-module(nova_request_plugin).
-behaviour(nova_plugin).
-include_lib("kernel/include/logger.hrl").
-export([
pre_request/2,
post_request/2,
plugin_info/0
]).
%%--------------------------------------------------------------------
%% @doc
%% Pre-request callback
%% @end
%%--------------------------------------------------------------------
-spec pre_request(Req :: cowboy_req:req(), Options :: map()) ->
{ok, Req0 :: cowboy_req:req()}.
pre_request(Req, Options) ->
Options0 = nova_plugin_utilities:parse_options(Options),
{ok, _Req0} = modulate_state(Req, Options0).
%%--------------------------------------------------------------------
%% @doc
%% Post-request callback
%% @end
%%--------------------------------------------------------------------
-spec post_request(Req :: cowboy_req:req(), Options :: map()) ->
{ok, Req0 :: cowboy_req:req()}.
post_request(Req, _Options) ->
{ok, Req}.
%%--------------------------------------------------------------------
%% @doc
%% nova_plugin callback. Returns information about the plugin.
%% @end
%%--------------------------------------------------------------------
-spec plugin_info() -> {Title :: binary(),
Version :: binary(),
Author :: binary(),
Description :: binary(),
Options :: [{Key :: atom(), OptionDescription :: binary()}]}.
plugin_info() ->
{<<"Nova body plugin">>,
<<"0.0.1">>,
<<"Nova team <info@novaframework.org">>,
<<"This plugin modulates the body of a request.">>,
[
{parse_bindings, <<"Used to parse bindings and put them in state under `bindings` key">>},
{read_body, <<"Reads the body and put it under the `body`">>},
{decode_json_body, <<"Decodes the body as JSON and puts it under `json`">>},
{parse_qs, <<"Used to parse qs and put hem in state under `qs` key">>}
]}.
%%%%%%%%%%%%%%%%%%%%%%
%% Private functions
%%%%%%%%%%%%%%%%%%%%%%
modulate_state(Req, []) ->
{ok, Req};
modulate_state(Req = #{headers := #{<<"content-type">> := <<"application/json", _/binary>>}}, [decode_json_body|Tl]) ->
case cowboy_req:has_body(Req) of
true ->
%% First read in the body
{ok, Data, Req0} = cowboy_req:read_body(Req),
%% Decode the data
JSON = json:decode(Data, [maps, binary]),
modulate_state(Req0#{json => JSON}, Tl);
false ->
modulate_state(Req#{json => #{}}, Tl)
end;
modulate_state(#{headers := #{<<"content-type">> := <<"application/x-www-form-urlencoded", _/binary>>}} = Req,
[read_urlencoded_body|Tl]) ->
case cowboy_req:has_body(Req) of
true ->
%% First read in the body
{ok, Data, Req0} = cowboy_req:read_urlencoded_body(Req),
Params = maps:from_list(Data),
modulate_state(Req0#{params => Params}, Tl);
false ->
modulate_state(Req#{params => #{}}, Tl)
end;
modulate_state(Req, [parse_qs|T1]) ->
Qs = cowboy_req:parse_qs(Req),
MapQs = maps:from_list(Qs),
modulate_state(Req#{parsed_qs => MapQs}, T1);
modulate_state(Req, [read_body|Tl]) ->
%% Fetch the body
{ok, Data, Req0} = cowboy_req:read_body(Req),
modulate_state(Req0#{body => Data}, Tl);
modulate_state(State, [_|Tl]) ->
modulate_state(State, Tl).