Add support for count endpoint

src/Database/Bloodhound/Client.hs

@@ -57,6 +57,7 @@ module Database.Bloodhound.Client
        -- ** Searching
        , searchAll
        , searchByIndex
+       , countByIndex
        , searchByIndices
        , searchByIndexTemplate
        , searchByIndicesTemplate
@@ -66,6 +67,7 @@ module Database.Bloodhound.Client
        , advanceScroll
        , refreshIndex
        , mkSearch
+       , mkCount
        , mkAggregateSearch
        , mkHighlightSearch
        , mkSearchTemplate
@@ -1050,6 +1052,11 @@ dispatchSearch :: MonadBH m => Text -> Search -> m Reply
 dispatchSearch url search = post url' (Just (encode search))
   where url' = appendSearchTypeParam url (searchType search)
 
+appendCountTypeParam = appendSearchTypeParam
+dispatchCount :: MonadBH m => Text -> Count -> m Reply
+dispatchCount url count = post url' (Just (encode count))
+  where url' = appendCountTypeParam url (countSearchType count)
+
 -- | 'searchAll', given a 'Search', will perform that search against all indexes
 --   on an Elasticsearch server. Try to avoid doing this if it can be helped.
 --
@@ -1070,6 +1077,16 @@ searchByIndex :: MonadBH m => IndexName -> Search -> m Reply
 searchByIndex (IndexName indexName) = bindM2 dispatchSearch url . return
   where url = joinPath [indexName, "_search"]
 
+-- | 'countByIndex', given a 'Search' and an 'IndexName', will perform that search
+--   within an index on an Elasticsearch server.
+--
+-- >>> let query = TermQuery (Term "user" "bitemyapp") Nothing
+-- >>> let search = mkSearch (Just query) Nothing
+-- >>> reply <- runBH' $ countByIndex testIndex search
+countByIndex :: MonadBH m => IndexName -> Count -> m Reply
+countByIndex (IndexName indexName) = bindM2 dispatchCount url . return
+  where url = joinPath [indexName, "_count"]
+
 -- | 'searchByIndices' is a variant of 'searchByIndex' that executes a
 --   'Search' over many indices. This is much faster than using
 --   'mapM' to 'searchByIndex' over a collection since it only
@@ -1227,6 +1244,17 @@ scanSearch indexName search = do
 mkSearch :: Maybe Query -> Maybe Filter -> Search
 mkSearch query filter = Search query filter Nothing Nothing Nothing False (From 0) (Size 10) SearchTypeQueryThenFetch Nothing Nothing Nothing Nothing Nothing
 
+
+-- | 'mkCount' is a helper function for defaulting additional field of a 'Count'
+--   and resemble the similar function for Search endpoint
+--
+-- >>> let query = TermQuery (Term "user" "bitemyapp") Nothing
+-- >>> mkCount (Just query)
+-- Count {countQueryBody = Just (TermQuery (Term {termField = "user", termValue = "bitemyapp"}) Nothing), countSearchType = SearchTypeQueryThenFetch}
+mkCount :: Maybe Query -> Count
+mkCount query = Count query SearchTypeQueryThenFetch
+
+
 -- | 'mkAggregateSearch' is a helper function that defaults everything in a 'Search' except for
 --   the 'Query' and the 'Aggregation'.
 --

src/Database/Bloodhound/Types.hs

@@ -105,9 +105,11 @@ module Database.Bloodhound.Types
        , JoinRelation(..)
        , IndexDocumentSettings(..)
        , Query(..)
+       , Count(..)
        , Search(..)
        , SearchType(..)
        , SearchResult(..)
+       , CountResult(..)
        , ScrollId(..)
        , HitsTotalRelation(..)
        , HitsTotal(..)
@@ -459,7 +461,15 @@ data Search = Search { queryBody       :: Maybe Query
                      , suggestBody     :: Maybe Suggest -- ^ Only one Suggestion request / response per Search is supported.
                      } deriving (Eq, Show)
 
+data Count = Count { countQueryBody       :: Maybe Query
+                    , countSearchType      :: SearchType
+                     } deriving (Eq, Show)
+
+instance ToJSON Count where
+  toJSON (Count mquery _) =
+    omitNulls [ "query" .= mquery]
 
+
 instance ToJSON Search where
   toJSON (Search mquery sFilter sort searchAggs
           highlight sTrackSortScores sFrom sSize _ sAfter sFields
@@ -530,6 +540,18 @@ newtype Pattern = Pattern Text deriving (Eq, Read, Show)
 instance ToJSON Pattern where
   toJSON (Pattern pattern) = toJSON pattern
 
+data CountResult a =
+  CountResult { crCount         :: Int
+               , crShards       :: ShardResult
+               }
+  deriving (Eq, Show)
+
+instance (FromJSON a) => FromJSON (CountResult a) where
+  parseJSON (Object v) = CountResult <$>
+                         v .:  "count"         <*>
+                         v .:  "_shards"
+  parseJSON _          = empty
+
 data SearchResult a =
   SearchResult { took         :: Int
                , timedOut     :: Bool
@@ -657,4 +679,4 @@ instance FromJSON GetTemplateScript where
         v .: "found"
       )
       script
-  parseJSON _          = empty
+  parseJSON _          = empty