#!/usr/bin/env escript

main([File]) ->
    Dir = get_root(filename:dirname(File)),
    Defs = [strong_validation,
            warn_export_all,
            warn_export_vars,
            warn_shadow_vars,
            warn_obsolete_guard,
            warn_unused_import,
            report,
            {i, Dir ++ "/include"}],
    RebarFile = rebar_file(Dir),
    RebarOpts = rebar_opts(Dir ++ "/" ++ RebarFile),
    code:add_patha(filename:absname("ebin")),
    compile:file(File, Defs ++ RebarOpts);

main(_) ->
    io:format("Usage: ~s <file>~n", [escript:script_name()]),
    halt(1).

rebar_file(Dir) ->
    DirList = filename:split(Dir),
    case lists:last(DirList) of
        "test" ->
            "rebar.test.config";
        _ ->
            "rebar.config"
    end.

rebar_opts(RebarFile) ->
    Dir = get_root(filename:dirname(RebarFile)),
    case file:consult(RebarFile) of
        {ok, Terms} ->
            RebarLibDirs = proplists:get_value(lib_dirs, Terms, []),
            lists:foreach(
                fun(LibDir) ->
                        code:add_pathsa(filelib:wildcard(LibDir ++ "/*/ebin"))
                end, RebarLibDirs),
            RebarDepsDir = proplists:get_value(deps_dir, Terms, "deps"),
            code:add_pathsa(filelib:wildcard(RebarDepsDir ++ "/*/ebin")),
            IncludeDeps = {i, filename:join(Dir, RebarDepsDir)},
            proplists:get_value(erl_opts, Terms, []) ++ [IncludeDeps];
        {error, _} when RebarFile == "rebar.config" ->
          fallback_opts();
        {error, _} ->
            rebar_opts("rebar.config")
    end.

fallback_opts() ->
    code:add_pathsa(filelib:wildcard("deps/*/ebin")),
    code:add_pathsa(nested_app_ebins()),
    [ { i, filename:absname("deps") }
      | [ { i, filename:absname(Path) } || Path <- filelib:wildcard("deps/*/apps")]
    ].

nested_app_ebins() ->
    DetectedAppSrcFiles = filelib:wildcard("deps/*/apps/**/*.app.src"),
    [apps_dir_from_src(AppSrcFile)||AppSrcFile<-DetectedAppSrcFiles].

apps_dir_from_src(SrcFile) ->
    SrcDir = filename:dirname(SrcFile),
    filename:join(SrcDir, "../../ebin").

get_root(Dir) ->
    Path = filename:split(filename:absname(Dir)),
    filename:join(get_root(lists:reverse(Path), Path)).

get_root([], Path) ->
    Path;
get_root(["src" | Tail], _Path) ->
    lists:reverse(Tail);
get_root(["test" | Tail], _Path) ->
    lists:reverse(Tail);
get_root([_ | Tail], Path) ->
    get_root(Tail, Path).