hark-store, hark-chat-hook: support mentions in chat

pkg/arvo/app/hark-chat-hook.hoon

@@ -13,6 +13,7 @@
 +$  state-0
   $:  %0
       watching=(set path)
+      mentions=_&
   ==
 ::
 --
@@ -75,6 +76,7 @@
     ?-  -.action
       %listen  (listen +.action)
       %ignore  (ignore +.action)
+      %set-mentions  (set-mentions +.action)
     ==
     ++  listen
       |=  chat=path
@@ -87,6 +89,12 @@
       ^-  (quip card _state)
       :-  (give:ha ~[/updates] [%ignore chat])
       state(watching (~(del in watching) chat))
+    ::
+    ++  set-mentions
+      |=  ment=?
+      ^-  (quip card _state)
+      :-  (give:ha ~[/updates] [%set-mentions ment])
+      state(mentions ment)
     --
   --
 ::
@@ -121,16 +129,29 @@
       %-  zing
       (turn envelopes.update (cury process-envelope path.update))
     ==
+  ++  is-mention
+    |=  [=path =envelope:chat-store]
+    ?.  ?=(%text -.letter.envelope)  %.n
+    ?&  mentions
+        ?=  ^ 
+        (find (scow %p our.bowl) (trip text.letter.envelope))
+    ==
+  ::
+  ++  is-notification
+    |=  [=path =envelope:chat-store]
+    ?&  (~(has in watching) path)
+        !=(author.envelope our.bowl)
+    ==  
   ::
   ++  process-envelope
     |=  [=path =envelope:chat-store]
     ^-  (list card)
-    ?.  ?&  (~(has in watching) path)
-            !=(author.envelope our.bowl)
-        ==
+    =/  mention=?
+      (is-mention path envelope)
+    ?.  ?|(mention (is-notification path envelope))
       ~
     =/  =index:store
-      [%chat path]
+      [%chat path mention]
     =/  =contents:store
       [%chat ~[envelope]]
     ~[(poke-store %add index when.envelope %.n contents)]

pkg/arvo/lib/hark/chat-hook.hoon

@@ -12,6 +12,7 @@
     %-  of
     :~  listen+pa
         ignore+pa
+        set-mentions+bo
     ==
   --
 ::
@@ -24,6 +25,7 @@
     %+  frond  -.upd
     ?-  -.upd
       ?(%listen %ignore)  (path chat.upd)
+      %set-mentions  b+mentions.upd
       %initial   a+(turn ~(tap in watching.upd) path)
     ==
   --

pkg/arvo/lib/hark/store.hoon

@@ -11,7 +11,13 @@
     %-  of
     :~  graph+graph-index
         group+group-index
-        chat+pa
+        chat+chat-index
+    ==
+  ::
+  ++  chat-index
+    %-  ot
+    :~  chat+pa
+        mention+bo
     ==
   ::
   ++  group-index
@@ -107,7 +113,15 @@
       ?-  -.index
         %graph  (graph-index +.index)
         %group  (group-index +.index)
-        %chat   (path chat.index)
+        %chat   (chat-index +.index)
+      ==
+      ::
+      ++  chat-index
+        |=  [chat=^path mention=?]
+        ^-  json
+        %-  pairs
+        :~  chat+(path chat)
+            mention+b+mention
         ==
       :: 
       ++  graph-index

pkg/arvo/sur/hark-chat-hook.hoon

@@ -3,6 +3,7 @@
 ::
 +$  action
   $%  [?(%listen %ignore) chat=path]
+      [%set-mentions mentions=?]
   ==
 ::
 +$  update

pkg/arvo/sur/hark-store.hoon

@@ -5,7 +5,7 @@
 +$  index
   $%  [%graph group=resource graph=resource module=@t description=@t]
       [%group group=resource description=@t]
-      [%chat chat=path]
+      [%chat chat=path mention=?]
   ==
 ::
 +$  group-contents