{-|
Module      : Gargantext.Database.Node.Document.Insert
Description : Importing context of texts (documents)
Copyright   : (c) CNRS, 2017-Present
License     : AGPL + CECILL v3
Maintainer  : team@gargantext.org
Stability   : experimental
Portability : POSIX

* Purpose of this module

Enabling "common goods" of text data and respecting privacy.

Gargantext shares as "common good" the links between context of texts
and terms / words / ngrams.

Basically a context of text can be defined as a document (see 'Gargantext.Text').

Issue to tackle in that module: each global document of Gargantext has
to be unique, then shared, but how to respect privacy if needed ?


* Methodology to get uniqueness and privacy by design

As a consequence, when importing/inserting a new document in Gargantext,
a policy for the uniqueness of the inserted docuemnts has to be defined.

That is the purpose of this module which defines its main concepts.

Unique identifier in database is of a 3-tuple of 3 policies that
together define uniqueness:

- Design policy: type of node is needed as TypenameId, that is a
Document or Individual or something else;

- Privacy policy: with ParentId, parent becomes unique, then it enables
users to get their own copy without sharing it with all the users of the
database (in others words parent_id is necessary to preserve privacy for
instance).

- Hash policy: this UniqId is a sha256 uniq id which is the result of
the concatenation of the parameters defined by @shaParameters@.

> -- * Example
> insertTest :: FromRow r => CorpusId -> [Node HyperdataDocument] -> IO [r]
> insertTest :: IO [ReturnId]
> insertTest = runCmdDev $ insertDocuments 1 452162 hyperdataDocuments

-}
------------------------------------------------------------------------
{-# LANGUAGE DeriveGeneric        #-}
{-# LANGUAGE FlexibleInstances    #-}
{-# LANGUAGE NoImplicitPrelude    #-}
{-# LANGUAGE OverloadedStrings    #-}
{-# LANGUAGE QuasiQuotes          #-}
{-# LANGUAGE RankNTypes           #-}
{-# LANGUAGE TypeSynonymInstances #-}
------------------------------------------------------------------------
module Gargantext.Database.Node.Document.Insert where

import Control.Lens (set, view)
import Control.Lens.Prism
import Control.Lens.Cons
import Data.Aeson (toJSON)
import Data.Maybe (maybe)
import Data.Time.Segment (jour)
import Data.Text (Text)
import Database.PostgreSQL.Simple (FromRow, Query, Only(..))
import Database.PostgreSQL.Simple.FromRow (fromRow, field)
import Database.PostgreSQL.Simple.SqlQQ
import Database.PostgreSQL.Simple.ToField (toField, Action)
import Database.PostgreSQL.Simple.Types (Values(..), QualifiedIdentifier(..))
import GHC.Generics (Generic)
import Gargantext.Database.Config (nodeTypeId)
import Gargantext.Database.Utils (Cmd, runPGSQuery)
import Gargantext.Database.Node.Contact -- (HyperdataContact(..), ContactWho(..))
import Gargantext.Database.Types.Node
import Gargantext.Prelude
import qualified Data.ByteString.Lazy.Char8  as DC (pack)
import qualified Data.Digest.Pure.SHA        as SHA (sha256, showDigest)
import qualified Data.Text                   as DT (pack, unpack, concat, take)
import Gargantext.Prelude.Utils (sha)
-- TODO : the import of Document constructor below does not work
-- import Gargantext.Database.Types.Node (Document)
--import Gargantext.Database.Types.Node (docExample, hyperdataDocument, HyperdataDocument(..)
--                                  , hyperdataDocument_uniqId
--                                  , hyperdataDocument_title
--                                  , hyperdataDocument_abstract
--                                  , hyperdataDocument_source
--                                  , Node(..), node_typename
--                                            , node_userId
--                                            , node_parentId, node_name, node_hyperdata, hyperdataDocuments
--                                  , NodeTypeId
--                                  )
{-| To Print result query
import Data.ByteString.Internal (ByteString)
import Database.PostgreSQL.Simple (formatQuery)
-}

---------------------------------------------------------------------------
-- * Main Insert functions

-- | Insert Document main function
-- UserId : user who is inserting the documents
-- ParentId : folder ID which is parent of the inserted documents
-- Administrator of the database has to create a uniq index as following SQL command:
-- `create unique index on nodes (typename, parent_id, (hyperdata ->> 'uniqId'));`
insertDb :: InsertDb a => UserId -> ParentId -> [a] -> Cmd err [ReturnId]
insertDb u p = runPGSQuery queryInsert . Only . Values fields . map (insertDb' u p)
      where
        fields    = map (\t-> QualifiedIdentifier Nothing t) inputSqlTypes

class InsertDb a
  where
    insertDb' :: UserId -> ParentId -> a -> [Action]


instance InsertDb HyperdataDocument
  where
    insertDb' u p h = [ toField $ nodeTypeId NodeDocument
                      , toField u
                      , toField p
                      , toField $ maybe "No Title" (DT.take 255)  (_hyperdataDocument_title h)
                      , toField $ _hyperdataDocument_publication_date h -- TODO USE UTCTime
                      , (toField . toJSON) h
                      ]

instance InsertDb HyperdataContact
  where
    insertDb' u p h = [ toField $ nodeTypeId NodeContact
                      , toField u
                      , toField p
                      , toField $ maybe "Contact" (DT.take 255) (Just "Name") -- (_hc_name h)
                      , toField $ jour 2010 1 1 -- TODO put default date
                      , (toField . toJSON) h
                      ]


