From 70713fc6cd143e6cb67bd1e82d486e6686a6d621 Mon Sep 17 00:00:00 2001
From: Adrian Cochrane <adrian@openwork.nz>
Date: Sun, 19 Apr 2020 13:33:47 +1200
Subject: [PATCH] Fix compilation of Assets StyleSheets.

---
 src/Data/CSS/Preprocessor/Assets.hs | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/src/Data/CSS/Preprocessor/Assets.hs b/src/Data/CSS/Preprocessor/Assets.hs
index b880a7b..70bd69c 100644
--- a/src/Data/CSS/Preprocessor/Assets.hs
+++ b/src/Data/CSS/Preprocessor/Assets.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE OverloadedStrings #-}
+-- | Utilities for rewriting URLs referenced via CSS properties.
 module Data.CSS.Preprocessor.Assets(StyleAssets(..), URIRewriter) where
 
 -- TODO Unit test!
@@ -5,6 +7,7 @@ import           Data.Text as Txt
 import           Network.URI
 import qualified Data.CSS.Syntax.StyleSheet as CSS
 import qualified Data.CSS.Syntax.Tokens as CSSTok
+import           Data.List (nub, elem)
 
 -- | Extracts referenced URLs from specified properties.
 data StyleAssets = StyleAssets {
@@ -15,25 +18,26 @@ data StyleAssets = StyleAssets {
 }
 
 instance CSS.StyleSheet StyleAssets where
-    addRule (StyleAssets filterProps self) (CSS.StyleRule _ props _) =
-        StyleAssets filterProps $ nub (
-            self ++ [uri | (prop, val) <- props,
-                    prop `elem` filterProps,
+    addRule self (CSS.StyleRule _ props _) =
+        StyleAssets (filterProps self) $ nub (
+            assets self ++ [uri | (prop, val) <- props,
+                    prop `elem` filterProps self,
                     CSSTok.Url text <- val,
                     Just uri <- [parseAbsoluteURI $ Txt.unpack text]]
             )
 
 
 -- | Substitutes in given URLs into a property value.
+rewritePropertyVal :: [(URI, URI)] -> [CSSTok.Token] -> [CSSTok.Token] 
 rewritePropertyVal rewrites (CSSTok.Url text:vals)
-    | Just uri <- parseURIReference $ Txt.unpack text, Just rewrite <- uri `M.lookup` rewrites =
+    | Just uri <- parseURIReference $ Txt.unpack text, Just rewrite <- uri `lookup` rewrites =
         CSSTok.Url (Txt.pack $ uriToString id rewrite "") : rewritePropertyVal rewrites vals
     | otherwise = CSSTok.Url "" : rewritePropertyVal rewrites vals
 rewritePropertyVal rewrites (val:vals) = val:rewritePropertyVal rewrites vals
 rewritePropertyVal _ [] = []
 
 -- | Substitutes in given URLs into the inner stylesheet being parsed.
-data URIRewriter s = URIRewriter (M.Map URI URI) s
+data URIRewriter s = URIRewriter [(URI, URI)] s
 instance CSS.StyleSheet s => CSS.StyleSheet (URIRewriter s) where
     setPriority p (URIRewriter r s) = URIRewriter r $ CSS.setPriority p s
     addRule (URIRewriter r s) (CSS.StyleRule sel props psuedo) =
@@ -41,4 +45,4 @@ instance CSS.StyleSheet s => CSS.StyleSheet (URIRewriter s) where
             (prop, rewritePropertyVal r val) | (prop, val) <- props
         ] psuedo
     addAtRule (URIRewriter r s) name toks =
-        let (self', toks') = CSS.addAtRule s name toks in (URIRewriter r s, toks)
+        let (self', toks') = CSS.addAtRule s name toks in (URIRewriter r self', toks')
-- 
2.30.2