Add Strike quote endpoint for real sats price with fee-adjusted amount

Use POST /v1/currency-exchange-quotes to get actual buy price including
spread, matching the Strike app. Fee is cached daily to calculate the
pre-fee amount from the configured total (default 55 EUR). Store
quote_sats in the strike_price DB table.

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

resources/migrations/20260306100000-add-strike-quote-sats.down.sql

@@ -0,0 +1 @@
+ALTER TABLE strike_price DROP COLUMN quote_sats;

resources/migrations/20260306100000-add-strike-quote-sats.up.sql

@@ -0,0 +1 @@
+ALTER TABLE strike_price ADD COLUMN quote_sats BIGINT;

resources/queries.sql

@@ -45,7 +45,7 @@ SELECT ts FROM kraken_day ORDER BY ts DESC LIMIT 1
 
 -- :name insert-strike-price! :! :n
 -- :doc Insert a Strike ticker snapshot
-INSERT INTO strike_price (rates) VALUES (:rates)
+INSERT INTO strike_price (rates, quote_sats) VALUES (:rates, :quote-sats)
 
 -- :name get-latest-strike-price :? :1
 -- :doc Get the most recent Strike ticker snapshot

resources/system.edn

@@ -64,5 +64,6 @@
  {:url #or [#env FRANKFURTER_URL "http://localhost:8080"]}
 
  :strike/ticker
- {:query-fn #ig/ref :db.sql/query-fn
+ {:query-fn        #ig/ref :db.sql/query-fn
-  :api-key  #env STRIKE_API_KEY}}
+  :api-key         #env STRIKE_API_KEY
+  :sats-eur-amount #or [#env SATS_EUR_AMOUNT "55"]}}

src/clj/pmagnus/btcdata/strike/ticker.clj

@@ -7,6 +7,7 @@
   (:import
    [java.net URI]
    [java.net.http HttpClient HttpRequest HttpResponse$BodyHandlers]
+   [java.time Duration Instant]
    [org.postgresql.util PGobject]))
 
 (defn- ->jsonb
@@ -29,6 +30,58 @@
         body    (.body resp)]
     body))
 
+(defn- post-quote
+  "POST /v1/currency-exchange-quotes. Returns parsed response map or nil."
+  [^HttpClient client ^String api-key ^String eur-amount]
+  (let [body-str (json/write-str {:sell "EUR" :buy "BTC"
+                                  :amount {:amount eur-amount :currency "EUR"}})
+        request  (-> (HttpRequest/newBuilder)
+                     (.uri (URI. "https://api.strike.me/v1/currency-exchange-quotes"))
+                     (.header "Accept" "application/json")
+                     (.header "Content-Type" "application/json")
+                     (.header "Authorization" (str "Bearer " api-key))
+                     (.POST (java.net.http.HttpRequest$BodyPublishers/ofString body-str))
+                     (.build))
+        resp     (.send client request (HttpResponse$BodyHandlers/ofString))
+        status   (.statusCode resp)
+        body     (.body resp)]
+    (if (= 200 status)
+      (json/read-str body :key-fn keyword)
+      (do (log/warn "Strike quote HTTP" status body)
+          nil))))
+
+(def ^:private fee-max-age (Duration/ofHours 24))
+
+(defn- refresh-fee!
+  "Fetch fee for sats-eur-amount and cache it. Returns the fee BigDecimal or nil."
+  [client api-key sats-eur-amount fee-cache]
+  (when-let [parsed (post-quote client api-key sats-eur-amount)]
+    (let [fee (bigdec (get-in parsed [:fee :amount]))]
+      (log/info "Strike fee for" sats-eur-amount "EUR:" fee "EUR")
+      (reset! fee-cache {:fee fee :fetched-at (Instant/now)})
+      fee)))
+
+(defn- cached-fee
+  "Return cached fee if fresh, otherwise refresh. Returns BigDecimal or nil."
+  [client api-key sats-eur-amount fee-cache]
+  (let [{:keys [fee fetched-at]} @fee-cache]
+    (if (and fee fetched-at
+             (.isBefore (Instant/now) (.plus ^Instant fetched-at fee-max-age)))
+      fee
+      (refresh-fee! client api-key sats-eur-amount fee-cache))))
+
+(defn- fetch-quote-sats
+  "Get sats for a total EUR amount (including fee). Uses cached fee to calculate
+   pre-fee amount, then quotes that. Returns sats as long or nil."
+  [client api-key sats-eur-amount fee-cache]
+  (let [total   (bigdec sats-eur-amount)
+        fee     (cached-fee client api-key sats-eur-amount fee-cache)
+        pre-fee (if fee (.toPlainString (.subtract total fee)) sats-eur-amount)]
+    (when-let [parsed (post-quote client api-key pre-fee)]
+      (let [btc-amt (get-in parsed [:target :amount])]
+        (when btc-amt
+          (long (* (bigdec btc-amt) 100000000)))))))
+
 (defn- format-rates
   "Build a compact log string from the parsed rates array."
   [rates]
@@ -47,36 +100,49 @@
 
