69 lines
1.6 KiB
Haskell
69 lines
1.6 KiB
Haskell
{-# LANGUAGE OverloadedStrings, DeriveGeneric #-}
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module Main where
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import GHC.Generics
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import Data.ByteString.Lazy
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import Database.PostgreSQL.Simple
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import Database.PostgreSQL.Simple.FromRow
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import Control.Applicative
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import Network.Wai
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import Network.Wai.Handler.Warp hiding (Connection)
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import Network.HTTP.Types.Status
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import qualified Data.Aeson as JSON
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data View = View {
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viewSchema :: String
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, viewName :: String
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, viewUpdatable :: Bool
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, viewInsertable :: Bool
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} deriving (Show, Generic)
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instance FromRow View where
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fromRow = View <$> field <*> field <*>
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fmap toBool field <*> fmap toBool field
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instance JSON.ToJSON View
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toBool :: String -> Bool
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toBool = (== "YES")
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data Column = Column {
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colSchema :: String
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, colTable :: String
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, colName :: String
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, colPosition :: Int
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, colNullable :: Bool
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, colType :: String
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, colUpdatable :: Bool
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, colMaxLen :: Maybe Int
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, colPrecision :: Maybe Int
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} deriving (Show)
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views :: String -> Connection -> IO [View]
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views s conn = query conn q $ Only s
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where q = "select table_schema, table_name,\
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\ is_updatable, is_insertable_into \
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\ from information_schema.views\
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\ where table_schema = ?"
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main :: IO ()
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main = do
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let port = 3000
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Prelude.putStrLn $ "Listening on port " ++ show port
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run port app
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payload :: Connection -> IO ByteString
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payload conn = JSON.encode <$> views "base" conn
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app :: Application
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app req respond =
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respond =<< responseLBS status200 [] <$> (payload =<< conn)
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where
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conn = connect defaultConnectInfo {
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connectDatabase = "dbapi_test"
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}
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