Ensure correct sorting of children of tree nodes

src/lib/components/publications/table_of_contents.svelte.ts

@@ -181,7 +181,7 @@ export class TableOfContents {
         return;
       }
 
-      const childAddresses = await this.#publicationTree.getChildAddresses(address);
+      const childAddresses = await this.#publicationTree.getChildAddresses(entry.address);
       for (const childAddress of childAddresses) {
         if (!childAddress) {
           continue;
@@ -205,6 +205,8 @@ export class TableOfContents {
         this.addressMap.set(childAddress, childEntry);
       }
 
+      await this.#matchChildrenToTagOrder(entry);
+
       entry.childrenResolved = true;
     }
 
@@ -237,6 +239,31 @@ export class TableOfContents {
     return entry;
   }
 
+  /**
+   * Reorders the children of a ToC entry to match the order of 'a' tags in the corresponding
+   * Nostr index event.
+   * 
+   * @param entry The ToC entry to reorder.
+   */
+  async #matchChildrenToTagOrder(entry: TocEntry) {
+    const parentEvent = await this.#publicationTree.getEvent(entry.address);
+    if (parentEvent?.kind === indexKind) {
+      const tagOrder = parentEvent.getMatchingTags('a').map(tag => tag[1]);
+      const addressToOrdinal = new Map<string, number>();
+
+      // Build map of addresses to their ordinals from tag order
+      tagOrder.forEach((address, index) => {
+        addressToOrdinal.set(address, index);
+      });
+
+      entry.children.sort((a, b) => {
+        const aOrdinal = addressToOrdinal.get(a.address) ?? Number.MAX_SAFE_INTEGER;
+        const bOrdinal = addressToOrdinal.get(b.address) ?? Number.MAX_SAFE_INTEGER;
+        return aOrdinal - bOrdinal;
+      });
+    }
+  }
+
   #buildTocEntryFromResolvedNode(address: string) {
     if (this.addressMap.has(address)) {
       return;