-module(nitro_static).
-description('NITRO Static bridge for MAD containers').
-author('Maxim Sokhatsky').
-compile(export_all).
-include_lib("kernel/include/file.hrl").

init(_, _, _) -> {upgrade, protocol, cowboy_rest}.

rest_init(Req, {dir, Path, Extra}) when is_binary(Path) -> rest_init(Req, {dir, binary_to_list(Path), Extra});
rest_init(Req, {dir, Path, Extra}) ->
    {PathInfo, Req2} = cowboy_req:path_info(Req),
    Info = {ok, #file_info{type=regular,size=0}},
    FileName = filename:join([Path|PathInfo]),
    {ok, Req2, {FileName, Info, Extra}}.

malformed_request(Req, State) -> {State =:= error, Req, State}.

forbidden(Req, State={_, {ok, #file_info{type=directory}}, _}) -> {true, Req, State};
forbidden(Req, State={_, {error, eacces}, _}) -> {true, Req, State};
forbidden(Req, State={_, {ok, #file_info{access=Access}}, _}) when Access =:= write; Access =:= none -> {true, Req, State};
forbidden(Req, State) -> {false, Req, State}.



fixpath(Path) -> {Module,Fun} = application:get_env(n2o,fixpath,{nitro_static,fix}),
                 Module:Fun(Path).

fix(A) -> A.

content_types_provided(Req, State={Path, _, Extra}) ->
    case lists:keyfind(mimetypes, 1, Extra) of
         false -> {[{cow_mimetypes:web(Path), get_file}], Req, State};
         {mimetypes, Module, Function} ->
            {[{Module:Function(fixpath(Path)), get_file}], Req, State};
         {mimetypes, Type} -> {[{Type, get_file}], Req, State}
    end.

resource_exists(Req, State={_, {ok, #file_info{type=regular}}, _}) -> {true, Req, State};
resource_exists(Req, State) -> {false, Req, State}.

generate_etag(Req, State={Path, {ok, #file_info{size=Size, mtime=Mtime}}, Extra}) ->
    case lists:keyfind(etag, 1, Extra) of
         false -> {generate_default_etag(Size, Mtime), Req, State};
         {etag, Module, Function} -> {Module:Function(Path, Size, Mtime), Req, State};
         {etag, false} -> {undefined, Req, State}
    end.

generate_default_etag(Size, Mtime) ->
    {strong, list_to_binary(integer_to_list(erlang:phash2({Size, Mtime}, 16#ffffffff)))}.

last_modified(Req, State={_, {ok, #file_info{mtime=Modified}}, _}) -> {Modified, Req, State}.

get_file(Req, State={P, {ok, #file_info{size=_Size}}, _}) ->
    Path = fixpath(P),
    StringPath = nitro:to_list(unicode:characters_to_binary(Path,utf8,utf8)),
    [_Type,Name|RestPath] = filename:split(StringPath),
    FileName = filename:absname(StringPath),
    Raw = case file:read_file(FileName) of
          {ok,Bin} -> Bin;
          {error,_} ->
              case mad_repl:load_file(StringPath) of
                   {ok,ETSFile} -> ETSFile;
                   {error,_} ->
                        case file:read_file(filename:join([code:lib_dir(Name)|RestPath])) of
                             {ok,ReleaseFile} -> ReleaseFile;
                             {error,_} -> <<>> end end end,
    Sendfile = fun (Socket, Transport) -> Transport:send(Socket, Raw) end,
    {{stream, size(Raw), Sendfile}, Req, State}.