-module(couch_numidx).
-behaviour(gen_server).

% gen_server exports
-export([start_link/0, init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).

% API exports
-export([get_docs/1, range_search/2]).

-include("couch_db.hrl").


get_docs(Db) ->
    gen_server:call(couch_numidx, {do_get_docs, Db}).

range_search(Ni, Range) ->
    gen_server:call(couch_numidx, {do_range_search, Ni, Range}).

start_link() ->
    ?LOG_DEBUG("Numidx daemon: starting link.", []),
    gen_server:start_link({local, couch_numidx}, couch_numidx, [], []).

init([]) ->
    {ok, {}}.

terminate(_Reason, _Srv) ->
    ok.

handle_call({do_get_docs, Db}, _From, State) ->
    {ok, _Cnt, Acc} = couch_db:enum_docs_since(Db, 0,
            fun(DocInfo, _, NumidxDs) ->
        {ok, Doc} = couch_db:open_doc(Db, DocInfo),
        {Body} = Doc#doc.body,
        case proplists:get_value(<<"numidx">>, Body) of
        undefined ->
            {ok, NumidxDs};
        Numidx ->
            {doc_info, DocId, _DocSeq, _RevInfo} = DocInfo,
            NumidxDs2 = numidx:add(NumidxDs, {DocId, Numidx}),
            {ok, NumidxDs2}
        end
    end,
    nil, []),
    {reply, Acc, State};

handle_call({do_range_search, Ni, Range}, _From, State) ->
    Result = numidx:range(Ni, Range),
    {reply, Result, State};

handle_call(_Req, _From, State) ->
    {noreply, State}.

handle_cast(_Msg, State) ->
    {noreply, State}.

handle_info(_Msg, Server) ->
    {noreply, Server}.

code_change(_OldVsn, State, _Extra) ->
    {ok, State}.