Erlang 코드 맞보기 , SNS 에서 유저를 follow 하는 Request 처리

v1_user_follow.erl

%%%-------------------------------------------------------------------
%%% @author 신원동 <wdshin@CTO-Wondong-Shin.local>
%%% @copyright (C) 2015, 신원동
%%% @doc
%%%
%%% @end
%%% Created : 22 Oct 2015 by 신원동 <wdshin@CTO-Wondong-Shin.local>
%%%-------------------------------------------------------------------
-module(v1_user_follow).

-include("common.hrl").

%%-export([req/3]).

-include("fa.hrl").

%% API
-export([init/3,service_available/2]).
-export([allowed_methods/2,known_methods/2]).
-export([content_types_provided/2,content_types_accepted/2]).
-export([is_authorized/2,forbidden/2,resource_exists/2]).
-export([delete_resource/2, delete_completed/2]).

-export([handle_html/2]).
-export([handle_json/2]).
-export([handle_text/2]).

-export([process_post/2,handle_post/4,handle_proplists/3]).
-export([multiple_choices/2]).

%%%===================================================================
%%% API
%%%===================================================================


init(_Transport, _Req, []) ->
    {upgrade, protocol, cowboy_rest}.

%% 서비스 사용 가능 상태
service_available(Req, Opts) ->
    {true, Req, Opts}.

known_methods(Req, State) ->
  {[<<"PUT">>, <<"POST">>,<<"DELETE">>,<<"GET">>], Req, State}.

allowed_methods(Req, State) ->
  {[<<"PUT">>, <<"POST">>,<<"DELETE">>,<<"GET">>], Req, State}.

content_types_provided(Req, State) ->
    {[
      {{<<"application">>, <<"json">>, '*'}, handle_json},
      {{<<"text">>, <<"html">>, '*'}, handle_html},
      {{<<"text">>, <<"plain">>, '*'}, handle_text}
     ],Req, State}.

content_types_accepted(Req, State) ->
    {[
      {{<<"application">>, <<"json">>, '*' }, process_post}
     ],
     Req, State}.

%% 인증처리 실패 응답 : 401 Unauthorized
is_authorized(Req, State) ->
    f_auth:is_authorized(Req, State).

forbidden(Req, State) ->
    %% Assume the users have access to everything (default value)
    {false, Req, State}.

resource_exists(Req, State = #resource{method=_Method} )  -> %% Method =:= <<"GET">> <<"DELETE">> <<"PUT">>
    f_resource:exists(Req, State , user_id ).

delete_resource(Req,State = #resource{user_id=SessionUserID,contents=Contents,error_code=ErrCode}) ->
    try 
        case ErrCode of
            undefined -> 

                {UserID} = Contents,


                R = f_user_follow:stop(SessionUserID,UserID),

                Result = [ { <<"user_id">> , UserID },
                           { <<"stop_follow">> , m_conv:any_to_binary(R) } ],

                Response = [
                            { <<"result_code">> , ?RESULT_OK },
                            { <<"result_msg">> , <<"">> },
                            { <<"result_data">> , Result }
                           ],
                Ret = m_json:safe_encode(Response),

                v1_common:handle_response(true,Ret,Req,State);

            _ -> 
                throw({common_error,ErrCode})
        end
    catch
        throw:Exception ->
            v1_common:handle_exception(Exception,Req,State)
    end.

delete_completed(Req, State) ->
    { true, Req, State }.


process_post(Req, State) ->
    v1_common:process_post(Req, State, ?MODULE, handle_post ).

multiple_choices(Req,State = #resource{method=Method,user_id=SessionUserID,contents=Contents,error_code=ErrCode}) 
  when Method == <<"POST">> orelse Method == <<"PUT">> orelse Method == <<"GET">> orelse Method == <<"DELETE">> ->
    { false,  Req, State };%% false returns 200  ,
multiple_choices(Req,State ) ->
    { true, Req, State }. %% true returns 300

handle_html(Req, State) -> 
    v1_common:handle_proplists(Req, State, ?MODULE, handle_proplists ).
handle_text(Req, State) -> 
    v1_common:handle_proplists(Req, State, ?MODULE, handle_proplists ).
handle_json(Req, State) -> 
    v1_common:handle_proplists(Req, State, ?MODULE, handle_proplists ).
handle_post(Req,_,Body,State) ->
    handle_proplists(Req,Body,State).



