relx

%% -*- erlang-indent-level: 4; indent-tabs-mode: nil; fill-column: 80 -*-
%%% Copyright 2012 Erlware, LLC. All Rights Reserved.
%%%
%%% This file is provided to you under the Apache License,
%%% Version 2.0 (the "License"); you may not use this file
%%% except in compliance with the License.  You may obtain
%%% a copy of the License at
%%%
%%%   http://www.apache.org/licenses/LICENSE-2.0
%%%
%%% Unless required by applicable law or agreed to in writing,
%%% software distributed under the License is distributed on an
%%% "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
%%% KIND, either express or implied.  See the License for the
%%% specific language governing permissions and limitations
%%% under the License.
%%%-------------------------------------------------------------------
%%% @author Eric Merritt <ericbmerritt@gmail.com>
%%% @copyright 2011 Erlware, LLC.
%%% @doc
%%%  A module that provides config parsing and support to the system
%%% @end
%%%-------------------------------------------------------------------
-module(rlx_config).

%% API
-export([do/1,
         format_error/1]).

-export([load_terms/2]).

-include("relx.hrl").

%%%===================================================================
%%% API
%%%===================================================================

%% @doc parse all the configs currently specified in the state,
%% populating the state as a result.
-spec do(rlx_state:t()) ->{ok,  rlx_state:t()} | relx:error().
do(State) ->
    case rlx_state:config_file(State) of
        [] ->
            search_for_dominating_config(State);
        undefined ->
            search_for_dominating_config(State);
        ConfigFile when erlang:is_list(ConfigFile) ->
            load_config(ConfigFile, State)
    end.

-spec format_error(Reason::term()) -> iolist().
format_error({consult, ConfigFile, Reason}) ->
    io_lib:format("Unable to read file ~s: ~s", [ConfigFile,
                                                 file:format_error(Reason)]);
format_error({invalid_term, Term}) ->
    io_lib:format("Invalid term in config file: ~p", [Term]).

%%%===================================================================
%%% Internal Functions
%%%===================================================================
search_for_dominating_config({ok, Cwd}) ->
    ConfigFile = filename:join(Cwd, "relx.config"),
    case ec_file:exists(ConfigFile) of
        true ->
            {ok, ConfigFile};
        false ->
            search_for_dominating_config(parent_dir(Cwd))
    end;
search_for_dominating_config({error, _}) ->
    no_config;
search_for_dominating_config(State0) ->
    {ok, Cwd} = file:get_cwd(),
    case search_for_dominating_config({ok, Cwd}) of
        {ok, Config} ->
            %% we need to set the root dir on state as well
            {ok, RootDir} = parent_dir(Config),
            State1 = rlx_state:root_dir(State0, RootDir),
            load_config(Config, rlx_state:config_file(State1, Config));
        no_config ->
            {ok, State0}
    end.

%% @doc Given a directory returns the name of the parent directory.
-spec parent_dir(Filename::string()) ->
                        {ok, DirName::string()} | {error, no_parent_dir}.
parent_dir(Filename) ->
    parent_dir(filename:split(Filename), []).

%% @doc Given list of directories, splits the list and returns all dirs but the
%%  last as a path.
-spec parent_dir([string()], [string()]) ->
                        {ok, DirName::string()} | {error, no_parent_dir}.
parent_dir([_H], []) ->
    {error, no_parent_dir};
parent_dir([], []) ->
    {error, no_parent_dir};
parent_dir([_H], Acc) ->
    {ok, filename:join(lists:reverse(Acc))};
parent_dir([H | T], Acc) ->
    parent_dir(T, [H | Acc]).

-spec config_script_file(file:filename(), rlx_state:t()) -> file:filename().
config_script_file(ConfigFile, _State) ->
    ConfigFile ++ ".script".

bs(Vars) ->
    lists:foldl(fun({K,V}, Bs) ->
                        erl_eval:add_binding(K, V, Bs)
                end, erl_eval:new_bindings(), Vars).

-spec apply_config_script(proplists:proplist(), file:filename()) ->
                                proplists:proplist().
apply_config_script(ConfigData, ConfigScriptFile) ->
    {ok, Config} = file:script(ConfigScriptFile, bs([{'CONFIG', ConfigData},
                                                     {'SCRIPT', ConfigScriptFile}])),
    Config.

-spec load_config(file:filename() | proplists:proplist(), rlx_state:t()) ->
                         {ok, rlx_state:t()} | relx:error().
load_config(ConfigFile, State) ->
    {ok, CurrentCwd} = file:get_cwd(),
    CliTerms = rlx_state:cli_args(State),
    Config0 = case filelib:is_regular(ConfigFile) of
                true ->
                    ok = file:set_cwd(filename:dirname(ConfigFile)),
                    Result = case file:consult(ConfigFile) of
                                {error, Reason} ->
                                    ?RLX_ERROR({consult, ConfigFile, Reason});
                                {ok, Terms} -> merge_configs(CliTerms, Terms)
                             end,
                    ok = file:set_cwd(CurrentCwd),
                    Result;
                false -> merge_configs(CliTerms, ConfigFile)
              end,
    % we now take the merged config and try to apply a config script to it,
    % get a new config as a result
    case Config0 of
        {error, _} = Error -> Error;
        _ ->
            ConfigScriptFile = config_script_file(ConfigFile, State),
            Config1 = case filelib:is_regular(ConfigScriptFile) of
                        false -> Config0;
                        true -> apply_config_script(Config0, ConfigScriptFile)
                      end,
            lists:foldl(fun load_terms/2, {ok, State}, Config1)
    end.

