1 files changed, 34 insertions, 5 deletions
diff --git a/shard/lib/app/chat.ex b/shard/lib/app/chat.ex
index d8ba5da..8d55cda 100644
--- a/shard/lib/app/chat.ex
+++ b/shard/lib/app/chat.ex
@@ -82,7 +82,10 @@ defmodule SApp.Chat do
         end
         Shard.Manager.dispatch_to(id, nil, self())
         {:ok, page_store} = SApp.PageStore.start_link(id, :page_store, netgroup)
-        root = Shard.Manager.load_state id
+        {root, read} = case Shard.Manager.load_state id do
+          %{root: root, read: read} -> {root, read}
+          _ -> {nil, nil}
+        end
         root = cond do
           root == nil -> nil
           GenServer.call(page_store, {:have_rec, root}) -> root
@@ -101,6 +104,7 @@ defmodule SApp.Chat do
             page_store: page_store,
             mst: mst,
             subs: MapSet.new,
+            read: read,
           }
         }
       :redundant ->
@@ -120,6 +124,26 @@ defmodule SApp.Chat do
     {:reply, ret, state}
   end
 
+  def handle_call(:has_unread, _from, state) do
+    if state.mst.root != state.read do
+      case MST.last(state.mst, nil, 1) do
+        [{{_, msgbin, _}, true}] ->
+          {ts, _} = SData.term_unbin msgbin
+          {:reply, ts, state}
+        [] ->
+          {:reply, nil, state}
+      end
+    else
+      {:reply, nil, state}
+    end
+  end
+
+  def handle_cast(:mark_read, state) do
+    state = %{state | read: state.mst.root}
+    save_state(state)
+    {:noreply, state}
+  end
+
   @doc """
   Implementation of the :chat_send handler. This is the main handler that is used
   to send a message to the chat room. Puts the message in the store and syncs
@@ -133,7 +157,7 @@ defmodule SApp.Chat do
     prev_root = state.mst.root
     mst = MST.insert(state.mst, msgitem)
     state = %{state | mst: mst}
-    Shard.Manager.save_state(state.id, mst.root)
+    save_state(state)
 
     for pid <- state.subs do
       if Process.alive?(pid) do
@@ -202,7 +226,7 @@ defmodule SApp.Chat do
                 if mst2.root == new_root do
                   state = %{state | mst: mst2}
                   GenServer.cast(state.page_store, {:set_roots, [mst2.root]})
-                  Shard.Manager.save_state(state.id, mst2.root)
+                  save_state(state)
                   msg_callback(state, msgitem)
                   state
                 else
@@ -265,8 +289,9 @@ defmodule SApp.Chat do
           msg_callback(state, x)
         end
         GenServer.cast(state.page_store, {:set_roots, [mst.root]})
-        Shard.Manager.save_state(state.id, mst.root)
-        %{state | mst: mst}
+        state = %{state | mst: mst}
+        save_state(state)
+        state
       else
         Logger.warn("Incorrect signatures somewhere while merging, dropping merged data")
         state
@@ -279,6 +304,10 @@ defmodule SApp.Chat do
     {:noreply, %{ state | subs: new_subs }}
   end
 
+  defp save_state(state) do
+    Shard.Manager.save_state(state.id, %{root: state.mst.root, read: state.read})
+  end
+
   defp msg_callback(state, {pk, msgbin, sign}) do
     for pid <- state.subs do
       if Process.alive?(pid) do