%%--------------------------------------------------------------------
%% @doc
%% @spec
%% @end
%%--------------------------------------------------------------------

%%%===================================================================
%%% Internal functions
%%%===================================================================


handle_proplists(Req,_,State = #resource{method=Method,error_code=ErrCode}) when ErrCode =/= undefined ->
    case Method of
        <<"GET">> -> v1_common:handle_exception(get,{common_error,ErrCode},Req,State);
        _ ->         v1_common:handle_exception({common_error,ErrCode},Req,State)
    end;
handle_proplists(Req,PropLists,State = #resource{method= <<"GET">>,user_id=SessionUserID,locale=Locale,contents=Contents}) ->

    %%m_logger:log("~p ~p GET ~p ",[?MODULE,?LINE,SessionUserID]),
    try

        {UserID} = Contents,

        case f_user_block_user:is_block_user(SessionUserID, UserID) of
            true ->
                throw({common_error,?OBJECT_NOT_FOUND});%% TODO USER_BLOCKED_YOU
            _ ->
                noop
        end,
        case f_user_block_user:is_block_user(UserID, SessionUserID) of
            true ->
                throw({common_error,?OBJECT_NOT_FOUND});%% TODO USER_BLOCKED_YOU
            _ ->
                noop
        end,


        {_Code,Params} = v1_common:make_params_detector([],
                                                        [{<<"paging_id">>,m_uuid:v1(binary)},{<<"limit">>,10},{<<"list">>,<<"followers">>},{<<"mutual_page_limit">>,5}],
                                                        PropLists),

        [ PagingID , Limit , ListMode , MutualPageLimit ] = Params,


        case ListMode of
            <<"follower">> ->
                R = f_user_follow:list_followers(SessionUserID,UserID,PagingID,Limit,MutualPageLimit),

                Result = [ { <<"followers">> , R } ];
            <<"following">> ->
                R = f_user_follow:list_followings(SessionUserID,UserID,PagingID,Limit,MutualPageLimit),

                Result = [ { <<"followings">> , R } ];
            _ ->
                R = f_user_follow:list_followers(SessionUserID,UserID,PagingID,Limit,MutualPageLimit),
                Result = [ { <<"followers">> , R } ]
        end,
        

        Response = [
                    { <<"result_code">> , ?RESULT_OK },
                    { <<"result_msg">> , <<"">> },
                    { <<"result_data">> , Result }
                   ],
        Ret = m_json:safe_encode(Response),

        v1_common:handle_response(true,Ret,Req,State)
    catch
         throw:Exception ->
            v1_common:handle_exception(get,Exception,Req,State)
    end;
handle_proplists(Req,PropLists,State = #resource{method= <<"PUT">>,user_id=SessionUserID,contents=Contents,locale=Locale,error_code=ErrCode}) ->

    try

        {UserID} = Contents,

        if SessionUserID == UserID ->
                throw({common_error,?PARAMS_ERROR});
           true ->
                noop
        end,

        case f_user_block_user:is_block_user(SessionUserID, UserID) of
            true ->
                throw({common_error,?OBJECT_NOT_FOUND});%% TODO USER_BLOCKED_YOU
            _ ->
                noop
        end,
        case f_user_block_user:is_block_user(UserID, SessionUserID) of
            true ->
                throw({common_error,?OBJECT_NOT_FOUND});%% TODO USER_BLOCKED_YOU
            _ ->
                noop
        end,

        {_Code,Params} = v1_common:make_params_detector([],
                                                        [{<<"follow_post">>,true}],
                                                        PropLists),

        [ FollowPost0 ] = Params,


        m_logger:log("~p ~p SessionUserID ~p UserID ~p FollowPost0 ~p ",[?MODULE,?LINE,SessionUserID,UserID,FollowPost0]),

        bq_api_call:new(SessionUserID,<<"v1_user_follow">>,Locale),

        R = f_user_follow:start(SessionUserID,UserID),
        case R of
            ok ->
                %%m_logger:log("~p ~p SessionUserID ~p UserID ~p NEW FOLLOW force FollowPost true ",[?MODULE,?LINE,SessionUserID,UserID]),
                FollowPost = true;
            _ ->
                FollowPost = FollowPost0
        end,

        %%m_logger:log("~p ~p SessionUserID ~p UserID ~p FollowPost ~p ",[?MODULE,?LINE,SessionUserID,UserID,FollowPost]),

        FollowingInfo = db_user_follow:get_following(SessionUserID,UserID,[user_id,following_user_id,is_following_post]),

        OldFollowingPost = m_kv:get_bool_default(is_following_post,FollowingInfo,true),

        if OldFollowingPost =/= FollowPost ->
                f_user_follow:follow_post(SessionUserID,UserID,FollowPost),
                NewFollowingPost = FollowPost;
           true ->
                NewFollowingPost = OldFollowingPost
        end,


        SelectFields = [user_id, screen_name,profile,status,page_like_list,type],

        UserInfo = db_user:get(UserID,SelectFields),
        MyLikes = db_user:get_page_likes(SessionUserID),
        MyLikesSet = sets:from_list(MyLikes),

        UserLikes = m_kv:get_list(page_like_list,UserInfo),

        UserLikesSet = sets:from_list(UserLikes),
        MutualLikeSet = sets:intersection(MyLikesSet,UserLikesSet),
        MutualCount = sets:size(MutualLikeSet),

