-module(proc).
-export([loop/1]).



loop(Setting) ->

        #{uid := Uid} = Setting,
        #{map := Map} = Setting,
        #{logPid := LogPid} = Setting,

        receive
            {From, {To, Msg, NewMap}}  ->
                log(Uid,LogPid, Msg),
                case is_map_change(Map, NewMap) of
                    true -> log(Uid,LogPid, "Карта изменилась"), SettingNew = update_map(Uid,NewMap,LogPid);
                    false -> log(Uid,LogPid, "Карта не изменилась"), SettingNew = Setting
                end,
                case is_end_destination(Uid, To) of
                    true -> log(Uid,LogPid, "Пакет прибыл в место назначения");
                    false -> log(Uid,LogPid, "Передаем пакет дальше"),
                    case is_process_alive(get_link(Uid, NewMap)) of
                        true -> get_link(Uid, NewMap) ! {From, {To, Msg, NewMap}};
                        false -> log(Uid,LogPid, "Процесс не в сети, перестраиваем сеть"),
                        UpdatedMap = reMap(Uid, get_link(get_link(Uid, NewMap),NewMap),NewMap ),
                        SettingNew = update_map(Uid,UpdatedMap, NewMap),
                        get_link(Uid, UpdatedMap) ! {From, {To, Msg, UpdatedMap}}
                    end
                end
         end,
        loop(SettingNew).

%is_process_alive(Pid).

%update current proc link and map ver.
reMap(Uid, NewUidLink, OldMap) ->
        #{ver := Ver} = OldMap,
        OldMap#{Uid => NewUidLink, ver => Ver+1}.

get_link(Uid, Map) ->
    #{Uid := Next} = Map, Next.

is_map_change(Map, NewMap) ->
    #{ver := Old} = Map, #{ver := New} = NewMap,
    Old < New.

%update map in Setting
update_map(Uid, NewMap, LogPid) ->
    #{uid => Uid, map => NewMap, logPid => LogPid}.

is_end_destination(Uid, To) ->
    Uid =:= To.


log(Uid, Pid, Msg) -> Pid ! {Uid, Msg}.