-module(lr3_comp_util).

-export([config/2,
         copy_app_src/1,
         out_dir/0, out_dir/1, relative_out_dir/1,
         include_dir/0, include_dir/1,
         ensure_dir/1,
         get_apps/1,
         get_first_files/2,
         get_src_dirs/2,
         relative/1]).

%% -spec config(file:dirname(), dict:dict()) -> dict:dict().
config(OutDir, Config) ->
    Key      = lfe_opts,
    Defaults = [{outdir, OutDir}] ++ rebar_opts:erl_opts(Config) ++
        [{i, include_dir()}, return, verbose],
    case dict:is_key(Key, Config) of
        true  -> dict:append_list(Key, Defaults, Config);
        false -> dict:store(Key, Defaults, Config)
    end.

copy_app_src(AppInfo) ->
    rebar_api:debug("\t\tEntered copy_app_src/1 ...", []),
    AppOutDir  = rebar_app_info:out_dir(AppInfo),
    AppSrcFile = rebar_app_info:app_file_src(AppInfo),
    AppFile    = rebar_app_utils:app_src_to_app(AppOutDir, AppSrcFile),
    rebar_api:debug("\t\tAppOutDir: ~p", [AppOutDir]),
    rebar_api:debug("\t\tAppSrcFile: ~p", [AppSrcFile]),
    rebar_api:debug("\t\tAppFile: ~p", [AppFile]),
    rebar_api:debug("\t\tCopying ~p to ~p ...", [AppSrcFile, AppFile]),
    copy_file(AppSrcFile, AppFile).

copy_file(Src, Dst) ->
    case file:copy(Src, Dst) of
        {ok, BytesCopied} ->
            rebar_api:debug("\t\tCopied ~p bytes.", [BytesCopied]);
        {error, Reason} ->
            rebar_api:error("\t\tFailed to copy ~p: ~p", [Src, Reason])
    end.

out_dir()                 -> "ebin".
out_dir(AppDir)           -> filename:join(AppDir, "ebin").
relative_out_dir(AppInfo) -> out_dir(rebar_app_info:out_dir(AppInfo)).

include_dir()             -> "include".
include_dir(AppDir)       -> filename:join(AppDir, "include").

-spec ensure_dir(file:dirname()) -> ok.
ensure_dir(OutDir) ->
    %% Make sure that ebin/ exists and is on the path
    ok = filelib:ensure_dir(filename:join(OutDir, "dummy.beam")),
    AbsOutDir = filename:absname(OutDir),
    rebar_api:debug("\t\tAdding ~p to path ...", [AbsOutDir]),
    true = code:add_patha(AbsOutDir),
    ok.

get_apps(State) ->
    case rebar_state:current_app(State) of
        undefined ->
            rebar_api:debug("\tCurrent app state is undefined ...", []),
            rebar_state:project_apps(State);
        AppInfo ->
            rebar_api:debug("\tConverting current app state to list ...", []),
            [AppInfo]
    end.

get_first_files(Opts, AppDir) ->
    Dirs = rebar_opts:get(Opts, lfe_first_files, []),
    [filename:join(AppDir, Dir) || Dir <- Dirs].

get_src_dirs(AppDir, Dirs) ->
    rebar_api:debug("\tDirs: ~p", [Dirs]),
    lists:usort([filename:join(AppDir, DirName) || DirName <- Dirs]).

relative(Filename) ->
    {ok, Cwd} = file:get_cwd(),
    re:replace(Filename, Cwd, ".", [{return,list}]).