{-|
Module      : Gargantext.API.Public
Description :
Copyright   : (c) CNRS, 2017-Present
License     : AGPL + CECILL v3
Maintainer  : team@gargantext.org
Stability   : experimental
Portability : POSIX

-}

{-# LANGUAGE TemplateHaskell     #-}
{-# LANGUAGE TypeOperators       #-}
{-# LANGUAGE ScopedTypeVariables #-}

module Gargantext.API.Public
      where

import Data.Set (Set)
import Control.Lens ((^?), (^.), _Just)
import Data.Maybe (catMaybes)
import Data.Text (Text)
import Data.List (replicate, null)
import Data.Aeson
import Data.Swagger
import GHC.Generics (Generic)
import Gargantext.API.Prelude
import Gargantext.API.Node.File
import Gargantext.Database.Query.Table.Node.Error (HasNodeError(..))
import Gargantext.Database.Prelude
import Gargantext.Database.Admin.Types.Node
import Gargantext.Database.Query.Table.NodeNode (selectPublicNodes)
import Gargantext.Core.Utils.DateUtils (utc2year)
import Gargantext.Database.Admin.Types.Hyperdata
import Gargantext.Database.Schema.Node -- (NodePoly(..))
import Gargantext.Prelude
import Servant
import Test.QuickCheck (elements)
import Test.QuickCheck.Arbitrary

import qualified Data.List as List
import qualified Data.Map as Map
import qualified Data.Set as Set

------------------------------------------------------------------------
type API =  API_Home
       -- :<|> API_Node

api :: Text -> GargServer API
api baseUrl = (api_home baseUrl)
          -- :<|> api_node
-------------------------------------------------------------------------
type API_Home = Summary " Public API"
         :> Get '[JSON] [PublicData]

api_home :: Text -> GargServer API_Home
api_home baseUrl = catMaybes
   <$> map (toPublicData baseUrl)
   <$> filterPublicDatas
   <$> selectPublic

-------------------------------------------------------------------------
type API_Node = Summary " Public Node API"
              :> FileApi

api_node :: UserId -> NodeId -> GargServer FileApi
api_node uid nId = do
  pubNodes <- publicNodes
  case Set.member nId pubNodes of
    False -> panic "Not allowed" -- TODO throwErr
    True  -> fileApi uid nId

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


selectPublic :: HasNodeError err
             => Cmd err [( Node HyperdataFolder, Maybe Int)]
selectPublic = selectPublicNodes

  -- For tests only
  -- pure $ replicate 6 defaultPublicData

filterPublicDatas :: [(Node HyperdataFolder, Maybe Int)]
                  -> [(Node HyperdataFolder, [NodeId])]
filterPublicDatas datas =
  map (\(n,mi) ->
          let mi' = NodeId <$> mi in
                  ( _node_id n, (n, maybe [] (:[]) mi' ))
      ) datas
      & Map.fromListWith (\(n1,i1) (_n2,i2) -> (n1, i1 <> i2))
      & Map.filter (not . null . snd)
      & Map.elems

publicNodes :: HasNodeError err
            => Cmd err (Set NodeId)
publicNodes = do
  candidates <- filterPublicDatas <$> selectPublicNodes
  pure $ Set.fromList
       $ List.concat
       $ map (\(n, ns) -> (_node_id n) : ns) candidates


-- http://localhost:8008/api/v1.0/node/23543/file/download<Paste>
-- http://localhost:8000/images/Gargantextuel-212x300.jpg
toPublicData :: Text -> (Node HyperdataFolder, [NodeId]) -> Maybe PublicData
toPublicData base (n , mn) = PublicData <$> (hd ^? (_Just . hf_data . cf_title))
                                   <*> (hd ^? (_Just . hf_data . cf_desc ))
                                   <*> (Just $ url' mn) -- "images/Gargantextuel-212x300.jpg"
                                   <*> (Just $ url' mn)
                                   <*> Just (cs $ show $ utc2year (n^.node_date))
                                   <*> (hd ^? (_Just . hf_data . cf_query))
                                   <*> (hd ^? (_Just . hf_data . cf_authors))
  where
    hd = head
       $ filter (\(HyperdataField cd _ _) -> cd == JSON)
       $ n^. (node_hyperdata . hc_fields)
    url' :: [NodeId] -> Text 
    url' mn' = base 
           <>   "/node/" 
           <> (cs $ show $ (maybe 0 unNodeId $ head mn'))
           <> "/file/download"


data PublicData = PublicData
  { title    :: Text
  , abstract :: Text
  , img      :: Text
  , url      :: Text
  , date     :: Text
  , database :: Text
  , author   :: Text
  } | NoData { nodata:: Text}
  deriving (Generic)


instance FromJSON  PublicData where
  parseJSON = genericParseJSON (defaultOptions { sumEncoding = ObjectWithSingleField })

instance ToJSON    PublicData where
  toJSON = genericToJSON (defaultOptions { sumEncoding = ObjectWithSingleField })

instance ToSchema  PublicData
instance Arbitrary PublicData where
  arbitrary = elements
            $ replicate 6 defaultPublicData 

defaultPublicData :: PublicData
defaultPublicData =
  PublicData "Title"
             (foldl (<>) "" $ replicate 100 "abstract ")
             "images/Gargantextuel-212x300.jpg"
             "https://.."
             "YY/MM/DD"
             "database"
             "Author"