{-# LANGUAGE CPP #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE KindSignatures #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE TypeFamilies #-}
module Database.Relational.PostgreSQL.Pure.TH (
makeRelationalRecord,
makeRelationalRecord',
defineTableDefault',
defineTableDefault,
defineTableFromDB',
defineTableFromDB,
inlineVerifiedQuery
) where
import Control.Monad (void, when)
import qualified Data.Map as Map
import Data.Maybe (fromMaybe, listToMaybe)
import Data.String (fromString)
import Database.PostgreSQL.Pure (ColumnInfo, Connection, FromRecord, Length, Oid, ToRecord,
disconnect, parse, sync)
import Language.Haskell.TH (Dec, Name, Q, TyLit (NumTyLit), Type (AppT, ConT, LitT), TypeQ,
runIO)
import Language.Haskell.TH.Lib.Extra (reportError, reportWarning)
import Language.Haskell.TH.Name.CamelCase (varCamelcaseName)
import Language.Haskell.TH.Syntax (returnQ)
import Database.Record.TH (recordTemplate)
import Database.Relational (Config, Relation, defaultConfig, enableWarning, nameConfig,
recordConfig, relationalQuery_, untypeQuery,
verboseAsCompilerWarning)
import qualified Database.Relational.TH as Relational
import Language.SQL.Keyword (Keyword)
import Database.Schema.PostgreSQL.Pure.Driver (Driver, driverConfig, emptyLogChan, foldLog, getFields,
getPrimaryKey, takeLogs)
import Data.Tuple.Homotuple (IsHomolisttuple, IsHomotupleItem)
import GHC.TypeLits (KnownNat)
defineInstancesForRecord :: TypeQ -- ^ Record type constructor.
-> Q [Dec] -- ^ Instance declarations.
defineInstancesForRecord typeCon = do
[d| instance FromRecord $typeCon
instance ToRecord $typeCon
|]
defineInstancesForLength :: TypeQ -> Int -> Q [Dec]
defineInstancesForLength typeCon len = do
let len' = returnQ $ LitT $ NumTyLit $ toInteger len
[d| type instance Length $typeCon = $len' |]
-- | Generate all persistable templates against defined record like type constructor.
makeRelationalRecord' :: Config
-> Name -- ^ Type constructor name
-> Q [Dec] -- ^ Result declaration
makeRelationalRecord' config recTypeName =
Relational.makeRelationalRecordDefault' config recTypeName
-- | Generate all persistable templates against defined record like type constructor.
makeRelationalRecord :: Name -- ^ Type constructor name
-> Q [Dec] -- ^ Result declaration
makeRelationalRecord = makeRelationalRecord' defaultConfig
-- | Generate all HDBC templates about table except for constraint keys.
defineTableDefault' :: Config -- ^ Configuration to generate query with
-> String -- ^ Schema name
-> String -- ^ Table name
-> [(String, TypeQ)] -- ^ List of column name and type
-> [Name] -- ^ Derivings
-> Q [Dec] -- ^ Result declaration
defineTableDefault' config schema table columns derives =
Relational.defineTableTypesAndRecord config schema table columns derives
-- | Generate all HDBC templates about table.
defineTableDefault :: Config -- ^ Configuration to generate query with
-> String -- ^ Schema name
-> String -- ^ Table name
-> [(String, TypeQ)] -- ^ List of column name and type
-> [Name] -- ^ Derivings
-> [Int] -- ^ Indexes to represent primary key
-> Maybe Int -- ^ Index of not-null key
-> Q [Dec] -- ^ Result declaration
defineTableDefault config schema table columns derives primary notNull = do
modelD <- Relational.defineTable config schema table columns derives primary notNull
let typeCon = fst $ recordTemplate (recordConfig $ nameConfig config) schema table
recordD <- defineInstancesForRecord typeCon
lengthD <- defineInstancesForLength typeCon $ length columns
return $ modelD ++ recordD ++ lengthD
tableAlongWithSchema :: IO Connection -- ^ Connect action to system catalog database
-> Driver -- ^ Driver definition
-> String -- ^ Schema name
-> String -- ^ Table name
-> [(String, TypeQ)] -- ^ Additional column-name and column-type mapping to overwrite default
-> [Name] -- ^ Derivings
-> Q [Dec] -- ^ Result declaration
tableAlongWithSchema connect drv scm tbl cmap derives = do
let config = driverConfig drv
getDBinfo = do
logChan <- emptyLogChan
infoP <- do
conn <- connect
p <-
(,)
<$> getFields drv conn logChan scm tbl
<*> getPrimaryKey drv conn logChan scm tbl
disconnect conn
pure p
(,) infoP <$> takeLogs logChan
(((cols, notNullIdxs), primaryCols), logs) <- runIO getDBinfo
let reportWarning'
| enableWarning config = reportWarning
| otherwise = const $ pure ()
reportVerbose
| verboseAsCompilerWarning config = reportWarning
| otherwise = const $ pure ()
mapM_ (foldLog reportVerbose reportWarning' reportError) logs
when (null primaryCols) . reportWarning'
$ "getPrimaryKey: Primary key not found for table: " ++ scm ++ "." ++ tbl
let colIxMap = Map.fromList $ zip [c | (c, _) <- cols] [(0 :: Int) .. ]
ixLookups = [ (k, Map.lookup k colIxMap) | k <- primaryCols ]
warnLk k = maybe
(reportWarning $ "defineTableFromDB: fail to find index of pkey - " ++ k ++ ". Something wrong!!")
