-module(rebar_path_resource).

-export([init/2,
         lock/2,
         download/4, download/3,
         needs_update/2,
         make_vsn/1]).

-include_lib("kernel/include/file.hrl").

init(Type, _State) ->
   Resource = rebar_resource_v2:new(Type, ?MODULE, #{}),
   {ok, Resource}.

lock(Dir, Source) when is_tuple(Source) ->
  lock_(Dir, Source);

lock(AppInfo, _) ->
  lock_(rebar_app_info:dir(AppInfo), rebar_app_info:source(AppInfo)).

lock_(Dir, {path, Path, _}) ->
  lock_(Dir, {path, Path});

lock_(_Dir, {path, Path}) ->
  {ok, Cwd} = file:get_cwd(),
  Source = filename:join([Cwd, Path]),
  {path, Path, {mtime, to_iso8601(last_modified(Source))}}.

download(TmpDir, {path, Path, _}, State) ->
  download(TmpDir, {path, Path}, State);
download(TmpDir, {path, Path}, State) ->
  case download_(TmpDir, {path, Path}, State) of
    ok -> {ok, State};
    Error -> Error
  end.

download(TmpDir, AppInfo, State, _) ->
  case rebar_app_info:source(AppInfo) of
    {path, Path} ->
      download_(TmpDir, {path, Path}, State);
    {path, Path, _} ->
      download_(TmpDir, {path, Path}, State)
  end.

download_(Dir, {path, Path}, _State) ->
  ok = filelib:ensure_dir(Dir),
  {ok, Cwd} = file:get_cwd(),
  Source = filename:join([Cwd, Path]),
  ok = ec_file:copy(Source, Dir, [recursive, {file_info, [mode, time, owner, group]}]),
  rebar_log:log(debug, "copied source from=~p, to=~p ~n", [Path, Dir]),
  LastModified = last_modified(Source),
  {ok, A} = file:read_file_info(Dir),
  file:write_file_info(Path, A#file_info{mtime = LastModified, atime = LastModified}).


make_vsn(_Dir) ->
  {error, "Replacing version of type path not supported."}.

needs_update(Dir, {path, Path, _}) ->
  needs_update_(Dir, {path, Path});
needs_update(AppInfo, _) ->
  needs_update_(rebar_app_info:dir(AppInfo), rebar_app_info:source(AppInfo)).

needs_update_(Dir, {path, Path}) ->
  {ok, Cwd} = file:get_cwd(),
  Source = filename:join([Cwd, Path]),
  LastModified = last_modified(Source),
  Old = filelib:last_modified(Dir),
  rebar_log:log(debug, "compare dir=~p, path=~p last modified=~p, old=~p~n", [Dir, Path, LastModified, Old]),
  (Old < LastModified).


last_modified(Source) ->
  Files = filter_files(dir_files(Source)),
  last_modified_(Files).

last_modified_([]) -> calendar:local_time();
last_modified_(Files) ->
  lists:foldl(
    fun(Path, OldT) ->
        T = filelib:last_modified(Path),
        if
          T > OldT -> T;
          true -> OldT
        end
    end,
    0,
    Files).

to_iso8601({{Y,Mo,D}, {H,Mn,S}}) ->
    FmtStr = "~4.10.0B-~2.10.0B-~2.10.0BT~2.10.0B:~2.10.0B:~2.10.0BZ",
    IsoStr = io_lib:format(FmtStr, [Y, Mo, D, H, Mn, S]),
    list_to_binary(IsoStr).


dir_files(Path) ->
  case filelib:is_dir(Path) of
    true ->
      filelib:wildcard(filename:join(Path, "**"));
    false ->
      [Path]
  end.


filter_files(Files) ->
    lists:filter(fun is_excluded/1, [filename:absname(F) || F <- Files]).


is_excluded(Path) ->
      KnownExcludes = [
                     "^.",
                     "~$"
                      ],

      lists:foldl(fun(_, true) -> true;
                     (RE, false) ->
                      (re:run(Path, RE) =/= nomatch) orelse (filelib:is_regular (Path) /= true)
                  end, false, KnownExcludes).