-module(ephp_shutdown).

-author('manuel@altenwald.com').

-include("ephp.hrl").

%% ------------------------------------------------------------------
%% API Function Exports
%% ------------------------------------------------------------------

-export([start_link/0, destroy/1, register_func/3, unregister_func/3, get_funcs/1,
         shutdown/1]).

%% ------------------------------------------------------------------
%% API Function Definitions
%% ------------------------------------------------------------------

-spec start_link() -> {ok, reference()}.
start_link() ->
    Ref = make_ref(),
    erlang:put(Ref, []),
    {ok, Ref}.

-spec destroy(ephp:shutdown_id()) -> ok.
destroy(Ref) ->
    erlang:erase(Ref),
    ok.

-spec register_func(reference(), ephp_ns:namespace(), callable()) -> ok.
register_func(Ref, NS, FuncName) ->
    erlang:put(Ref, erlang:get(Ref) ++ [{NS, FuncName}]),
    ok.

-spec unregister_func(reference(), ephp_ns:namespace(), callable()) -> ok.
unregister_func(Ref, NS, FuncName) ->
    erlang:put(Ref, erlang:get(Ref) -- [{NS, FuncName}]),
    ok.

-spec get_funcs(reference()) -> [callable()].
get_funcs(Ref) ->
    erlang:get(Ref).

-spec shutdown(ephp:context_id()) -> undefined.
shutdown(Context) ->
    Line = {{line, 0}, {column, 0}},
    Result =
        lists:foldl(fun ({NS, FuncName}, false) ->
                            Shutdown =
                                #call{name = FuncName,
                                      namespace = NS,
                                      line = Line},
                            Eval = #eval{statements = [Shutdown], line = Line},
                            ephp_interpr:run(Context, Eval);
                        (_, Break) ->
                            Break
                    end,
                    false,
                    ephp_context:get_shutdown_funcs(Context)),
    if Result =:= false ->
           ephp_object:remove_all(Context, ephp_context:get_objects(Context)),
           ephp_vars:destroy(Context, ephp_context:get_vars(Context));
       true ->
           undefined
    end.