fix: use canonical highlight history for bragi evaluation

src/common/channelHighlight/channels.ts

@@ -0,0 +1,52 @@
+import type { HighlightPost } from './types';
+import { buildStoryFamilies } from './storyFamilies';
+
+type HighlightChannelResolverInput = {
+  posts: HighlightPost[];
+  relations: { postId: string; relatedPostId: string }[];
+  fallbackPostIds: Map<string, string>;
+};
+
+export type HighlightChannelResolver = (postId: string) => string[];
+
+const getPostChannels = (post: HighlightPost | undefined): string[] => {
+  const contentMeta = post?.contentMeta as { channels?: unknown } | undefined;
+  const channels = contentMeta?.channels;
+  if (!Array.isArray(channels)) {
+    return [];
+  }
+
+  return [
+    ...new Set(
+      channels.filter(
+        (channel): channel is string => typeof channel === 'string',
+      ),
+    ),
+  ].sort();
+};
+
+export const createHighlightChannelResolver = ({
+  posts,
+  relations,
+  fallbackPostIds,
+}: HighlightChannelResolverInput): HighlightChannelResolver => {
+  const postsById = new Map(posts.map((post) => [post.id, post]));
+  const shareToUnderlying = new Map(
+    [...fallbackPostIds].map(([underlying, share]) => [share, underlying]),
+  );
+  const storyFamilies = buildStoryFamilies({ relations });
+
+  return (postId) => {
+    const underlyingPostId = shareToUnderlying.get(postId) || postId;
+    const storyPostIds = storyFamilies.getFamilyPostIds(underlyingPostId);
+    const channels = new Set<string>();
+
+    for (const storyPostId of storyPostIds) {
+      for (const channel of getPostChannels(postsById.get(storyPostId))) {
+        channels.add(channel);
+      }
+    }
+
+    return [...channels].sort();
+  };
+};

src/common/channelHighlight/constants.ts

@@ -0,0 +1,8 @@
+export const GLOBAL_HIGHLIGHT_CHANNEL = 'global';
+
+export const DEFAULT_CANDIDATE_HORIZON_HOURS = 168;
+
+export const DEFAULT_MAX_ITEMS = 20;
+
+export const GLOBAL_TARGET_AUDIENCE =
+  'software engineers and engineering leaders who want to stay current on meaningful developments that affect how modern software is built, shipped, operated, and grown';

src/common/channelHighlight/decisions.ts

@@ -28,24 +28,20 @@ export const compareSnapshots = ({
   const changed =
     baseline.map(toItemSignature).join('||') !==
     internal.map(toItemSignature).join('||');
+  const addedPostIds = [...internalByPostId.keys()].filter(
+    (postId) => !baselineByPostId.has(postId),
+  );
+  const removedPostIds = [...baselineByPostId.keys()].filter(
+    (postId) => !internalByPostId.has(postId),
+  );
 
   return {
     changed,
     baselineCount: baseline.length,
     internalCount: internal.length,
     overlapCount: overlap.length,
-    addedPostIds: [...internalByPostId.keys()].filter(
-      (postId) => !baselineByPostId.has(postId),
-    ),
-    removedPostIds: [...baselineByPostId.keys()].filter(
-      (postId) => !internalByPostId.has(postId),
-    ),
-    churnCount:
-      [...internalByPostId.keys()].filter(
-        (postId) => !baselineByPostId.has(postId),
-      ).length +
-      [...baselineByPostId.keys()].filter(
-        (postId) => !internalByPostId.has(postId),
-      ).length,
+    addedPostIds,
+    removedPostIds,
+    churnCount: addedPostIds.length + removedPostIds.length,
   };
 };

src/common/channelHighlight/evaluate.ts

@@ -6,11 +6,10 @@ import {
   EvaluateChannelHighlightsRequest as BragiEvaluateChannelHighlightsRequest,
 } from '@dailydotdev/schema';
 import { getBragiClient } from '../../integrations/bragi/clients';
+import { GLOBAL_HIGHLIGHT_CHANNEL, GLOBAL_TARGET_AUDIENCE } from './constants';
 import type { HighlightCandidate, HighlightItem } from './types';
 
-export type EvaluateChannelHighlightsRequest = {
-  channel: string;
-  targetAudience: string;
+export type EvaluateHighlightsRequest = {
   maxItems: number;
   currentHighlights: HighlightItem[];
   newCandidates: HighlightCandidate[];
@@ -23,7 +22,7 @@ export type EvaluatedHighlightItem = {
   reason: string;
 };
 
-export type EvaluateChannelHighlightsResponse = {
+export type EvaluateHighlightsResponse = {
   items: EvaluatedHighlightItem[];
 };
 
@@ -95,13 +94,11 @@ const toCandidate = (
     relatedItemsCount: candidate.relatedItemsCount,
   });
 
-export const evaluateChannelHighlights = async ({
-  channel,
-  targetAudience,
+export const evaluateHighlights = async ({
   maxItems,
   currentHighlights,
   newCandidates,
-}: EvaluateChannelHighlightsRequest): Promise<EvaluateChannelHighlightsResponse> => {
+}: EvaluateHighlightsRequest): Promise<EvaluateHighlightsResponse> => {
   if (!newCandidates.length) {
     return {
       items: [],
@@ -110,8 +107,8 @@ export const evaluateChannelHighlights = async ({
 
   const bragiClient = getBragiClient();
   const request = new BragiEvaluateChannelHighlightsRequest({
-    channel,
-    targetAudience,
+    channel: GLOBAL_HIGHLIGHT_CHANNEL,
+    targetAudience: GLOBAL_TARGET_AUDIENCE,
     maxItems,
     currentHighlights: currentHighlights.map(toCurrentHighlight),
     newCandidates: newCandidates.map(toCandidate),