wip

- Relates to #2

ebook-manager.cabal

@@ -1,6 +1,3 @@
--- Initial ebook-manager.cabal generated by cabal init.  For further
--- documentation, see http://haskell.org/cabal/users-guide/
-
 name:                ebook-manager
 version:             0.1.0.0
 -- synopsis:

migrations/V1.1__Channel_visibility.sql

@@ -0,0 +1 @@
+alter table channels add column visibility text NOT NULL default 'Private';

src/API/Catalogue.hs

@@ -96,15 +96,34 @@ instance ToNode (Catalog 1) where
 
 class Monad m => VersionedCatalog m (v :: Nat) where
   getChannels :: SafeUser -> m (Catalog v)
+  getBooks :: Channel.ChannelID -> SafeUser -> m (Catalog v)
 
 instance VersionedCatalog AppM 1 where
-  getChannels SafeUser{username} = do
+  getChannels = getChannelsV1
+  getBooks = getBooksV1
+
+relUrl :: Link -> Rel
+relUrl x = Rel ("/api/current/" <> (pack . uriPath . linkURI $ x))
+
+getBooksV1 :: Channel.ChannelID -> SafeUser -> AppM (Catalog 1)
+getBooksV1 identifier SafeUser{} = do
   updated <- liftIO getCurrentTime
-    let self = Rel ("/api/current/" <> selfUrl)
+  let self = relUrl selfUrl
+      start = relUrl startUrl
+      selfUrl = safeLink (Proxy @(BaseAPI 1)) (Proxy @(ChannelCatalog 1)) identifier
+      startUrl = safeLink (Proxy @(BaseAPI 1)) (Proxy @(RootCatalog 1))
+      entries = mempty
+      pagination = Pagination Nothing Nothing
+  pure CatalogV1{..}
+
+getChannelsV1 :: SafeUser -> AppM (Catalog 1)
+getChannelsV1 SafeUser{username} = do
+  updated <- liftIO getCurrentTime
+  let self = relUrl selfUrl
       -- I'm not sure if this safe link approach is really useable with this
       -- api hierarchy since I can't access the topmost api from here. Also
       -- authentication would bring a little bit of extra effort as well
-        selfUrl = pack . uriPath . linkURI $ safeLink (Proxy @(BaseAPI 1)) (Proxy @(RootCatalog 1))
+      selfUrl = safeLink (Proxy @(BaseAPI 1)) (Proxy @(RootCatalog 1))
       start = self
       pagination = Pagination Nothing Nothing
   entries <- map (fromChannel updated) <$> runDB (Channel.userChannels username)
@@ -112,14 +131,16 @@ instance VersionedCatalog AppM 1 where
   where
     fromChannel :: UTCTime -> Channel.Channel -> Entry 1
     fromChannel updated Channel.Channel{..} =
-        let url = pack . uriPath . linkURI $ safeLink (Proxy @(BaseAPI 1)) (Proxy @(ChannelCatalog 1)) identifier
-            self = Rel ("/api/current/" <> url)
+      let url = safeLink (Proxy @(BaseAPI 1)) (Proxy @(ChannelCatalog 1)) identifier
+          self = relUrl url
       in EntryV1 channel channel updated channel (Left $ SubSection self)
 
 type VersionedAPI (v :: Nat) = Auth '[SA.BasicAuth, SA.JWT] SafeUser :> BaseAPI v
 
-type RootCatalog (v :: Nat) = "catalog" :> Get '[XML] (Catalog v)
-type ChannelCatalog (v :: Nat) = "catalog" :> "channel" :> Capture "channel_id" Channel.ChannelID :> Get '[XML] (Catalog v)
+type CatalogContent = '[XML, OPDS]
+
+type RootCatalog (v :: Nat) = "catalog" :> Get CatalogContent (Catalog v)
+type ChannelCatalog (v :: Nat) = "catalog" :> "channel" :> Capture "channel_id" Channel.ChannelID :> Get CatalogContent (Catalog v)
 type BaseAPI (v :: Nat) = RootCatalog v
                     :<|> ChannelCatalog v
 
