% coding: utf-8
% Ce module gére les différents messages envoyés par le client (javascript) via AJAX.
% Les messages donnés ainsi que les réponses sont au format JSON.
% @author G.Burri

-module(euphorik_protocole).
-export([
   register/1,
   login/1,
   logout/1,
   profile/1,
   wait_event/1,
   put_message/1,
   erreur/1
]).

-include_lib("xmerl/include/xmerl.hrl").
-include("../include/euphorik_bd.hrl").
-include("../include/euphorik_defines.hrl").


% Une utilisateur s'enregistre avec un tuple {Login, Password}.
register([{login, Login}, {password, Password}]) ->
   case euphorik_minichat:user_by_login(Login) of
      {ok, _} ->
         erreur("Login déjà existant");
      _ ->
         User = euphorik_minichat:nouveau_user(Login, Password, generer_cookie()),
         json_reponse_login_ok(User)
   end;
% Enregistrement sans {Login, Password}
register([]) ->   
   User = euphorik_minichat:nouveau_user("<nick>", generer_cookie()),
   json_reponse_login_ok(User).
   

% Un utilisateur se logge (avec un couple {login, mot de passe})
login([{login, Login}, {password, Password}]) ->
   loginUser(euphorik_minichat:user_by_login_password(Login, Password));
% Un utilisateur se logge (avec un cookie)
login([{cookie, Cookie}]) ->
   loginUser(euphorik_minichat:user_by_cookie(Cookie)).
   
loginUser({ok, User}) ->
   euphorik_minichat:update_date_derniere_connexion(User#user.id),
   json_reponse_login_ok(User);
loginUser(_) ->
   erreur("Erreur login").
   
   
% Renvoie un string() représentant un cookie en base 36. Il y a 10^32 possibillités.
generer_cookie() ->
   {A1,A2,A3} = now(),
   random:seed(A1, A2, A3),
   erlang:integer_to_list(random:uniform(math:pow(10, 32)), 36).


% Un utilisateur se délogge.
logout(_) ->
   do_nothing.


% Modification du profile.
profile(
   [
      {cookie, Cookie},
      {login, Login},
      {password, Password},
      {nick, Pseudo},
      {email, Email},
      {css, Css},
      {main_page, Main_page},
      {conversations, Conversations_json}
   ]
) ->
   % est-ce que les messages auquel on répond existent ?
   Conversations = lists:foldr(
      fun([struct, {root, Root}, {page, Page}], Acc) ->
         Message_existe = euphorik_minichat:message_existe(Root),
         if  Message_existe ->
            [{Root, Page} | Acc];
            true ->
               Acc
         end
      end,
      [],
      Conversations_json
   ),
   case euphorik_minichat:set_profile(Cookie, Login, Password, Pseudo, Email, Css, Main_page, Conversations) of
      ok ->
         json_reponse_ok();
      login_deja_pris ->
         erreur("Login déjà pris");
      _ ->
         erreur("Impossible de mettre à jour le profile")
   end.


% Renvoie les messages appropriés.
% last_message id et cookie sont facultatifs
% TODO : erreur : {badmatch,false}
wait_event(Data) ->
   Cookie = case lists:keysearch(cookie, 1, Data) of {value, {_, C}} -> C; _ -> inconnu end,
   Last_message_id = case lists:keysearch(last_message_id, 1, Data) of {value, {_, Id}} -> Id; _ -> 0 end,
   {value, {_, Message_count}} = lists:keysearch(message_count, 1, Data),
   Main_page = case lists:keysearch(main_page, 1, Data) of {value, {_, P}} -> P; _ -> 1 end,
   {value, {_, {array, Conversations_json}}} = lists:keysearch(conversations, 1, Data),
   Conversations = lists:map(fun({struct, [{racine, Racine}, {page, Page}]}) -> {Racine, Page} end, Conversations_json),
   User = case euphorik_minichat:user_by_cookie(Cookie) of
      {ok, U} -> U;
      _ -> inconnu
   end,
   {struct, [
      {reply, "new_message"},
      {conversations, {array,
         % accrochez-vous ca va siouxer ;)
         lists:map(
            fun({Conv, Plus}) ->
               {struct, [
                  {last_page, not Plus},
                  {messages, {array, 
                     lists:map(
                        fun({Mess, Repond_a}) ->                                 
                           Est_proprietaire = User =/= inconnu andalso User#user.id =:= Mess#minichat.auteur_id,
                           A_repondu_a_message = User =/= inconnu andalso euphorik_minichat:a_repondu_a_message(User#user.id, Mess#minichat.id),
                           Est_une_reponse_a_user = User =/= inconnu andalso euphorik_minichat:est_une_reponse_a_user(User#user.id, Mess#minichat.id),
                           % io:format("Repond_a : ~p~n", [Repond_a]),
                           User_mess =
                              if Mess#minichat.auteur_id =:= 0 ->
                                    inconnu;
                                 true ->
                                    {ok, U2} = euphorik_minichat:user_by_id(Mess#minichat.auteur_id),
                                    U2
                              end,
                              {struct, [
                                 {id, Mess#minichat.id},
                                 {date, format_date(Mess#minichat.date)},
                                 {system, Mess#minichat.auteur_id =:= 0},
                                 {owner, Est_proprietaire},
                                 {answered, A_repondu_a_message},
                                 {is_a_reply, Est_une_reponse_a_user},
                                 {nick, Mess#minichat.pseudo},
                                 {login, if User_mess =:= inconnu -> Mess#minichat.pseudo; true -> User_mess#user.login end},
                                 {content, Mess#minichat.contenu},
                                 {answer_to, {array, lists:map(
                                    fun(Id_mess) ->                   
                                       {ok, M} = euphorik_minichat:message_by_id(Id_mess),
                                       {ok, User_reponse} = euphorik_minichat:user_by_mess(M#minichat.id),
                                       {struct, [{id, M#minichat.id}, {nick, M#minichat.pseudo}, {login, User_reponse#user.login}]}
                                    end,
                                    Repond_a
                                 )}}
                              ]}
                        end,
                        Conv
                     )
                  }}
               ]}
            end,
            euphorik_minichat_conversation:conversations(
               Conversations,
               Message_count,
               Last_message_id,
               Main_page
            )
         )
      }}
   ]}.
            
