path: root/tools/acid-migrate/Acid.hs

{-# LANGUAGE DeriveDataTypeable, GeneralizedNewtypeDeriving, RecordWildCards, 
TemplateHaskell, TypeFamilies, OverloadedStrings, ScopedTypeVariables #-}

module Main where
import Control.Applicative  ((<$>), optional)
import Control.Exception    (bracket)
import Control.Monad        (msum, mzero)
import Control.Monad.IO.Class (MonadIO)
import Control.Monad.Reader (ask)
import Control.Monad.State  (get, put)
import Control.Monad.Trans  (liftIO)
import Data.Acid
import Data.Acid.Advanced 
import Data.Acid.Local
import Data.ByteString      (ByteString)
import Data.Data            (Data, Typeable)
import Data.IxSet           (Indexable(..), IxSet(..), (@=), Proxy(..), getOne, ixFun, ixSet)
import Data.SafeCopy        (SafeCopy, base, deriveSafeCopy)
import Data.Text            (Text, pack)
import Data.Text.Lazy       (toStrict)
import Data.Time
import Happstack.Server hiding (Session)

import qualified Crypto.Hash.SHA512 as SHA (hash)
import qualified Data.ByteString.Char8 as B
import qualified Data.ByteString.Base64 as B64 (encode)
import qualified Data.IxSet as IxSet
import qualified Data.Text  as Text


{-CouchDB imports-}

import Database.CouchDB
import Database.CouchDB.JSON
import Text.JSON
import Data.List (intersperse)
import System.Locale (defaultTimeLocale)

-- data types and acid-state setup

newtype EntryId = EntryId { unEntryId :: Integer }
    deriving (Eq, Ord, Data, Enum, Typeable, SafeCopy)

data BlogLang = EN | DE 
	deriving (Eq, Ord, Data, Typeable)

instance Show BlogLang where
	show DE = "de"
	show EN = "en"

$(deriveSafeCopy 0 'base ''BlogLang)

data Comment = Comment { 
	cauthor :: Text,
	ctext   :: Text,
	cdate   :: UTCTime
} deriving (Eq, Ord, Data, Typeable)

$(deriveSafeCopy 0 'base ''Comment)

data Entry = Entry {
	entryId :: EntryId,
	lang   :: BlogLang,
	author :: Text,
	title  :: Text,
	btext  :: Text, 
	mtext  :: Text,
	edate  :: UTCTime,
	tags   :: [Text],
	comments :: [Comment]
} deriving (Eq, Ord, Data, Typeable)

$(deriveSafeCopy 0 'base ''Entry)

-- ixSet requires different datatypes for field indexes, so let's define some
newtype Author = Author Text   deriving (Eq, Ord, Data, Typeable, SafeCopy)
newtype Title  = Title Text    deriving (Eq, Ord, Data, Typeable, SafeCopy)
newtype BText  = BText Text    deriving (Eq, Ord, Data, Typeable, SafeCopy) -- standard text
newtype MText  = MText Text    deriving (Eq, Ord, Data, Typeable, SafeCopy) -- "read more" text
newtype Tag    = Tag Text 	   deriving (Eq, Ord, Data, Typeable, SafeCopy)
newtype EDate  = EDate UTCTime deriving (Eq, Ord, Data, Typeable, SafeCopy)
newtype SDate  = SDate UTCTime   deriving (Eq, Ord, Data, Typeable, SafeCopy)
newtype Username = Username Text deriving (Eq, Ord, Data, Typeable, SafeCopy)
newtype SessionID = SessionID Text deriving (Eq, Ord, Data, Typeable, SafeCopy)

instance Indexable Entry where 
	empty = ixSet [ ixFun $ \e -> [ entryId e]
				  , ixFun $ (:[]) . lang
				  , ixFun $ \e -> [ Author $ author e ]
				  , ixFun $ \e -> [ Title $ title e]
				  , ixFun $ \e -> [ BText $ btext e]
				  , ixFun $ \e -> [ MText $ mtext e]
				  , ixFun $ \e -> [ EDate $ edate e]
				  , ixFun $ \e -> map Tag (tags e)
				  , ixFun $ comments
				  ]

data User = User {
	username :: Text,
	password :: ByteString
} deriving (Eq, Ord, Data, Typeable)

$(deriveSafeCopy 0 'base ''User)

data Session = Session {
	sessionID :: Text,
	user	  :: User,
	sdate	  :: UTCTime
} deriving (Eq, Ord, Data, Typeable)

