-module(json_logger_formatter).

-export([format/2,output_message/7]).

format( #{level := Level,
      msg := Message,
      meta := #{pid := Pid,
      time := Timestamp,
      line := Line} = Meta} = MI, _FConfig)->
    {MODULE, FUNCTION_NAME, _FUNCTION_ARITY} = get_mfa_data(Meta),
  output_message(Level,Message,msToDate(Timestamp), MODULE,FUNCTION_NAME,MI,Pid);
format( #{level := Level,
      msg := Message,
    meta := #{pid := Pid}} = MI, _FConfig) ->
output_message(Level,Message,calendar:now_to_local_time(os:timestamp()), unknown,unknown, MI,Pid);

format( #{level := Level,
      msg := Message} = MI, _FConfig) ->
output_message(Level,Message,calendar:now_to_local_time(os:timestamp()), unknown,unknown, MI,erlang:list_to_pid("<0.1.0>")).

get_message({report, Report})->
  Report;
get_message({string, Chardata})->
#{text => unicode:characters_to_binary(Chardata)};
get_message({Io, Data})-> #{ text => unicode:characters_to_binary(io_lib:format(Io,Data)), param => Data}.

get_default_config()->
  #{chars_limit => unlimited,
      depth =>  unlimited,
      legacy_header => true,
      max_size => unlimited,
      report_cb => fun(Report) -> logger:format_report(Report) end,
      single_line => true,
      template => [time," ",level,": ",msg,"\n"],
      time_designator => $T,
      time_offset => ""}.

msToDate(Milliseconds) ->
  MegaSecs = Milliseconds div 1000000000000,
  Secs = Milliseconds div 1000000 - MegaSecs*1000000,
  MicroSecs = Milliseconds rem 1000000,
  calendar:now_to_local_time({MegaSecs, Secs, MicroSecs}).
  % BaseDate      = calendar:datetime_to_gregorian_seconds({{1970,1,1},{0,0,0}}),
  % Seconds       = BaseDate + (Milliseconds div 1000000),
  % {Date, {Hour, Minute, Second}} = calendar:gregorian_seconds_to_datetime(Seconds),
  % {Date,{Hour + 3 rem 23,Minute, Second}}.

get_mfa_data(Meta) ->
    case Meta of
        #{mfa := MFA} ->
        case MFA of
            {MODULE, _FUNCTION_NAME, _FUNCTION_ARITY} -> {MODULE, _FUNCTION_NAME, _FUNCTION_ARITY};
        _else -> {unknown, unknown, unknown}
        end;
    _else -> {unknown, unknown, unknown}
end.

output_message(Level,Message,Time, MODULE,FUNCTION_NAME,MI,Pid) ->
case jsone:try_encode(#{level => Level, message => get_message(Message), time => Time,module => MODULE,func_name => FUNCTION_NAME, pid => erlang:pid_to_list(Pid)},[native_utf8]) of
    {ok,Bin} -> Bin;
    _ -> case jsone:try_encode(#{message => #{text =>unicode:characters_to_binary(logger_formatter:format(MI,get_default_config()))}, level => Level, time => Time, module => MODULE,func_name => FUNCTION_NAME, pid => erlang:pid_to_list(Pid)},[native_utf8]) of
                  {ok,Bin} -> Bin;
                  _ -> {ok,Bin} = jsone:try_encode(#{message => #{ text => <<"критическая ошибка логирования">>}, level => <<"Fatal">>, pid => erlang:pid_to_list(Pid)}), Bin
             end
  end.