%% Copyright (c) 2009 Electronic Arts, Inc.

%% Permission is hereby granted, free of charge, to any person obtaining a copy
%% of this software and associated documentation files (the "Software"), to deal
%% in the Software without restriction, including without limitation the rights
%% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
%% copies of the Software, and to permit persons to whom the Software is
%% furnished to do so, subject to the following conditions:
%%
%% The above copyright notice and this permission notice shall be included in
%% all copies or substantial portions of the Software.
%%
%% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
%% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
%% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
%% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
%% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
%% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
%% THE SOFTWARE.

-module(giza_query).

-author("Kevin A. Smith <kevin@hypotheticalabs.com>").

-include("giza.hrl").
-include("giza_internal.hrl").

-export([new/0, new/1, new/2]).
-export([query_string/1, query_string/2]).
-export([host/1, host/2, port/1, port/2]).
-export([index/1, index/2, limit/1, limit/2]).
-export([offset/1, offset/2, min_id/1, min_id/2]).
-export([max_id/1, max_id/2]).
-export([max_matches/1, max_matches/2]).
-export([sort_extended/2, sort_relevance/1]).
-export([filters/1, add_filter/3, add_filter/4, remove_filter/2,
         add_filter_range/4, add_filter_range/5]).
-export([geo/1, geo/3]).
-export([index_weights/1, index_weights/2]).
-export([field_weights/1, field_weights/2]).
-export([group_by/2, group_by/3, group_by/4]).
-export([params/2]).
-export([to_bytes/1]).

%% @spec new() -> Result
%%       Result = any()
%% @doc Create a new giza query pointing with default values
new() ->
  new_with_defaults().

%% @spec new(Host, Port) -> Result
%%       Host = string()
%%       Port = integer()
%%       Result = any()
%% @doc Create a new giza query pointing to the given host and port
new(Host, Port) when is_list(Host),
                     is_integer(Port) ->
  R = new_with_defaults(),
  R#giza_query{host=Host, port=Port};

%% @spec new(Index, QueryString) -> Result
%%       Index = string()
%%       QueryString = string()
%%       Result = any()
%% @doc Create a new giza query using the specified index name and query string
new(Index, QueryString) when is_list(Index),
                             is_list(QueryString) ->
  R = new_with_defaults(),
  index(query_string(R, QueryString), Index).

%% @spec new(QueryString) -> Result
%%       QueryString = string()
%%       Result = any()
%% @doc Create a new giza query with the specified query string
new(QueryString) when is_list(QueryString) ->
  R = new_with_defaults(),
  query_string(R, QueryString).

%% @spec query_string(Query) -> Result
%%       Query = any()
%%       Result = binary()
%% @doc Retrieve the current query string
query_string(Query) ->
  Query#giza_query.query_string.

%% @spec query_string(Query, NewQueryString) -> Result
%%       Query = any()
%%       NewQueryString = string()
%%       Result = any()
%% @doc Set the query string
query_string(Query, NewQueryString) when is_list(NewQueryString) ->
  query_string(Query, list_to_binary(NewQueryString));
query_string(Query, NewQueryString) when is_binary(NewQueryString) ->
  set_query_field(query_string, Query, NewQueryString).

%% @spec index(Query) -> Result
%%       Query = any()
%%       Result = string()
%% @doc Get the current search index name
index(Query) ->
  Query#giza_query.index.

%% @spec index(Query, Index) -> Result
%%       Query = any()
%%       Index = string()
%%       Result = any()
%% @doc Set the search index name
index(Query, Index) when is_list(Index) ->
  index(Query, list_to_binary(Index));
index(Query, Index) when is_binary(Index) ->
  Query#giza_query{index=Index}.

%% @spec host(Query) -> Result
%%       Query = any()
%%       Result = string()
%% @doc Get the current target host
host(Query) ->
  Query#giza_query.host.

%% @spec host(Query, Host) -> Result
%%       Query = any()
%%       Host = string()
%%       Result = any()
%% @doc Set the target host
host(Query, Host) when is_list(Host) ->
  set_query_field(host, Query, Host).

%% @spec port(Query) -> Result
%%       Query = any()
%%       Result = integer()
%% @doc Get the current target port
port(Query) ->
  Query#giza_query.port.

%% @spec port(Query, Port) -> Result
%%       Query = any()
%%       Port = integer()
%%       Result = any()
%% @doc Set the current target port
port(Query, Port) when is_number(Port) ->
  set_query_field(port, Query, Port).

