Add shared hashtag normalization helper

js/feedEngine/index.js

@@ -8,6 +8,7 @@ export {
 export {
   createDedupeByRootStage,
   createBlacklistFilterStage,
+  createTagPreferenceFilterStage,
   createWatchHistorySuppressionStage,
   createModerationStage,
   createResolvePostedAtStage,

js/feedEngine/stages.js

@@ -10,10 +10,25 @@ import nostrService from "../services/nostrService.js";
 import moderationService from "../services/moderationService.js";
 import logger from "../utils/logger.js";
 import { dedupeToNewestByRoot } from "../utils/videoDeduper.js";
+import { normalizeHashtag } from "../utils/hashtagNormalization.js";
 import { isPlainObject, toSet, hasDisinterestedTag } from "./utils.js";
 
 const FEED_HIDE_BYPASS_NAMES = new Set(["home", "recent"]);
 
+function normalizeTagSet(values) {
+  const normalized = new Set();
+  const source = toSet(values);
+
+  for (const value of source) {
+    const tag = normalizeHashtag(value);
+    if (tag) {
+      normalized.add(tag);
+    }
+  }
+
+  return normalized;
+}
+
 function resolveDedupeFunction(customDedupe) {
   if (typeof customDedupe === "function") {
     return customDedupe;
@@ -258,6 +273,43 @@ export function createResolvePostedAtStage({
   };
 }
 
+export function createTagPreferenceFilterStage({
+  stageName = "tag-preference-filter",
+} = {}) {
+  return async function tagPreferenceFilterStage(items = [], context = {}) {
+    const tagPreferences = context?.runtime?.tagPreferences;
+    const disinterests = normalizeTagSet(tagPreferences?.disinterests);
+    if (!disinterests.size) {
+      return items;
+    }
+
+    const results = [];
+
+    for (const item of items) {
+      const video = item?.video;
+      if (!video || typeof video !== "object") {
+        results.push(item);
+        continue;
+      }
+
+      if (hasDisinterestedTag(video, disinterests)) {
+        context?.addWhy?.({
+          stage: stageName,
+          type: "filter",
+          reason: "disinterested-tag",
+          videoId: typeof video.id === "string" ? video.id : null,
+          pubkey: typeof video.pubkey === "string" ? video.pubkey : null,
+        });
+        continue;
+      }
+
+      results.push(item);
+    }
+
+    return results;
+  };
+}
+
 export function createBlacklistFilterStage({
   stageName = "blacklist-filter",
   shouldIncludeVideo,
@@ -277,7 +329,7 @@ export function createBlacklistFilterStage({
     const options = { blacklistedEventIds: blacklist, isAuthorBlocked };
 
     const tagPreferences = context?.runtime?.tagPreferences;
-    const disinterests = toSet(tagPreferences?.disinterests);
+    const disinterests = normalizeTagSet(tagPreferences?.disinterests);
     const hasTagPreferences = disinterests.size > 0;
 
     const results = [];

js/feedEngine/utils.js

@@ -1,5 +1,7 @@
 // js/feedEngine/utils.js
 
+import { normalizeHashtag } from "../utils/hashtagNormalization.js";
+
 export function isPlainObject(value) {
   if (value === null || typeof value !== "object") {
     return false;
@@ -33,11 +35,16 @@ export function hasDisinterestedTag(video, disinterestsSet) {
     return false;
   }
 
+  const matchesDisinterest = (tag) => {
+    const normalized = normalizeHashtag(tag);
+    return Boolean(normalized && disinterestsSet.has(normalized));
+  };
+
   // Check raw tags
   if (Array.isArray(video.tags)) {
     for (const tag of video.tags) {
       if (Array.isArray(tag) && tag[0] === "t" && typeof tag[1] === "string") {
-        if (disinterestsSet.has(tag[1].toLowerCase())) {
+        if (matchesDisinterest(tag[1])) {
           return true;
         }
       }
@@ -47,7 +54,7 @@ export function hasDisinterestedTag(video, disinterestsSet) {
   // Check NIP-71 metadata hashtags if available
   if (video.nip71 && Array.isArray(video.nip71.hashtags)) {
     for (const tag of video.nip71.hashtags) {
-      if (typeof tag === "string" && disinterestsSet.has(tag.toLowerCase())) {
+      if (typeof tag === "string" && matchesDisinterest(tag)) {
         return true;
       }
     }