feat: add PATCH endpoint for recipe title updates

src/Roux/Server.hs

@@ -43,6 +43,7 @@ import System.FSNotify (
 import System.FilePath (makeRelative, takeBaseName, takeExtension, (</>))
 
 import qualified Data.Aeson as A
+import qualified Data.Aeson.KeyMap as KM
 import qualified Data.ByteString as BS
 import Data.Maybe (mapMaybe)
 import qualified Data.Text.Encoding as TE
@@ -183,6 +184,9 @@ router recipeDir config state changeLog request respond =
         ["import"] -> importHandler recipeDir config state request respond
         ["upload-image"] -> uploadImageHandler recipeDir state request respond
         ["recipe-images", filename] -> serveRecipeImage recipeDir (T.unpack filename) request respond
+        ["recipes", _, "title"]
+            | Wai.requestMethod request == "PATCH" ->
+                titleUpdateHandler recipeDir state request respond
         _ -> handleRequest state request respond
 
 {- | Handle GET and POST requests to /import.
@@ -743,6 +747,20 @@ updateImageMetadata cookFilePath imageUrl = do
                 "---\nimage: " <> imageUrl <> "\n---\n\n" <> text
     BS.writeFile cookFilePath (TE.encodeUtf8 updated)
 
+-- | Update the title in a .cook file's YAML front matter.
+updateTitleInCookFile :: FilePath -> Text -> IO ()
+updateTitleInCookFile filepath newTitle = do
+    content <- BS.readFile filepath
+    let text = TE.decodeUtf8 content
+        updated = case T.stripPrefix "---\n" text of
+            Just afterOpen ->
+                let (yamlBlock, rest) = T.breakOn "\n---" afterOpen
+                    newYaml = addOrUpdateYamlKey "title" newTitle yamlBlock
+                 in "---\n" <> newYaml <> rest
+            Nothing ->
+                "---\ntitle: " <> newTitle <> "\n---\n\n" <> text
+    BS.writeFile filepath (TE.encodeUtf8 updated)
+
 -- | Add or update a key: value line in a YAML block, preserving other keys.
 addOrUpdateYamlKey :: Text -> Text -> Text -> Text
 addOrUpdateYamlKey key value yaml =
@@ -773,3 +791,43 @@ jsonError msg =
         HTTP.status400
         [("Content-Type", "application/json")]
         (LB.fromStrict (encodeUtf8 ("{\"error\":\"" <> msg <> "\"}")))
+
+-- | Handle PATCH /recipes/{filename}/title -- update the recipe title.
+titleUpdateHandler :: FilePath -> IORef (Map FilePath Idx.RecipeInfo) -> Wai.Application
+titleUpdateHandler recipeDir state request respond = do
+    recipes <- readIORef state
+    case Wai.pathInfo request of
+        ["recipes", rawPath, "title"] -> do
+            let key = map toLower (stripCookExt (T.unpack rawPath))
+            case Map.lookup key recipes of
+                Nothing -> respond (jsonError "Recipe not found")
+                Just info -> do
+                    body <- readRequestBody request
+                    case A.decode body of
+                        Nothing -> respond (jsonError "Invalid JSON body")
+                        Just (val :: A.Value) ->
+                            case titleFromJson val of
+                                Nothing -> respond (jsonError "Missing 'title' field")
+                                Just title -> do
+                                    let trimmed = T.strip title
+                                    if T.null trimmed
+                                        then respond (jsonError "Title cannot be empty")
+                                        else do
+                                            let filepath = recipeDir </> Idx.riFilename info
+                                            result <- try $ updateTitleInCookFile filepath trimmed
+                                            case result of
+                                                Left (_ :: IOException) ->
+                                                    respond (jsonError "Could not update recipe file")
+                                                Right () ->
+                                                    respond $
+                                                        jsonOk
+                                                            [ ("success", "true")
+                                                            , ("title", trimmed)
+                                                            ]
+        _ -> respond notFound
+  where
+    titleFromJson :: A.Value -> Maybe Text
+    titleFromJson (A.Object obj) = case KM.lookup "title" obj of
+        Just (A.String t) -> Just t
+        _ -> Nothing
+    titleFromJson _ = Nothing