj/pmagnus/btcprice/web/routes/ui.clj

@@ -1,96 +1,60 @@
 (ns pmagnus.btcprice.web.routes.ui
   (:require
-   [clojure.string :as str]
-   [hiccup2.core :as h]
    [integrant.core :as ig]
    [pmagnus.btcprice.web.htmx :refer [page]]
    [pmagnus.btcprice.web.middleware.exception :as exception]
    [pmagnus.btcprice.web.middleware.formats :as formats]
    [reitit.ring.middleware.muuntaja :as muuntaja]
-   [reitit.ring.middleware.parameters :as parameters])
+   [reitit.ring.middleware.parameters :as parameters]))
-  (:import
-   [io.undertow.server HttpServerExchange]
-   [io.undertow.util HttpString]
-   [java.io BufferedWriter OutputStreamWriter]
-   [java.time ZoneId]
-   [java.time.format DateTimeFormatter]
-   [java.util.concurrent LinkedBlockingQueue TimeUnit]))
 
-(def ^:private time-fmt
+(defn- home-page [{:keys [btcdata-url]} _req]
-  (-> (DateTimeFormatter/ofPattern "dd-MM HH:mm:ss")
-      (.withZone (ZoneId/systemDefault))))
-
-(defn home-page [_req]
   (page {:title "BTC Price"}
     [:header.text-center.mb-8
      [:h1.text-3xl.font-bold.text-gray-900 "BTC Price"]
      [:p.text-sm.text-gray-500.mt-1 "Bitcoin price tracker"]]
 
-    [:div#price-panel {:hx-ext "sse" :sse-connect "/price/stream"}
+    [:div#price-panel
-     [:div {:sse-swap "price-update"}
+     [:div#price-display
       [:div.bg-white.rounded-2xl.shadow-sm.border.border-gray-200.p-6
-       [:p.text-center.text-gray-400.text-sm "Connecting..."]]]]))
+       [:p.text-center.text-gray-400.text-sm "Connecting..."]]]]
 
-;; Tailwind classes referenced for price color:
+    [:script
-;; text-green-600 text-red-600 text-gray-900
+     (hiccup2.core/raw
-(defn- render-price-html [{:keys [price prev-price recorded-at]}]
-  (let [color (cond
-                (nil? prev-price)      "text-gray-900"
-                (> price prev-price)   "text-green-600"
-                (< price prev-price)   "text-red-600"
-                :else                  "text-gray-900")]
       (str
-     (h/html
+       "document.addEventListener('DOMContentLoaded', function() {\n"
-      [:div.bg-white.rounded-2xl.shadow-sm.border.border-gray-200.p-6
+       "  var btcdataUrl = '" btcdata-url "';\n"
-       [:div.text-center
+       "  var display = document.getElementById('price-display');\n"
-        [:p {:class (str "text-4xl font-bold " color)}
+       "  var source = new EventSource(btcdataUrl + '/api/price/stream');\n"
-         (str "$" (format "%,.2f" (double price)))]
+       "\n"
-        [:p.text-xs.text-gray-400.mt-2
+       "  source.addEventListener('price-update', function(e) {\n"
-         (str "Updated " (.format time-fmt recorded-at))]]]))))
+       "    var d = JSON.parse(e.data);\n"
-
+       "    var price = parseFloat(d.price);\n"
-(defn- format-sse [event data]
+       "    var prevPrice = d.prev_price ? parseFloat(d.prev_price) : null;\n"
-  (str "event: " event "\n"
+       "    var color = 'text-gray-900';\n"
-       (str/join "\n" (map #(str "data: " %) (str/split-lines data)))
+       "    if (prevPrice !== null) {\n"
-       "\n\n"))
+       "      if (price > prevPrice) color = 'text-green-600';\n"
-
+       "      else if (price < prevPrice) color = 'text-red-600';\n"
-(defn- price-stream-handler [{:keys [binance]} req]
+       "    }\n"
-  (let [^HttpServerExchange exchange (:server-exchange req)
+       "    var fmt = '$' + price.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});\n"
-        price-atom (:latest-price binance)
+       "    var ts = new Date(d.recorded_at);\n"
-        headers    (.getResponseHeaders exchange)]
+       "    var pad = function(n) { return n < 10 ? '0' + n : n; };\n"
-    (.setStatusCode exchange 200)
+       "    var timeStr = pad(ts.getDate()) + '-' + pad(ts.getMonth()+1) + ' ' + pad(ts.getHours()) + ':' + pad(ts.getMinutes()) + ':' + pad(ts.getSeconds());\n"
-    (.put headers (HttpString. "Content-Type") "text/event-stream")
+       "    display.innerHTML = '<div class=\"bg-white rounded-2xl shadow-sm border border-gray-200 p-6\">' +\n"
-    (.put headers (HttpString. "Cache-Control") "no-cache")
+       "      '<div class=\"text-center\">' +\n"
-    (.put headers (HttpString. "X-Accel-Buffering") "no")
+       "      '<p class=\"text-4xl font-bold ' + color + '\">' + fmt + '</p>' +\n"
-    (when-not (.isBlocking exchange)
+       "      '<p class=\"text-xs text-gray-400 mt-2\">Updated ' + timeStr + '</p>' +\n"
-      (.startBlocking exchange))
+       "      '</div></div>';\n"
-    (let [out    (.getOutputStream exchange)
+       "  });\n"
-          writer (BufferedWriter. (OutputStreamWriter. out "UTF-8"))
+       "\n"
-          queue  (LinkedBlockingQueue.)
+       "  source.onerror = function() {\n"
-          wkey   (keyword (gensym "sse-"))]
+       "    display.innerHTML = '<div class=\"bg-white rounded-2xl shadow-sm border border-gray-200 p-6\">' +\n"
-      (add-watch price-atom wkey
+       "      '<p class=\"text-center text-red-400 text-sm\">Connection lost. Reconnecting...</p></div>';\n"
-        (fn [_ _ _ v] (.offer queue v)))
+       "  };\n"
-      (when-let [v @price-atom]
+       "});\n"))]))
-        (.offer queue v))
-      (try
-        (loop []
-          (if-let [v (.poll queue 15 TimeUnit/SECONDS)]
-            (do (.write writer (format-sse "price-update" (render-price-html v)))
-                (.flush writer))
-            (do (.write writer ": heartbeat\n\n")
-                (.flush writer)))
-          (recur))
-        (catch Exception _)
-        (finally
-          (remove-watch price-atom wkey)
-          (try (.close writer) (catch Exception _)))))
-    nil))
 