@@ -127,6 +148,8 @@ handler :: forall v. VersionedCatalog AppM v => ServerT (VersionedAPI v) AppM
 handler auth = catalogRoot :<|> catalogChannels
   where
     catalogChannels :: Channel.ChannelID -> AppM (Catalog v)
-    catalogChannels _ = throwM err403{errBody="Not implemented"}
+    -- Channel specific catalog returns tags inside the catalog
+    catalogChannels identifier = flip requireLoggedIn auth (getBooks identifier)
     catalogRoot :: AppM (Catalog v)
+    -- catalog root returns channels
     catalogRoot = flip requireLoggedIn auth getChannels

src/API/Channels.hs

@@ -11,6 +11,8 @@
 {-# Language FlexibleInstances #-}
 {-# Language TypeApplications #-}
 {-# Language DataKinds #-}
+{-# Language DuplicateRecordFields #-}
+{-# Language NamedFieldPuns #-}
 module API.Channels (API, handler, JsonChannel(..)) where
 
 import Servant
@@ -25,18 +27,37 @@ import Data.Aeson
 import Control.Lens
 import Data.Generics.Product
 
-data JsonChannel = JsonChannel { channel :: Text } deriving (Show, Generic)
+data JsonChannel = JsonChannel { channel :: Text
+                               , visibility :: Visibility }
+                 deriving (Show, Generic)
+data UpdateChannel = UpdateChannel { identifier :: ChannelID
+                                   , channel :: Text
+                                   , visibility :: Visibility }
+                 deriving (Show, Generic)
 
 instance ToJSON JsonChannel
 instance FromJSON JsonChannel
+instance ToJSON UpdateChannel
+instance FromJSON UpdateChannel
 
 type API = Auth '[SA.BasicAuth, SA.Cookie, SA.JWT] SafeUser :> BaseAPI
 
-type BaseAPI = "channels" :> ReqBody '[JSON] JsonChannel :> Put '[JSON] JsonChannel
+type BaseAPI = "channels" :> ReqBody '[JSON] JsonChannel :> Post '[JSON] UpdateChannel
+          :<|> "channels" :> Capture "channel_id" ChannelID :> ReqBody '[JSON] UpdateChannel :> Put '[JSON] UpdateChannel
           :<|> "channels" :> Get '[JSON] [JsonChannel]
 
 handler :: ServerT API AppM
-handler user = newChannelHandler user :<|> listChannelsHandler user
+handler user = newChannelHandler user :<|> updateChannelHandler user :<|> listChannelsHandler user
+
+requireChannelOwner :: AuthResult SafeUser -> ChannelID -> (SafeUser -> AppM a) -> AppM a
+requireChannelOwner auth channelId f = flip requireLoggedIn auth $ \u@SafeUser{username} -> do
+  unlessM (runDB . channelExists $ channelId) $ throwM err404
+  runDB (isChannelOwner channelId username) >>= \o -> if o then f u else throwM err403
+
+updateChannelHandler :: AuthResult SafeUser -> ChannelID -> UpdateChannel -> AppM UpdateChannel
+updateChannelHandler auth channelId UpdateChannel{visibility} = requireChannelOwner auth channelId $ \_ -> do
+  mChannel <- fmap toChannel <$> runDB (updateChannelPrivacy channelId visibility)
+  maybe (throwM err403) return mChannel
 
 listChannelsHandler :: AuthResult SafeUser -> AppM [JsonChannel]
 listChannelsHandler = requireLoggedIn $ \user ->
@@ -44,8 +65,11 @@ listChannelsHandler = requireLoggedIn $ \user ->
   -- use the 'channel' accessor somehow or export it
   fmap (\Channel{..} -> JsonChannel{..}) <$> runDB (userChannels (view (field @"username") user))
 
