contacts: import lib-subscriber

desk/lib/subscriber.hoon

@@ -0,0 +1,47 @@
+=<  subscriber
+|%
++$  sub
+  $:  =dock
+      =path
+      fires-at=@da
+  ==
+::
++$  subs  (map wire sub)
+::
+++  verb  |
+++  subscriber
+  |_  [=subs bowl:gall]
+  ++  interval  ~s30
+  ++  handle-wakeup
+    |=  =wire
+    ^-  [(list card:agent:gall) _subs]
+    ?>  ?=([%~.~ %retry *] wire)
+    ~?  verb  ['waking up' wire]
+    =/  sub  (~(get by subs) t.t.wire)
+    ?~  sub  [~ subs]
+    :-  ~[[%pass t.t.wire %agent dock.u.sub %watch path.u.sub]]
+    (~(del by subs) t.t.wire)
+  ++  subscribe
+    |=  [=wire =dock =path delay=?]
+    ^-  [(list card:agent:gall) _subs]
+    ?:  (~(has by subs) wire)
+      ((slog 'Duplicate subscription' >[wire dock]< ~) [~ subs])
+    ?.  delay  [~[[%pass wire %agent dock %watch path]] subs]
+    ~?  verb  ['subscribing with delay' wire]
+    =/  fires-at  (add now interval)
+    :_  (~(put by subs) wire [dock path fires-at])
+    ~[[%pass (weld /~/retry wire) %arvo %b %wait fires-at]]
+  ++  unsubscribe
+    |=  [=wire =dock]
+    ^-  [(list card:agent:gall) _subs]
+    =/  leave  [%pass wire %agent dock %leave ~]
+    =/  sub  (~(get by subs) wire)
+    ?~  sub
+      ((slog 'No such subscription' >[wire]< ~) [~[leave] subs])
+    ~?  verb  ['cancelling' wire]
+    :_  (~(del by subs) wire)
+    :~  [%pass (weld /~/retry wire) %arvo %b %rest fires-at.u.sub]
+        leave
+    ==
+  --
+--