$(deriveSafeCopy 0 'base ''Session)

instance Indexable User where
	empty = ixSet [ ixFun $ \u -> [Username $ username u]
				  , ixFun $ (:[]) . password 
				  ]

instance Indexable Session where
	empty = ixSet [ ixFun $ \s -> [SessionID $ sessionID s]
				  , ixFun $ (:[]) . user
				  , ixFun $ \s -> [SDate $ sdate s]
				  ]

data Blog = Blog {
	blogSessions :: IxSet Session,
	blogUsers    :: IxSet User,
	blogEntries  :: IxSet Entry
} deriving (Data, Typeable)

$(deriveSafeCopy 0 'base ''Blog)

initialBlogState :: Blog 
initialBlogState = 
	Blog { blogSessions = empty
		 , blogUsers = empty
		 , blogEntries = empty }

-- acid-state database functions (purity is necessary!)

insertEntry :: Entry -> Update Blog Entry
insertEntry e = 
	do b@Blog{..} <- get
	   put $ b { blogEntries = IxSet.insert e blogEntries }
	   return e

updateEntry :: Entry -> Update Blog Entry
updateEntry e = 
	do b@Blog{..} <- get
	   put $ b { blogEntries = IxSet.updateIx (entryId e) e blogEntries}
	   return e

getPost :: EntryId -> Query Blog (Maybe Entry)
getPost eid =
	do b@Blog{..} <- ask
	   return $ getOne $ blogEntries @= eid

latestPosts :: Query Blog [Entry]
latestPosts =
	do b@Blog{..} <- ask
	   return $ IxSet.toDescList (Proxy :: Proxy UTCTime) $ blogEntries

addSession :: Text -> User -> UTCTime -> Update Blog Session
addSession sId u t =
	do b@Blog{..} <- get
	   let s = Session sId u t
	   put $ b { blogSessions = IxSet.insert s blogSessions}
	   return s

addUser :: Text -> String -> Update Blog User
addUser un pw =
	do b@Blog{..} <- get
	   let u = User un $ hashString pw
	   put $ b { blogUsers = IxSet.insert u blogUsers}
	   return u

-- various functions
hashString :: String -> ByteString
hashString = B64.encode .  SHA.hash . B.pack

$(makeAcidic ''Blog
	[ 'insertEntry
	, 'updateEntry
	, 'getPost
	, 'latestPosts
	, 'addSession
	, 'addUser
	])

-- CouchDB database functions
instance JSON Comment where
	showJSON = undefined
	readJSON val = do
		obj <- jsonObject val
		scauthor <- jsonField "cauthor" obj
		scdate <- jsonField "cdate" obj
		sctext <- jsonField "cdate" obj
		return $ Comment (pack scauthor) (pack sctext) (parseSeconds scdate)

instance JSON Entry where
	showJSON = undefined
	readJSON val = do
		obj <- jsonObject val
		sauthor <- jsonField "author" obj
		stitle <- jsonField "title" obj
		day <- jsonField "day" obj
		month <- jsonField "month" obj
		year <- jsonField "year" obj
		stext <- jsonField "text" obj
		comments <- jsonField "comments" obj
		oldid <- jsonField "id_" obj
		let leTime = parseShittyTime year month day oldid
		return $ Entry (EntryId $ getUnixTime leTime) DE (pack sauthor) (pack stitle) (pack stext) (Text.empty) 
						leTime [] comments


getUnixTime :: UTCTime -> Integer
getUnixTime t = read $ formatTime defaultTimeLocale "%s" t

parseSeconds :: Integer -> UTCTime
parseSeconds t = readTime defaultTimeLocale "%s" $ show t

parseShittyTime :: Int -> Int -> Int -> String -> UTCTime
parseShittyTime y m d i = readTime defaultTimeLocale "%Y %m %e  %k:%M:%S" newPartTime
	where
		firstPart = take 2 i
		secondPart = take 2 $ drop 2 i
		thirdPart = drop 4 i
		newPartTime =  concat $ intersperse " " [show y, showMonth m, show d, " "] ++ 
						intersperse ":" [firstPart, secondPart, thirdPart]
		showMonth mn  
				| mn < 10 = "0" ++ show mn
				| otherwise = show mn

getOldEntries = runCouchDB' $ queryView (db "tazblog") (doc "entries") (doc "latestDE") []

parseOldEntries :: IO [Entry]
parseOldEntries = do
	queryResult <- getOldEntries
	let entries = map (stripResult . readJSON . snd) queryResult
	return entries

stripResult :: Result a -> a
stripResult (Ok z) = z
stripResult (Error s) = error $ "JSON error: " ++ s

pasteToDB :: AcidState Blog -> Entry -> IO (EventResult InsertEntry)
pasteToDB acid e = update' acid (InsertEntry e)

main :: IO()
main = do
	bracket (openLocalState initialBlogState)
			(createCheckpointAndClose)
			(\acid -> convertEntries acid)

convertEntries acid = do
	entries <- parseOldEntries
	let x = map (pasteToDB acid) entries
	putStrLn "Conversion successful"