wip

- Closes #28

backend/ChangeLog.md

@@ -0,0 +1,5 @@
+# Revision history for backend
+
+## 0.1.0.0 -- YYYY-mm-dd
+
+* First version. Released on an unsuspecting world.

backend/LICENSE

@@ -0,0 +1,30 @@
+Copyright (c) 2018, Mats Rauhala
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    * Neither the name of Mats Rauhala nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

backend/Setup.hs

@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain

backend/backend.cabal

@@ -1,7 +1,7 @@
--- Initial ebook-manager.cabal generated by cabal init.  For further
+-- Initial backend.cabal generated by cabal init.  For further
 -- documentation, see http://haskell.org/cabal/users-guide/
 
-name:                ebook-manager
+name:                backend
 version:             0.1.0.0
 -- synopsis:
 -- description:
@@ -15,30 +15,29 @@ build-type:          Simple
 extra-source-files:  ChangeLog.md
 cabal-version:       >=1.10
 
-executable ebook-manager
+executable backend
   main-is:             Main.hs
   other-modules:       Devel.Main
-                     , API
-                     , API.Books
-                     , API.Catalogue
-                     , API.Channels
-                     , API.Users
-                     , Configuration
-                     , Data.Versioned
                      , Database
                      , Database.Book
                      , Database.Channel
-                     , Database.Tag
                      , Database.Schema
+                     , Database.Tag
                      , Database.User
                      , Datastore
                      , Servant.XML
                      , Server
+                     , Server.API
+                     , Server.API.Books
+                     , Server.API.Catalogue
+                     , Server.API.Channels
+                     , Server.API.Users
                      , Server.Auth
                      , Types
                      , View
   -- other-extensions:
   build-depends:       base >=4.10 && <4.11
+                     , common
                      , aeson
                      , asn1-data
                      , asn1-types
@@ -80,8 +79,8 @@ executable ebook-manager
                      , xml-conduit
                      , xml-hamlet
   hs-source-dirs:      src
+  default-language:    Haskell2010
   default-extensions:  DeriveGeneric
                      , NoImplicitPrelude
                      , OverloadedStrings
                      , RecordWildCards
-  default-language:    Haskell2010

backend/src/Database/Book.hs

@@ -51,7 +51,7 @@ getBook identifier owner = listToMaybe . fromRels <$> query q
       return book
 
 data InsertBook = InsertBook { contentType :: Text
-                             , title :: Maybe Text
+                             , title :: Text
                              , description :: Maybe Text
                              , owner :: Username }
 
@@ -68,7 +68,7 @@ insertBook InsertBook{..} = do
 
 data UpdateBook = UpdateBook { identifier :: BookID
                              , contentType :: Text
-                             , title :: Maybe Text
+                             , title :: Text
                              , description :: Maybe Text
                              , owner :: Username
                              , tags :: [Text]

backend/src/Database/Channel.hs

@@ -11,8 +11,9 @@ module Database.Channel
   , Visibility(..)
   , clearChannels
   , booksChannels
+  , channelBooks
   , Channel(..)
-  , ChannelID )
+  , ChannelID(..) )
   where
 
 import ClassyPrelude
@@ -80,6 +81,19 @@ insertChannel username channel visibility = runMaybeT $ do
       restrict (user .== literal username)
       return userId
 
+channelBooks :: (MonadSelda m, MonadMask m, MonadIO m) => Username -> ChannelID -> m [Book]
+channelBooks username identifier = fromRels <$> query q
+  where
+    q = do
+      channelId :*: bookId' <- select (gen bookChannels)
+      channelId' :*: _ :*: owner :*: _ <- select (gen channels)
+      userId :*: _ :*: username' :*: _ <- select (gen users)
+      book@(bookId :*: _) <- select (gen books)
+      restrict (username' .== literal username .&& owner .== userId)
+      restrict (channelId .== literal identifier .&& channelId .== channelId')
+      restrict (bookId .== bookId')
+      return book
+
 booksChannels :: (MonadSelda m, MonadMask m, MonadIO m) => BookID -> m [Channel]
 booksChannels bookId = fromRels <$> query q
   where

backend/src/Database/Schema.hs

@@ -18,9 +18,6 @@ newtype PlainPassword = PlainPassword Text deriving (Show, ToJSON, FromJSON, ToH
 newtype HashedPassword = HashedPassword {unHashed :: ByteString}
 data NoPassword = NoPassword
 
