@@ 241,7 241,7 @@ known IDs gets to its limit."
             ;; We can safely tombstone the ID and empty the
             ;; trustlists. They are deleted in a deferred reindexing
             ;; (~garbage collecting) step.
-            
+
             ;; We need to also check the ranks, because the ownid may
             ;; have no trust
             define indexes-without-any-trust

          
@@ 429,7 429,7 @@ define : get-score wotstate ownkey other
         wotcache-scores
             update-wotcache-from-wotstate! wotstate-with-cache ownid
     define otherindex : key->index otherkey
-    cond 
+    cond
       : equal? ownkey otherkey
         . "100" ;; trust of own ID is always 100
       {otherindex >= (vector-length scores)}

          
@@ 580,17 580,116 @@ define : add-for-ownid! subs ownid id
     define updated
         cons (car entry) : cons id : cdr entry
     list-set! subs index updated
-define-syntax-rule : add-to-subscription! subs ownid id
-  begin
+define-syntax-rule : ensure-ownid-entry-exists! subs ownid
     unless : assoc ownid subs
       set! subs
            alist-cons ownid '() subs
+define-syntax-rule : add-to-subscription! subs ownid id
+  begin
+    ensure-ownid-entry-exists! subs ownid
     add-for-ownid! subs ownid id
-define : get-subscriptions ownid
+define : set-subscriptions-for-ownid-helper! subs ownid updated
+    define index
+        list-index : λ (x) : equal? ownid : first x
+                   . subs
+    list-set! subs index updated
+define-syntax-rule : set-subscriptions-for-ownid! subs ownid updated
+  begin
+    ensure-ownid-entry-exists! subs ownid
+    set-subscriptions-for-ownid-helper! subs ownid updated
+define : get-own-subscriptions subs ownid
+    or : assoc-ref subs ownid
+       . '()
+define : next-subscriptions wotstate ownid
+    . "Calculate the subscriptions to use in the next step."
     ;; TODO: update subscription-lists from wot and retrieve the
     ;; defined IDs.
-    or : assoc-ref subscriptions-updated ownid
-       . '()
+
+    ;; Run a pruning check against those that did not update. Then
+    ;; this is driving the WoT again.
+    ;; limitfor indirect subscriptions per type
+    define max-indirect 25
+
+    ;; update the wotstate
+    define ranks
+        wotcache-ranks
+            update-wotcache-from-wotstate! wotstate ownid
+    define known-ids : wotstate-known-ids wotstate
+    define id-count : vector-length known-ids
+    define updated-rank1-ids '()
+    define updated-rank2-ids '()
+    define updated-rank3+-ids '()
+    define failed-rank2 '()
+    define failed-rank3+ '()
+    define id-to-index-map : make-id-to-index-map wotstate
+    define : get-updated-ids
+        or : assoc-ref subscriptions-updated ownid
+           . '()
+    define : get-rank id
+        and=> : hash-ref id-to-index-map id
+            cut ranks-ref ranks <>
+    ;; sort the updated IDs iby rank
+    let loop : : updated : get-updated-ids
+        unless : null? updated
+            let*
+                : id : first updated
+                  rank : get-rank id
+              cond
+                {rank = 1} : set! updated-rank1-ids : cons id updated-rank1-ids
+                {rank = 2} : set! updated-rank2-ids : cons id updated-rank2-ids
+                {rank > 2} : set! updated-rank3+-ids : cons id updated-rank3+-ids
+                else #t
+              loop : cdr updated
+    ;; clear updated IDs
+    set-subscriptions-for-ownid! subscriptions-updated ownid '()
+    ;; reorder rank1 subscriptions
+    let : : rank1-subs : get-own-subscriptions rank1-subscriptions ownid
+        set-subscriptions-for-ownid! rank1-subscriptions ownid
+            delete-duplicates
+                append updated-rank1-ids rank1-subscriptions
+    let : : rank2-subs-recent : get-own-subscriptions rank2-subscriptions-most-recent ownid
+        define rank2-subs
+            delete-duplicates
+                append updated-rank2-ids rank2-subscriptions-most-recent
+        set! failed-rank2
+            drop rank2-subs : min max-indirect : length rank2-subscriptions-most-recent
+        set-subscriptions-for-ownid! rank2-subscriptions-most-recent ownid
+            take rank2-subs : min max-indirect : length rank2-subs
+    ;; TDOD: add pruning
+    let : : rank3+-subs-recent : get-own-subscriptions rank3+-subscriptions-most-recent ownid
+        define rank3+-subs
+            delete-duplicates
+                append updated-rank3+-ids rank3+-subscriptions-most-recent
+        set! failed-rank3+
+            drop rank3+-subs : min max-indirect : length rank3+-subscriptions-most-recent
+        set-subscriptions-for-ownid! rank3+-subscriptions-most-recent ownid
+            take rank3+-subs : min max-indirect : length rank3+-subs
+    ;; choose at random TODO: make less primitive
+    let loop : (rank2-ids '()) (rank3+-ids '()) (tries {2 * max-indirect})
+        define index : random id-count
+        define id : vector-ref known-ids index
+        define rank : ranks-ref ranks index
+        cond
+          : zero? tries
+            set-subscriptions-for-ownid! rank2-subscriptions-random ownid
+                delete-duplicates rank2-ids
+            set-subscriptions-for-ownid! rank3+-subscriptions-random ownid
+                delete-duplicates rank3+-ids
+          {rank = 2}
+            loop : cons id rank2-ids
+                 . rank3+-ids {tries - 1}
+          {rank > 2}
+            loop rank2-ids
+                 cons id rank3+-ids
+                 . {tries - 1}
+          else
+              loop rank2-ids rank3+-ids {tries - 1}
+    append
+      .  rank1-subscriptions
+      .  rank2-subscriptions-most-recent
+      .  rank2-subscriptions-random
+      .  rank3+-subscriptions-most-recent
+      .  rank3+-subscriptions-random
 
