From 7e34c2d78f967c7164560bc2f6a84cec72d934b6 Mon Sep 17 00:00:00 2001
From: Sridhar Ratnakumar <srid@srid.ca>
Date: Fri, 12 Jan 2024 21:13:25 +0530
Subject: [PATCH] lua: Look up in all layers

---
 emanote/emanote.cabal               |  2 +-
 emanote/src/Emanote/Model/Note.hs   | 19 ++++++++++++++++---
 emanote/src/Emanote/Source/Loc.hs   | 14 ++++++++++++++
 emanote/src/Emanote/Source/Patch.hs |  8 ++------
 4 files changed, 33 insertions(+), 10 deletions(-)

diff --git a/emanote/emanote.cabal b/emanote/emanote.cabal
index e08f2c906..2c6f8180b 100644
--- a/emanote/emanote.cabal
+++ b/emanote/emanote.cabal
@@ -1,6 +1,6 @@
 cabal-version:      2.4
 name:               emanote
-version:            1.3.5.0
+version:            1.3.5.1
 license:            AGPL-3.0-only
 copyright:          2022 Sridhar Ratnakumar
 maintainer:         srid@srid.ca
diff --git a/emanote/src/Emanote/Model/Note.hs b/emanote/src/Emanote/Model/Note.hs
index 316e61216..371bb4968 100644
--- a/emanote/src/Emanote/Model/Note.hs
+++ b/emanote/src/Emanote/Model/Note.hs
@@ -36,6 +36,7 @@ import Text.Pandoc.Definition (Pandoc (..))
 import Text.Pandoc.Readers.Org (readOrg)
 import Text.Pandoc.Scripting (ScriptingEngine)
 import Text.Pandoc.Walk qualified as W
+import UnliftIO.Directory (doesPathExist)
 
 data Feed = Feed
   { _feedEnable :: Bool
@@ -300,7 +301,7 @@ parseNote ::
   forall m.
   (MonadIO m, MonadLogger m) =>
   ScriptingEngine ->
-  FilePath ->
+  [FilePath] ->
   R.LMLRoute ->
   FilePath ->
   Text ->
@@ -324,7 +325,7 @@ parseNoteOrg s =
       -- TODO: Merge Pandoc's Meta in here?
       pure (preparePandoc doc, defaultFrontMatter)
 
-parseNoteMarkdown :: (MonadIO m, MonadLogger m) => ScriptingEngine -> FilePath -> FilePath -> Text -> WriterT [Text] m (Pandoc, Aeson.Value)
+parseNoteMarkdown :: (MonadIO m, MonadLogger m) => ScriptingEngine -> [FilePath] -> FilePath -> Text -> WriterT [Text] m (Pandoc, Aeson.Value)
 parseNoteMarkdown scriptingEngine pluginBaseDir fp md = do
   case Markdown.parseMarkdown fp md of
     Left err -> do
@@ -335,7 +336,19 @@ parseNoteMarkdown scriptingEngine pluginBaseDir fp md = do
       --
       -- Some are user-defined; some builtin. They operate on Pandoc, or the
       -- frontmatter meta.
-      let filterPaths = (pluginBaseDir </>) <$> SData.lookupAeson @[FilePath] mempty ("pandoc" :| ["filters"]) frontmatter
+      filterPaths <- fmap catMaybes $ forM (SData.lookupAeson @[FilePath] mempty ("pandoc" :| ["filters"]) frontmatter) $ \p -> do
+        res :: [FilePath] <- flip mapMaybeM pluginBaseDir $ \baseDir -> do
+          doesPathExist (baseDir </> p) >>= \case
+            False -> do
+              pure Nothing
+            True ->
+              pure $ Just $ baseDir </> p
+        case res of
+          [] -> do
+            tell [toText $ "Pandoc filter " <> p <> " not found in any of: " <> show pluginBaseDir]
+            pure Nothing
+          (x : _) -> pure $ Just x
+
       doc <- applyPandocFilters scriptingEngine filterPaths $ preparePandoc doc'
       let meta = applyNoteMetaFilters doc frontmatter
       pure (doc, meta)
diff --git a/emanote/src/Emanote/Source/Loc.hs b/emanote/src/Emanote/Source/Loc.hs
index 4849f43d4..8ce6700aa 100644
--- a/emanote/src/Emanote/Source/Loc.hs
+++ b/emanote/src/Emanote/Source/Loc.hs
@@ -14,6 +14,7 @@ module Emanote.Source.Loc (
   -- * Dealing with layers of locs
   LocLayers,
   primaryLayer,
+  userLayersToSearch,
 ) where
 
 import Data.Set qualified as Set
@@ -46,6 +47,19 @@ primaryLayer =
       LocUser _ _ -> True
       _ -> False
 
+{- | List of user layers, highest precedent being at first.
+
+This is useful to delay searching for content in layers.
+-}
+userLayersToSearch :: LocLayers -> [FilePath]
+userLayersToSearch =
+  mapMaybe
+    ( \case
+        LocUser _ fp -> Just fp
+        LocDefault _ -> Nothing
+    )
+    . Set.toAscList
+
 defaultLayer :: FilePath -> Loc
 defaultLayer = LocDefault
 
diff --git a/emanote/src/Emanote/Source/Patch.hs b/emanote/src/Emanote/Source/Patch.hs
index 7d5d84986..cd7a1479b 100644
--- a/emanote/src/Emanote/Source/Patch.hs
+++ b/emanote/src/Emanote/Source/Patch.hs
@@ -22,7 +22,7 @@ import Emanote.Prelude (
   logD,
  )
 import Emanote.Route qualified as R
-import Emanote.Source.Loc (Loc, LocLayers, locPath, locResolve, primaryLayer)
+import Emanote.Source.Loc (Loc, LocLayers, locResolve, userLayersToSearch)
 import Emanote.Source.Pattern (filePatterns, ignorePatterns)
 import Heist.Extra.TemplateState qualified as T
 import Optics.Operators ((%~))
@@ -91,12 +91,8 @@ patchModel' layers noteF storkIndexTVar scriptingEngine fpType fp action = do
           case action of
             UM.Refresh refreshAction overlays -> do
               let fpAbs = locResolve $ head overlays
-                  -- TODO: This should automatically be computed, instead of being passed.
-                  -- We need access to the model though! With dependency management to boot.
-                  -- Until this, `layers` is threaded through as a hack.
-                  currentLayerPath = locPath $ primaryLayer layers
               s <- readRefreshedFile refreshAction fpAbs
-              note <- N.parseNote scriptingEngine currentLayerPath r fpAbs (decodeUtf8 s)
+              note <- N.parseNote scriptingEngine (userLayersToSearch layers) r fpAbs (decodeUtf8 s)
               pure $ M.modelInsertNote $ noteF note
             UM.Delete -> do
               log $ "Removing note: " <> toText fp