yammat/Handler/Avatar.hs

--  yammat - Yet Another MateMAT
--  Copyright (C) 2015  Amedeo Molnár
--
--  This program is free software: you can redistribute it and/or modify
--  it under the terms of the GNU Affero General Public License as published
--  by the Free Software Foundation, either version 3 of the License, or
--  (at your option) any later version.
--
--  This program is distributed in the hope that it will be useful,
--  but WITHOUT ANY WARRANTY; without even the implied warranty of
--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--  GNU Affero General Public License for more details.
--
--  You should have received a copy of the GNU Affero General Public License
--  along with this program.  If not, see <http://www.gnu.org/licenses/>.
module Handler.Avatar where

import Import
import Data.Conduit.Binary
import qualified Data.Text as T
import qualified Data.ByteString as B
import qualified Data.ByteString.Lazy as L
import Data.ByteString.Base64
import Graphics.ImageMagick.MagickWand
import qualified Crypto.Hash.SHA3 as SHA3

getAvatarR :: Handler Html
getAvatarR = do
  avatars <- runDB $ selectList [] [Asc AvatarIdent]
  defaultLayout $
    $(widgetFile "avatars")

getNewAvatarR :: Handler Html
getNewAvatarR = do
  (newAvatarWidget, enctype) <- generateFormPost avatarNewForm
  defaultLayout $
    $(widgetFile "newAvatar")

postNewAvatarR :: Handler Html
postNewAvatarR = do
  ((res, _), _) <- runFormPost avatarNewForm
  case res of
    FormSuccess na -> do
      raw <- runResourceT $ fileSource (avatarNewFile na) $$ sinkLbs
      (thumb, hash) <- generateThumb $ B.concat $ L.toChunks raw
      runDB $ insert_ $ Avatar (avatarNewIdent na) thumb hash
      setMessageI MsgAvatarUploadSuccessfull
      redirect HomeR
    _ -> do
      setMessageI MsgErrorOccured
      redirect NewAvatarR

avatarNewForm :: Form AvatarNew
avatarNewForm = renderDivs $ AvatarNew
  <$> areq textField (fieldSettingsLabel MsgAvatarIdent) Nothing
  <*> areq fileField (fieldSettingsLabel MsgAvatarFile) Nothing

data AvatarNew = AvatarNew
  { avatarNewIdent :: Text
  , avatarNewFile :: FileInfo
  }

getModifyAvatarR :: AvatarId -> Handler Html
getModifyAvatarR aId = do
  ma <- runDB $ get aId
  case ma of
    Just avatar -> do
      (avatarModifyWidget, enctype) <- generateFormPost $ avatarModForm avatar
      defaultLayout $
        $(widgetFile "modifyAvatar")
    Nothing -> do
      setMessageI MsgAvatarUnknown
      redirect AvatarR

postModifyAvatarR :: AvatarId -> Handler Html
postModifyAvatarR aId = do
  ma <- runDB $ get aId
  case ma of
    Just avatar -> do
      ((res, _), _) <- runFormPost $ avatarModForm avatar
      case res of
        FormSuccess md -> do
          updateAvatar aId md
          setMessageI MsgAvatarUpdateSuccessfull
          redirect AvatarR
        _ -> do
          setMessageI MsgErrorOccured
          redirect $ ModifyAvatarR aId
    Nothing -> do
      setMessageI MsgAvatarUnknown
      redirect HomeR

avatarModForm :: Avatar -> Form AvatarMod
avatarModForm a = renderDivs $ AvatarMod
  <$> areq textField (fieldSettingsLabel MsgAvatarIdent) (Just $ avatarIdent a)
  <*> aopt fileField (fieldSettingsLabel MsgAvatarFileChange) Nothing

data AvatarMod = AvatarMod
  { avatarModIdent :: Text
  , avatarModFile :: Maybe FileInfo
  }

updateAvatar :: AvatarId -> AvatarMod -> Handler ()
updateAvatar aId (AvatarMod ident Nothing) =
  runDB $ update aId [AvatarIdent =. ident]
updateAvatar aId (AvatarMod ident (Just fi)) = do
  raw <- runResourceT $ fileSource fi $$ sinkLbs
  (thumb, hash) <- generateThumb $ B.concat $ L.toChunks raw
  runDB $ update aId
    [ AvatarIdent =. ident
    , AvatarData =. thumb
    , AvatarHash =. hash
    ]

generateThumb :: ByteString -> Handler (ByteString, ByteString)
generateThumb raw = do
  thumb <- liftIO $ withMagickWandGenesis $ do
    (_, w) <- magickWand
    readImageBlob w raw
    w1 <- getImageWidth w
    h1 <- getImageHeight w
    let h2 = 140 :: Int
    let w2 = floor (fromIntegral w1 / fromIntegral h1 * fromIntegral h2 :: Double) :: Int
    resizeImage w w2 h2 lanczosFilter 1
    setImageCompressionQuality w 95
    setImageFormat w "png"
    getImageBlob w
  let h = encode (SHA3.hash 8 thumb)
  return (thumb, h)

getGetAvatarR :: AvatarId -> Handler TypedContent
getGetAvatarR aId = do
  avatar <- runDB $ get404 aId
  setEtag $ decodeUtf8 $ avatarHash avatar
  return $ TypedContent typePng $ toContent $ avatarData avatar

getAvatarDeleteR :: AvatarId -> Handler Html
getAvatarDeleteR aId = do
  ma <- runDB $ get aId
  case ma of
    Just _ -> do
      c <- runDB $ selectList [UserAvatar ==. Just aId] []
      d <- runDB $ selectList [BeverageAvatar ==. Just aId] []
      if null c && null d
        then do
          runDB $ delete aId
          setMessageI MsgAvatarDeleted
          redirect HomeR
        else do
          setMessageI MsgAvatarInUseError
          redirect AvatarR
    Nothing -> do
      setMessageI MsgAvatarUnknown
      redirect AvatarR