         
% Un utilisateur envoie un message
put_message(
   [
      {cookie, Cookie},
      {nick, Nick},
      {content, Content},
      {answer_to, {array, Answer_to}}
   ]
) ->
   case euphorik_minichat:user_by_cookie(Cookie) of
      {ok, User} ->
         Strip_content = string:strip(Content),
         if (Strip_content =:= []) ->
               erreur("Message vide");
            true ->
               % TODO : non-atomique (update_pseudo+nouveau_message)
               euphorik_minichat:update_pseudo_user(User#user.id, Nick),
               case euphorik_minichat:nouveau_message(Strip_content, User#user.id, Answer_to) of
                     erreur -> erreur("Impossible d'ajouter un nouveau message");
                  _ ->
                     json_reponse_ok()
               end
         end;
      _ ->
         erreur("Utilisateur inconnu")
      end.


% Construit une erreur
erreur(Message) ->
   {
      struct, [
         {reply, "error"},
         {error_message, Message}
      ]
   }.
   
   
% Formatage d'une heure
% local_time() -> string
format_date(Date) ->
   DateLocal = calendar:now_to_local_time(Date),
   DateNowLocal = calendar:local_time(),
   {{Annee, Mois, Jour}, {Heure, Minute, Seconde}} = DateLocal,
   {{AnneeNow, _, _}, {_, _, _}} = DateNowLocal,
   Hier = calendar:date_to_gregorian_days(element(1, DateLocal)) =:=  calendar:date_to_gregorian_days(element(1, DateNowLocal)) - 1,
   lists:flatten(
      if element(1, DateLocal) =:= element(1, DateNowLocal) ->
         "";
         Hier ->
            "Hier ";
         Annee =:= AnneeNow ->
            io_lib:format("~2.10.0B/~2.10.0B ", [Jour, Mois]);         
         true ->
            io_lib:format("~2.10.0B/~2.10.0B/~B ", [Jour, Mois, Annee])
      end ++
      io_lib:format("~2.10.0B:~2.10.0B:~2.10.0B", [Heure, Minute, Seconde])
   ).


%%%%%%%%% <Réponses JSON> %%%%%%%%%

json_reponse_ok() ->
   {struct, [{reply, "ok"}]}.
   
   
json_reponse_login_ok(User) ->
   {
      struct, [
         {reply, "login"},
         {status, if (User#user.password =/= []) and (User#user.login =/= []) -> "auth_registered"; true -> "auth_not_registered" end},
         {cookie, User#user.cookie},
         {id, User#user.id},
         {nick, User#user.pseudo},
         {login, User#user.login},
         {email, User#user.email},
         {css, User#user.css},
         {main_page, User#user.page_principale},
         {conversations, 
            {array,
               lists:map(
                  fun(C) ->
                     {struct,
                        {root, element(1, C)},
                        {page, element(2, C)}
                     }
                  end,
                  User#user.conversations
               )
            }
         }
      ]
   }.
   
   
%%%%%%%%% </réponses JSON> %%%%%%%%%