snippet.erl

%% A faire
% - passer en configuration l'arborescence des facette (par type)
% {mod_search, [{facet, {type, "produit"}, [{"facet.limit",5}], [
%	style, 
%	{price, [{query, "price:[*+TO+500]"}, 
%				{query, "price:[500+TO+*]"}]}
%	]}
%	{facet, {type, "session"}, [], [style, gangs]}
%	]
% }
% - mettre un superviseur pour esolr
% - faire un configuration 
-module(mod_search).
-author('eric@ohmforce.com').

-behaviour(gen_server).
-behaviour(gen_mod).
-compile(export_all).
%% API
-export([start_link/2, start/2, stop/1]).
-export([process_iq_disco_info/5, process_iq_disco_items/5]).
%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
	 terminate/2, code_change/3]).

-include("ejabberd.hrl").
-include("jlib.hrl").
-record(state, {host, facet_fields=[], facet_queries=[]}).
-define(NODEJID(To, Name, Node),
	{xmlelement, "item",
	 [{"jid", To},
	  {"name",  Name},
	  {"node", Node}], []}).
-define(PROCNAME, mod_search).

%%====================================================================
%% API
%%====================================================================
%%--------------------------------------------------------------------
%% Function: start_link() -> {ok,Pid} | ignore | {error,Error}
%% Description: Starts the server
%%--------------------------------------------------------------------
start_link(Host, Opts) ->
    Proc = gen_mod:get_module_proc(Host, ?PROCNAME),
    gen_server:start_link({local, Proc}, ?MODULE, [Host, Opts], []).

start(Host, Opts) ->
	Proc = gen_mod:get_module_proc(Host, esolr),
	EsolrOpts = gen_mod:get_opt(esolr_opts, Opts, []),
    ChildSpec =
	{Proc,
	 {esolr, start_link, [EsolrOpts]},
	 permanent,
	 1000,
	 worker,
	 [esolr]},
    supervisor:start_child(ejabberd_sup, ChildSpec),
    Proc2 = gen_mod:get_module_proc(Host, ?PROCNAME),
    ChildSpec2 =
	{Proc2,
	 {?MODULE, start_link, [Host, Opts]},
	 permanent,
	 1000,
	 worker,
	 [?MODULE]},
    supervisor:start_child(ejabberd_sup, ChildSpec2).

stop(Host) ->
	lists:map(fun(Name)-> 
		Proc = gen_mod:get_module_proc(Host, Name),
		gen_server:call(Proc, stop),
	    supervisor:terminate_child(ejabberd_sup, Proc),
	    supervisor:delete_child(ejabberd_sup, Proc)
	end, [?PROCNAME, esolr]	).
    


%%====================================================================
%% gen_server callbacks
%%====================================================================

%%--------------------------------------------------------------------
%% Function: init(Args) -> {ok, State} |
%%                         {ok, State, Timeout} |
%%                         ignore               |
%%                         {stop, Reason}
%% Description: Initiates the server
%%--------------------------------------------------------------------
init([Host, Opts]) ->
    MyHost = gen_mod:get_opt_host(Host, Opts, "search.@HOST@"),
	Fields = gen_mod:get_opt(facet_fields, Opts, []),
	Queries = gen_mod:get_opt(facet_queries, Opts, []),
    ejabberd_router:register_route(MyHost),
    {ok, #state{host = MyHost, facet_fields=Fields, facet_queries=Queries}}.

%%--------------------------------------------------------------------
%% Function: %% handle_call(Request, From, State) -> {reply, Reply, State} |
%%                                      {reply, Reply, State, Timeout} |
%%                                      {noreply, State} |
%%                                      {noreply, State, Timeout} |
%%                                      {stop, Reason, Reply, State} |
%%                                      {stop, Reason, State}
%% Description: Handling call messages
%%--------------------------------------------------------------------
handle_call(stop, _From, State) ->
    {stop, normal, ok, State}.

%%--------------------------------------------------------------------
%% Function: handle_cast(Msg, State) -> {noreply, State} |
%%                                      {noreply, State, Timeout} |
%%                                      {stop, Reason, State}
%% Description: Handling cast messages
%%--------------------------------------------------------------------
handle_cast(_Msg, State) ->
    {noreply, State}.

