comment pagination with limit/offset (#1824)

* basic query with limit/offset

* roughly working increment

* working limiting/pageable queries

* denormalize direct comments + full comments below threshold

* notifications in megathread + working nest view more buttons

* fix empty comment footer

* make comments nested resolver again

* use time in cursor to avoid duplicates

* squash migrations

* do not need item.comments undefined checks

api/paidAction/itemCreate.js

@@ -235,7 +235,9 @@ export async function onPaid ({ invoice, id }, context) {
         SET ncomments = "Item".ncomments + 1,
           "lastCommentAt" = GREATEST("Item"."lastCommentAt", comment.created_at),
           "weightedComments" = "Item"."weightedComments" +
-            CASE WHEN comment."userId" = "Item"."userId" THEN 0 ELSE comment.trust END
+            CASE WHEN comment."userId" = "Item"."userId" THEN 0 ELSE comment.trust END,
+          "nDirectComments" = "Item"."nDirectComments" +
+            CASE WHEN comment."parentId" = "Item".id THEN 1 ELSE 0 END
         FROM comment
         WHERE "Item".path @> comment.path AND "Item".id <> comment.id
         RETURNING "Item".*

api/resolvers/item.js

@@ -9,7 +9,10 @@ import {
   USER_ID, POLL_COST, ADMIN_ITEMS, GLOBAL_SEED,
   NOFOLLOW_LIMIT, UNKNOWN_LINK_REL, SN_ADMIN_IDS,
   BOOST_MULT,
-  ITEM_EDIT_SECONDS
+  ITEM_EDIT_SECONDS,
+  COMMENTS_LIMIT,
+  COMMENTS_OF_COMMENT_LIMIT,
+  FULL_COMMENTS_THRESHOLD
 } from '@/lib/constants'
 import { msatsToSats } from '@/lib/format'
 import { parse } from 'tldts'
@@ -25,39 +28,76 @@ import { GqlAuthenticationError, GqlInputError } from '@/lib/error'
 import { verifyHmac } from './wallet'
 
 function commentsOrderByClause (me, models, sort) {
+  const sharedSortsArray = []
+  sharedSortsArray.push('("Item"."pinId" IS NOT NULL) DESC')
+  sharedSortsArray.push('("Item"."deletedAt" IS NULL) DESC')
+  const sharedSorts = sharedSortsArray.join(', ')
+
   if (sort === 'recent') {
-    return 'ORDER BY ("Item"."deletedAt" IS NULL) DESC, ("Item".cost > 0 OR "Item"."weightedVotes" - "Item"."weightedDownVotes" > 0) DESC, COALESCE("Item"."invoicePaidAt", "Item".created_at) DESC, "Item".id DESC'
+    return `ORDER BY ${sharedSorts},
+      ("Item".cost > 0 OR "Item"."weightedVotes" - "Item"."weightedDownVotes" > 0) DESC,
+      COALESCE("Item"."invoicePaidAt", "Item".created_at) DESC, "Item".id DESC`
   }
 
   if (me && sort === 'hot') {
-    return `ORDER BY ("Item"."deletedAt" IS NULL) DESC, COALESCE(
+    return `ORDER BY ${sharedSorts},
-        personal_hot_score,
+      "personal_hot_score" DESC NULLS LAST,
-        ${orderByNumerator({ models, commentScaler: 0, considerBoost: true })}/POWER(GREATEST(3, EXTRACT(EPOCH FROM (now_utc() - "Item".created_at))/3600), 1.3)) DESC NULLS LAST,
+      "Item".msats DESC, ("Item".cost > 0) DESC, "Item".id DESC`
-        "Item".msats DESC, ("Item".cost > 0) DESC, "Item".id DESC`
   } else {
     if (sort === 'top') {
-      return `ORDER BY ("Item"."deletedAt" IS NULL) DESC, ${orderByNumerator({ models, commentScaler: 0 })} DESC NULLS LAST, "Item".msats DESC, ("Item".cost > 0) DESC,  "Item".id DESC`
+      return `ORDER BY ${sharedSorts}, ${orderByNumerator({ models, commentScaler: 0 })} DESC NULLS LAST, "Item".msats DESC, ("Item".cost > 0) DESC,  "Item".id DESC`
     } else {
-      return `ORDER BY ("Item"."deletedAt" IS NULL) DESC, ${orderByNumerator({ models, commentScaler: 0, considerBoost: true })}/POWER(GREATEST(3, EXTRACT(EPOCH FROM (now_utc() - "Item".created_at))/3600), 1.3) DESC NULLS LAST, "Item".msats DESC, ("Item".cost > 0) DESC, "Item".id DESC`
+      return `ORDER BY ${sharedSorts}, ${orderByNumerator({ models, commentScaler: 0, considerBoost: true })}/POWER(GREATEST(3, EXTRACT(EPOCH FROM (now_utc() - "Item".created_at))/3600), 1.3) DESC NULLS LAST, "Item".msats DESC, ("Item".cost > 0) DESC, "Item".id DESC`
     }
   }
 }
 
-async function comments (me, models, id, sort) {
+async function comments (me, models, item, sort, cursor) {
   const orderBy = commentsOrderByClause(me, models, sort)
 