-spec load_terms(term(), {ok, rlx_state:t()} | relx:error()) ->
                        {ok, rlx_state:t()} | relx:error().
load_terms({default_release, {RelName, RelVsn}}, {ok, State}) ->
    NewVsn = parse_vsn(RelVsn),
    {ok, rlx_state:default_configured_release(State, RelName, NewVsn)};
load_terms({paths, Paths}, {ok, State}) ->
    code:add_pathsa([filename:absname(Path) || Path <- Paths]),
    {ok, State};
load_terms({default_libs, DefaultLibs}, {ok, State}) ->
    State2 = rlx_state:put(State,
                           default_libs,
                           DefaultLibs),
    {ok, State2};
load_terms({lib_dirs, Dirs}, {ok, State}) ->
    State2 =
        rlx_state:add_lib_dirs(State,
                               [list_to_binary(Dir) || Dir <- rlx_util:wildcard_paths(Dirs)]),
    {ok, State2};
load_terms({hooks, Hooks}, {ok, State0}) ->
    add_hooks(Hooks, State0);
load_terms({providers, Providers0}, {ok, State0}) ->
    gen_providers(Providers0, State0);
load_terms({add_providers, Providers0}, {ok, State0}) ->
    gen_providers(Providers0, State0);
load_terms({skip_apps, SkipApps0}, {ok, State0}) ->
    {ok, rlx_state:skip_apps(State0, SkipApps0)};
load_terms({exclude_apps, ExcludeApps0}, {ok, State0}) ->
    {ok, rlx_state:exclude_apps(State0, ExcludeApps0)};
load_terms({debug_info, DebugInfo}, {ok, State0}) ->
    {ok, rlx_state:debug_info(State0, DebugInfo)};
load_terms({overrides, Overrides0}, {ok, State0}) ->
    {ok, rlx_state:overrides(State0, Overrides0)};
load_terms({dev_mode, DevMode}, {ok, State0}) ->
    {ok, rlx_state:dev_mode(State0, DevMode)};
load_terms({goals, Goals}, {ok, State0}) ->
    {ok, rlx_state:goals(State0, Goals)};
load_terms({upfrom, UpFrom}, {ok, State0}) ->
    {ok, rlx_state:upfrom(State0, UpFrom)};
load_terms({include_src, IncludeSrc}, {ok, State0}) ->
    {ok, rlx_state:include_src(State0, IncludeSrc)};
load_terms({release, {RelName, Vsn, {extend, RelName2}}, Applications}, {ok, State0}) ->
    NewVsn = parse_vsn(Vsn),
    Release0 = rlx_release:new(RelName, NewVsn),
    ExtendRelease = rlx_state:get_configured_release(State0, RelName2, NewVsn),
    Applications1 = rlx_release:goals(ExtendRelease),
    case rlx_release:goals(Release0,
                          lists:umerge(lists:usort(Applications),
                                      lists:usort(Applications1))) of
        E={error, _} ->
            E;
        {ok, Release1} ->
            {ok, rlx_state:add_configured_release(State0, Release1)}
        end;
load_terms({release, {RelName, Vsn, {extend, RelName2}}, Applications, Config}, {ok, State0}) ->
    NewVsn = parse_vsn(Vsn),
    Release0 = rlx_release:new(RelName, NewVsn),
    ExtendRelease = rlx_state:get_configured_release(State0, RelName2, NewVsn),
    Applications1 = rlx_release:goals(ExtendRelease),
    case rlx_release:goals(Release0,
                          lists:umerge(lists:usort(Applications),
                                      lists:usort(Applications1))) of
        E={error, _} ->
            E;
        {ok, Release1} ->
            Release2 = rlx_release:config(Release1, Config),
            {ok, rlx_state:add_configured_release(State0, Release2)}
        end;
load_terms({release, {RelName, Vsn}, {erts, ErtsVsn}, Applications}, {ok, State}) ->
    NewVsn = parse_vsn(Vsn),
    Release0 = rlx_release:erts(rlx_release:new(RelName, NewVsn), ErtsVsn),
    case rlx_release:goals(Release0, Applications) of
        E={error, _} ->
            E;
        {ok, Release1} ->
            {ok, rlx_state:add_configured_release(State, Release1)}
    end;
load_terms({release, {RelName, Vsn}, {erts, ErtsVsn}, Applications, Config}, {ok, State}) ->
    NewVsn = parse_vsn(Vsn),
    Release0 = rlx_release:erts(rlx_release:new(RelName, NewVsn), ErtsVsn),
    case rlx_release:goals(Release0, Applications) of
        E={error, _} ->
            E;
        {ok, Release1} ->
            Release2 = rlx_release:config(Release1, Config),
            {ok, rlx_state:add_configured_release(State, Release2)}
    end;
load_terms({release, {RelName, Vsn}, Applications}, {ok, State0}) ->
    NewVsn = parse_vsn(Vsn),
    Release0 = rlx_release:new(RelName, NewVsn),
    case rlx_release:goals(Release0, Applications) of
        E={error, _} ->
            E;
        {ok, Release1} ->
            {ok, rlx_state:add_configured_release(State0, Release1)}
        end;
load_terms({release, {RelName, Vsn}, Applications, Config}, {ok, State0}) ->
    NewVsn = parse_vsn(Vsn),
    Release0 = rlx_release:new(RelName, NewVsn),
    case rlx_release:goals(Release0, Applications) of
        E={error, _} ->
            E;
        {ok, Release1} ->
            Release2 = rlx_release:config(Release1, Config),
            {ok, rlx_state:add_configured_release(State0, Release2)}
        end;
load_terms({vm_args, VmArgs}, {ok, State}) ->
    {ok, rlx_state:vm_args(State, filename:absname(VmArgs))};
load_terms({sys_config, SysConfig}, {ok, State}) ->
    {ok, rlx_state:sys_config(State, filename:absname(SysConfig))};
load_terms({root_dir, Root}, {ok, State}) ->
    {ok, rlx_state:root_dir(State, filename:absname(Root))};
load_terms({output_dir, OutputDir}, {ok, State}) ->
    {ok, rlx_state:base_output_dir(State, filename:absname(OutputDir))};
load_terms({overlay_vars, OverlayVars}, {ok, State}) ->
    CurrentOverlayVars = rlx_state:get(State, overlay_vars),
    NewOverlayVars0 = list_of_overlay_vars_files(OverlayVars),
    NewOverlayVars1 = lists:umerge(lists:usort(NewOverlayVars0), lists:usort(CurrentOverlayVars)),
    {ok, rlx_state:put(State, overlay_vars, NewOverlayVars1)};
load_terms({Name, Value}, {ok, State})
  when erlang:is_atom(Name) ->
    {ok, rlx_state:put(State, Name, Value)};
load_terms(_, Error={error, _}) ->
    Error;
load_terms(InvalidTerm, _) ->
    ?RLX_ERROR({invalid_term, InvalidTerm}).