-- | Debug SQL function
--
-- to print rendered query (Debug purpose) use @formatQuery@ function.
{-
insertDocuments_Debug :: (Hyperdata a, ToJSON a, ToRow a) => UserId -> ParentId -> [a] -> Cmd ByteString
insertDocuments_Debug uId pId hs = formatPGSQuery queryInsert (Only $ Values fields inputData)
  where
    fields    = map (\t-> QualifiedIdentifier Nothing t) inputSqlTypes
    inputData = prepare uId pId hs
-}


-- | Input Tables: types of the tables
inputSqlTypes :: [Text]
inputSqlTypes = map DT.pack ["int4","int4","int4","text","date","jsonb"]

-- | SQL query to insert documents inside the database
queryInsert :: Query
queryInsert = [sql|
    WITH input_rows(typename,user_id,parent_id,name,date,hyperdata) AS (?)
    , ins AS (
       INSERT INTO nodes (typename,user_id,parent_id,name,date,hyperdata)
       SELECT * FROM input_rows
       ON CONFLICT ((hyperdata ->> 'uniqIdBdd')) DO NOTHING -- on unique index
       -- ON CONFLICT (typename, parent_id, (hyperdata ->> 'uniqId')) DO NOTHING -- on unique index
       RETURNING id,hyperdata
       )

    SELECT true AS source                     -- true for 'newly inserted'
         , id
         , hyperdata ->> 'uniqId'  as doi
    FROM   ins
    UNION  ALL
    SELECT false AS source                    -- false for 'not inserted'
         , c.id
         , hyperdata ->> 'uniqId' as doi
    FROM   input_rows
    JOIN   nodes c USING (hyperdata);         -- columns of unique index
           |]

------------------------------------------------------------------------
-- * Main Types used

-- ** Return Types

-- | When documents are inserted
-- ReturnType after insertion
data ReturnId = ReturnId { reInserted :: Bool -- if the document is inserted (True: is new, False: is not new)
                         , reId       :: NodeId  -- always return the id of the document (even new or not new)
                                         --   this is the uniq id in the database
                         , reUniqId   :: Text -- Hash Id with concatenation of hash parameters
                         } deriving (Show, Generic)

instance FromRow ReturnId where
  fromRow = ReturnId <$> field <*> field <*> field

---------------------------------------------------------------------------
-- * Uniqueness of document definition

class AddUniqId a
  where
    addUniqId :: a -> a

instance AddUniqId HyperdataDocument
  where
    addUniqId = addUniqIdsDoc
      where
        addUniqIdsDoc :: HyperdataDocument -> HyperdataDocument
        addUniqIdsDoc doc = set hyperdataDocument_uniqIdBdd (Just hashBdd)
                          $ set hyperdataDocument_uniqId    (Just hashUni) doc
          where
            hashUni = hash $ DT.concat $ map ($ doc) hashParametersDoc
            hashBdd = hash $ DT.concat $ map ($ doc) ([(\d -> maybeText (_hyperdataDocument_bdd d))] <> hashParametersDoc)

        hashParametersDoc :: [(HyperdataDocument -> Text)]
        hashParametersDoc = [ \d -> maybeText (_hyperdataDocument_title    d)
                            , \d -> maybeText (_hyperdataDocument_abstract d)
                            , \d -> maybeText (_hyperdataDocument_source   d)
                            , \d -> maybeText (_hyperdataDocument_publication_date   d)
                            ]

    ---------------------------------------------------------------------------
-- * Uniqueness of document definition
-- TODO factorize with above (use the function below for tests)

instance AddUniqId HyperdataContact
  where
    addUniqId = addUniqIdsContact

addUniqIdsContact :: HyperdataContact -> HyperdataContact
addUniqIdsContact hc = set (hc_uniqIdBdd) (Just hashBdd)
                     $ set (hc_uniqId   ) (Just hashUni) hc
  where
    hashUni = uniqId $ DT.concat $ map ($ hc) hashParametersContact
    hashBdd = uniqId $ DT.concat $ map ($ hc) ([\d -> maybeText (view hc_bdd d)] <> hashParametersContact)

    uniqId :: Text -> Text
    uniqId = DT.pack . SHA.showDigest . SHA.sha256 . DC.pack . DT.unpack

    -- | TODO add more hashparameters
    hashParametersContact :: [(HyperdataContact -> Text)]
    hashParametersContact = [ \d -> maybeText $ view (hc_who . _Just . cw_firstName) d
                            , \d -> maybeText $ view (hc_who . _Just . cw_lastName ) d
                            , \d -> maybeText $ view (hc_where . _head . cw_touch . _Just . ct_mail) d
                            ]



maybeText :: Maybe Text -> Text
maybeText = maybe (DT.pack "") identity

---------------------------------------------------------------------------