defmodule NDCEx do
  require HTTPoison
  require NDCLogger
  use Timex

  def request(method, data, config) do
    request_start_time = Time.now
    NDCEx.Message.Base.build_document(method, data, config)
    |> rest_call_with_message(method, data, config, request_start_time)
  end

  def rest_call_with_message({:ok, request_xml}, method, data, config, request_start_time) do
    url = NDCEx.Message.Base.build_url(config[:server][:url], method)
    headers = get_headers(config[:rest][:headers], method)
    #processing_end = Time.now
    #TODO Handle different exceptions during request and return different errors
    # try do
      case HTTPoison.post(url, request_xml, headers, is_ssl(config[:ssl], config[:label])) do
        {:ok, %HTTPoison.Response{body: response_xml,  headers: headers, status_code: 200 }} ->
          decode_response(response_xml, headers)
            |> NDCNormalize.remove_soap_header(config[:soap][:soap_header])
            |> NDCNormalize.remove_soap_tags(config[:soap][:response_namespace_tags])
            |> NDCNormalize.remove_namespace(config[:soap][:response_namespace])
            |> NDCNormalize.remove_message_wrapper(config[:message])
            |> NDCNormalize.check_ndc_errors() ## This function returns a tuple including the xml and the atom :error or :ok depending if there are any error on the response or not.
            |> process_response(method, request_xml, data, config, request_start_time)
        {:ok, %HTTPoison.Response{body: response_xml, headers: _headers, status_code: _status_code }} ->
          process_response({:error, NDCNormalize.remove_soap_tags(response_xml, config[:soap][:response_namespace])}, method, request_xml, data, config, request_start_time)
        {:error, %HTTPoison.Error{id: id, reason: reason}}->
          process_response({:error, "Error. Reason of error: #{to_string(reason)}"}, method, request_xml, data, config, request_start_time)
        #{:ok, %HTTPoison.Response{status_code: 404}} ->
          #{:error, error_message("NDC host/URL invalid or missing")}
        {:error, reason} ->
          IO.inspect reason
          {:error, reason}
        reason ->
          IO.inspect reason
          {:error, error_message("Unknown HTTP response error")}
      end
    # catch _ , _ ->
    #   {:error, error_message("Exception while HTTP request")}
    # end
  end

  defp build_url(url, method), do: String.replace(url, "{{NDC-method}}", Atom.to_string(method))
  defp error_message(message), do: "<Error><Message>#{message}</Message></Error>"
  defp remove_tag(doc, tag), do: String.replace(doc, tag, "")
  def get_mix_config(key) when is_atom(key), do: Application.get_env(:ndc_ex_sdk, key)
  defp get_headers(headers, method) do
    Enum.map(headers, fn ({key, value}) ->
      {key, String.replace(value, "{{NDC-method}}", Atom.to_string(method))}
    end)
  end

  defp process_response({status, response}, method, request, data, config, request_start_time) do
    response_time = Time.diff(Time.now, request_start_time, :milliseconds)
    request_xml = request
    response_xml = "<!-- AG-Info: ProviderName: #{config[:label]} | NDCMethod: #{method} | ResponseTime: #{response_time} | ProcessingTime: - -->\n\n\n#{response}"
    NDCLogger.event(config[:label], method, data, request_xml, response_xml)
    {status, response_xml}
  end

  defp is_ssl(config, _) when config == nil, do: [timeout: 60000, recv_timeout: 60000]
  defp is_ssl(ssl_config, provider) when ssl_config != nil do
   dir = "ndc_providers/#{String.downcase(provider)}/"
   path = if File.exists?(Path.expand(File.cwd! <> "../../../config/#{dir}/#{ssl_config[:certfile]}")) do
     Path.expand(File.cwd! <> "../../../config/#{dir}")
   else
     "test/#{dir}"
   end
   [
     hackney: [ # :hackney options
      ssl_options: [ # :ssl options
        cacertfile: path <> ssl_config[:cacertfile], # CA certificate used to validate server cert; path(), "string" is ok
        certfile: path <> ssl_config[:certfile], # client certificate, signed by CA; path(), "string" is ok
        keyfile: path <> ssl_config[:keyfile], # private key for client.crt; path(). "string" is ok
        password: ssl_config[:password] # password for keyfile; string(), "string" not ok, use 'char list'
      ]
    ],
    timeout: 60000, recv_timeout: 60000
   ]
  end

  defp decode_response(body, headers) do
  	gzipped = Enum.any?(headers, fn (kv) ->
    	case kv do
      		{"Content-Encoding", "gzip"} -> true
      		_ -> false
    	end
  	end)

  	# body is an Elixir string
  	if gzipped do
      :zlib.gunzip(body)
    else
      body
    end
  end
end