;; ported-from: src/app/history.ts
;;
;; READ-ONLY loader for v1 device-local history (IndexedDB `sueta-history`).
;; v2 persistence is the replicated log itself (the encrypted blockstore in
;; IndexedDB) — this module only survives to feed the one-shot legacy import
;; (app/migrate.cljs), after which the old records are left untouched as a
;; safety net and simply stop being read.
;;
;; A StoredRoom is {msgs, mineIds, savedAt}; a PersistMsg is
;; {id, from, name, ts, seq, text?, thread?, img?, rx?, blob?}. Nothing is
;; reshaped here — the raw IDB record is handed to the migrator, which validates
;; every field.
(ns sueta.app.history)

;; Deliberately NOT namespaced (config/NS): this is the literal database name
;; the v1 app wrote. Forks never have it; load-history just returns nil there.
(def ^:private DB-NAME "sueta-history")
(def ^:private STORE "rooms")

(defn load-history
  "The v1 record for `room-id`, or nil (absent, or no IndexedDB at all)."
  [room-id]
  (-> (js/Promise.
       (fn [resolve reject]
         (let [^js req (js/indexedDB.open DB-NAME 1)]
           (set! (.-onupgradeneeded req) (fn [] (.createObjectStore ^js (.-result req) STORE)))
           (set! (.-onsuccess req) (fn [] (resolve (.-result req))))
           (set! (.-onerror req) (fn [] (reject (.-error req)))))))
      (.then
       (fn [db]
         (js/Promise.
          (fn [resolve _reject]
            (let [^js req (-> ^js db (.transaction STORE) (.objectStore STORE) (.get room-id))]
              ;; TS `req.result ?? null` — NULLISH, so a stored 0/"" would be
              ;; honoured (the v1 records are always objects, but keep the
              ;; semantics identical)
              (set! (.-onsuccess req)
                    (fn [] (let [r (.-result req)]
                             (resolve (if (or (nil? r) (identical? r js/undefined)) nil r)))))
              (set! (.-onerror req) (fn [] (resolve nil))))))))
      ;; no IDB (private mode) — nothing to migrate
      (.catch (fn [_] nil))))