1 files changed, 0 insertions, 182 deletions
diff --git a/services/tazblog/src/BlogStore.hs b/services/tazblog/src/BlogStore.hs
deleted file mode 100644
index 60ccd0b5a003..000000000000
--- a/services/tazblog/src/BlogStore.hs
+++ /dev/null
@@ -1,182 +0,0 @@
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
-{-# LANGUAGE LambdaCase #-}
-{-# LANGUAGE OverloadedStrings #-}
-
--- |This module implements fetching of individual blog entries from
--- DNS. Yes, you read that correctly.
---
--- Each blog post is stored as a set of records in a designated DNS
--- zone. For the production blog, this zone is `blog.tazj.in.`.
---
--- A top-level record at `_posts` contains a list of all published
--- post IDs.
---
--- For each of these post IDs, there is a record at `_meta.$postID`
--- that contains the title and number of post chunks.
---
--- For each post chunk, there is a record at `_$chunkID.$postID` that
--- contains a base64-encoded post fragment.
---
--- This module implements logic for assembling a post out of these
--- fragments and caching it based on the TTL of its `_meta` record.
-module BlogStore
-  ( BlogCache,
-    EntryId (..),
-    Entry (..),
-    withCache,
-    listEntries,
-    getEntry,
-    show'
-    )
-where
-
-import Control.Applicative ((<$>), (<*>))
-import Control.Monad (mzero)
-import Control.Monad.IO.Class (MonadIO, liftIO)
-import Data.Aeson ((.:), FromJSON (..), Value (Object), decodeStrict)
-import Data.ByteString.Base64 (decodeLenient)
-import Data.Either (fromRight)
-import Data.List (sortBy)
-import Data.Text as T (Text, concat, pack)
-import Data.Text.Encoding (decodeUtf8', encodeUtf8)
-import Data.Time (Day)
-import Network.DNS (DNSError, lookupTXT)
-import qualified Network.DNS.Resolver as R
-
-newtype EntryId = EntryId {unEntryId :: Integer}
-  deriving (Eq, Ord, FromJSON)
-
-instance Show EntryId where
-
-  show = show . unEntryId
-
-data Entry
-  = Entry
-      { entryId :: EntryId,
-        author :: Text,
-        title :: Text,
-        text :: Text,
-        edate :: Day
-        }
-  deriving (Eq, Ord, Show)
-
--- | Wraps a DNS resolver with caching configured. For the initial
--- version of this, all caching of entries is done by the resolver
--- (i.e. no pre-assembled versions of entries are cached).
-data BlogCache = BlogCache R.Resolver Text
-
-data StoreError
-  = PostNotFound EntryId
-  | DNS DNSError
-  | InvalidMetadata
-  | InvalidChunk
-  | InvalidPosts
-  deriving (Show)
-
-type Offset = Int
-
-type Count = Int
-
-withCache :: Text -> (BlogCache -> IO a) -> IO a
-withCache zone f = do
-  let conf =
-        R.defaultResolvConf
-          { R.resolvCache = Just R.defaultCacheConf,
-            R.resolvConcurrent = True
-            }
-  seed <- R.makeResolvSeed conf
-  R.withResolver seed (\r -> f $ BlogCache r zone)
-
-listEntries :: MonadIO m => BlogCache -> Offset -> Count -> m [Entry]
-listEntries cache offset count = liftIO $ do
-  posts <- postList cache
-  entries <- mapM (entryFromDNS cache) $ take count $ drop offset $ fromRight (error "no posts") posts
-  -- TODO: maybe don't just drop broken entries
-  return
-    $ fromRight (error "no entries")
-    $ sequence entries
-
-getEntry :: MonadIO m => BlogCache -> EntryId -> m (Maybe Entry)
-getEntry cache eid = liftIO $ entryFromDNS cache eid >>= \case
-  Left _ -> return Nothing -- TODO: ??
-  Right entry -> return $ Just entry
-
-show' :: Show a => a -> Text
-show' = pack . show
-
--- * DNS fetching implementation
-type Chunk = Integer
-
--- | Represents the metadata stored for each post in the _meta record.
-data Meta = Meta Integer Text Day
-  deriving (Show)
-
-instance FromJSON Meta where
-
-  parseJSON (Object v) =
-    Meta
-      <$> v
-      .: "c"
-      <*> v
-      .: "t"
-      <*> v
-      .: "d"
-  parseJSON _ = mzero
-
-entryMetadata :: BlogCache -> EntryId -> IO (Either StoreError Meta)
-entryMetadata (BlogCache r z) (EntryId eid) =
-  let domain = encodeUtf8 ("_meta." <> show' eid <> "." <> z)
-      record = lookupTXT r domain
-      toMeta rrdata = case decodeStrict $ decodeLenient rrdata of
-        Nothing -> Left InvalidMetadata
-        Just m -> Right m
-   in record >>= \case
-        (Left err) -> return $ Left $ DNS err
-        (Right [bs]) -> return $ toMeta bs
-        _ -> return $ Left InvalidMetadata
-
-entryChunk :: BlogCache -> EntryId -> Chunk -> IO (Either StoreError Text)
-entryChunk (BlogCache r z) (EntryId eid) c =
-  let domain = encodeUtf8 ("_" <> show' c <> "." <> show' eid <> "." <> z)
-      record = lookupTXT r domain
-      toChunk rrdata = case decodeUtf8' $ decodeLenient rrdata of
-        Left _ -> Left InvalidChunk
-        Right chunk -> Right chunk
-   in record >>= \case
-        (Left err) -> return $ Left $ DNS err
-        (Right [bs]) -> return $ toChunk bs
-        _ -> return $ Left InvalidChunk
-
-fetchAssembleChunks :: BlogCache -> EntryId -> Meta -> IO (Either StoreError Text)
-fetchAssembleChunks cache eid (Meta n _ _) = do
-  chunks <- mapM (entryChunk cache eid) [0 .. (n - 1)]
-  return $ fmap T.concat $ sequence chunks
-
-entryFromDNS :: BlogCache -> EntryId -> IO (Either StoreError Entry)
-entryFromDNS cache eid = do
-  meta <- entryMetadata cache eid
-  case meta of
-    Left err -> return $ Left err
-    Right meta -> do
-      chunks <- fetchAssembleChunks cache eid meta
-      let (Meta _ t d) = meta
-      return
-        $ either Left
-            ( \text -> Right $ Entry
-                { entryId = eid,
-                  author = "tazjin",
-                  title = t,
-                  text = text,
-                  edate = d
-                  }
-              )
-            chunks
-
-postList :: BlogCache -> IO (Either StoreError [EntryId])
-postList (BlogCache r z) =
-  let domain = encodeUtf8 ("_posts." <> z)
-      record = lookupTXT r domain
-      toPosts =
-        fmap (sortBy (flip compare))
-          . mapM (maybe (Left InvalidPosts) Right . decodeStrict)
-   in either (Left . DNS) toPosts <$> record