1
1
mirror of https://github.com/aelve/guide.git synced 2024-11-23 21:13:07 +03:00
guide/lib/Utils.hs
Artyom c72815c436 Big switch to Mustache (only half-done)
* Render some elements of some pages with Mustache
* Switch to Stack
* Add a bit of tests
* Turn the project into a library
2016-08-17 11:18:57 +03:00

298 lines
8.3 KiB
Haskell
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

{-# LANGUAGE
OverloadedStrings,
GeneralizedNewtypeDeriving,
FlexibleContexts,
FlexibleInstances,
TypeFamilies,
NoImplicitPrelude
#-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
module Utils
(
-- * Lists
moveUp,
moveDown,
deleteFirst,
insertAtGuaranteed,
ordNub,
-- * 'Eq'
equating,
-- * URLs
Url,
sanitiseUrl,
makeSlug,
-- * IP
sockAddrToIP,
-- * UID
Uid(..),
Node,
randomShortUid,
randomLongUid,
uid_,
-- * Lucid
includeJS,
includeCSS,
-- * Spock
atomFeed,
-- * Safecopy
GenConstructor(..),
genVer,
MigrateConstructor(..),
migrateVer,
-- * Instances
-- ** 'MonadThrow' for 'HtmlT'
)
where
import BasePrelude
-- Lenses
import Lens.Micro.Platform hiding ((&))
-- Monads and monad transformers
import Control.Monad.Trans
import Control.Monad.Catch
-- Containers
import qualified Data.Set as S
-- Hashable (needed for Uid)
import Data.Hashable
-- Randomness
import System.Random
-- Text
import Data.Text.All (Text)
import qualified Data.Text.All as T
-- JSON
import qualified Data.Aeson as A
-- Network
import qualified Network.Socket as Network
import Data.IP
-- Web
import Lucid
import Web.Spock
import Text.HTML.SanitizeXSS (sanitaryURI)
import Web.PathPieces
-- Feeds
import qualified Text.Atom.Feed as Atom
import qualified Text.Atom.Feed.Export as Atom
import qualified Text.XML.Light.Output as XML
-- acid-state
import Data.SafeCopy
-- Template Haskell
import Language.Haskell.TH
-- | Move the -1st element that satisfies the predicate- up.
moveUp :: (a -> Bool) -> [a] -> [a]
moveUp p (x:y:xs) = if p y then (y:x:xs) else x : moveUp p (y:xs)
moveUp _ xs = xs
-- | Move the -1st element that satisfies the predicate- down.
moveDown :: (a -> Bool) -> [a] -> [a]
moveDown p (x:y:xs) = if p x then (y:x:xs) else x : moveDown p (y:xs)
moveDown _ xs = xs
deleteFirst :: (a -> Bool) -> [a] -> [a]
deleteFirst _ [] = []
deleteFirst f (x:xs) = if f x then xs else x : deleteFirst f xs
insertAtGuaranteed :: Int -> a -> [a] -> [a]
insertAtGuaranteed _ a [] = [a]
insertAtGuaranteed 0 a xs = a:xs
insertAtGuaranteed n a (x:xs) = x : insertAtGuaranteed (n-1) a xs
ordNub :: Ord a => [a] -> [a]
ordNub = go mempty
where
go _ [] = []
go s (x:xs) | x `S.member` s = go s xs
| otherwise = x : go (S.insert x s) xs
equating :: Eq b => (a -> b) -> (a -> a -> Bool)
equating f = (==) `on` f
type Url = Text
sanitiseUrl :: Url -> Maybe Url
sanitiseUrl u
| not (sanitaryURI u) = Nothing
| "http:" `T.isPrefixOf` u = Just u
| "https:" `T.isPrefixOf` u = Just u
| otherwise = Just ("http://" <> u)
-- | Make text suitable for inclusion into an URL (by turning spaces into
-- hyphens and so on)
makeSlug :: Text -> Text
makeSlug =
T.intercalate "-" . T.words .
T.filter (\c -> isLetter c || isDigit c || c == ' ' || c == '-') .
T.toLower .
T.map (\x -> if x == '_' || x == '/' then '-' else x)
deriveSafeCopySimple 0 'base ''IPv4
deriveSafeCopySimple 0 'base ''IPv6
deriveSafeCopySimple 0 'base ''IP
sockAddrToIP :: Network.SockAddr -> Maybe IP
sockAddrToIP (Network.SockAddrInet _ x) = Just (IPv4 (fromHostAddress x))
sockAddrToIP (Network.SockAddrInet6 _ _ x _) = Just (IPv6 (fromHostAddress6 x))
sockAddrToIP _ = Nothing
-- | Unique id, used for many things categories, items, and anchor ids.
newtype Uid a = Uid {uidToText :: Text}
deriving (Eq, Ord, Show, PathPiece, T.Buildable, Hashable, A.ToJSON)
-- See Note [acid-state]
deriveSafeCopySimple 2 'extension ''Uid
newtype Uid_v1 a = Uid_v1 {uidToText_v1 :: Text}
-- TODO: at the next migration change this to deriveSafeCopySimple!
