[feature] implement erc20 get-transaction for SNT and STT

- change `ethereum/get-transaction` to use call-private-rpc instead
of web3 object
- implement a version for erc20 tokens SNT and STT that provides enriches
result of get-transaction with `:recipient` and `:snt-amount`

Signed-off-by: yenda <eric@status.im>

src/status_im/utils/ethereum/core.cljs

@@ -3,6 +3,7 @@
             [status-im.js-dependencies :as dependencies]
             [status-im.native-module.core :as status]
             [status-im.utils.ethereum.tokens :as tokens]
+            [status-im.utils.ethereum.abi-spec :as abi-spec]
             [status-im.utils.money :as money]
             [taoensso.timbre :as log]))
 
@@ -132,7 +133,7 @@
                                  :method  "eth_call"
                                  :params  [params "latest"]}))
    (fn [response]
-     (if (= "" response)
+     (if (string/blank? response)
        (log/warn :web3-response-error)
        (callback (get (js->clj (.parse js/JSON response)) "result"))))))
 
@@ -175,11 +176,25 @@
                                      (cb (js->clj result :keywordize-keys true))
                                      (handle-error error)))))
 
-(defn get-transaction [web3 number cb]
-  (.getTransaction (.-eth web3) number (fn [error result]
-                                         (if-not error
-                                           (cb (js->clj result :keywordize-keys true))
-                                           (handle-error error)))))
+(defn- decode-uint
+  [hex]
+  (first (abi-spec/decode hex ["uint"])))
+
+(defn get-transaction [transaction-hash callback]
+  (status/call-private-rpc
+   (.stringify js/JSON (clj->js {:jsonprc "2.0"
+                                 :id      1
+                                 :method  "eth_getTransactionByHash"
+                                 :params  [transaction-hash]}))
+   (fn [response]
+     (if (string/blank? response)
+       (log/warn :web3-response-error)
+       (callback (-> (.parse js/JSON response)
+                     (js->clj :keywordize-keys true)
+                     :result
+                     (update :gasPrice decode-uint)
+                     (update :value decode-uint)
+                     (update :gas decode-uint)))))))
 
 (defn get-transaction-receipt [web3 number cb]
   (.getTransactionReceipt (.-eth web3) number (fn [error result]

src/status_im/utils/ethereum/erc20.cljs

@@ -15,7 +15,9 @@
 
   => 29166666
   "
-  (:require [status-im.utils.ethereum.core :as ethereum]
+  (:require [clojure.string :as string]
+            [status-im.utils.ethereum.core :as ethereum]
+            [status-im.utils.ethereum.abi-spec :as abi-spec]
             [status-im.native-module.core :as status]
             [status-im.utils.security :as security]
             [status-im.js-dependencies :as dependencies]
@@ -26,7 +28,7 @@
 
 (def snt-contracts
   {:mainnet "0x744d70fdbe2ba4cf95131626614a1763df805b9e"
-   :testnet "0xc55cF4B03948D7EBc8b9E8BAD92643703811d162"
+   :testnet "0xc55cf4b03948d7ebc8b9e8bad92643703811d162"
    :rinkeby nil})
 
 (def abi
@@ -147,3 +149,26 @@
                                        (ethereum/normalized-address owner-address)
                                        (ethereum/normalized-address spender-address))
                  #(cb (ethereum/hex->bignumber %))))
+
+(defn is-transfer?
+  [input-data]
+  (string/starts-with? input-data "0xa9059cbb"))
+
+(defn is-snt-contract?
+  [contract]
+  ((into #{} (vals snt-contracts)) contract))
+
+(defn get-transaction
+  "only supports SNT for now"
+  [transaction-hash callback]
+  (ethereum/get-transaction
+   transaction-hash
+   (fn [{:keys [to input] :as result}]
+     (when (and result
+                (is-snt-contract? to)
+                (is-transfer? input))
+       (let [[recipient snt-value]
+             (abi-spec/decode (subs input 10) ["address" "uint"])]
+         (callback (assoc result
+                          :recipient recipient
+                          :snt-value snt-value)))))))