 (defn- poll!
   "Fetch rates and insert into the database. Updates latest-atom."
-  [client api-key query-fn latest-atom]
+  [client api-key query-fn latest-atom sats-eur-amount fee-cache]
-  (let [body  (fetch-rates client api-key)
+  (let [body       (fetch-rates client api-key)
-        rates (json/read-str body :key-fn keyword)]
+        rates      (json/read-str body :key-fn keyword)
-    (query-fn :insert-strike-price! {:rates (->jsonb body)})
+        rmap       (rates->map rates)
-    (reset! latest-atom (rates->map rates))
+        quote-sats (when sats-eur-amount
+                     (try
+                       (let [sats (fetch-quote-sats client api-key sats-eur-amount fee-cache)]
+                         (when sats
+                           (log/info "Strike quote:" sats-eur-amount "EUR ->" sats "sats"))
+                         sats)
+                       (catch Exception e
+                         (log/error e "Strike quote fetch failed")
+                         nil)))
+        rmap       (if quote-sats (assoc rmap "quote-sats" quote-sats) rmap)]
+    (query-fn :insert-strike-price! {:rates     (->jsonb body)
+                                     :quote-sats quote-sats})
+    (reset! latest-atom rmap)
     (log/info "Strike:" (format-rates rates))))
 
 (defn- start-poll-loop!
   "Fetch immediately, then poll every 10 seconds."
-  [client api-key query-fn running? latest-atom]
+  [client api-key query-fn running? latest-atom sats-eur-amount fee-cache]
   (future
     (try
-      (poll! client api-key query-fn latest-atom)
+      (poll! client api-key query-fn latest-atom sats-eur-amount fee-cache)
       (catch Exception e
         (log/error e "Strike initial fetch failed")))
     (while @running?
       (Thread/sleep 10000)
       (when @running?
         (try
-          (poll! client api-key query-fn latest-atom)
+          (poll! client api-key query-fn latest-atom sats-eur-amount fee-cache)
           (catch Exception e
             (log/error e "Strike poll failed")))))))
 
 (defmethod ig/init-key :strike/ticker
-  [_ {:keys [query-fn api-key]}]
+  [_ {:keys [query-fn api-key sats-eur-amount]}]
   (log/info "Starting Strike ticker poller")
   (let [client       (HttpClient/newHttpClient)
         running?     (atom true)
         latest-rates (atom nil)
-        fut          (start-poll-loop! client api-key query-fn running? latest-rates)]
+        fee-cache    (atom nil)
+        fut          (start-poll-loop! client api-key query-fn running? latest-rates sats-eur-amount fee-cache)]
     {:running?     running?
      :future       fut
      :latest-rates latest-rates}))