%% @spec limit(Query) -> Result
%%       Query = any()
%%       Result = integer()
%% @doc Get the current query result limit
limit(Query) ->
  Query#giza_query.limit.

%% @spec limit(Query, Limit) -> Result
%%       Query = any()
%%       Limit = integer()
%%       Result = any()
%% @doc Set the query result limit
limit(Query, Limit) when is_number(Limit) ->
  set_query_field(limit, Query, Limit).

%% @spec offset(Query) -> Result
%%       Query = any()
%%       Result = integer()
%% @doc Get the current offset
offset(Query) ->
  Query#giza_query.offset.

%% @spec offset(Query, Offset) -> Result
%%       Query = any()
%%       Offset = integer()
%%       Result = any()
%% @doc Set the query offset
offset(Query, Offset) ->
  set_query_field(offset, Query, Offset).

%% @spec min_id(Query) -> Result
%%       Query = any()
%%       Result = integer()
%% @doc Get the minimum doc id limit
min_id(Query) ->
  Query#giza_query.min_id.

%% @spec min_id(Query, MinId) -> Result
%%       Query = any()
%%       MinId = integer()
%%       Result = any()
%% @doc Set the minimum doc id limit
min_id(Query, MinId) ->
  set_query_field(min_id, Query, MinId).

%% @spec max_id(Query) -> Result
%%       Query = any()
%%       Result = integer()
%% @doc Get the maximum doc id limit
max_id(Query) ->
  Query#giza_query.max_id.

%% @spec max_id(Query, MaxId) -> Result
%%       Query = any()
%%       MaxId = integer()
%%       Result = any()
%% @doc Set the maximum doc id limit
max_id(Query, MaxId) ->
  set_query_field(max_id, Query, MaxId).

%% @spec max_matches(Query) -> Result
%%       Query = any()
%%       Result = integer()
%% @doc Get the maximum matches limit
max_matches(Query) ->
  Query#giza_query.max_matches.

%% @spec max_matches(Query, MaxMatches) -> Result
%%       Query = any()
%%       MaxMatches = integer()
%%       Result = any()
%% @doc Set the maximum matches
max_matches(Query, MaxMatches) ->
  set_query_field(max_matches, Query, MaxMatches).

%% @spec sort_extended(Query, Expression) -> Result
%%       Query = any()
%%       Expression = string()
%%       Result = any()
%% @doc Sort result by specified expression
sort_extended(Query, Expression) ->
  Q1 = set_query_field(sort, Query, ?SPHINX_SORT_EXTENDED),
  set_query_field(sort_by, Q1, Expression).

%% @spec sort_relevance(Query) -> Result
%%       Query = any()
%%       Result = any()
%% @doc Sort result by relevance
sort_relevance(Query) ->
  set_query_field(sort, Query, ?SPHINX_SORT_RELEVANCE).

%% @spec filters(Query) -> Result
%%       Query = any()
%%       Result = list(tuple())
%% @doc Retrieve currently set filters
filters(Query) ->
  Query#giza_query.filters.

%% @spec add_filter(Query, Name, Values) -> Result
%%       Query = any()
%%       Name = list() | binary()
%%       Values = list()
%%       Result = any()
%% @doc Adds a inclusionary filter
add_filter(Query, Name, Values) ->
  add_filter(Query, Name, false, Values).
%% @spec add_filter(Query, Name, Type, Values) -> Result
%%       Query = any()
%%       Name = list()
%%       Exclude = true | false
%%       Values = list()
%%       Result = any()
%% @doc Add a new filter to a query
add_filter(Query, Name, Exclude, Values) when is_list(Name) ->
  add_filter(Query, list_to_binary(Name), Exclude, Values);
add_filter(#giza_query{filters=Filters}=Query, Name, Exclude, Values)
    when is_binary(Name),
    Exclude =:= true orelse Exclude =:= false ->
  Query#giza_query{filters=[{value, Name, Exclude, Values}|Filters]}.

%% @spec add_filter_range(Query, Name, Min, Max) -> Result
%%       Query = any()
%%       Name = list() | binary()
%%       Min = int()
%%       Max = int()
%%       Result = any()
%% @doc Adds a inclusionary range filter
add_filter_range(Query, Name, Min, Max) ->
  add_filter_range(Query, Name, false, Min, Max).
%% @spec add_filter_range(Query, Name, Exclude, Min, Max) -> Result
%%       Query = any()
%%       Name = list()
%%       Exclude = true | false
%%       Min = int()
%%       Max = int()
%%       Result = any()
%% @doc Add a new filter to a query
add_filter_range(Query, Name, Exclude, Min, Max)
    when is_list(Name) ->
  add_filter_range(Query, list_to_binary(Name), Exclude, Min, Max);
add_filter_range(#giza_query{filters=Filters}=Query, Name, Exclude, Min, Max)
    when is_binary(Name),
    Exclude =:= true orelse Exclude =:= false ->
  Query#giza_query{filters=[{range, Name, Exclude, {Min, Max}}|Filters]}.