 (defn- ui-routes [opts]
   [["/"
-    {:get home-page}]
+    {:get (fn [req] (home-page opts req))}]])
-   ["/price/stream"
-    {:get        (fn [req] (price-stream-handler opts req))
-     :middleware []}]])
 
 (defn route-data [opts]
   (merge

src/clj/pmagnus/btcprice/ws/binance.clj

@@ -1,93 +0,0 @@
-(ns pmagnus.btcprice.ws.binance
-  (:require
-   [clojure.data.json :as json]
-   [clojure.tools.logging :as log]
-   [integrant.core :as ig])
-  (:import
-   [java.net URI]
-   [java.net.http HttpClient WebSocket WebSocket$Listener]
-   [java.util.concurrent CompletableFuture CompletionStage]))
-
-(defn- save-price! [query-fn price]
-  (try
-    (query-fn :insert-binance-price! {:price price})
-    (catch Exception e
-      (log/error e "Failed to save BTC price"))))
-
-(defn- connect!
-  "Opens a WebSocket to Binance trade stream and returns the WebSocket instance.
-   `state` is an atom with keys :running?, :last-write, :buffer.
-   `latest-price` is an atom reset with each throttled price for SSE consumers."
-  [uri query-fn state latest-price]
-  (let [client   (HttpClient/newHttpClient)
-        listener (reify WebSocket$Listener
-                   (onOpen [_ ws]
-                     (log/info "Binance WebSocket connected")
-                     (.request ws 1))
-
-                   (onText [_ ws data last?]
-                     (let [buf (:buffer @state)]
-                       (.append buf data)
-                       (when last?
-                         (let [text (str buf)]
-                           (.setLength buf 0)
-                           (try
-                             (let [msg   (json/read-str text :key-fn keyword)
-                                   price (some-> (:p msg) bigdec)]
-                               (when price
-                                 (let [now (System/currentTimeMillis)]
-                                   (when (> (- now (:last-write @state)) 5000)
-                                     (swap! state assoc :last-write now)
-                                     (log/info "BTC price:" (str price))
-                                     (save-price! query-fn price)
-                                     (let [prev-price (:price @latest-price)]
-                                       (reset! latest-price
-                                               {:price      price
-                                                :prev-price prev-price
-                                                :recorded-at (java.time.Instant/now)}))))))
-                             (catch Exception e
-                               (log/error e "Failed to parse Binance message")))))
-                       (let [^CompletionStage cf (CompletableFuture/completedFuture nil)]
-                         (.request ws 1)
-                         cf)))
-
-                   (onClose [_ _ws code reason]
-                     (log/warn "Binance WebSocket closed:" code reason)
-                     (when (:running? @state)
-                       (future
-                         (Thread/sleep 3000)
-                         (when (:running? @state)
-                           (log/info "Reconnecting to Binance...")
-                           (try
-                             (let [ws (connect! uri query-fn state latest-price)]
-                               (swap! state assoc :ws ws))
-                             (catch Exception e
-                               (log/error e "Binance reconnect failed")))))))
-
-                   (onError [_ _ws error]
-                     (log/error error "Binance WebSocket error")))]
-    (-> (.newWebSocketBuilder client)
-        (.buildAsync (URI. uri) listener)
-        (.join))))
-
-(defmethod ig/init-key :ws/binance
-  [_ {:keys [query-fn uri]}]
-  (log/info "Starting Binance WebSocket listener:" uri)
-  (let [latest-price (atom nil)
-        state        (atom {:running?   true
-                            :last-write 0
-                            :buffer     (StringBuilder.)
-                            :ws         nil})
-        ws           (connect! uri query-fn state latest-price)]
-    (swap! state assoc :ws ws)
-    {:state        state
-     :latest-price latest-price}))
-
-(defmethod ig/halt-key! :ws/binance
-  [_ {:keys [state]}]
-  (log/info "Stopping Binance WebSocket listener")
-  (swap! state assoc :running? false)
-  (when-let [ws (:ws @state)]
-    (try
-      (.sendClose ws WebSocket/NORMAL_CLOSURE "shutting down")
-      (catch Exception _))))