        User = 
            [
             {<<"user_id">>, UserID },
             {<<"screen_name">> , m_kv:get_binary(screen_name,UserInfo) },
             {<<"profile">> , m_kv:get_binary(profile,UserInfo) },
             {<<"status">> , m_kv:get_integer(status,UserInfo) },
             {<<"type">> ,  m_kv:get_integer(type,UserInfo) } 
            ] ,

        Result = [  { <<"user">> , User },
                    { <<"is_following_post">> , NewFollowingPost },
                    { <<"mutual_like_count">> , MutualCount },
                    { <<"follow">> , m_conv:any_to_binary(R) } ],

        Response = [
                    { <<"result_code">> , ?RESULT_OK },
                    { <<"result_msg">> , <<"">> },
                    { <<"result_data">> , Result }
                   ],
        Ret = m_json:encode(Response),

        v1_common:handle_response(true,Ret,Req,State)
    catch
        throw:Exception ->
            v1_common:handle_exception(Exception,Req,State)
    end;
handle_proplists(Req,PropLists,State = #resource{method= <<"POST">> ,user_id=SessionUserID,contents=Contents,locale=Locale,error_code=ErrCode}) ->
    try

        {UserID} = Contents,

        if SessionUserID == UserID ->
                throw({common_error,?PARAMS_ERROR});
           true ->
                noop
        end,

        case f_user_block_user:is_block_user(SessionUserID, UserID) of
            true ->
                throw({common_error,?OBJECT_NOT_FOUND});%% TODO USER_BLOCKED_YOU
            _ ->
                noop
        end,
        case f_user_block_user:is_block_user(UserID, SessionUserID) of
            true ->
                throw({common_error,?OBJECT_NOT_FOUND});%% TODO USER_BLOCKED_YOU
            _ ->
                noop
        end,


        {_Code,Params} = v1_common:make_params_detector([],
                                                        [{<<"follow_post">>,true}],
                                                        PropLists),

        [ FollowPost0 ] = Params,


        m_logger:log("~p ~p SessionUserID ~p UserID ~p FollowPost0 ~p ",[?MODULE,?LINE,SessionUserID,UserID,FollowPost0]),

        bq_api_call:new(SessionUserID,<<"v1_user_follow">>,Locale),

        R = f_user_follow:start(SessionUserID,UserID),
        case R of
            ok ->
                m_logger:log("~p ~p SessionUserID ~p UserID ~p NEW FOLLOW force FollowPost true ",[?MODULE,?LINE,SessionUserID,UserID]),
                FollowPost = true;
            _ ->
                FollowPost = FollowPost0
        end,

        m_logger:log("~p ~p SessionUserID ~p UserID ~p FollowPost ~p ",[?MODULE,?LINE,SessionUserID,UserID,FollowPost]),

        FollowingInfo = db_user_follow:get_following(SessionUserID,UserID,[user_id,following_user_id,is_following_post]),

        OldFollowingPost = m_kv:get_bool_default(is_following_post,FollowingInfo,true),

        if OldFollowingPost =/= FollowPost ->
                f_user_follow:follow_post(SessionUserID,UserID,FollowPost),
                NewFollowingPost = FollowPost;
           true ->
                NewFollowingPost = OldFollowingPost
        end,


        SelectFields = [user_id, screen_name,profile,status,page_like_list,type],

        UserInfo = db_user:get(UserID,SelectFields),
        MyLikes = db_user:get_page_likes(SessionUserID),
        MyLikesSet = sets:from_list(MyLikes),

        UserLikes = m_kv:get_list(page_like_list,UserInfo),

        UserLikesSet = sets:from_list(UserLikes),
        MutualLikeSet = sets:intersection(MyLikesSet,UserLikesSet),
        MutualCount = sets:size(MutualLikeSet),

        User = 
            [
             {<<"user_id">>, UserID },
             {<<"screen_name">> , m_kv:get_binary(screen_name,UserInfo) },
             {<<"profile">> , m_kv:get_binary(profile,UserInfo) },
             {<<"status">> , m_kv:get_integer(status,UserInfo) },
             {<<"type">> ,  m_kv:get_integer(type,UserInfo) } 
            ] ,

        Result = [  { <<"user">> , User },
                    { <<"mutual_like_count">> , MutualCount },
                    { <<"follow">> , m_conv:any_to_binary(R) } ],


        Response = [
                    { <<"result_code">> , ?RESULT_OK },
                    { <<"result_msg">> , <<"">> },
                    { <<"result_data">> , Result }
                   ],
        Ret = m_json:encode(Response),

        v1_common:handle_response(true,Ret,Req,State)
    catch
        throw:Exception  ->
            v1_common:handle_exception(Exception,Req,State)
    end.