wm_elm.erl

-module(wm_elm).
-compile(export_all).
%-compile({parse_transform, ct_expand}).
%-pt_pp_src(false).
-include_lib("webmachine/include/webmachine.hrl").

-include("squaretarget.hrl").
-spec(routes() ->[webmachine_dispatcher:route()]).
-type rd() :: wrq:reqdata().

-type elm_file() :: elm|elm_trial.
-type state() :: term().
-ifndef(DEV).
-compile({parse_transform, ct_expand}).
-define(PT(X),ct_expand:term(X)).
-else.
-define(PT(X),identity(X)).
-endif.

identity(X) ->
    X.

routes() ->
    [
     {["elm-front.js"],  ?MODULE, ['elm_front']}
    ,{["elm-reset.js"], ?MODULE, ['elm_reset']}
    ,{["elm-dashboard.js"], ?MODULE, ['elm_dashboard']}
    ,{["elm-dashboard-login.js"], ?MODULE, ['elm_dashboard_login']}
    ].



-spec( init([elm_file()]) -> {?INIT_RETURN_TYPE, elm_file()}).
init([File]) ->
    {?INIT_RETURN_CODE, File }.


resource_exists(RD, State) ->
    {true, RD, State}.



-spec encodings_provided(rd(), state()) -> {[{Encoding::string(), Encoder}], rd(), state()}
           when Encoder :: fun((iodata()) -> iodata()).
encodings_provided(ReqData, State) ->
    {[{"identity", fun(X) -> X end},
      {"gzip", fun(X) -> zlib:gzip(X) end}],
     ReqData, State}.


% IN dev mode we load the elm from disk, in prod load it from the beam file
-spec to_javascript(wrq:reqdata(), term()) -> {iodata(), wrq:reqdata(), term()}.

to_javascript(ReqData, State) ->
    lager:debug("Load Elm", []),

    {ok, Elm} = case State of
                    elm_front           -> ?PT(elm_front_live());
                    elm_reset           -> ?PT(elm_reset_live());
                    elm_dashboard       -> ?PT(elm_dashboard_live());
                    elm_dashboard_login -> ?PT(elm_dashboard_login_live())
                end,

    {Elm, ReqData, State}.


-spec generate_etag(rd(), state()) -> {string() | undefined, rd(), state()}.
generate_etag(RD, State= elm_front) ->
    {?PT(etag(elm_front)), RD, State};
generate_etag(RD, State= elm_reset) ->
    {?PT(etag(elm_reset)), RD, State};
generate_etag(RD, State= elm_dashboard) ->
    {?PT(etag(elm_dashboard)), RD, State};
generate_etag(RD, State= elm_dashboard_login) ->
    {?PT(etag(elm_dashboard_login)), RD, State}.






-spec content_types_provided(wrq:reqdata(), state()) -> {[{MediaType::string(), Handler::atom()}], wrq:reqdata(), state()}.
content_types_provided(ReqData, State) ->
    {[{"application/javascript", to_javascript}],ReqData,State}.



etag(elm_front) ->
    {ok, Data} = elm_front_live(),
    binary_to_list(base64:encode(crypto:hash(md5,Data)));
etag(elm_reset) ->
    {ok, Data} =elm_reset_live(),
    binary_to_list(base64:encode(crypto:hash(md5,Data)));
etag(elm_dashboard) ->
    {ok, Data} =elm_dashboard_live(),
    binary_to_list(base64:encode(crypto:hash(md5,Data)));
etag(elm_dashboard_login) ->
    {ok, Data} =elm_dashboard_login_live(),
    binary_to_list(base64:encode(crypto:hash(md5,Data))).





elm_front_live() ->
    PrivDir    = code:priv_dir('squaretarget'),
    Filename   = filename:join([PrivDir, "elm-front.js"]),
    {ok, Data} = file:read_file(Filename),
    {ok, Data}.




elm_reset_live() ->
    PrivDir    = code:priv_dir('squaretarget'),
    Filename   = filename:join([PrivDir, "elm-reset.js"]),
    {ok, Data} = file:read_file(Filename),
    {ok, Data}.


elm_dashboard_live() ->
    PrivDir    = code:priv_dir('squaretarget'),
    Filename   = filename:join([PrivDir, "elm-dashboard.js"]),
    {ok, Data} = file:read_file(Filename),
    {ok, Data}.


elm_dashboard_login_live() ->
    PrivDir    = code:priv_dir('squaretarget'),
    Filename   = filename:join([PrivDir, "elm-dashboard-login.js"]),
    {ok, Data} = file:read_file(Filename),
    {ok, Data}.