%% @spec remove_filter(Query, Name) -> Result
%%       Query = any()
%%       Name = list() | binary()
%%       Result = any()
%% @doc Remove a filter from a query
remove_filter(Query, Name) when is_list(Name) ->
  remove_filter(Query, list_to_binary(Name));
remove_filter(#giza_query{filters=Filters}=Query, Name) when is_binary(Name) ->
  Query#giza_query{filters=proplists:delete(Name, Filters)}.

%% @spec geo(Query) -> Result
%%       Query = any()
%%       Lat = tuple()
%%       Long = tuple()
%%       Result = list(tuple())
%% @doc Use index weights for query
geo(Query, Lat, Long) ->
    set_query_field(geo, Query, {deg, Lat, Long}).

%% @spec index_weights(Query) -> Result
%%       Query = any()
%%       Result = list(tuple())
%% @doc Get index weights for query.
geo(Query) ->
    Query#giza_query.geo.

%% @spec index_weights(Query) -> Result
%%       Query = any()
%%       Result = list(tuple())
%% @doc Use index weights for query
index_weights(Query, IndexWeights) ->
    set_query_field(index_weights, Query, IndexWeights).

%% @spec index_weights(Query) -> Result
%%       Query = any()
%%       Result = list(tuple())
%% @doc Get index weights for query.
index_weights(Query) ->
    Query#giza_query.index_weights.

%% @spec field_weights(Query) -> Result
%%       Query = any()
%%       Result = list(tuple())
%% @doc Use field weights for query
field_weights(Query, FieldWeights) ->
    set_query_field(field_weights, Query, FieldWeights).

%% @spec field_weights(Query) -> Result
%%       Query = any()
%%       Result = list(tuple())
%% @doc Get field weights for query.
field_weights(Query) ->
    Query#giza_query.field_weights.

group_by(Query, GroupAttr, GroupFun, GroupSort) ->
    set_query_field(group_by, Query, {GroupAttr, GroupFun, GroupSort}).
group_by(Query, GroupAttr, GroupFun) ->
    set_query_field(group_by, Query, {GroupAttr, GroupFun, ?SPHINX_GROUP_SORT_DESC}).
group_by(Query, GroupAttr) ->
    set_query_field(group_by, Query, {GroupAttr, ?SPHINX_GROUPBY_ATTR, ?SPHINX_GROUP_SORT_DESC}).

%% @spec params(Query, Parameters) -> Result
%%       Query = any()
%%       Parameters = list(tuple())
%%       Result = list(tuple())
%% @doc Set multiple params at once.
params(_Query, []) -> ok;
params(Query, [{Parameter, Value} | Tail]) when is_atom(Parameter) ->
    params(Query, Tail),
    set_query_field(Parameter, Query, Value).

to_bytes(Query) ->
  Commands = query_to_commands(Query),
  giza_protocol:commands_to_bytes(Commands).

%% @hidden
%%Internal functions
new_with_defaults() ->
  #giza_query{mode=?SPHINX_MATCH_ALL,
              sort=?SPHINX_SORT_RELEVANCE,
              group_fun=?SPHINX_GROUPBY_DAY,
              group_sort=?SPHINX_GROUP_SORT_DESC,
              ranker=?SPHINX_RANK_PROXIMITY_BM25}.

