Use coinmarketcap API for getting bounty USD values

Support both cryptonator and coinmarketcap APIs for getting current
token + bounty USD values. Coinmarketcap used by default.

Fixes: #171

src/clj/commiteth/util/crypto_fiat_value.clj

@@ -1,27 +1,72 @@
 (ns commiteth.util.crypto-fiat-value
   (:require [clj-http.client :as http]
-            [clojure.string :as str]
+            [mount.core :as mount]
+            [clojure.tools.logging :as log]
+            [commiteth.config :refer [env]]
             [clojure.data.json :as json]))
 
 
-(defn get-token-usd-price
+(defn fiat-api-provider []
+  (env :fiat-api-provider :coinmarketcap))
+
+(defn json-api-request [url]
+  (->> (http/get url)
+       (:body)
+       (json/read-str)))
+
+
+(defn get-token-usd-price-cryptonator
   "Get current USD value for a token using cryptonator API"
-  [token]
-  (let [url (str "https://api.cryptonator.com/api/ticker/"
+  [tla]
+  (let [token (subs (str tla) 1)
+        url (str "https://api.cryptonator.com/api/ticker/"
                  token
                  "-usd")
-        m (->> (http/get url)
-               (:body)
-               (json/read-str))]
+        m (json-api-request url)]
     (-> (get-in m ["ticker" "price"])
         (read-string))))
 
 
+(def tla-to-id-mapping (atom {}))
+
+(defn make-tla-to-id-mapping
+  "Coinmarketcap API uses it's own IDs for tokens instead of TLAs"
+  []
+  (let [data (json-api-request "https://api.coinmarketcap.com/v1/ticker/?limit=0")]
+    (into {} (map
+              (fn [x] [(keyword (get x "symbol")) (get x "id")])
+              data))))
+
+(defn get-token-usd-price-coinmarketcap
+  "Get current USD value for a token using coinmarketcap API"
+  [tla]
+  (let [token-id (get @tla-to-id-mapping tla)
+        url (format "https://api.coinmarketcap.com/v1/ticker/%s" token-id)
+        data (json-api-request url)]
+    (-> (first data)
+        (get "price_usd")
+        (read-string))))
+
+(defn- get-price-fn []
+  (let [fns {:cryptonator get-token-usd-price-cryptonator
+                      :coinmarketcap get-token-usd-price-coinmarketcap}]
+    (get fns (fiat-api-provider))))
+
 (defn bounty-usd-value
   "Get current USD value of a bounty. bounty is a map of token-tla (keyword) to value"
   [bounty]
-  (reduce + (map (fn [[token value]]
-                   (let [tla (subs (str token) 1)
-                         usd-price (get-token-usd-price tla)]
-                     (* usd-price value)))
-                 bounty)))
+  (let [get-token-usd-price (get-price-fn)]
+    (reduce + (map (fn [[tla value]]
+                     (let [usd-price (get-token-usd-price tla)]
+                       (* usd-price value)))
+                   bounty))))
+
+
+(mount/defstate
+  crypto-fiat-util
+  :start
+  (do
+    (reset! tla-to-id-mapping (make-tla-to-id-mapping))
+    (log/info "crypto-fiat-util started"))
+  :stop
+  (log/info "crypto-fiat-util stopped"))