defmodule SimpleHttp do
  @docmodule """
     #Author: Alexandru Bagu 
     #Email: contact@alexandrubagu.info
  """
 
  @doc """
    Create virtual methods:
    SimpleHttp.get(...)
    SimpleHttp.post(...)
    SimpleHttp.delete(...)
    SimpleHttp.put(...)
    SimpleHttp.put(...)
  """
  alias SimpleHttp.Request
  alias SimpleHttp.Response
  alias SimpleHttp.Exception.BadArgument

  methods = ["get", "post", "delete", "put", "patch"]
  Enum.each methods, fn method ->
    def unquote(:"#{method}")(url, args \\ []) do 
      create_request(unquote(String.to_atom(method)), url, args)
      |> execute
    end
  end

  @doc """
    Before you use this module you SHOULD call SimpleHttp.start
  """
  def start do
    :inets.start
  end

  defp execute(request) do
    response = struct(Response)
    httpc_response = if request.body do
      :httpc.request(request.method, { request.url, request.headers, request.content_type, request.body }, request.http_options, request.options)
    else 
      :httpc.request(request.method, { request.url, request.headers }, request.http_options, request.options)
    end
    
    case httpc_response do
      {:ok, {status, headers, body} } -> 
        {:ok, %{ response | status: status, headers: headers, body: body } }
      {:error, error } -> IO.inspect error
    end
  end

  defp create_request(method, url, args) do
    #create struct
    request = struct(Request)

    #update method (post/get/put/patch/detele)
    request = %{request | method: method }

    url = if String.valid?(url) do
      if is_map(args[:query_params]) || Keyword.keyword?(args[:query_params]) do
        url <> "?" <> URI.encode_query(args[:query_params]) |> to_charlist
      else
        url |> to_charlist
      end
    else 
      raise BadArgument
    end
    request = %{ request | url: url }


    request = with body <- args[:body], params <- args[:params] do
      if body do
        %{ request | body: body }
      else 
        query = if params do
          URI.encode_query(params) |> to_charlist
        else
          nil
        end
        %{ request | body: query }
      end
    end
  
    #update content type

    request = if String.valid?(args[:content_type]) do
      %{ request | content_type: to_charlist(args[:content_type]) }
    else
      %{ request | content_type: args[:content_type] }
    end

    keys = [:timeout, :connect_timeout, :autoredirect]
	http_options = Enum.filter_map keys, fn key ->
      args[key]
	end, fn key ->
      Tuple.append(Tuple.append({}, key), args[key])
	end
    %{ request | http_options: http_options }

    if args[:debug] do
      IO.puts "------------ DEBUG --------------"
      IO.inspect request
      IO.puts "------------ DEBUG --------------"
    end

    request
  end
end