[FEAT] Full Text Search query Doc facet.

src/Gargantext/Database/TextSearch.hs

+{-|
+Module      : Gargantext.Database.TextSearch
+Description : 
+Copyright   : (c) CNRS, 2017-Present
+License     : AGPL + CECILL v3
+Maintainer  : team@gargantext.org
+Stability   : experimental
+Portability : POSIX
+
+Here is a longer description of this module, containing some
+commentary with @some markup@.
+-}
+
+--{-# LANGUAGE NoImplicitPrelude #-}
+--{-# LANGUAGE OverloadedStrings #-}
+
+module Gargantext.Database.TextSearch where
+
+import Prelude (print)
+import Gargantext (connectGargandb)
+import Data.Aeson
+import Database.PostgreSQL.Simple
+import Control.Applicative
+import Control.Monad
+import Data.Text (Text)
+import Gargantext.Prelude
+
+
+type TextQuery= Text
+type ParentId = Int
+type Limit    = Int
+type Offset   = Int
+
+data Order = Asc | Desc
+
+toQuery :: Order -> Query
+toQuery Asc  = "ASC"
+toQuery Desc = "DESC"
+
+-- TODO
+-- FIX fav
+-- ADD ngrams count
+-- TESTS
+textSearchQuery :: Order -> Query
+textSearchQuery o = "SELECT n.id, n.hyperdata -> 'publication_date'   \
+\                   , n.hyperdata -> 'title'                          \
+\                   , n.hyperdata -> 'source'                         \
+\                   , COALESCE(nn.score,null)                         \
+\                      FROM nodes n                                   \
+\            LEFT JOIN nodes_nodes nn  ON nn.node2_id = n.id          \
+\              WHERE                                                  \
+\                n.title_abstract @@ to_tsquery(?)                    \
+\                AND n.parent_id = ?   AND n.typename  = 4            \
+\                ORDER BY n.hyperdata -> 'publication_date' "
+      <> toQuery o <>  " offset ? limit ?;"
+
+
+textSearch :: Connection 
+           -> TextQuery -> ParentId
+           -> Limit -> Offset -> Order
+           -> IO [(Int,Value,Value,Value, Maybe Int)]
+textSearch conn q p l o ord = query conn (textSearchQuery ord) (q,p,o,l)
+
+textSearchTest :: TextQuery -> IO ()
+textSearchTest q = connectGargandb "gargantext.ini"
+  >>= \conn -> textSearch conn q 421968 10 0 Asc
+  >>= mapM_ print