-module(elvis_result).

-compile({no_auto_import, [error/2]}).

%% API
-export([
         new/3,
         new/4,
         status/1,
         clean/1,
         print_results/1
        ]).

-export([
         get_path/1,
         get_rules/1,
         get_name/1,
         get_items/1,
         get_message/1,
         get_info/1,
         get_line_num/1
        ]).

%% Types
-export_type([
              item/0,
              rule/0,
              file/0
             ]).

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Records
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

-type item() ::
        #{
           message => string(),
           info => iodata(),
           line_num => integer()
         }.
-type rule() ::
        #{
           name => atom(),
           items => [item()]
         }.
-type file() ::
        #{
           file => string(),
           rules => [rule()]
         }.
-type elvis_error() ::
        #{
           error_msg => string(),
           info => list()
         }.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Public
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%% New

-spec new(item, string(), [term()]) -> item()
       ; (rule, atom(), [item()]) -> rule()
       ; (file, elvis_file:file(), [elvis_error() | rule()]) -> file()
       ; (error, string(), string()) -> elvis_error().
new(item, Msg, Info) ->
    new(item, Msg, Info, 0);
new(rule, Name, Results) ->
    #{name => Name, items => Results};
new(file, #{path := Path}, Rules) ->
    #{file => Path, rules => Rules};
new(error, Msg, Info) ->
    #{error_msg => Msg, info => Info}.

-spec new(item, string(), [term()], integer()) -> item().
new(item, Msg, Info, LineNum) ->
    #{message => Msg,
      info => Info,
      line_num => LineNum}.

%% Getters

-spec get_path(file()) -> string().
get_path(#{file := File}) -> File.

-spec get_rules(file()) -> [rule()].
get_rules(#{rules := Rules}) -> Rules.

-spec get_name(rule()) -> atom().
get_name(#{name := Name}) -> Name.

-spec get_items(rule()) -> [item()].
get_items(#{items := Items}) -> Items;
get_items(_) -> [].

-spec get_message(item()) -> string().
get_message(#{message := Message}) -> Message.

-spec get_info(item()) -> string().
get_info(#{info := Info}) -> Info.

-spec get_line_num(item()) -> integer().
get_line_num(#{line_num := LineNum}) -> LineNum.

%% Print

-spec print_results(file()) -> ok.
print_results(Results) ->
    Format = application:get_env(elvis_core, output_format, colors),
    print(Format, Results).

-spec print(plain | colors | parsable, [file()] | file()) -> ok.
print(_, []) ->
    ok;
print(Format, [Result | Results]) ->
    print(Format, Result),
    print(Format, Results);
%% File
print(Format, #{file := Path, rules := Rules}) ->
    case Format of
        parsable -> ok;
        _ ->
            case status(Rules) of
                ok ->
                    elvis_utils:notice("# ~s [{{green-bold}}OK{{white-bold}}]", [Path]);
                fail ->
                    elvis_utils:error("# ~s [{{red-bold}}FAIL{{white-bold}}]", [Path])
            end
    end,
    print_rules(Format, Path, Rules);
print(_, Error) ->
    print_error(Error).

print_rules(_Format, _File, []) ->
    ok;
print_rules(Format, File, [#{items := []} | Items]) ->
    print_rules(Format, File, Items);
print_rules(Format, File, [#{items := Items, name := Name} | EItems]) ->
    case Format of
        parsable -> ok;
        _ ->
            elvis_utils:error("  - ~s", [atom_to_list(Name)])
    end,
    print_item(Format, File, Name, Items),
    print_rules(Format, File, EItems);
print_rules(Format, File, [Error | Items]) ->
    print_error(Error),
    print_rules(Format, File, Items).

%% Item
print_item(Format, File, Name, [#{message := Msg, line_num := Ln, info := Info} | Items]) ->
    case Format of
        parsable ->
            FMsg = io_lib:format(Msg, Info),
            io:format("~s:~p:~p:~s~n", [File, Ln, Name, FMsg]);
        _ ->
            elvis_utils:error("    - " ++ Msg, Info)
    end,
    print_item(Format, File, Name, Items);
print_item(Format, File, Name, [Error|Items]) ->
    print_error(Error),
    print_item(Format, File, Name, Items);
print_item(_Format, _File, _Name, []) ->
    ok.

print_error(#{error_msg := Msg, info := Info}) ->
    elvis_utils:error_prn(Msg, Info).

-spec status([file() | rule()]) -> ok | fail.
status([]) ->
    ok;
status([#{rules := Rules} | Files]) ->
    case status(Rules) of
        fail -> fail;
        ok -> status(Files)
    end;
status([#{items := []} | Rules]) ->
    status(Rules);
status(_Rules) ->
    fail.


%% @doc Removes files that don't have any failures.
-spec clean([file() | rule()]) -> [file() | rule()].
clean(Files)->
    clean(Files, []).

%% @private
-spec clean([file() | rule()], [file() | rule()]) -> [file() | rule()].
clean([], Result) ->
    lists:reverse(Result);
clean([#{rules := []} | Files], Result) ->
    clean(Files, Result);
clean([File = #{rules := Rules} | Files], Result) ->
    CleanRules = clean(Rules),
    NewFile = File#{rules => CleanRules},
    clean(Files, [NewFile | Result]);
clean([#{items := []} | Rules], Result) ->
    clean(Rules, Result);
clean([Rule | Rules], Result) ->
    clean(Rules, [Rule | Result]).