-newtype Email = Email { unEmail :: Text } deriving (Show, ToJSON, FromJSON, ToHttpApiData, FromHttpApiData)
-
-newtype Username = Username { unUsername :: Text } deriving (Show, ToJSON, FromJSON, ToHttpApiData, FromHttpApiData)
 
 instance SqlType HashedPassword where
   mkLit = LCustom . LBlob . unHashed
@@ -42,7 +39,7 @@ instance SqlType Username where
 
 newtype UserID = UserID {unUserID :: Int} deriving (Show)
 
-newtype BookID = BookID {unBookID :: Int} deriving (Show, ToJSON, FromJSON, FromHttpApiData, Eq, Ord)
+newtype BookID = BookID {unBookID :: Int} deriving (Show, ToJSON, FromJSON, FromHttpApiData, Eq, Ord, ToHttpApiData)
 
 newtype ChannelID = ChannelID {unChannelID :: Int} deriving (Show, ToHttpApiData, FromHttpApiData, ToJSON, FromJSON)
 
@@ -101,7 +98,7 @@ newtype HashDigest = HashDigest { unHex :: ByteString } deriving Show
 data Book = Book { identifier :: BookID
                  , contentHash :: Maybe HashDigest
                  , contentType :: Text
-                 , title :: Maybe Text
+                 , title :: Text
                  , description :: Maybe Text
                  , owner :: UserID }
           deriving (Show, Generic)

backend/src/Devel/Main.hs

@@ -37,7 +37,7 @@ update = do
 
 develMain :: IO ()
 develMain = do
-  conf <- input auto "./config/devel.dhall"
+  conf <- input auto "../config/devel.dhall"
   withApp conf $ \app -> do
     void $ runReaderT (runDB migrate) app
     defaultMain app

backend/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"
 

backend/src/Server.hs

@@ -12,7 +12,7 @@
 {-# Language TypeApplications #-}
 module Server where
 
-import qualified API as API
+import qualified Server.API as API
 import Server.Auth (authCheck)
 import Servant
 import Types

backend/src/Server/API.hs

@@ -9,7 +9,7 @@
 {-# Language RecordWildCards #-}
 {-# Language DeriveGeneric #-}
 {-# Language FlexibleInstances #-}
-module API (API, handler) where
+module Server.API (API, handler) where
 
 
 import Servant
@@ -18,17 +18,17 @@ import Types
 
 import View
 
-import qualified API.Users as Users
-import qualified API.Channels as Channels
-import qualified API.Books as Books
-import qualified API.Catalogue as Catalogue
+import qualified Server.API.Users as Users
+import qualified Server.API.Channels as Channels
+import qualified Server.API.Books as Books
+import qualified Server.API.Catalogue as Catalogue
 
 data Index = Index
 
 type API = Get '[HTML] (AppView Index)
       :<|> Users.API
-      :<|> "api" :> Channels.API
-      :<|> "api" :> Books.API
+      :<|> "api" :> "current" :> Channels.API
+      :<|> "api" :> "current" :> Books.API
       :<|> "api" :> "1" :> Catalogue.VersionedAPI 1
       :<|> "api" :> "current" :> Catalogue.VersionedAPI 1
 

backend/src/Server/API/Books.hs

@@ -13,7 +13,7 @@
 {-# Language TypeApplications #-}
 {-# Language DataKinds #-}
 {-# Language NamedFieldPuns #-}
-module API.Books where
+module Server.API.Books where
 
 import Servant hiding (contentType)
 import Types
@@ -36,14 +36,14 @@ import Crypto.Hash (digestFromByteString)
 
 data JsonBook = JsonBook { identifier :: BookID
                          , contentType :: Text
-                         , title :: Maybe Text
+                         , title :: Text
                          , description :: Maybe Text
                          , channels :: [Text]
                          , tags :: [Text] }
               deriving (Generic, Show)
 
 data PostBook = PostBook { contentType :: Text
-                         , title :: Maybe Text
+                         , title :: Text
                          , description :: Maybe Text
                          , channels :: [Text]
                          , tags :: [Text] }
@@ -61,7 +61,9 @@ type BaseAPI = "books" :> Get '[JSON] [JsonBook]
        :<|> "books" :> ReqBody '[JSON] PostBook :> Post '[JSON] JsonBook
        :<|> "books" :> Capture "book_id" BookID :> "meta" :> ReqBody '[JSON] JsonBook :> Put '[JSON] JsonBook
        :<|> "books" :> Capture "book_id" BookID :> ReqBody '[OctetStream] ByteString :> Put '[JSON] NoContent
-       :<|> "books" :> Capture "book_id" BookID :> Get '[OctetStream] ByteString
+       :<|> GetBook
+
+type GetBook = "books" :> Capture "book_id" BookID :> Get '[OctetStream] ByteString
 
