-module(ephp_include).

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

-include("ephp.hrl").

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

-export([start_link/0, load_once/2, load/2, destroy/1]).

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

start_link() ->
    Ref = make_ref(),
    erlang:put(Ref, dict:new()),
    {ok, Ref}.

load_once(Ref, Name) ->
    Inc = erlang:get(Ref),
    case dict:find(Name, Inc) of
        {ok, _Value} ->
            {return, true};
        error ->
            case find_file(Name) of
                {error, enoent} ->
                    {error, enoent};
                {ok, File, Content} ->
                    FullPath = filename:join([ephp_stream:get_initial_path(), File]),
                    Value = ephp_parser:parse(FullPath, Content),
                    erlang:put(Ref, dict:store(Name, Value, Inc)),
                    Value
            end
    end.

load(Ref, Name) ->
    Inc = erlang:get(Ref),
    case dict:find(Name, Inc) of
        {ok, Value} ->
            Value;
        error ->
            case find_file(Name) of
                {error, enoent} ->
                    {error, enoent};
                {ok, File, Content} ->
                    FullPath = filename:join([ephp_stream:get_initial_path(), File]),
                    Value = ephp_parser:parse(FullPath, Content),
                    erlang:put(Ref, dict:store(Name, Value, Inc)),
                    Value
            end
    end.

destroy(Inc) ->
    erlang:erase(Inc),
    ok.

%% ----------------------------------------------------------------------------
%% Internal functions
%% ----------------------------------------------------------------------------

get_paths() ->
    IncludePath = ephp_config:get(<<"include_path">>, <<".:">>),
    binary:split(IncludePath, ?PATH_SEP, [global]).

find_file(Name) ->
    lists:foldl(fun (<<>>, FullPath) ->
                        FullPath;
                    (Path, {error, enoent}) ->
                        FullPath = filename:join(Path, Name),
                        case ephp_stream:read_file(FullPath) of
                            {ok, Content} ->
                                {ok, FullPath, Content};
                            Else ->
                                Else
                        end;
                    (_, FullPath) ->
                        FullPath
                end,
                {error, enoent},
                get_paths()).