%%--------------------------------------------------------------------
%% Function: handle_info(Info, State) -> {noreply, State} |
%%                                       {noreply, State, Timeout} |
%%                                       {stop, Reason, State}
%% Description: Handling all non call/cast messages
%%--------------------------------------------------------------------
handle_info({route, From, To, Packet}, State) ->
	case From#jid.user of
		"" -> jlib:make_error_reply(Packet, ?ERR_BAD_REQUEST);
		_ -> do_route(From, To, Packet, State)
	end,
    {noreply, State};


handle_info(_Info, State) ->
    {noreply, State}.
terminate(_Reason, State) ->
    ejabberd_router:unregister_route(State#state.host),
    ok.

%%--------------------------------------------------------------------
%% Func: code_change(OldVsn, State, Extra) -> {ok, NewState}
%% Description: Convert process state when code is changed
%%--------------------------------------------------------------------
code_change(_OldVsn, State, _Extra) ->
    {ok, State}.

%%--------
%% API
%%--------


do_route(From, To, Packet, State) ->
	{xmlelement, Name, _Attrs, _Els} = Packet,
	case Name of 
		"iq" ->
			process_iq(From, To, jlib:iq_query_info(Packet) , State);
		_ ->
			ohm_misc:send_error(To, From, Packet)
	end	.
	
process_iq(From, To, 	#iq{type = get,
	    xmlns = ?NS_DISCO_ITEMS,
	    sub_el = SubEl}=IQ, State) ->
	{xmlelement, _Q, Attr, _SubEl} = SubEl,
    Node = xml:get_attr_s("node", Attr),
    spawn(?MODULE, process_iq_disco_items, [From, To, Node, IQ, State]);


process_iq(From, To, 	#iq{type = get,
	    xmlns = ?NS_DISCO_INFO,
	    sub_el = SubEl}=IQ, State) ->
   {xmlelement, _Q, Attr, _SubEl} = SubEl,
   Node = xml:get_attr_s("node", Attr),
   spawn(?MODULE, process_iq_disco_info, [From, To, Node, IQ, State]).

process_iq_disco_info( From, To, _Node, IQ, _State) ->
	Res = IQ#iq{type = result,
	     		sub_el = [{xmlelement, "query",
	     			   [{"xmlns", ?NS_DISCO_INFO},
	     			   {"category", "none"},
	     		       {"type", "item"}], []
	     			}]},
	ejabberd_router:route(To,From, jlib:iq_to_xml(Res)).


process_iq_disco_items(From, To, "/id/"++Node, IQ, _State) ->
	Res = IQ#iq{type = result,
	  	sub_el = [{xmlelement, "query",
	  		   [{"xmlns", ?NS_DISCO_ITEMS}],
	  			[]}]},
	ejabberd_router:route(To,From, jlib:iq_to_xml(Res));

process_iq_disco_items(From, To, Node, IQ, State) ->
	RSM = rsm:decode(IQ),
	Nodes = fetch_results_for_node(Node, RSM, jlib:jid_to_string(To), State),
	Res = IQ#iq{type = result,
	  	sub_el = [{xmlelement, "query",
	  		   [{"xmlns", ?NS_DISCO_ITEMS}],
	  			Nodes}]},
	ejabberd_router:route(To,From, jlib:iq_to_xml(Res)).



fetch_results_for_node("", RSM, To, #state{facet_fields=Fields})->
	create_nodes_for_facets("",Fields, To);
		
