restructure lib/oauth2 for more convenient token extension

lib/oauth2.hoon

@@ -30,6 +30,7 @@
 |%
 ++  token  ?(~ @t)
 ++  keys  cord:,[cid=@t cis=@t]
+++  core-move  |*(a=* $&([sec-move _a] sec-move))
 ++  decode-keys                       :: XX from bale w/ typed %jael
   |=(key=keys ((hard ,[cid=@t cis=@t ~]) (lore key)))
 --
@@ -107,13 +108,18 @@
 ++  expires-in  'expires_in'^ni:jo
 ++  access-token  'access_token'^so:jo
 ++  refresh-token  'refresh_token'^so:jo
-++  bak-parse-access
+++  bak-save-access
+  |*  [done=* handle=$+(cord:token *)]  :: $+(token _done)
+  %-  (bak-parse done access-token ~)
+  |=(tok=token [[%redo ~] (handle tok)])
+::
+++  bak-parse
   |*  [done=* parse=(pole ,[span fist]:jo)]
-  |=  handle=$+(_?~(parse *token [*token (need *(ot:jo parse))]) _done)
-  |=  a=httr  ^-  [sec-move _done] 
-  :-  [%redo ~]
-  ?:  (bad-response p.a)  done  ::  handle 4xx?
-  (handle (grab-json a (ot:jo access-token parse)))
+  =+  fin=$&([sec-move _done] sec-move)
+  |=  handle=$+(_?~(parse ~ (need *(ot:jo parse))) fin)
+  |=  a=httr  ^-  fin
+  ?:  (bad-response p.a)  [%redo ~]  ::  handle 4xx?
+  (handle (grab-json a (ot:jo parse)))
 ::
 :: ++  bak-parse-refresh
 ::   |=  a=httr  ^-  [sec-move _+>]

sec/com/facebook/graph.hoon

@@ -6,16 +6,15 @@
 =+  aut=(oauth2 - /'v2.3'/oauth/'access_token')
 |_  [bal=(bale keys.aut) access-token=token.aut]
 ++  auth  ~(. aut bal /'user_about_me'/'user_posts')
-++  out  (out-quay:auth 'access_token'^access-token)
+++  out  
+  ~&  access-token
+  (out-quay:auth 'access_token'^access-token)
 ++  in   in-code:auth
 ++  bak
-  |=  res=httr
-  =+  a=auth
-  ?:  (bad-response.a p.res)  [%redo ~]
-  =+  ^-  [access-token=@t expires-in=@u]
-      (grab-json.a res (ot:jo access-token expires-in ~):a)
+  %-  (bak-parse:auth . access-token.aut expires-in.aut ~)
+  |=  [access-token=@t expires-in=@u]
   ?:  (lth expires-in ^~((div ~d7 ~s1)))  ::  short-lived token
-    (toke-req:a 'fb_exchange_token' fb-exchange-token/access-token ~)
+    (toke-req:auth 'fb_exchange_token' fb-exchange-token/access-token ~)
   [[%redo ~] ..bak(access-token access-token)]
 ::++  wipe  !!
 --

sec/com/slack.hoon

@@ -7,5 +7,5 @@
 ++  aut  ~(. ^aut +<- /client/admin)
 ++  out  (out-quay:aut 'token'^tok)
 ++  in   in-code:aut
-++  bak  ((bak-parse-access:aut . ~) |=(tok=token:aut +>(tok tok)))
+++  bak  (bak-save-access:aut . |=(tok=token:aut +>(tok tok)))
 --