set_query_field(mode, Query, MatchMode) ->
  Query#giza_query{mode=MatchMode};
set_query_field(sort, Query, SortMode) ->
  Query#giza_query{sort=SortMode};
set_query_field(sort_by, Query, SortBy) ->
  Query#giza_query{sort_by=SortBy};
set_query_field(query_string, Query, QueryString) ->
  Query#giza_query{query_string=QueryString};
set_query_field(host, Query, Host) ->
  Query#giza_query{host=Host};
set_query_field(port, Query, Port) ->
  Query#giza_query{port=Port};
set_query_field(limit, Query, Limit) ->
  Query#giza_query{limit=Limit};
set_query_field(min_id, Query, MinId) ->
  Query#giza_query{min_id=MinId};
set_query_field(max_id, Query, MaxId) ->
  Query#giza_query{max_id=MaxId};
set_query_field(max_matches, Query, MaxMatches) ->
  Query#giza_query{max_matches=MaxMatches};
set_query_field(offset, Query, Offset) ->
  Query#giza_query{offset=Offset};
set_query_field(geo, Query, {deg, {AttrLat, Lat}, {AttrLong, Long}}) when is_list(AttrLat), is_float(Lat), is_list(AttrLong), is_float(Long) ->
  Query#giza_query{geo=[{AttrLat, deg2rad(Lat)}, {AttrLong, deg2rad(Long)}]};
set_query_field(geo, Query, {rad, {AttrLat, Lat}, {AttrLong, Long}}) when is_list(AttrLat), is_float(Lat), is_list(AttrLong), is_float(Long) ->
  Query#giza_query{geo=[{AttrLat, Lat}, {AttrLong, Long}]};
set_query_field(index_weights, Query, IndexWeights) ->
  Query#giza_query{index_weights=IndexWeights};
set_query_field(field_weights, Query, FieldWeights) ->
  Query#giza_query{field_weights=FieldWeights};
set_query_field(group_by, Query, {GroupAttr, GroupFun, GroupSort}) ->
  Query#giza_query{group_by=GroupAttr,group_fun=GroupFun,group_sort=GroupSort}.

query_to_commands(Query) ->
  lists:flatten([{32, 1}, %% Number of queries
                 {32, Query#giza_query.offset},
                 {32, Query#giza_query.limit},
                 {32, Query#giza_query.mode},
                 {32, Query#giza_query.ranker},
                 {32, Query#giza_query.sort},
                 {string, Query#giza_query.sort_by},
                 {string, Query#giza_query.query_string},
                 %% query weights
                 {32, 0},
                 {string, Query#giza_query.index},
                 {32, 0},
                 {32, Query#giza_query.min_id},
                 {32, Query#giza_query.max_id},
                 %% Filters
                 process_filters(Query),
                 {32, Query#giza_query.group_fun},
                 {string, Query#giza_query.group_by},
                 %% Max matches
                 {32, Query#giza_query.max_matches},
                 {string, Query#giza_query.group_sort},
                 %% Cutoff
                 {32, 0},
                 %% Retry count
                 {32, 5},
                 %% Retry wait
                 {32, 5},
                 %% Group distinct
                 {32, 0},
                 %% Disable geo searching
                 process_geo(Query),
                 %% Index weights
                 process_index_weights(Query),
                 %% Max query time -- essentially unlimited
                 {32, 0},
                 %% Field weights
                 process_field_weights(Query),
                 %% Comment
                 {string, ?EMPTY_STRING}]).

process_filters(#giza_query{filters=[]}=_Query) ->
  [{32, 0}];
process_filters(#giza_query{filters=Filters}=_Query) ->
  encode_filters(Filters, []).
encode_filters([], []) ->
  [{32, 0}];
encode_filters([], Accum) ->
  lists:flatten([{32, length(Accum)}, lists:reverse(Accum)]);
encode_filters([{Type, Name, Exclude, Spec}|T], Accum) ->
  EV = if
    Exclude =:= true -> 1;
    Exclude =:= false -> 0
  end,
  EncodedFilter = case Type of
    value -> 
      Values = Spec,
      [{string, Name},
        {32, ?SPHINX_FILTER_VALUES},
        {32, length(Values)},
        lists:map(fun(V) -> {32, V} end, Values),
        {32, EV}];
    range ->
      {Min, Max} = Spec,
      [{string, Name},
        {32, ?SPHINX_FILTER_RANGE},
        {32, Min},
        {32, Max},
        {32, EV}]
    end,
  encode_filters(T, [EncodedFilter|Accum]).

process_index_weights(#giza_query{index_weights=IndexWeights}) ->
  process_weights(IndexWeights).

process_field_weights(#giza_query{field_weights=FieldWeights}) ->
  process_weights(FieldWeights).

process_weights([]) ->
  [{32, 0}];
process_weights(Weights) ->
  EncodedPairs = lists:foldl(
    fun({K, V}, Acc) -> [{string, K}, {32, V} | Acc] end,
    [],
    Weights),
  [{32, length(Weights)} | EncodedPairs].

process_geo(#giza_query{geo=[{AttrLat, Lat}, {AttrLong, Long}]}) ->
    [{32, 1},
    {string, AttrLat},
    {string, AttrLong},
    {float, Lat},
    {float, Long}];

process_geo(_) ->
   {32, 0}.

deg2rad(Deg) -> Deg * math:pi()/180.