 handler :: ServerT API AppM
 handler user = listBooksHandler user

backend/src/Server/API/Catalogue.hs

@@ -14,17 +14,19 @@
 {-# Language TemplateHaskell #-}
 {-# Language MultiParamTypeClasses #-}
 {-# Language ScopedTypeVariables #-}
-module API.Catalogue (VersionedAPI, handler) where
+module Server.API.Catalogue (VersionedAPI, handler) where
 
 import Types
-import Servant
+import Servant hiding (contentType)
 import ClassyPrelude
 import GHC.TypeLits
 import Server.Auth
 import Servant.Auth as SA
 import Servant.XML
 import qualified Database.Channel as Channel
+import Database.Book (Book(..))
 import Database
+import qualified Server.API.Books as API.Books
 
 -- This is my first try on going to versioned apis, things might change
 -- I think my rule of thumb is that you can add new things as you want, but
@@ -96,15 +98,40 @@ 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 channelID SafeUser{username} = 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)) channelID
+      startUrl = safeLink (Proxy @(BaseAPI 1)) (Proxy @(RootCatalog 1))
+      pagination = Pagination Nothing Nothing
+  entries <- map (toEntry updated) <$> runDB (Channel.channelBooks username channelID)
+  pure CatalogV1{..}
+  where
+    toEntry updated Book{description,title,identifier=bookId} =
+      let content = fromMaybe "no content" description
+          identifier = pack . show $ bookId
+          link = Right (Acquisition (relUrl (safeLink (Proxy @API.Books.BaseAPI) (Proxy @API.Books.GetBook) bookId)))
+      in EntryV1{..}
+
+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 +139,16 @@ 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 +156,8 @@ 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

backend/src/Server/API/Channels.hs

@@ -13,7 +13,7 @@
 {-# Language DataKinds #-}
 {-# Language DuplicateRecordFields #-}
 {-# Language NamedFieldPuns #-}
-module API.Channels (API, handler, JsonChannel(..)) where
+module Server.API.Channels (API, handler, JsonChannel(..)) where
 
 import Servant
 import Types

backend/src/Server/API/Users.hs

@@ -5,7 +5,7 @@
 {-# Language TypeOperators #-}
 {-# Language DuplicateRecordFields #-}
 {-# Language TypeApplications #-}
-module API.Users  where
+module Server.API.Users  where
 
 import Servant
 import ClassyPrelude

backend/src/Server/Auth.hs

@@ -24,21 +24,8 @@ import Control.Lens (view)
 import Data.Generics.Product
 import Servant (err401)
 import Control.Monad.Logger
+import Auth (SafeUser(..))
 
--- generic-lens can convert similar types to this
--- I'm trying out servant-auth-server which uses a jwt style login. IIRC anyone
--- can open the jwt token and view what's inside, you just can't modify it.
---
--- Is it a problem that a human readable username and email are visible?
-data SafeUser = SafeUser { email :: Email
-                         , username :: Username
-                         , role :: Role }
-              deriving (Show, Generic)
-
-instance ToJSON SafeUser where
-instance FromJSON SafeUser where
-instance ToJWT SafeUser where
-instance FromJWT SafeUser where
 
 type instance BasicAuthCfg = BasicAuthData -> IO (AuthResult SafeUser)
 

common/LICENSE

@@ -0,0 +1,30 @@
+Copyright (c) 2018, Mats Rauhala
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    * Neither the name of Mats Rauhala nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

common/common.cabal

@@ -0,0 +1,48 @@
+name:                common
+version:             0.1.0.0
+-- synopsis:
+-- description:
+license:             BSD3
+license-file:        LICENSE
+author:              Mats Rauhala
+maintainer:          mats.rauhala@iki.fi
+-- copyright:
+category:            Web
+build-type:          Simple
+extra-source-files:  ChangeLog.md
+cabal-version:       >=1.10
+
+library
+  exposed-modules:     Configuration
+                     , Data.Versioned
+                     , API
+                     , API.Books
+                     , API.Catalogue
+                     , API.Channels
+                     , API.Users
+                     , Auth
+  -- other-extensions:
+  build-depends:       base >=4.10 && <4.11
+                     , aeson
+                     , classy-prelude
+                     , dhall
+                     , foreign-store
+                     , generic-lens
+                     , lens
+                     , mtl
+                     , servant
+                     , servant-auth
+                     , servant-auth-server
+                     , servant-docs
+                     , servant-lucid
+                     , servant-multipart
+                     , text
+                     , transformers
+  hs-source-dirs:      src
+  default-extensions:  DeriveGeneric
+                     , NoImplicitPrelude
+                     , OverloadedStrings
+                     , RecordWildCards
+                     , TypeOperators
+                     , DataKinds
+  default-language:    Haskell2010