-newChannelHandler :: AuthResult SafeUser -> JsonChannel -> AppM JsonChannel
-newChannelHandler auth ch@JsonChannel{..} = flip requireLoggedIn auth $ \user -> do
+newChannelHandler :: AuthResult SafeUser -> JsonChannel -> AppM UpdateChannel
+newChannelHandler auth JsonChannel{..} = flip requireLoggedIn auth $ \user -> do
   $logInfo $ "Creating channel for user " <> pack (show user)
-  runDB (insertChannel (view (field @"username") user) channel)
-  return ch
+  mChannel <- fmap toChannel <$> runDB (insertChannel (view (field @"username") user) channel visibility)
+  maybe (throwM err403{errBody="Could not create the channel"}) return mChannel
+
+toChannel :: Channel -> UpdateChannel
+toChannel Channel{..} = UpdateChannel{..}

src/Database/Channel.hs

@@ -4,11 +4,15 @@
 module Database.Channel
   ( userChannels
   , insertChannel
+  , channelExists
+  , isChannelOwner
+  , updateChannelPrivacy
   , attachChannel
+  , Visibility(..)
   , clearChannels
   , booksChannels
   , Channel(..)
-  , ChannelID )
+  , ChannelID(..) )
   where
 
 import ClassyPrelude
@@ -17,23 +21,60 @@ import Database
 import Database.Selda
 import Database.Selda.Generic
 
+import Control.Monad.Trans.Maybe
+
+getChannel :: (MonadSelda m, MonadMask m, MonadIO m) => ChannelID -> m (Maybe Channel)
+getChannel identifier = listToMaybe . fromRels <$> query q
+  where
+    q = do
+      ch@(channelId :*: _) <- select (gen channels)
+      restrict (channelId .== literal identifier)
+      return ch
+
+channelExists :: (MonadSelda m, MonadMask m, MonadIO m) => ChannelID -> m Bool
+channelExists identifier = not . null <$> getChannel identifier
+
+isChannelOwner :: (MonadSelda m, MonadIO m, MonadMask m) => ChannelID -> Username -> m Bool
+isChannelOwner identifier username = not . null <$> query q
+  where
+    q = do
+      userId :*: _ :*: username' :*: _ <- select (gen users)
+      channelId :*: _ :*: channelOwner :*: _ <- select (gen channels)
+      restrict (userId .== channelOwner)
+      restrict (username' .== literal username)
+      restrict (channelId .== literal identifier)
+      return channelId
+
 userChannels :: (MonadMask m, MonadIO m) => Username -> SeldaT m [Channel]
 userChannels username = fromRels <$> query q
   where
     q = do
       userId :*: _ :*: username' :*: _ <- select (gen users)
-      channel@(_ :*: _ :*: owner) <- select (gen channels)
+      channel@(_ :*: _ :*: owner :*: _) <- select (gen channels)
       restrict (owner .== userId)
       restrict (username' .== literal username)
       return channel
 
-insertChannel :: (MonadMask m, MonadIO m) => Username -> Text -> SeldaT m ()
-insertChannel username channel = do
-  mUserId <- listToMaybe <$> getUser
-  void $ forM mUserId $ \userId ->
-    insertUnless (gen channels) (doesNotExist userId) [ def :*: channel :*: userId ]
+updateChannelPrivacy :: (MonadMask m, MonadIO m, MonadSelda m) => ChannelID -> Visibility -> m (Maybe Channel)
+updateChannelPrivacy channelId visibility = do
+  void $ update (gen channels) predicate (\channel -> channel `with` [pVis := literal visibility])
+  getChannel channelId
   where
-    doesNotExist userId (_ :*: channel' :*: userId') = channel' .== literal channel .&& userId' .== literal userId
+    predicate (channelId' :*: _) = channelId' .== literal channelId
+    _ :*: _ :*: _ :*: pVis = selectors (gen channels)
+
+insertChannel :: (MonadMask m, MonadIO m, MonadSelda m) => Username -> Text -> Visibility -> m (Maybe Channel)
+insertChannel username channel visibility = runMaybeT $ do
+  userId <- MaybeT (listToMaybe <$> getUser)
+  channelId <- toChannelId <$> MaybeT (insertUnless (gen channels) (doesNotExist userId) [ def :*: channel :*: userId :*: visibility ])
+  MaybeT (listToMaybe . fromRels <$> query (q channelId))
+  where
+    q channelId = do
+      ch@(channelId' :*: _) <- select (gen channels)
+      restrict (channelId' .== literal channelId)
+      return ch
+    toChannelId = ChannelID . fromRowId
+    doesNotExist userId (_ :*: channel' :*: userId' :*: _) = channel' .== literal channel .&& userId' .== literal userId
     getUser = query $ do
       userId :*: _ :*: user :*: _ <- select (gen users)
       restrict (user .== literal username)
@@ -62,7 +103,7 @@ attachChannel username bookId channel = do
       return channelId'
     channelQ = do
       userId :*: _ :*: username' :*: _ <- select (gen users)
-      ch@(_ :*: channel' :*: owner) <- select (gen channels)
+      ch@(_ :*: channel' :*: owner :*: _) <- select (gen channels)
       restrict (username' .== literal username)
       restrict (owner .== userId)
       restrict (channel' .== literal channel)