 
 ;; alist of hash-tables (one per ownid) with ids as key and alists of metadata as value

          
@@ 613,7 712,7 @@ define : get-metadata ownid id
 
 define-handler 'PUT "/subscription-updated/ownkey/" : put-subscription-updated-handler request body wotstate
     . "Endpoint: /subscription-updated/ownkey/OWN/otherid/ID
-    
+
     Add metadata needed to check the ID as form-data.
     "
     define path : split-and-decode-uri-path : uri-path : request-uri request

          
@@ 638,17 737,17 @@ define-handler 'PUT "/subscription-updat
           build-response
             . #:headers `((content-type . (text/plain)))
           . ""
-    
+
 
 define-handler 'GET "/subscriptions/" : get-subscriptions-handler request body wotstate
     . "Endpoint: /subscriptions/ownid
-    
+
     Returns a list of IDs to check for updates, separated by empty lines."
     define path-raw : uri-path : request-uri request
     define path : string-join (split-and-decode-uri-path path-raw) "/"
     define ownid : string-drop path : string-length "subscriptions/"
     ;; TODO: get subscriptions for ownid
-    define subscriptions : get-subscriptions ownid
+    define subscriptions : next-subscriptions wotstate ownid
     define : metadata-strings ownid id
         define metadata : get-metadata ownid id
         map : lambda (cel) : string-join (list (first cel) (second cel)) ": "

          

@@ 27,7 27,7 @@ 
 
 
 define-module : wispwot wispwot
-  . #:export : wispwot-read-trustfile wispwot-get-score read-known-identities make-wotstate wotstate-known-ids wotstate-trustlists trustlists-empty wotstate-ranks wotstate-scores read-all-trust calculate-ranks calculate-scores import-trust-csv get-trust-edge add-trust-edge ids-max ids->list id->key key->index index->identity write-store update-ranks-and-scores-from-trust-edge! update-ranks-and-scores-from-trust-identity-edges! ranks->list list->ranks ranks-ref set-wotstate-known-ids! set-wotstate-trustlists!
+  . #:export : wispwot-read-trustfile wispwot-get-score read-known-identities make-wotstate wotstate-known-ids wotstate-trustlists trustlists-empty wotstate-ranks wotstate-scores read-all-trust calculate-ranks calculate-scores import-trust-csv get-trust-edge add-trust-edge ids-max ids->list id->key key->index index->identity write-store update-ranks-and-scores-from-trust-edge! update-ranks-and-scores-from-trust-identity-edges! ranks->list list->ranks ranks-ref set-wotstate-known-ids! set-wotstate-trustlists! make-id-to-index-map
 
 import : wispwot doctests
          srfi srfi-1 ; lists