feat: eth client to get block by number

Author: MarcosNicolau

explorer/lib/explorer/eth_client.ex

@@ -0,0 +1,30 @@
+defmodule Explorer.EthClient do
+  require Logger
+  @rpc_url System.get_env("RPC_URL")
+
+  def get_block_by_number(block_number) do
+    eth_send("eth_getBlockByNumber", [block_number, false])
+  end
+
+  def eth_send(method, params, id \\ 1) do
+    headers = [{"Content-Type", "application/json"}]
+    body = Jason.encode!(%{jsonrpc: "2.0", method: method, params: params, id: id})
+    request = Finch.build(:post, @rpc_url, headers, body)
+    response = Finch.request(request, Explorer.Finch, [])
+
+    case response do
+      {:ok, %Finch.Response{status: 200, body: body}} ->
+        case Jason.decode(body) do
+          {:ok, %{error: error} = _} -> {:error, error.message}
+          {:ok, body} -> {:ok, Map.get(body, "result")}
+          {:error, _} -> {:error, :invalid_json}
+        end
+
+      {:ok, %Finch.Response{status: status}} ->
+        {:error, status}
+
+      {:error, reason} ->
+        {:error, reason}
+    end
+  end
+end