{-# LANGUAGE TemplateHaskell, BangPatterns #-}

module LazyTest where

import Database.MetaHDBC

import Data.Maybe
import Language.Haskell.TH
import Test.HUnit

import Database.HDBC
import Database.HDBC.ODBC

import DSN

elementCount :: Int
elementCount = 2500

-- lazyTest* are ExpQ so they will not be evaluated unless we call them

lazyTestPQ :: ExpQ -- Test
lazyTestPQ =
 [| let input = map show [1..elementCount]
        elements :: [Maybe Int]
        elements = map Just [1..elementCount]
    in TestLabel ("LazyTest with dsn " ++ pqDsn) $ test $
          do conn <- connectODBC pqDsn
             $(runStmt pqDsn "DELETE FROM lazytest") conn
             commit conn
             stmt <- $(prepareStmt pqDsn "INSERT INTO lazytest (id, val) VALUES ( ?, ? )") conn
             mapM_ (uncurry stmt) $ zip input input
             commit conn
             --
             resStrict <- strict ( $(runStmt pqDsn "SELECT * FROM lazytest") conn )
             disconnect conn    -- Here DB2 stumbles. I think it cannot
                                -- handle closing connection with unevaluated
                                -- parts.
             assertEqual "Retrieved strict query (length)" (length elements) (length resStrict)
             assertEqual "Retrieved strict query (last)" (last elements) (snd $ last resStrict)
          `rethrowDoing` "Running lazytest"
  |]

lazyTestDb2 :: ExpQ -- Test
lazyTestDb2 =
 [| let elements :: [Int]
        elements = [1..elementCount]
    in TestLabel ("LazyTest with dsn " ++ db2Dsn) $ test $
          do conn <- connectODBC db2Dsn
             $(runStmt db2Dsn "DELETE FROM lazytest") conn
             commit conn
             stmt <- $(prepareStmt db2Dsn "INSERT INTO lazytest (id, val) VALUES ( ?, ? )") conn
             mapM_ (uncurry stmt) $ zip elements elements
             commit conn
             --
             resStrict <- strict ( $(runStmt db2Dsn "SELECT * FROM lazytest") conn )
             commit conn
             disconnect conn
             assertEqual "Retrieved strict query (length)" (length elements) (length resStrict)
             assertEqual "Retrieved strict query (last)" (last elements) (snd $ last resStrict)
          `rethrowDoing` "Running db2-lazytest"
  |]
 
 
lazyTestMSSQL :: ExpQ -- Test
lazyTestMSSQL =
 [| let elements :: [Int]
        elements = [1..elementCount]
    in TestLabel ("LazyTest with dsn " ++ msSqlDsn) $ test $
          do conn <- connectODBC msSqlDsn
             $(runStmt msSqlDsn "DELETE FROM lazytest") conn
             commit conn
             stmt <- $(prepareStmt msSqlDsn "INSERT INTO lazytest (id, val) VALUES ( ?, ? )") conn
             mapM_ (uncurry stmt) $ zip elements elements
             commit conn
             --
             resStrict <- strict ( $(runStmt msSqlDsn "SELECT * FROM lazytest") conn )
             commit conn
             disconnect conn
             assertEqual "Retrieved strict query (length)" (length elements) (length resStrict)
             assertEqual "Retrieved strict query (last)" (last elements) (snd $ last resStrict)
          `rethrowDoing` "Running mssql-lazytest"
  |]