[day-01] setup imc calc and route

lib/wabanex/imc.ex

@@ -0,0 +1,32 @@
+defmodule Wabanex.IMC do
+  def calculate(%{"filename" => filename}) do
+    filename
+    |> File.read()
+    |> handle_file()
+  end
+
+  defp handle_file({:ok, content}) do
+    data =
+      content
+      |> String.trim()
+      |> String.split("\n")
+      |> Enum.map(&parse_line/1)
+      |> Enum.into(%{})
+
+    {:ok, data}
+  end
+
+  defp handle_file({:error, _reason}) do
+    {:error, "Error while opening the file"}
+  end
+
+  defp parse_line(line) do
+    line
+    |> String.split(",")
+    |> List.update_at(1, &String.to_float/1)
+    |> List.update_at(2, &String.to_float/1)
+    |> calculate_imc()
+  end
+
+  defp calculate_imc([name, height, weight]), do: {name, weight / :math.pow(height / 100, 2)}
+end