fetch_results_for_node(Node,RSM, To, State)->
	Nodes = string:tokens(Node,"/"),
	{Query, Options, Facets} = build_query(Nodes, State),
	Options2 = build_rsm_q(RSM, Options),
	?DEBUG("Solar query : ~p, ~p, ~p,  ~p~n", [Query, Options2,Facets, RSM]),
	case esolr:search(Query, Options2) of
		{ok, Stats,[], Rest} ->
			{obj, Props} = proplists:get_value("facet_counts", Rest),
			Fields = case  proplists:get_value("facet_fields", Props) of
				{obj, [{FName, F}]} -> F;
				{obj, []} -> 
					{obj, F} = proplists:get_value("facet_queries", Props),
					F
			end,
			facets_to_items(Fields, [], Node, To);
		{ok, Stats,Docs, Rest}->
				?DEBUG("query results : ~p, ~p, ~p, ~n", [Stats, Docs,Rest]),
				create_nodes_for_facets(Node,Facets, To) 
					++ lists:map(fun({doc, Proplist})->
						Name = case proplists:get_value("word",Proplist) of
							undefined -> binary_to_list(proplists:get_value("name",Proplist));
							N ->binary_to_list(N)
						end,
						SKU = binary_to_list(proplists:get_value("sku",Proplist)),
						?NODEJID(To,Name , "/id/"++SKU)
					end, Docs) ++ build_rsm_response(Stats, erlang:length(Docs));
		_ ->
			[]
	end.

build_rsm_response(Stats, Length)->
	RSM = #rsm_out{count=proplists:get_value("numFound", Stats), 
			index=proplists:get_value("start", Stats),
			first=i2l(proplists:get_value("start", Stats)),
			last=i2l(proplists:get_value("start", Stats) + Length)},
	rsm:encode(RSM).

build_rsm_q(#rsm_in{max=Max, direction=Direction, id=Id}, Options)->
	Q1 = case Max of
		undefined -> Options;	
		_ -> [{rows, Max}| Options]
	end,
	case Direction of
		undefined ->
			Q1;
		before -> 
		 [{start, Id - Max}|Q1];
		aft ->
		 [{start, Id}|Q1]
	end;
build_rsm_q(none, Options)->
	Options.
	
% /cat:electronic/popularity:6
% /cat:electronic/popularity:4
%esolr:search("*:*",[{rows, -1},{facets,[{f, "cat"}, {f,"popularity"}] }]).

%% build solar query from node name.
build_query(Nodes, #state{facet_fields=Fields}=State)->
	build_query(Nodes, {"",[], Fields}, State).
build_query([], {[], Options, Facets}, State)-> {"*:*", Options, Facets};
build_query([], Acc, State)-> Acc;
build_query([ Node |R], {Query, Options,Facets }, #state{facet_queries=FQueries}=State)->
	case string:tokens(Node,":" ) of
	["q", Search]->
		Q=Query ++ " " ++Search,
		build_query(R, {Q, Options,  Facets}, State);
	[Facet, Value] ->	
		build_query(R, {Query, [{"fq", Facet++":"++Value} | Options], lists:delete(Facet, Facets)}, State);
	[Facet] ->
		Options2 = case proplists:get_value(Facet,FQueries) of
			undefined -> 
			  	[{facets, [{f, Facet}]}, {rows, -1}, {"facet.mincount",1}| Options];
			List ->
				lists:merge([
					[{"facet.query", Facet++":"++Range} || Range <- List],
					[{rows, -1}, {"facet.mincount",1},{"facet", "true"}],
					Options])
			end,
		build_query(R, {Query, Options2, lists:delete(Facet, Facets)}, State)
	end.
	
%% transforms facets into nodes	
facets_to_items(Array, Root, To)->
	facets_to_items(Array,[], Root, To).
facets_to_items([], Items, Root, To)-> Items;
% Pour les facet.queries
facets_to_items([{Name, Count}|R], Items, Root, To)->
	[Facet, Range]=string:tokens(Name,":" ),
	Items2=[?NODEJID(To, Name++" ("++ i2l(Count) ++")", Root++":"++Range)| Items],
	facets_to_items(R, Items2, Root, To);
facets_to_items([BinName, Count|R], Items, Root, To)->
	Name = binary_to_list(BinName),
	Items2=[?NODEJID(To, Name++" ("++ i2l(Count) ++")", Root++":"++Name)| Items],
	facets_to_items(R, Items2, Root, To).
	
create_nodes_for_facets(Root,Facets, To)->
	lists:zf(fun(Name) ->
	 				{true,?NODEJID(To, "->"++Name, Root++"/"++Name)}
		end,Facets).
		

	
i2l(I) when integer(I) -> integer_to_list(I);
i2l(L) when list(L)    -> L.