deriveSafeCopy 1 'base ''Uid_v1
instance SafeCopy a => Migrate (Uid a) where
type MigrateFrom (Uid a) = Uid_v1 a
migrate Uid_v1{..} = Uid {
uidToText = uidToText_v1 }
instance IsString (Uid a) where
fromString = Uid . T.pack
randomText :: MonadIO m => Int -> m Text
randomText n = liftIO $ do
-- We don't want the 1st char to be a digit. Just in case (I don't really
-- have a good reason). Maybe to prevent Javascript from doing automatic
-- conversions or something (tho it should never happen).
x <- randomRIO ('a', 'z')
let randomChar = do
i <- randomRIO (0, 35)
return $ if i < 10 then toEnum (fromEnum '0' + i)
else toEnum (fromEnum 'a' + i - 10)
xs <- replicateM (n-1) randomChar
return (T.pack (x:xs))
randomLongUid :: MonadIO m => m (Uid a)
randomLongUid = Uid <$> randomText 12
-- These are only used for items and categories (because their uids can occur
-- in links and so they should look a bit nicer).
randomShortUid :: MonadIO m => m (Uid a)
randomShortUid = Uid <$> randomText 8
-- | A marker for Uids that would be used with HTML nodes
data Node
uid_ :: Uid Node -> Attribute
uid_ = id_ . uidToText
includeJS :: Monad m => Url -> HtmlT m ()
includeJS url = with (script_ "") [src_ url]
includeCSS :: Monad m => Url -> HtmlT m ()
includeCSS url = link_ [rel_ "stylesheet", type_ "text/css", href_ url]
atomFeed :: MonadIO m => Atom.Feed -> ActionCtxT ctx m ()
atomFeed feed = do
setHeader "Content-Type" "application/atom+xml; charset=utf-8"
bytes $ T.encodeUtf8 (T.pack (XML.ppElement (Atom.xmlFeed feed)))
data GenConstructor = Copy Name | Custom String [(String, Name)]
genVer :: Name -> Int -> [GenConstructor] -> Q [Dec]
genVer tyName ver constructors = do
-- Get information about the new version of the datatype
TyConI (DataD _cxt _name _vars cons _deriving) <- reify tyName
-- Let's do some checks first
unless (null _cxt) $
fail "genVer: can't yet work with types with context"
unless (null _vars) $
fail "genVer: can't yet work with types with variables"
let oldName n = mkName (nameBase n ++ "_v" ++ show ver)
let copyConstructor conName =
case [c | c@(RecC n _) <- cons, n == conName] of
[] -> fail ("genVer: couldn't find a record constructor " ++
show conName)
[RecC _ fields] ->
recC (oldName conName)
(map return (fields & each._1 %~ oldName))
other -> fail ("genVer: copyConstructor: got " ++ show other)
let customConstructor conName fields =
recC (oldName (mkName conName))
[varStrictType (oldName (mkName fName))
(strictType notStrict (conT fType))
| (fName, fType) <- fields]
cons' <- for constructors $ \genCons -> do
case genCons of
Copy conName -> copyConstructor conName
Custom conName fields -> customConstructor conName fields
decl <- dataD
-- no context
(cxt [])
-- name of our type (e.g. SomeType_v3 if the previous version was 3)
(oldName tyName)
-- no variables
[]
-- constructors
(map return cons')
-- not deriving anything
[]
return [decl]
data MigrateConstructor = CopyM Name | CustomM Name ExpQ
migrateVer :: Name -> Int -> [MigrateConstructor] -> Q Exp
migrateVer tyName ver constructors = do
-- Get information about the new version of the datatype
TyConI (DataD _cxt _name _vars cons _deriving) <- reify tyName
-- Let's do some checks first
unless (null _cxt) $
fail "migrateVer: can't yet work with types with context"
unless (null _vars) $
fail "migrateVer: can't yet work with types with variables"
let oldName n = mkName (nameBase n ++ "_v" ++ show ver)
arg <- newName "x"
let copyConstructor conName =
case [c | c@(RecC n _) <- cons, n == conName] of
[] -> fail ("migrateVer: couldn't find a record constructor " ++
show conName)
[RecC _ fields] -> do
-- SomeConstr_v3{} -> SomeConstr (field1 x) (field2 x) ...
let getField f = varE (oldName (f ^. _1)) `appE` varE arg
match (recP (oldName conName) [])
(normalB (appsE (conE conName : map getField fields)))
[]
other -> fail ("migrateVer: copyConstructor: got " ++ show other)
let customConstructor conName res =
match (recP (oldName conName) [])
(normalB res)
[]
branches' <- for constructors $ \genCons -> do
case genCons of
CopyM conName -> copyConstructor conName
CustomM conName res -> customConstructor conName res
lam1E (varP arg) (caseE (varE arg) (map return branches'))
instance MonadThrow m => MonadThrow (HtmlT m) where
throwM e = lift $ throwM e