common/src/API.hs

@@ -0,0 +1 @@
+module API where

common/src/API/Books.hs

@@ -0,0 +1 @@
+module API.Books where

common/src/API/Catalogue.hs

@@ -0,0 +1 @@
+module API.Catalogue where

common/src/API/Channels.hs

@@ -0,0 +1,27 @@
+{-# Language DuplicateRecordFields #-}
+module API.Channels (API) where
+
+import Auth
+import ClassyPrelude
+import Data.Aeson
+import Servant.API
+import Servant.Auth as SA
+
+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 :> Post '[JSON] UpdateChannel
+          :<|> "channels" :> Capture "channel_id" ChannelID :> ReqBody '[JSON] UpdateChannel :> Put '[JSON] UpdateChannel
+          :<|> "channels" :> Get '[JSON] [JsonChannel]

common/src/API/Users.hs

@@ -0,0 +1 @@
+module API.Users where

common/src/Auth.hs

@@ -0,0 +1,26 @@
+{-# Language GeneralizedNewtypeDeriving #-}
+module Auth where
+
+import ClassyPrelude
+import Data.Aeson
+import Servant.Auth.Server (ToJWT, FromJWT)
+import Servant.API
+
+-- generic-lens can convert similar types to this
+-- I'm trying out servant-auth-server which uses a jwt style login. IIRC anyone
+-- can open the jwt token and view what's inside, you just can't modify it.
+--
+-- Is it a problem that a human readable username and email are visible?
+newtype Email = Email { unEmail :: Text } deriving (Show, ToJSON, FromJSON, ToHttpApiData, FromHttpApiData)
+
+newtype Username = Username { unUsername :: Text } deriving (Show, ToJSON, FromJSON, ToHttpApiData, FromHttpApiData)
+
+data SafeUser = SafeUser { email :: Email
+                         , username :: Username
+                         }
+              deriving (Show, Generic)
+
+instance ToJSON SafeUser where
+instance FromJSON SafeUser where
+instance ToJWT SafeUser where
+instance FromJWT SafeUser where

default.nix

@@ -1,10 +1,12 @@
-{ mkDerivation, base, stdenv }:
-mkDerivation {
-  pname = "ebook-manager";
-  version = "0.1.0.0";
-  src = ./.;
-  isLibrary = false;
-  isExecutable = true;
-  executableHaskellDepends = [ base ];
-  license = stdenv.lib.licenses.bsd3;
+{ nixpkgs, haskellPackages }:
+
+(import ./project.nix nixpkgs) {
+  packages = {
+    common = ./common;
+    backend = ./backend;
+  };
+  tools = with haskellPackages; [
+    ghcid
+    hasktags
+  ];
 }

project.nix

@@ -0,0 +1,38 @@
+nixpkgs:
+
+let
+
+  inherit (nixpkgs.lib) mapAttrs mapAttrsToList escapeShellArg optionalString concatStringsSep concatMapStringsSep;
+
+in
+
+{ packages
+, overrides ? _ : _ : {}
+, tools ? []
+}:
+
+let
+
+  overrides' = nixpkgs.lib.foldr nixpkgs.lib.composeExtensions (_: _: {}) [
+    (self: super: mapAttrs (name: path: self.callCabal2nix name path {}) packages)
+  ];
+  haskellPackages = nixpkgs.haskellPackages.override { overrides = overrides'; };
+  packages' = mapAttrs (name: _: haskellPackages."${name}") packages;
+  mkShell = name: pkg:
+  let
+    n =  "${name}-shell";
+    deps = haskellPackages.ghcWithPackages (pkgs: pkg.buildInputs);
+  in
+  {
+    name = "${n}";
+    value = nixpkgs.buildEnv {
+      name = "${n}";
+      paths = tools ++ [deps];
+      buildInputs = tools ++ [deps];
+    };
+  };
+  shells = nixpkgs.lib.listToAttrs (mapAttrsToList mkShell packages');
+
+in
+
+packages' // shells

release.nix

@@ -0,0 +1,15 @@
+{ nixpkgs ? import <nixpkgs> {} }:
+
+let
+
+  pinnedVersion = nixpkgs.lib.importJSON ./nixpkgs-version.json;
+  pinnedPkgs = import (nixpkgs.fetchFromGitHub {
+    owner = "NixOS";
+    repo = "nixpkgs";
+    inherit (pinnedVersion) rev sha256;
+  }) {};
+  inherit (pinnedPkgs) pkgs;
+
+  in
+
+import ./default.nix { nixpkgs = pinnedPkgs; haskellPackages = pinnedPkgs.haskellPackages; }