src/Database/Schema.hs

@@ -44,7 +44,7 @@ newtype UserID = UserID {unUserID :: Int} deriving (Show)
 
 newtype BookID = BookID {unBookID :: Int} deriving (Show, ToJSON, FromJSON, FromHttpApiData, Eq, Ord)
 
-newtype ChannelID = ChannelID {unChannelID :: Int} deriving (Show, ToHttpApiData, FromHttpApiData)
+newtype ChannelID = ChannelID {unChannelID :: Int} deriving (Show, ToHttpApiData, FromHttpApiData, ToJSON, FromJSON)
 
 newtype TagID = TagID {unTagID :: Int} deriving (Show)
 
@@ -124,9 +124,22 @@ data Tag = Tag { identifier :: TagID
                , owner :: UserID }
          deriving (Show, Generic)
 
+data Visibility = Public | Private | Followers
+                deriving (Show, Read, Generic)
+
+instance ToJSON Visibility
+instance FromJSON Visibility
+
+instance SqlType Visibility where
+  mkLit = LCustom . LText . pack . show
+  fromSql (SqlString x) = fromMaybe (error "fromSql: Not a valid visibility token") . readMay . unpack $ x
+  fromSql _             = error "fromSql: Not a valid visibility token"
+  defaultValue = mkLit Private
+
 data Channel = Channel { identifier :: ChannelID
                        , channel :: Text
-                       , owner :: UserID }
+                       , owner :: UserID
+                       , visibility :: Visibility }
              deriving (Show, Generic)
 
 tags :: GenTable Tag

src/Servant/XML.hs

@@ -1,9 +1,11 @@
 {-# Language OverloadedStrings #-}
 {-# Language FlexibleInstances #-}
 {-# Language MultiParamTypeClasses #-}
+{-# Language TypeApplications #-}
 module Servant.XML
   ( ToNode(..)
   , XML
+  , OPDS
   , Text.Hamlet.XML.xml
   , iso8601 )
   where
@@ -16,14 +18,22 @@ import Network.HTTP.Media.MediaType
 
 data XML
 
+data OPDS
+
 instance (ToNode a) => MimeRender XML a where
   mimeRender _ a =
     let [NodeElement root] = toNode a
     in renderLBS def (Document (Prologue [] Nothing []) root [])
 
+instance (ToNode a) => MimeRender OPDS a where
+  mimeRender _ a = mimeRender (Proxy @XML) a
+
 instance Accept XML where
   contentType _ = "application" // "xml" /: ("charset", "utf-8")
 
+instance Accept OPDS where
+  contentType _ = "application" // "atom+xml" /: ("charset", "utf-8") /: ("profile", "opds-catalog")
+
 iso8601 :: UTCTime -> Text
 iso8601 = pack . formatTime defaultTimeLocale "%Y-%m-%dT%H:%M:%SZ"