Add settings.json-backed KV string storage

Fixes #3461, #3443

public/scripts/util/AccountStorage.js

@@ -0,0 +1,116 @@
+import { saveSettingsDebounced } from '../../script.js';
+
+const MIGRATED_MARKER = '__migrated';
+const MIGRATABLE_KEYS = [
+    /^AlertRegex_/,
+    /^AlertWI_/,
+    /^Assets_SkipConfirm_/,
+    /^Characters_PerPage$/,
+    /^DataBank_sortField$/,
+    /^DataBank_sortOrder$/,
+    /^extension_update_nag$/,
+    /^extensions_sortByName$/,
+    /^FeatherlessModels_PerPage$/,
+    /^GroupMembers_PerPage$/,
+    /^GroupCandidates_PerPage$/,
+    /^LNavLockOn$/,
+    /^LNavOpened$/,
+    /^mediaWarningShown:/,
+    /^NavLockOn$/,
+    /^NavOpened$/,
+    /^Personas_PerPage$/,
+    /^Personas_GridView$/,
+    /^Proxy_SkipConfirm_/,
+    /^RegenerateWithCtrlEnter$/,
+    /^SelectedNavTab$/,
+    /^sendAsNamelessWarningShown$/,
+    /^StoryStringValidationCache$/,
+    /^WINavOpened$/,
+    /^WI_PerPage$/,
+    /^world_info_sort_order$/,
+];
+
+/**
+ * Provides access to account storage of arbitrary key-value pairs.
+ */
+class AccountStorage {
+    constructor() {
+        this.state = {};
+        this.ready = false;
+    }
+
+    #migrateLocalStorage() {
+        for (let i = 0; i < globalThis.localStorage.length; i++) {
+            const key = globalThis.localStorage.key(i);
+            const value = globalThis.localStorage.getItem(key);
+
+            if (MIGRATABLE_KEYS.some(k => k.test(key))) {
+                this.state[key] = value;
+                globalThis.localStorage.removeItem(key);
+            }
+        }
+    }
+
+    /**
+     * Initialize the account storage.
+     * @param {Object} state Initial state
+     */
+    init(state) {
+        if (state && typeof state === 'object') {
+            this.state = Object.assign(this.state, state);
+        }
+
+        if (!Object.hasOwn(this.state, MIGRATED_MARKER)) {
+            this.#migrateLocalStorage();
+            this.state[MIGRATED_MARKER] = 1;
+            saveSettingsDebounced();
+        }
+
+        this.ready = true;
+    }
+
+    /**
+     * Get the value of a key in account storage.
+     * @param {string} key Key to get
+     * @returns {string|null} Value of the key
+     */
+    getItem(key) {
+        if (!this.ready) {
+            console.warn(`AccountStorage not ready (trying to read from ${key})`);
+        }
+
+        return Object.hasOwn(this.state, key) ? String(this.state[key]) : null;
+    }
+
+    /**
+     * Set a key in account storage.
+     * @param {string} key Key to set
+     * @param {string} value Value to set
+     */
+    setItem(key, value) {
+        if (!this.ready) {
+            console.warn(`AccountStorage not ready (trying to write to ${key})`);
+        }
+
+        this.state[key] = String(value);
+        saveSettingsDebounced();
+    }
+
+    /**
+     * Remove a key from account storage.
+     * @param {string} key Key to remove
+     */
+    removeItem(key) {
+        if (!this.ready) {
+            console.warn(`AccountStorage not ready (trying to remove ${key})`);
+        }
+
+        delete this.state[key];
+        saveSettingsDebounced();
+    }
+}
+
+/**
+ * Account storage instance.
+ */
+export const accountStorage = new AccountStorage();