1 files changed, 25 insertions, 9 deletions

diff --git a/app/Main.hs b/app/Main.hs
index 11b7602..f3411ca 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -169,7 +169,8 @@ filtersArg =
           <> O.help "Filter documents by tag"
       )
   where
-    parse ('@' : tagKey) = Just (FilterByTag (T.pack tagKey))
+    parse ('@' : tagKey) = Just (Filter Include (FilterByTag (T.pack tagKey)))
+    parse ('!' : '@' : tagKey) = Just (Filter Exclude (FilterByTag (T.pack tagKey)))
     parse _ = Nothing
 
 indexNamesArg :: O.Parser [FilePath]
@@ -208,7 +209,11 @@ viewArg =
         <> O.help "Run command `view` on listed document(s)"
     )
 
-data Filter
+data Filter = Filter Mode SimpleFilter
+
+data Mode = Include | Exclude
+
+data SimpleFilter
   = FilterByTag T.Text
 
 main :: IO ()
@@ -234,7 +239,7 @@ main = do
       mapM_
         ( \doc -> do
             printf "%s\n" (takeBaseName doc.iFileName)
-            print doc.index.tags
+            printTags doc
         )
         docs'
     Args {cmd = Edit {indexNames}} -> do
@@ -243,10 +248,9 @@ main = do
     Args {cmd = List {filters, redo, todo = False, view = False, edit = False}} -> do
       doRedoIf filters redo
       mapM_
-        ( \(Document {iFileName, index}) -> do
-            if hasTag (Tag "todo" Nothing) index.tags
-              then printf "TODO %s\n" (takeBaseName iFileName)
-              else printf "     %s\n" (takeBaseName iFileName)
+        ( \doc -> do
+            printf "%s\n" (takeBaseName doc.iFileName)
+            printTags doc
         )
         . applyFilters filters
         =<< getDocuments
@@ -267,7 +271,7 @@ main = do
       allDocs <- getDocuments
       _ <-
         processDocumentsInteractively settings allDocs
-          . applyFilters [FilterByTag "todo"]
+          . applyFilters [Filter Include (FilterByTag "todo")]
           $ allDocs
       pure ()
     Args {cmd = List {filters, redo, view = True}} -> do
@@ -279,6 +283,16 @@ main = do
       viewDocuments
         =<< mapM (readDocument . (<.> "json")) indexNames
 
+printTags :: Document -> IO ()
+printTags doc =
+  mapM_
+    ( \tag ->
+        case tagValue tag of
+          Nothing -> printf "@%s\n" (tagKey tag)
+          Just tagValue -> printf "@%s %s\n" (tagKey tag) tagValue
+    )
+    doc.index.tags
+
 doRedoIf :: [Filter] -> Bool -> IO ()
 doRedoIf filters redo =
   when redo do
@@ -326,7 +340,9 @@ readDocument iFileName =
 applyFilters :: [Filter] -> [Document] -> [Document]
 applyFilters filters = filter (pred filters) `at` (.index.internalTags)
   where
-    pred1 (FilterByTag tagKey) = hasTag (Tag tagKey Nothing)
+    pred1 (Filter Include filter') = pred1' filter'
+    pred1 (Filter Exclude filter') = not . pred1' filter'
+    pred1' (FilterByTag tagKey) = hasTag (Tag tagKey Nothing)
     pred filters = \index -> all ($ index) (map pred1 filters)
 
     at :: ([a] -> [a]) -> (b -> a) -> [b] -> [b]