-module(handler_banned_words).
-include("records.hrl").

-export([init/2]).

init(Req, Opts) ->
  handle(Req, Opts).

handle(Req, _Opts) ->
  case cowboy_req:method(Req) of
    <<"GET">> -> list_banned_words(Req);
    <<"POST">> -> add_banned_word(Req);
    <<"DELETE">> -> remove_banned_word(Req);
    _ -> send_error(Req, 405, <<"Method not allowed">>)
  end.

%% GET /v1/admin/banned-words - список запрещённых слов
list_banned_words(Req) ->
  case handler_auth:authenticate(Req) of
    {ok, AdminId, Req1} ->
      case logic_moderation:list_banned_words(AdminId) of
        {ok, Words} ->
          send_json(Req1, 200, Words);
        {error, access_denied} ->
          send_error(Req1, 403, <<"Admin access required">>);
        {error, _} ->
          send_error(Req1, 500, <<"Internal server error">>)
      end;
    {error, Code, Message, Req1} ->
      send_error(Req1, Code, Message)
  end.

%% POST /v1/admin/banned-words - добавить запрещённое слово
add_banned_word(Req) ->
  case handler_auth:authenticate(Req) of
    {ok, AdminId, Req1} ->
      {ok, Body, Req2} = cowboy_req:read_body(Req1),
      try jsx:decode(Body, [return_maps]) of
        #{<<"word">> := Word} ->
          case logic_moderation:add_banned_word(AdminId, Word) of
            {ok, _} ->
              send_json(Req2, 201, #{word => Word, status => <<"added">>});
            {error, already_exists} ->
              send_error(Req2, 409, <<"Word already exists">>);
            {error, access_denied} ->
              send_error(Req2, 403, <<"Admin access required">>);
            {error, _} ->
              send_error(Req2, 500, <<"Internal server error">>)
          end;
        _ ->
          send_error(Req2, 400, <<"Missing 'word' field">>)
      catch
        _:_ ->
          send_error(Req2, 400, <<"Invalid JSON format">>)
      end;
    {error, Code, Message, Req1} ->
      send_error(Req1, Code, Message)
  end.

%% DELETE /v1/admin/banned-words - удалить запрещённое слово
remove_banned_word(Req) ->
  case handler_auth:authenticate(Req) of
    {ok, AdminId, Req1} ->
      Word = cowboy_req:binding(word, Req1),
      case logic_moderation:remove_banned_word(AdminId, Word) of
        {ok, removed} ->
          send_json(Req1, 200, #{word => Word, status => <<"removed">>});
        {error, not_found} ->
          send_error(Req1, 404, <<"Word not found">>);
        {error, access_denied} ->
          send_error(Req1, 403, <<"Admin access required">>);
        {error, _} ->
          send_error(Req1, 500, <<"Internal server error">>)
      end;
    {error, Code, Message, Req1} ->
      send_error(Req1, Code, Message)
  end.

%% Вспомогательные функции
send_json(Req, Status, Data) ->
  Body = jsx:encode(Data),
  cowboy_req:reply(Status, #{<<"content-type">> => <<"application/json">>}, Body, Req),
  {ok, Body, []}.

send_error(Req, Status, Message) ->
  Body = jsx:encode(#{error => Message}),
  cowboy_req:reply(Status, #{<<"content-type">> => <<"application/json">>}, Body, Req),
  {ok, Body, []}.