Add Websocket connection

eth_client/.iex.exs

@@ -6,6 +6,6 @@ bin_path = "../contracts/src/bin/Storage.bin"
 abi_path = "../contracts/src/bin/Storage.abi"
 
 # Uncomment and fill in for Rinkeby
-Context.set_infura_api_key("your_infura_api_key")
-Context.set_etherscan_api_key("your_eth_scan_api_key")
-EthClient.set_chain("rinkeby")
+#Context.set_infura_api_key("your_infura_api_key")
+#Context.set_etherscan_api_key("your_eth_scan_api_key")
+#EthClient.set_chain("rinkeby")

eth_client/lib/eth_client/context.ex

@@ -6,7 +6,7 @@ defmodule EthClient.Context do
   alias EthClient.Contract
   require Logger
 
-  def start_link(%{chain_id: _chain_id, rpc_host: _rpc_host, user_account: %Account{}} = config) do
+  def start_link(config) do
     Agent.start_link(fn -> config end, name: __MODULE__)
   end
 

eth_client/lib/eth_client/web_socket.ex

@@ -0,0 +1,42 @@
+defmodule EthClient.WebSocket do
+  use WebSockex
+  alias EthClient.Context
+  @wsocket System.fetch_env!("WS_URL")
+
+  def start_link(state \\ []) do
+    WebSockex.start_link(@wsocket, __MODULE__, state)
+  end
+
+  def suscribe(client) do
+    address = Context.contract() |> Map.get(:address)
+
+    {:ok, frame} =
+      Jason.encode(%{
+        jsonrpc: "2.0",
+        id: 1,
+        method: "eth_subscribe",
+        params: ["logs", %{address: address}]
+      })
+
+    WebSockex.send_frame(client, {:text, frame})
+  end
+
+  def handle_cast({:send, {type, msg} = frame}, state) do
+    IO.puts("Sending #{type} frame with payload: #{msg}")
+    {:reply, frame, state}
+  end
+
+  def handle_frame({_type, msg}, state) do
+    msg = decode_msg(msg)
+
+    IO.puts("Log received\n")
+    IO.puts("address: #{msg["address"]}\ndata: #{msg["data"]}\nTopic: #{msg["topics"]}")
+    {:ok, state}
+  end
+
+  defp decode_msg(msg) do
+    msg
+    |> Jason.decode!()
+    |> get_in(["params", "result"])
+  end
+end

eth_client/mix.exs

@@ -31,7 +31,8 @@ defmodule EthClient.MixProject do
       {:rustler, "~> 0.25.0"},
       {:ex_rlp, "~> 0.5.4"},
       {:dialyxir, "~> 1.1", only: [:dev, :test], runtime: false},
-      {:excoveralls, "~> 0.14.5", only: [:test], runtime: false}
+      {:excoveralls, "~> 0.14.5", only: [:test], runtime: false},
+      {:websockex, "~> 0.4.3"}
     ]
   end
 end

eth_client/mix.lock

@@ -21,4 +21,5 @@
   "tesla": {:hex, :tesla, "1.4.4", "bb89aa0c9745190930366f6a2ac612cdf2d0e4d7fff449861baa7875afd797b2", [:mix], [{:castore, "~> 0.1", [hex: :castore, repo: "hexpm", optional: true]}, {:exjsx, ">= 3.0.0", [hex: :exjsx, repo: "hexpm", optional: true]}, {:finch, "~> 0.3", [hex: :finch, repo: "hexpm", optional: true]}, {:fuse, "~> 2.4", [hex: :fuse, repo: "hexpm", optional: true]}, {:gun, "~> 1.3", [hex: :gun, repo: "hexpm", optional: true]}, {:hackney, "~> 1.6", [hex: :hackney, repo: "hexpm", optional: true]}, {:ibrowse, "4.4.0", [hex: :ibrowse, repo: "hexpm", optional: true]}, {:jason, ">= 1.0.0", [hex: :jason, repo: "hexpm", optional: true]}, {:mime, "~> 1.0 or ~> 2.0", [hex: :mime, repo: "hexpm", optional: false]}, {:mint, "~> 1.0", [hex: :mint, repo: "hexpm", optional: true]}, {:poison, ">= 1.0.0", [hex: :poison, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: true]}], "hexpm", "d5503a49f9dec1b287567ea8712d085947e247cb11b06bc54adb05bfde466457"},
   "toml": {:hex, :toml, "0.6.2", "38f445df384a17e5d382befe30e3489112a48d3ba4c459e543f748c2f25dd4d1", [:mix], [], "hexpm", "d013e45126d74c0c26a38d31f5e8e9b83ea19fc752470feb9a86071ca5a672fa"},
   "unicode_util_compat": {:hex, :unicode_util_compat, "0.7.0", "bc84380c9ab48177092f43ac89e4dfa2c6d62b40b8bd132b1059ecc7232f9a78", [:rebar3], [], "hexpm", "25eee6d67df61960cf6a794239566599b09e17e668d3700247bc498638152521"},
+  "websockex": {:hex, :websockex, "0.4.3", "92b7905769c79c6480c02daacaca2ddd49de936d912976a4d3c923723b647bf0", [:mix], [], "hexpm", "95f2e7072b85a3a4cc385602d42115b73ce0b74a9121d0d6dbbf557645ac53e4"},
 }