bingex

defmodule Bingex.HTTP.Request do
  @moduledoc """
  Represents HTTP request payload for the BingX API.
  """

  alias Bingex.{Helpers, Types}
  alias Bingex.HTTP.Signature

  defstruct [:method, :url, :headers, :body]

  @type t() :: %__MODULE__{
          url: binary(),
          method: method(),
          headers: [{binary(), binary()}],
          body: nil | binary()
        }

  @type options() :: [sign: nil | binary()]
  @type method() :: :get | :put | :post | :delete
  @type url() :: binary()
  @type path() :: binary()
  @type body() :: nil | binary()
  @type params() :: [{binary(), term()}]
  @type headers() :: [{binary(), binary()}]

  @methods [:get, :put, :post, :delete]
  @origin Application.compile_env(:bingx, :origin, "https://open-api.bingx.com")

  @spec new(method(), url(), headers(), body()) :: t()
  def new(method, url, headers, body)
      when method in @methods and
             is_binary(url) and
             is_list(headers) and
             (is_binary(body) or is_nil(body)) do
    %__MODULE__{method: method, url: url, headers: headers, body: body}
  end

  @spec auth_headers(headers(), Types.api_key()) :: headers()
  def auth_headers(headers \\ [], api_key)
      when is_list(headers) and is_binary(api_key) do
    [{"X-BX-APIKEY", api_key} | headers]
  end

  @spec build_url(path(), params(), options()) :: url :: binary()
  def build_url(path \\ "/", params \\ [], options \\ []) do
    url = @origin <> path

    query =
      params
      |> Helpers.reject_nils()
      |> set_timestamp()
      |> set_recv_window()
      |> maybe_set_signature(options)
      |> URI.encode_query()

    url <> "?" <> query
  end

  @spec maybe_set_signature(params(), options()) :: params()
  defp maybe_set_signature(params, options) do
    case Keyword.get(options, :sign) do
      nil -> params
      secret_key -> set_signature(params, secret_key)
    end
  end

  @spec set_recv_window(params(), value :: pos_integer()) ::
          params()
  def set_recv_window(params, value \\ 5000)
      when is_list(params) and is_integer(value) do
    [{"recvWindow", value} | params]
  end

  @spec set_timestamp(params()) :: params()
  def set_timestamp(params) when is_list(params) do
    [{"timestamp", Helpers.timestamp()} | params]
  end

  @spec set_signature(params(), Types.secret_key()) :: params()
  def set_signature(params, secret_key)
      when is_list(params) and is_binary(secret_key) do
    signature = Signature.generate(params, secret_key)
    params ++ [{"signature", signature}]
  end
end