Add kids audience filter stage

js/feedEngine/index.js

@@ -11,6 +11,7 @@ export {
   createResolvePostedAtStage,
 } from "./stages.js";
 export { createExploreScorerStage } from "./exploreScoring.js";
+export { createKidsAudienceFilterStage } from "./kidsAudienceFilterStage.js";
 export {
   createChronologicalSorter,
   createExploreDiversitySorter,

js/feedEngine/kidsAudienceFilterStage.js

@@ -0,0 +1,161 @@
+// js/feedEngine/kidsAudienceFilterStage.js
+
+import nostrService from "../services/nostrService.js";
+import { toSet } from "./utils.js";
+
+const DEFAULT_DISALLOWED_WARNINGS = [
+  "nudity",
+  "sexual",
+  "graphic-violence",
+  "self-harm",
+  "drugs",
+];
+
+function normalizeWarningValue(value) {
+  if (typeof value !== "string") {
+    return "";
+  }
+
+  return value.trim().toLowerCase().replace(/[\s_]+/g, "-");
+}
+
+function normalizeWarningList(values) {
+  const normalized = new Set();
+
+  if (values instanceof Set || Array.isArray(values)) {
+    for (const value of values) {
+      const entry = normalizeWarningValue(value);
+      if (entry) {
+        normalized.add(entry);
+      }
+    }
+  } else if (typeof values === "string") {
+    const entries = values.split(/[,;|]+/);
+    for (const entry of entries) {
+      const normalizedEntry = normalizeWarningValue(entry);
+      if (normalizedEntry) {
+        normalized.add(normalizedEntry);
+      }
+    }
+  }
+
+  return normalized;
+}
+
+function resolveDisallowedWarnings(context, fallback) {
+  const runtimeOverride = context?.runtime?.disallowedWarnings;
+  const configOverride = context?.config?.disallowedWarnings;
+  const resolved = runtimeOverride ?? configOverride ?? fallback;
+
+  return normalizeWarningList(resolved);
+}
+
+function parseContentWarnings(contentWarning) {
+  if (!contentWarning) {
+    return [];
+  }
+
+  if (Array.isArray(contentWarning)) {
+    return contentWarning
+      .map((value) => normalizeWarningValue(value))
+      .filter(Boolean);
+  }
+
+  if (typeof contentWarning === "string") {
+    return contentWarning
+      .split(/[,;|]+/)
+      .map((value) => normalizeWarningValue(value))
+      .filter(Boolean);
+  }
+
+  return [];
+}
+
+export function createKidsAudienceFilterStage({
+  stageName = "kids-audience-filter",
+  disallowedWarnings = DEFAULT_DISALLOWED_WARNINGS,
+} = {}) {
+  return async function kidsAudienceFilterStage(items = [], context = {}) {
+    const results = [];
+    const disallowedSet = resolveDisallowedWarnings(context, disallowedWarnings);
+
+    const blacklist = toSet(context?.runtime?.blacklistedEventIds);
+    const isAuthorBlocked =
+      typeof context?.runtime?.isAuthorBlocked === "function"
+        ? context.runtime.isAuthorBlocked
+        : () => false;
+
+    const options = { blacklistedEventIds: blacklist, isAuthorBlocked };
+
+    const includeFn =
+      typeof context?.runtime?.shouldIncludeVideo === "function"
+        ? context.runtime.shouldIncludeVideo
+        : (video, includeOptions) => nostrService.shouldIncludeVideo(video, includeOptions);
+
+    for (const item of items) {
+      const video = item?.video;
+      if (!video || typeof video !== "object") {
+        results.push(item);
+        continue;
+      }
+
+      const videoId = typeof video.id === "string" ? video.id : null;
+      const addWhy = (reason, extra = {}) => {
+        context?.addWhy?.({
+          stage: stageName,
+          type: "filter",
+          reason,
+          videoId,
+          ...extra,
+        });
+      };
+
+      if (video.isForKids !== true) {
+        addWhy("not-for-kids");
+        continue;
+      }
+
+      if (video.isNsfw === true) {
+        addWhy("nsfw");
+        continue;
+      }
+
+      if (video.invalid === true) {
+        addWhy("invalid");
+        continue;
+      }
+
+      let include = true;
+      try {
+        include = includeFn(video, options) !== false;
+      } catch (error) {
+        context?.log?.(`[${stageName}] shouldIncludeVideo threw`, error);
+        include = false;
+      }
+
+      if (!include) {
+        addWhy("blacklist");
+        continue;
+      }
+
+      if (disallowedSet.size > 0) {
+        const warnings = parseContentWarnings(video.contentWarning);
+        for (const warning of warnings) {
+          if (disallowedSet.has(warning)) {
+            addWhy("content-warning", { warning });
+            include = false;
+            break;
+          }
+        }
+      }
+
+      if (!include) {
+        continue;
+      }
+
+      results.push(item);
+    }
+
+    return results;
+  };
+}