Merge pull request #1 from scripbox/feature/add-instruments-api

Add Support for Instructions API

Author: nitinstp23

lib/kite_connect_ex.ex

@@ -1,5 +1,5 @@
 defmodule KiteConnectEx do
-  alias KiteConnectEx.{User, Response, Portfolio}
+  alias KiteConnectEx.{User, Response, Portfolio, Instrument}
 
   @api_url "https://api.kite.trade"
 
@@ -84,4 +84,14 @@ defmodule KiteConnectEx do
   """
   @spec holdings(String.t()) :: {:ok, List.t()} | Response.error()
   defdelegate holdings(access_token), to: Portfolio
+
+  @doc """
+  Get list of all tradable `instruments` by `exchange`
+
+  ## Example
+
+    {:ok, instruments} = KiteConnectEx.instruments("access-token")
+  """
+  @spec instruments(String.t(), String.t()) :: {:ok, List.t()} | Response.error()
+  defdelegate instruments(access_token, exchange), to: Instrument
 end

lib/kite_connect_ex/instrument.ex

@@ -0,0 +1,42 @@
+defmodule KiteConnectEx.Instrument do
+  @moduledoc """
+  Module to retrieve a list of tradable `instruments`
+  """
+
+  alias KiteConnectEx.Portfolio.Holding
+  alias KiteConnectEx.Request
+
+  @instruments_base_path "/instruments"
+
+  @doc """
+  Get all tradable `instruments` by `exchange`
+
+  ## Example
+
+    {:ok, instruments} = KiteConnectEx.Portfolio.instruments("access-token", "NSE")
+  """
+  @spec instruments(String.t(), String.t()) :: {:ok, List.t()} | Response.error()
+  def instruments(access_token, exchange) when is_binary(access_token) do
+    Request.get(
+      instruments_path(exchange),
+      nil,
+      auth_header(access_token),
+      KiteConnectEx.request_options()
+    )
+    |> case do
+      {:ok, instruments_csv_dump} ->
+        {:ok, instruments_csv_dump}
+
+      {:error, error} ->
+        {:error, error}
+    end
+  end
+
+  defp instruments_path(exchange) do
+    @instruments_base_path <> "/" <> exchange
+  end
+
+  defp auth_header(access_token) do
+    [{"Authorization", "token " <> KiteConnectEx.api_key() <> ":" <> access_token}]
+  end
+end

lib/kite_connect_ex/response.ex

@@ -7,28 +7,44 @@ defmodule KiteConnectEx.Response do
   @success_status "success"
   @error_status "error"
 
+
+  @csv_content_type {"Content-Type", "text/csv"}
+
   @doc false
   @spec parse_response(HTTPoison.Response.t()) :: success | error
   def parse_response(%HTTPoison.Response{} = response) do
     case response do
-      %{body: body, status_code: status} when status in @success_status_codes ->
-        body =
-          body
-          |> Jason.decode!()
-          |> parse_body()
+      %{body: body, headers: headers, status_code: status} when status in @success_status_codes ->
+        {:ok, do_parse_response(headers, body)}
 
-        {:ok, body}
+      %{body: body, headers: headers, status_code: _status} ->
+        {:error, do_parse_response(headers, body)}
+    end
+  end
 
-      %{body: body, status_code: _status} ->
-        error =
-          body
-          |> Jason.decode!()
-          |> parse_body()
+  defp do_parse_response(headers, body) do
+    has_csv_header?(headers)
+    |> case do
+      true ->
+        body
 
-        {:error, error}
+      _ ->
+        body
+        |> Jason.decode!()
+        |> parse_body()
     end
   end
 
+  defp has_csv_header?([]), do: false
+
+  defp has_csv_header?([header | _tail]) when header == @csv_content_type do
+    true
+  end
+
+  defp has_csv_header?([_header | tail]) do
+    has_csv_header?(tail)
+  end
+
   @doc false
   @spec parse_error(HTTPoison.Error.t()) :: error
   def parse_error(%HTTPoison.Error{} = error) do