1 files changed, 229 insertions, 0 deletions
diff --git a/src/Much/TreeView.hs b/src/Much/TreeView.hs
new file mode 100644
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--- /dev/null
+++ b/src/Much/TreeView.hs
@@ -0,0 +1,229 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE RecordWildCards #-}
+
+
+module Much.TreeView
+    ( module Export
+    , getMessage
+    , getSearchTerm
+    , isTVMessage
+    , isTVSearchResult
+    , fromSearchResults
+    , fromMessageForest
+    , fromMessageTree
+    , loadSubForest
+    , unloadSubForest
+    , hasUnloadedSubForest
+    ) where
+
+
+import qualified Data.Text as T
+import Data.Tree
+import Notmuch
+import Notmuch.Message
+import Notmuch.SearchResult
+import Much.TreeView.Types as Export
+
+
+getMessage :: TreeView -> Maybe Message
+getMessage = \case
+    TVMessage m -> Just m
+    TVMessageHeaderField m _ -> Just m
+    TVMessagePart m _ -> Just m
+    TVMessageQuoteLine m _ _ _ -> Just m
+    TVMessageLine m _ _ _ -> Just m
+    _ -> Nothing
+
+
+getSearchTerm :: TreeView -> Maybe String
+getSearchTerm = \case
+    TVSearch term -> Just term
+    _ -> Nothing
+
+
+isTVMessage :: TreeView -> Bool
+isTVMessage = \case
+    TVMessage _ -> True
+    _ -> False
+
+
+isTVMessagePart :: TreeView -> Bool
+isTVMessagePart = \case
+    TVMessagePart _ _ -> True
+    _ -> False
+
+
+isTVSearchResult :: TreeView -> Bool
+isTVSearchResult (TVSearchResult _) = True
+isTVSearchResult _ = False
+
+
+fromSearchResults :: String -> [SearchResult] -> Tree TreeView
+fromSearchResults query =
+    Node (TVSearch query) . map (\r -> Node (TVSearchResult r) [])
+
+
+fromMessageForest :: Forest Message -> Forest TreeView
+fromMessageForest = map fromMessageTree
+
+
+fromMessageTree :: Tree Message -> Tree TreeView
+fromMessageTree (Node m ms) =
+    Node (TVMessage m)
+         (xconvHead m <> xconvBody m <> map fromMessageTree ms)
+
+
+xconvHead :: Message -> Forest TreeView
+xconvHead m =
+    map conv [ "From", "To" ]
+    -- TODO add Subject if it differs from thread subject
+  where
+    conv k =
+      Node (TVMessageHeaderField m k) []
+
+
+xconvBody :: Message -> Forest TreeView
+xconvBody m = map (xconvPart m) (messageBody m)
+
+
+xconvPart :: Message -> MessagePart -> Tree TreeView
+xconvPart m p =
+    Node (TVMessagePart m p) contents
+  where
+    contents = case partContent p of
+        ContentText t ->
+            zipWith (curry $ xconvLine m p) [0..] (T.lines t)
+        ContentMultipart parts ->
+            map (xconvPart m) parts
+        ContentMsgRFC822 _ ->
+            []
+
+
+xconvLine
+  :: Message -> MessagePart -> (LineNr, T.Text) -> Tree TreeView
+xconvLine m p (i, s) =
+    Node (ctor m p i $ T.unpack s) []
+  where
+    ctor =
+        if isQuoteLine s
+            then TVMessageQuoteLine
+            else TVMessageLine
+
+
+isQuoteLine :: T.Text -> Bool
+isQuoteLine s0 = do
+    let s = T.stripStart s0
+
+    -- /^\s*>/
+    not (T.null s) && T.head s == '>'
+
+
+--
+-- Loading / Unloading
+--
+
+
+loadSubForest :: TreeView -> IO (Either String (Forest TreeView))
+loadSubForest = \case
+    TVMessage m ->
+        Right
+            . unloadPartsWithFilename
+            . map unloadReadSubForests
+            . concatMap subForest
+            . fromMessageForest
+            . findFirsts messageMatch
+            <$> notmuchShow (termFromMessage m)
+
+    TVMessagePart m mp ->
+        -- TODO parse --format=raw
+        notmuchShowPart (termFromMessage m) (partID mp) >>= return . \case
+            Left e -> Left $ show e
+            Right mp' ->
+                Right
+                    . unloadPartsWithFilename
+                    . subForest
+                    $ xconvPart m mp'
+
+    TVSearchResult sr ->
+        Right
+            . unloadPartsWithFilename
+            . map unloadReadSubForests
+            . fromMessageForest
+            <$> notmuchShow (termFromSearchResult sr)
+
+    TVSearch s ->
+        Right
+            . subForest
+            . fromSearchResults s
+            . either error id
+            <$> Notmuch.search [s]
+
+    _ ->
+        return $ Right []
+
+  where
+    termFromMessage = unMessageID . messageId
+    termFromSearchResult = unThreadID . searchThread
+
+
+unloadSubForest :: Tree TreeView -> Forest TreeView
+unloadSubForest t = case rootLabel t of
+    TVMessage _ ->
+        filter (isTVMessage . rootLabel) $ subForest t
+    TVMessagePart _ _ ->
+        filter (isTVMessagePart . rootLabel) $ subForest t
+    _ ->
+        []
+
+
+hasUnloadedSubForest :: Tree TreeView -> Bool
+hasUnloadedSubForest t = case rootLabel t of
+    TVMessage _ ->
+        all (isTVMessage . rootLabel) $ subForest t
+    TVMessagePart _ _ ->
+        all (isTVMessagePart . rootLabel) $ subForest t
+    _ ->
+        null $ subForest t
+
+
+unloadReadSubForests :: Tree TreeView -> Tree TreeView
+unloadReadSubForests t = case rootLabel t of
+    TVMessage m | "unread" `notElem` messageTags m ->
+        t { subForest =
+                map unloadReadSubForests $
+                filter (isTVMessage . rootLabel) $
+                subForest t
+          }
+    _ ->
+        t { subForest =
+                map unloadReadSubForests $
+                subForest t
+          }
+
+
+unloadPartsWithFilename :: Forest TreeView -> Forest TreeView
+unloadPartsWithFilename =
+    map rewriteTree
+  where
+    f x@Node{..} = case rootLabel of
+      TVMessagePart _ mp ->
+          case partContentFilename mp of
+              Nothing -> x
+              Just _ ->
+                  x { subForest = [] }
+      _ -> x
+
+    rewriteTree x =
+        let x' = f x
+        in x' { subForest = map rewriteTree $ subForest x' }
+
+
+findFirsts :: (a -> Bool) -> Forest a -> Forest a
+findFirsts p =
+    concatMap rec
+  where
+    rec t@Node{..} =
+      if p rootLabel
+          then [t]
+          else concatMap rec subForest