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module Store.Query
( module Store.Query.Type,
query,
)
where
import Control.Arrow (second)
import Control.Exception (throw)
import Control.Monad.Trans (lift)
import Data.Aeson qualified as J
import Data.Aeson.Encode.Pretty qualified as JP
import Data.Aeson.Key qualified as JK
import Data.Aeson.KeyMap qualified as JM
import Data.List (foldl', foldl1')
import Data.Map qualified as M
import Data.Maybe (fromMaybe)
import Data.Text qualified as T
import Data.Vector qualified as V
import GHC.Generics (Generic)
import Store.Exception (DecodeException (DecodeException), MissingFileName (MissingFileName))
import Store.Query.Parser ()
import Store.Query.Printer ()
import Store.Query.Record
import Store.Query.Type
import Store.Store qualified as S
import System.FilePath ((</>))
data Paginated = Paginated
{ count :: Int,
data_ :: [J.Value]
}
deriving (Show, Generic)
instance J.ToJSON Paginated
instance J.FromJSON Paginated
query :: Query -> S.StoreM J.Value
query (Delete c w) = do
c' <-
mapM (\fn -> fmap ((fn,) . fromValue c) . decodeFile c $ fn)
=<< S.listFiles c
let fps = map fst $ whereBy snd w (map (second (: [])) c')
lift $ print fps
mapM_ S.deleteFile (map (c </>) fps)
S.commit
pure (J.toJSON ([] @()))
query (Insert vs c) = do
let vs' = map (\v -> ((c, fileName v), v)) vs
fileName v@(J.Object kvs) =
case JM.lookup "$fileName" kvs of
Just (J.String fileName) -> T.unpack fileName
_ -> throw (MissingFileName v)
mapM_ (\((c, fn), v) -> encodeFile c fn v) vs'
S.commit
pure (J.toJSON ([] @()))
query (Select fs c js es w l o) = do
c' <-
mapM (\fn -> fromValue c <$> decodeFile c fn)
=<< S.listFiles c
js' <-
mapM
( \(JoinClause t c w) ->
fmap (\j' -> JoinClause t (map (fromValue c) j') w)
. mapM (decodeFile c)
=<< S.listFiles c
)
js
es' <-
mapM
( \(EmbedClause c w) ->
fmap (\e' -> EmbedClause (fromValue c e') w)
. mapM (decodeFile c)
=<< S.listFiles c
)
es
let rs =
map (Store.Query.select fs)
. where_ w
. embeds es'
. joins js'
$ c'
rs' =
case l >> o >> pure () of
(Just _) ->
J.toJSON (Paginated (length rs) . applyLimit l . applyOffset o $ rs)
_ -> J.toJSON rs
pure rs'
query (Update c v w) = do
c' <-
mapM (\fn -> fmap (((c, fn),) . fromValue c) . decodeFile c $ fn)
=<< S.listFiles c
let c'' = whereBy snd w (map (second (: [])) c')
mapM_
( \((c, fn), v') ->
encodeFile c fn (foldl1' union (map toValue v') `union` v)
)
c''
S.commit
pure (J.toJSON ([] @()))
applyLimit :: Maybe LimitClause -> [a] -> [a]
applyLimit Nothing = id
applyLimit (Just (Limit n)) = take n
applyOffset :: Maybe OffsetClause -> [a] -> [a]
applyOffset Nothing = id
applyOffset (Just (Offset n)) = drop n
embeds ::
EmbedClauses (Record [J.Value]) ->
[Records J.Value] ->
[Records J.Value]
embeds = flip (foldl' embed)
embed ::
[Records J.Value] ->
EmbedClause (Record [J.Value]) ->
[Records J.Value]
embed vss (EmbedClause (Record c es) w) =
map
( \vs ->
vs
++ [ fromValue
c
( J.Array
( V.fromList
[ e
| e <- es,
satisfies w (vs ++ [Record c e])
]
)
)
]
)
vss
joins ::
JoinClauses (Records J.Value) ->
[Record J.Value] ->
[Records J.Value]
joins js (map (: []) -> vss) = foldl' join vss js
join ::
[Records J.Value] ->
JoinClause (Records J.Value) ->
[Records J.Value]
join vss (JoinClause JoinLeft js w) =
concatMap
( \vs -> case filter (satisfies w) $ map (\j -> vs ++ [j]) js of
[] -> [vs]
vs' -> vs'
)
vss
join vss (JoinClause JoinRight js w) =
concatMap
( \j -> case filter (satisfies w) $ map (\vs -> vs ++ [j]) vss of
[] -> [[j]]
vs' -> vs'
)
js
join vss (JoinClause JoinFull js w) =
concatMap
( \vs -> case filter (satisfies w) $ map (\j -> vs ++ [j]) js of
[] -> [vs]
vs' -> vs'
)
vss
++ concatMap
( \j -> case filter (satisfies w) $ map (\vs -> vs ++ [j]) vss of
[] -> [[j]]
_ -> []
)
js
select :: FieldSelector -> Records J.Value -> J.Value
select (SelectObject kvs) vs =
J.Object
. JM.fromMap
. M.mapKeys JK.fromString
. (M.map (\s -> Store.Query.select s vs))
$ kvs
select (SelectField f) vs = fromMaybe J.Null (lookups f vs)
where_ :: Maybe WhereClause -> [Records J.Value] -> [Records J.Value]
where_ = whereBy id
whereBy :: (a -> [Record J.Value]) -> Maybe WhereClause -> [a] -> [a]
whereBy f w = filter (satisfies w . f)
satisfies :: Maybe WhereClause -> Records J.Value -> Bool
satisfies Nothing _ = True
satisfies (Just (And ws)) vs = all (\w -> satisfies (Just w) vs) ws
satisfies (Just (Or ws)) vs = any (\w -> satisfies (Just w) vs) ws
satisfies (Just (Where (Eq f g))) vs = either Just (flip lookups vs) f == either Just (flip lookups vs) g
decodeFile :: String -> String -> S.StoreM J.Value
decodeFile c fn = do
let fp = c </> fn
union (J.Object (JM.singleton "$fileName" (J.String (T.pack fn))))
. fromMaybe (throw DecodeException)
. J.decode
<$> S.readFile fp
encodeFile :: String -> String -> J.Value -> S.StoreM ()
encodeFile c fn (J.Object kvs) = do
let fp = c </> fn
S.writeFile fp (JP.encodePretty (J.Object (JM.filterWithKey (\k _ -> k /= "$fileName") kvs)))
|
