threads: reverse thread ordering

Add reverse-thread-order option to the ui config to enable reverse
display of the mesage threads. Default order is the the intial message
is on the top with all the replies being displayed below. The reverse
options will put the initial message at the bottom with the replies on
top.

Signed-off-by: Koni Marti <koni.marti@gmail.com>
Acked-by: Robin Jarry <robin@jarry.cc>

2 files changed, 30 insertions, 12 deletions

diff --git a/lib/msgstore.go b/lib/msgstore.go
index d6ca26e2..a22e1961 100644
--- a/lib/msgstore.go
+++ b/lib/msgstore.go
@@ -39,9 +39,10 @@ type MessageStore struct {
 
 	sortCriteria []*types.SortCriterion
 
-	threadedView bool
-	buildThreads bool
-	builder      *ThreadBuilder
+	threadedView       bool
+	reverseThreadOrder bool
+	buildThreads       bool
+	builder            *ThreadBuilder
 
 	// Map of uids we've asked the worker to fetch
 	onUpdate       func(store *MessageStore) // TODO: multiple onUpdate handlers
@@ -74,7 +75,7 @@ func NewMessageStore(worker *types.Worker,
 	dirInfo *models.DirectoryInfo,
 	defaultSortCriteria []*types.SortCriterion,
 	thread bool, clientThreads bool, clientThreadsDelay time.Duration,
-	reverseOrder bool,
+	reverseOrder bool, reverseThreadOrder bool,
 	triggerNewEmail func(*models.MessageInfo),
 	triggerDirectoryChange func(),
 ) *MessageStore {
@@ -91,8 +92,9 @@ func NewMessageStore(worker *types.Worker,
 
 		bodyCallbacks: make(map[uint32][]func(*types.FullMessage)),
 
-		threadedView: thread,
-		buildThreads: clientThreads,
+		threadedView:       thread,
+		buildThreads:       clientThreads,
+		reverseThreadOrder: reverseThreadOrder,
 
 		filter:       []string{"filter"},
 		sortCriteria: defaultSortCriteria,
@@ -231,7 +233,7 @@ func (store *MessageStore) Update(msg types.WorkerMessage) {
 		newMap := make(map[uint32]*models.MessageInfo)
 
 		builder := NewThreadBuilder(store.iterFactory)
-		builder.RebuildUids(msg.Threads)
+		builder.RebuildUids(msg.Threads, store.reverseThreadOrder)
 		store.uids = builder.Uids()
 		store.threads = msg.Threads
 
@@ -364,6 +366,14 @@ func (store *MessageStore) update(threads bool) {
 	}
 }
 
+func (store *MessageStore) SetReverseThreadOrder(reverse bool) {
+	store.reverseThreadOrder = reverse
+}
+
+func (store *MessageStore) ReverseThreadOrder() bool {
+	return store.reverseThreadOrder
+}
+
 func (store *MessageStore) SetThreadedView(thread bool) {
 	store.threadedView = thread
 	if store.buildThreads {
@@ -424,7 +434,7 @@ func (store *MessageStore) runThreadBuilderNow() {
 		}
 	}
 	// build new threads
-	th := store.builder.Threads(store.uids)
+	th := store.builder.Threads(store.uids, store.reverseThreadOrder)
 
 	// save local threads to the message store variable and
 	// run callback if defined (callback should reposition cursor)
diff --git a/lib/threadbuilder.go b/lib/threadbuilder.go
index 75a80797..b1609257 100644
--- a/lib/threadbuilder.go
+++ b/lib/threadbuilder.go
@@ -55,7 +55,7 @@ func (builder *ThreadBuilder) Update(msg *models.MessageInfo) {
 }
 
 // Threads returns a slice of threads for the given list of uids
-func (builder *ThreadBuilder) Threads(uids []uint32) []*types.Thread {
+func (builder *ThreadBuilder) Threads(uids []uint32, inverse bool) []*types.Thread {
 	builder.Lock()
 	defer builder.Unlock()
 
@@ -67,7 +67,7 @@ func (builder *ThreadBuilder) Threads(uids []uint32) []*types.Thread {
 	builder.sortThreads(threads, uids)
 
 	// rebuild uids from threads
-	builder.RebuildUids(threads)
+	builder.RebuildUids(threads, inverse)
 
 	elapsed := time.Since(start)
 	logging.Infof("%d threads created in %s", len(threads), elapsed)
@@ -155,15 +155,23 @@ func (builder *ThreadBuilder) sortThreads(threads []*types.Thread, orderedUids [
 }
 
 // RebuildUids rebuilds the uids from the given slice of threads
-func (builder *ThreadBuilder) RebuildUids(threads []*types.Thread) {
+func (builder *ThreadBuilder) RebuildUids(threads []*types.Thread, inverse bool) {
 	uids := make([]uint32, 0, len(threads))
 	iterT := builder.iterFactory.NewIterator(threads)
 	for iterT.Next() {
+		var threaduids []uint32
 		_ = iterT.Value().(*types.Thread).Walk(
 			func(t *types.Thread, level int, currentErr error) error {
-				uids = append(uids, t.Uid)
+				threaduids = append(threaduids, t.Uid)
 				return nil
 			})
+		if inverse {
+			for j := len(threaduids) - 1; j >= 0; j-- {
+				uids = append(uids, threaduids[j])
+			}
+		} else {
+			uids = append(uids, threaduids...)
+		}
 	}
 	result := make([]uint32, 0, len(uids))
 	iterU := builder.iterFactory.NewIterator(uids)