%%%----------------------------------------------------------------------
%%% File    : mod_vcard_xupdate.erl
%%% Author  : Igor Goryachev <igor@goryachev.org>
%%% Purpose : Add avatar hash in presence on behalf of client (XEP-0153)
%%% Created : 9 Mar 2007 by Igor Goryachev <igor@goryachev.org>
%%%----------------------------------------------------------------------

-module(mod_vcard_xupdate).

-behaviour(gen_mod).

%% gen_mod callbacks
-export([start/2, stop/1]).

-export([update_presence/3, vcard_set/3, export/1,
	 import_info/0, import/5, import_start/2,
	 mod_opt_type/1, depends/2]).

-include("ejabberd.hrl").
-include("logger.hrl").
-include("xmpp.hrl").

-callback init(binary(), gen_mod:opts()) -> any().
-callback import(binary(), binary(), [binary()]) -> ok.
-callback add_xupdate(binary(), binary(), binary()) -> {atomic, any()}.
-callback get_xupdate(binary(), binary()) -> binary() | undefined.
-callback remove_xupdate(binary(), binary()) -> {atomic, any()}.

%%====================================================================
%% gen_mod callbacks
%%====================================================================

start(Host, Opts) ->
    Mod = gen_mod:db_mod(Host, Opts, ?MODULE),
    Mod:init(Host, Opts),
    ejabberd_hooks:add(c2s_update_presence, Host, ?MODULE,
		       update_presence, 100),
    ejabberd_hooks:add(vcard_set, Host, ?MODULE, vcard_set,
		       100),
    ok.

stop(Host) ->
    ejabberd_hooks:delete(c2s_update_presence, Host,
			  ?MODULE, update_presence, 100),
    ejabberd_hooks:delete(vcard_set, Host, ?MODULE,
			  vcard_set, 100),
    ok.

depends(_Host, _Opts) ->
    [].

%%====================================================================
%% Hooks
%%====================================================================
-spec update_presence(presence(), binary(), binary()) -> presence().
update_presence(#presence{type = available} = Packet, User, Host) ->
    presence_with_xupdate(Packet, User, Host);
update_presence(Packet, _User, _Host) -> Packet.

-spec vcard_set(binary(), binary(), xmlel()) -> ok.
vcard_set(LUser, LServer, VCARD) ->
    US = {LUser, LServer},
    case fxml:get_path_s(VCARD,
			[{elem, <<"PHOTO">>}, {elem, <<"BINVAL">>}, cdata])
	of
      <<>> -> remove_xupdate(LUser, LServer);
      BinVal ->
	  add_xupdate(LUser, LServer,
		      p1_sha:sha(jlib:decode_base64(BinVal)))
    end,
    ejabberd_sm:force_update_presence(US).

%%====================================================================
%% Storage
%%====================================================================

add_xupdate(LUser, LServer, Hash) ->
    Mod = gen_mod:db_mod(LServer, ?MODULE),
    Mod:add_xupdate(LUser, LServer, Hash).

get_xupdate(LUser, LServer) ->
    Mod = gen_mod:db_mod(LServer, ?MODULE),
    Mod:get_xupdate(LUser, LServer).

remove_xupdate(LUser, LServer) ->
    Mod = gen_mod:db_mod(LServer, ?MODULE),
    Mod:remove_xupdate(LUser, LServer).

%%%----------------------------------------------------------------------
%%% Presence stanza rebuilding
%%%----------------------------------------------------------------------

presence_with_xupdate(Presence, User, Host) ->
    Hash = get_xupdate(User, Host),
    Presence1 = xmpp:remove_subtag(Presence, #vcard_xupdate{}),
    xmpp:set_subtag(Presence1, #vcard_xupdate{hash = Hash}).

import_info() ->
    [{<<"vcard_xupdate">>, 3}].

import_start(LServer, DBType) ->
    Mod = gen_mod:db_mod(DBType, ?MODULE),
    Mod:init(LServer, []).

import(LServer, {sql, _}, DBType, Tab, [LUser, Hash, TimeStamp]) ->
    Mod = gen_mod:db_mod(DBType, ?MODULE),
    Mod:import(LServer, Tab, [LUser, Hash, TimeStamp]).

export(LServer) ->
    Mod = gen_mod:db_mod(LServer, ?MODULE),
    Mod:export(LServer).

mod_opt_type(db_type) -> fun(T) -> ejabberd_config:v_db(?MODULE, T) end;
mod_opt_type(_) -> [db_type].