From aff235b9a9e2be702895d7431ce11ed44e141e98 Mon Sep 17 00:00:00 2001
From: arne <noreply@null.arnes.space>
Date: Sat, 22 Nov 2025 00:13:21 +0100
Subject: [PATCH] Clean up `fetch-more-posts!`

---
 src/computersandblues/lodestone/app.cljs | 44 ++++++++++++------------
 1 file changed, 22 insertions(+), 22 deletions(-)

diff --git a/src/computersandblues/lodestone/app.cljs b/src/computersandblues/lodestone/app.cljs
index b97af00..cffb1f7 100644
--- a/src/computersandblues/lodestone/app.cljs
+++ b/src/computersandblues/lodestone/app.cljs
@@ -448,7 +448,7 @@
                                      ; this returns a promise, but we don't care if these updates happen in sequence
                                      (db/put! ::db/posts (cond-> post
                                                            ; these IDs are internal server ids and it looks like
-                                                           ; they are not returned in any response; they are
+                                                           ; they are not returned in any response body; they are
                                                            ; required for pagination, so we're storing them to be
                                                            ; able to abort and continue pagination if we want or
                                                            ; if outer circumstances decide so (for example if the
@@ -461,29 +461,29 @@
                                  (swap! state assoc-in [:section/posts :last-update] (now)))}]
     (paginate-posts! (merge defaults opts))))
 
-(defn- internal-post-id
-  "Returns a promise which resolves to the smallest or largest internal post id.
-  This is useful to continue interrupted paginated requests."
-  [max-or-min]
-  (let [posts-cursor (db/open-cursor ::db/posts ::db/all {:index ::db/post-internal-id
-                                                          :direction (if (= max-or-min :min) :asc :desc)})]
-    (db/first-result (keep (j/get :internal_id)) posts-cursor)))
+(defn- bound
+  "Returns a promise which resolves to the smallest or largest value returned by
+  an index."
+  [store-id index xform max-or-min]
+  (let [cursor (db/open-cursor store-id ::db/all {:index index
+                                                  :direction (if (= max-or-min :min)
+                                                               :asc
+                                                               :desc)})]
+    (db/first-result xform cursor)))
 
 (defn- fetch-more-posts! [e]
-  (.preventDefault e)
-  (. (promise-all [(fetch-application-settings) (internal-post-id :min) (internal-post-id :max)])
-     (then (fn [[application min-id max-id]]
-             (when max-id
-               (fetch-posts! {:instance-url (:instance_url application)
-                              :bearer-token (:bearer_token application)
-                              :min-id max-id}))
-             (when min-id
-               (fetch-posts! {:instance-url (:instance_url application)
-                              :bearer-token (:bearer_token application)
-                              :max-id min-id}))
-             (when-not (or min-id max-id)
-               (fetch-posts! {:instance-url (:instance_url application)
-                              :bearer-token (:bearer_token application)}))))))
+  (let [internal-id-bound (partial bound ::db/posts ::db/post-internal-id (keep (j/get :internal_id)))]
+    (.preventDefault e)
+    (. (promise-all [(fetch-application-settings) (internal-id-bound :min) (internal-id-bound :max)])
+       (then (fn [[application min-id max-id]]
+               (let [opts {:instance-url (:instance_url application)
+                           :bearer-token (:bearer_token application)}]
+                 (when max-id
+                   (fetch-posts! (assoc opts :min-id max-id)))
+                 (when min-id
+                   (fetch-posts! (assoc opts :max-id min-id)))
+                 (when-not (or min-id max-id)
+                   (fetch-posts! opts))))))))
 
 (defn- disconnect-account! [e]
   (.preventDefault e)