(const $ return ())
primaryIxs = fromMaybe [] . sequence $ map snd ixLookups
mapM_ (uncurry warnLk) ixLookups
let liftMaybe tyQ sty = do
ty <- tyQ
case ty of
(AppT (ConT n) _) | n == ''Maybe -> [t| Maybe $(sty) |]
_ -> sty
cols1 = [ (,) cn . maybe ty (liftMaybe ty) . Map.lookup cn $ Map.fromList cmap | (cn, ty) <- cols ]
defineTableDefault config scm tbl cols1 derives primaryIxs (listToMaybe notNullIdxs)
-- | Generate all HDBC templates using system catalog informations with specified config.
defineTableFromDB' :: IO Connection -- ^ Connect action to system catalog database
-> Driver -- ^ Driver definition
-> String -- ^ Schema name
-> String -- ^ Table name
-> [(String, TypeQ)] -- ^ Additional column-name and column-type mapping to overwrite default
-> [Name] -- ^ Derivings
-> Q [Dec] -- ^ Result declaration
defineTableFromDB' = tableAlongWithSchema
-- | Generate all HDBC templates using system catalog informations.
defineTableFromDB :: IO Connection -- ^ Connect action to system catalog database
-> Driver -- ^ Driver definition
-> String -- ^ Schema name
-> String -- ^ Table name
-> [Name] -- ^ Derivings
-> Q [Dec] -- ^ Result declaration
defineTableFromDB connect driver scm tbl = tableAlongWithSchema connect driver scm tbl []
-- | Verify composed 'Query' and inline it in compile type.
inlineVerifiedQuery :: forall p r.
( KnownNat (Length p)
, KnownNat (Length r)
, IsHomotupleItem (Length p) Oid
, IsHomotupleItem (Length r) Oid
, IsHomotupleItem (Length r) ColumnInfo
, IsHomolisttuple (Length p) Oid
, IsHomolisttuple (Length r) Oid
, IsHomolisttuple (Length r) ColumnInfo
)
=> IO Connection -- ^ Connect action to system catalog database
-> Name -- ^ Top-level variable name which has 'Relation' type
-> Relation p r -- ^ Object which has 'Relation' type
-> Config -- ^ Configuration to generate SQL
-> [Keyword] -- ^ suffix SQL words. for example, `[FOR, UPDATE]`, `[FETCH, FIRST, "3", ROWS, ONLY]` ...
-> String -- ^ Variable name to define as inlined query
-> Q [Dec] -- ^ Result declarations
#if MIN_VERSION_relational_query(0,13,0)
inlineVerifiedQuery connect relVar rel config sufs declName =
Relational.inlineQuery_ check relVar rel config sufs declName
where
check sql = do
when (verboseAsCompilerWarning config) . reportWarning $ "Verify with prepare: " ++ sql
void . runIO $ do
conn <- connect
let psProc = parse @(Length p) @(Length r) "" (fromString sql) Nothing
void $ sync conn psProc
disconnect conn
#else
inlineVerifiedQuery connect relVar rel config sufs qns = do
(p, r) <- Relational.reifyRelation relVar
let sql = untypeQuery $ relationalQuery_ config rel sufs
when (verboseAsCompilerWarning config) . reportWarning $ "Verify with prepare: " ++ sql
void . runIO $ do
conn <- connect
let psProc = parse @(Length p) @(Length r) "" (fromString sql) Nothing
void $ sync conn psProc
disconnect conn
Relational.unsafeInlineQuery (return p) (return r) sql (varCamelcaseName qns)
#endif