#!/usr/bin/env escript

%% This script reads up emqx.conf and split the sections
%% and dump sections to separate files.
%% Sections are grouped between CONFIG_SECTION_BGN and
%% CONFIG_SECTION_END pairs
%%
%% NOTE: this feature is so far not used in opensource
%% edition due to backward-compatibility reasons.

-mode(compile).
-define(APPS, ["emqx", "emqx_dashboard", "emqx_auth"]).

main(_) ->
    {ok, BaseConf} = file:read_file("apps/emqx_conf/etc/emqx_conf.conf"),
    Cfgs = get_all_cfgs("apps/"),
    Conf = [
        merge(BaseConf, Cfgs),
        io_lib:nl()
    ],
    ok = file:write_file("apps/emqx_conf/etc/emqx.conf.all", Conf),
    merge_desc_files().

merge(BaseConf, Cfgs) ->
    Confs = [BaseConf | lists:map(fun read_conf/1, Cfgs)],
    infix(lists:filter(fun(I) -> iolist_size(I) > 0 end, Confs), [io_lib:nl()]).

read_conf(CfgFile) ->
    case filelib:is_regular(CfgFile) of
        true ->
            {ok, Bin1} = file:read_file(CfgFile),
            string:trim(Bin1, both);
        false ->
            <<>>
    end.

infix([], _With) -> [];
infix([One], _With) -> [One];
infix([H | T], With) -> [H, With, infix(T, With)].

get_all_cfgs(Root) ->
    Apps0 = filelib:wildcard("*", Root) -- ["emqx_machine", "emqx_conf"],
    Apps1 = (Apps0 -- ?APPS) ++ lists:reverse(?APPS),
    Dirs = [filename:join([Root, App]) || App <- Apps1],
    lists:foldl(fun get_cfgs/2, [], Dirs).

get_all_cfgs(Dir, Cfgs) ->
    Fun = fun(E, Acc) ->
        Path = filename:join([Dir, E]),
        get_cfgs(Path, Acc)
    end,
    lists:foldl(Fun, Cfgs, filelib:wildcard("*", Dir)).

get_cfgs(Dir, Cfgs) ->
    case filelib:is_dir(Dir) of
        false ->
            Cfgs;
        _ ->
            Files = filelib:wildcard("*", Dir),
            case lists:member("etc", Files) of
                false ->
                    try_enter_child(Dir, Files, Cfgs);
                true ->
                    EtcDir = filename:join([Dir, "etc"]),
                    %% the conf name must start with emqx
                    %% because there are some other conf, and these conf don't start with emqx
                    Confs = filelib:wildcard("emqx*.conf", EtcDir),
                    NewCfgs = [filename:join([EtcDir, Name]) || Name <- Confs],
                    try_enter_child(Dir, Files, NewCfgs ++ Cfgs)
            end
    end.

try_enter_child(Dir, Files, Cfgs) ->
    case lists:member("src", Files) of
        false ->
            Cfgs;
        true ->
            get_all_cfgs(filename:join([Dir, "src"]), Cfgs)
    end.

%% Merge English descriptions.
%% other translations are downloaded in pre-compile.sh
merge_desc_files() ->
    BaseConf = <<"">>,
    Cfgs0 = get_all_desc_files(),
    Conf = do_merge_desc_files(BaseConf, Cfgs0),
    OutputFile = "apps/emqx_dashboard/priv/desc.en.hocon",
    ok = filelib:ensure_dir(OutputFile),
    ok = file:write_file(OutputFile, Conf).

do_merge_desc_files(BaseConf, Cfgs) ->
    lists:foldl(
        fun(CfgFile, Acc) ->
            case filelib:is_regular(CfgFile) of
                true ->
                    {ok, Bin1} = file:read_file(CfgFile),
                    [Acc, io_lib:nl(), Bin1];
                false ->
                    Acc
            end
        end,
        BaseConf,
        Cfgs
    ).

get_all_desc_files() ->
    Dir = filename:join(["rel", "i18n"]),
    Files = filelib:wildcard("*.hocon", Dir),
    lists:map(fun(Name) -> filename:join([Dir, Name]) end, Files).