-spec gen_providers([module()], rlx_state:t()) ->
                           {ok, rlx_state:t()} | relx:error().
gen_providers(Providers, State) ->
    lists:foldl(fun(ProviderName, {ok, State1}) ->
                        providers:new(ProviderName, State1);
                   (_, E={_, {error, _}}) ->
                        E
                end, {ok, State}, Providers).

add_hooks(Hooks, State) ->
    {ok, lists:foldl(fun({pre, Target, Hook}, StateAcc) ->
                             rlx_state:prepend_hook(StateAcc, Target, Hook);
                        ({post, Target, Hook}, StateAcc) ->
                             rlx_state:append_hook(StateAcc, Target, Hook)
                     end, State, Hooks)}.

list_of_overlay_vars_files(undefined) ->
    [];
list_of_overlay_vars_files([]) ->
    [];
list_of_overlay_vars_files([H | _]=FileNames) when erlang:is_list(H) ->
    FileNames;
list_of_overlay_vars_files(FileName) when is_list(FileName) ->
    [FileName].

merge_configs([], ConfigTerms) ->
    ConfigTerms;
merge_configs([{_Key, undefined} | CliTerms], ConfigTerms) ->
    merge_configs(CliTerms, ConfigTerms);
merge_configs([{_Key, []} | CliTerms], ConfigTerms) ->
    merge_configs(CliTerms, ConfigTerms);
merge_configs([{Key, Value} | CliTerms], ConfigTerms) ->
    case Key of
        X when X =:= lib_dirs
             ; X =:= goals
             ; X =:= overlay_vars
             ; X =:= overrides ->
            case lists:keyfind(Key, 1, ConfigTerms) of
                {Key, Value2} ->
                    MergedValue = lists:umerge([Value, Value2]),
                    merge_configs(CliTerms, lists:keyreplace(Key, 1, ConfigTerms, {Key, MergedValue}));
                false ->
                    merge_configs(CliTerms, [{Key, Value} | ConfigTerms])
            end;
        _ ->
            merge_configs(CliTerms, lists:keystore(Key, 1, ConfigTerms, {Key, Value}))
    end.

parse_vsn(Vsn) when Vsn =:= semver ; Vsn =:= "semver" ->
    {ok, V} = ec_git_vsn:vsn([]),
    V;
parse_vsn({semver, _}) ->
    {ok, V} = ec_git_vsn:vsn([]),
    V;
parse_vsn({cmd, Command}) ->
    V = os:cmd(Command),
    V;
parse_vsn(Vsn) ->
    Vsn.