-  if (me) {
+  if (item.nDirectComments === 0) {
-    const filter = ` AND ("Item"."invoiceActionState" IS NULL OR "Item"."invoiceActionState" = 'PAID' OR "Item"."userId" = ${me.id}) `
+    return {
-    const [{ item_comments_zaprank_with_me: comments }] = await models.$queryRawUnsafe(
+      comments: [],
-      'SELECT item_comments_zaprank_with_me($1::INTEGER, $2::INTEGER, $3::INTEGER, $4::INTEGER, $5, $6)',
+      cursor: null
-      Number(id), GLOBAL_SEED, Number(me.id), COMMENT_DEPTH_LIMIT, filter, orderBy)
+    }
-    return comments
   }
 
-  const filter = ' AND ("Item"."invoiceActionState" IS NULL OR "Item"."invoiceActionState" = \'PAID\') '
+  const decodedCursor = decodeCursor(cursor)
-  const [{ item_comments: comments }] = await models.$queryRawUnsafe(
+  const offset = decodedCursor.offset
-    'SELECT item_comments($1::INTEGER, $2::INTEGER, $3, $4)', Number(id), COMMENT_DEPTH_LIMIT, filter, orderBy)
+
-  return comments
+  // XXX what a mess
+  let comments
+  if (me) {
+    const filter = ` AND ("Item"."invoiceActionState" IS NULL OR "Item"."invoiceActionState" = 'PAID' OR "Item"."userId" = ${me.id}) AND "Item".created_at <= '${decodedCursor.time.toISOString()}'::TIMESTAMP(3) `
+    if (item.ncomments > FULL_COMMENTS_THRESHOLD) {
+      const [{ item_comments_zaprank_with_me_limited: limitedComments }] = await models.$queryRawUnsafe(
+        'SELECT item_comments_zaprank_with_me_limited($1::INTEGER, $2::INTEGER, $3::INTEGER, $4::INTEGER, $5::INTEGER, $6::INTEGER, $7::INTEGER, $8, $9)',
+        Number(item.id), GLOBAL_SEED, Number(me.id), COMMENTS_LIMIT, offset, COMMENTS_OF_COMMENT_LIMIT, COMMENT_DEPTH_LIMIT, filter, orderBy)
+      comments = limitedComments
+    } else {
+      const [{ item_comments_zaprank_with_me: fullComments }] = await models.$queryRawUnsafe(
+        'SELECT item_comments_zaprank_with_me($1::INTEGER, $2::INTEGER, $3::INTEGER, $4::INTEGER, $5, $6)',
+        Number(item.id), GLOBAL_SEED, Number(me.id), COMMENT_DEPTH_LIMIT, filter, orderBy)
+      comments = fullComments
+    }
+  } else {
+    const filter = ` AND ("Item"."invoiceActionState" IS NULL OR "Item"."invoiceActionState" = 'PAID') AND "Item".created_at <= '${decodedCursor.time.toISOString()}'::TIMESTAMP(3) `
+    if (item.ncomments > FULL_COMMENTS_THRESHOLD) {
+      const [{ item_comments_limited: limitedComments }] = await models.$queryRawUnsafe(
+        'SELECT item_comments_limited($1::INTEGER, $2::INTEGER, $3::INTEGER, $4::INTEGER, $5::INTEGER, $6, $7)',
+        Number(item.id), COMMENTS_LIMIT, offset, COMMENTS_OF_COMMENT_LIMIT, COMMENT_DEPTH_LIMIT, filter, orderBy)
+      comments = limitedComments
+    } else {
+      const [{ item_comments: fullComments }] = await models.$queryRawUnsafe(
+        'SELECT item_comments($1::INTEGER, $2::INTEGER, $3, $4)', Number(item.id), COMMENT_DEPTH_LIMIT, filter, orderBy)
+      comments = fullComments
+    }
+  }
+
+  return {
+    comments,
+    cursor: comments.length + offset < item.nDirectComments ? nextCursorEncoded(decodedCursor, COMMENTS_LIMIT) : null
+  }
 }
 
 export async function getItem (parent, { id }, { me, models }) {
@@ -1173,11 +1213,25 @@ export default {
         }
       })
     },
-    comments: async (item, { sort }, { me, models }) => {
+    comments: async (item, { sort, cursor }, { me, models }) => {
-      if (typeof item.comments !== 'undefined') return item.comments
+      if (typeof item.comments !== 'undefined') {
-      if (item.ncomments === 0) return []
+        if (Array.isArray(item.comments)) {
+          return {
+            comments: item.comments,
+            cursor: null
+          }
+        }
+        return item.comments
+      }
 
-      return comments(me, models, item.id, sort || defaultCommentSort(item.pinId, item.bioId, item.createdAt))
+      if (item.ncomments === 0) {
+        return {
+          comments: [],
+          cursor: null
+        }
+      }
+
+      return comments(me, models, item, sort || defaultCommentSort(item.pinId, item.bioId, item.createdAt), cursor)
     },
     freedFreebie: async (item) => {
       return item.weightedVotes - item.weightedDownVotes > 0

api/typeDefs/item.js

@@ -145,7 +145,8 @@ export default gql`
     bio: Boolean!
     paidImgLink: Boolean
     ncomments: Int!
-    comments(sort: String): [Item!]!
+    nDirectComments: Int!
+    comments(sort: String, cursor: String): Comments!
     path: String
     position: Int
     prior: Int

components/comment.js

@@ -254,11 +254,17 @@ export default function Comment ({
                   </Reply>}
               {children}
               <div className={styles.comments}>
-                {item.comments && !noComments
+                {item.comments.comments && !noComments
-                  ? item.comments.map((item) => (
+                  ? (
-                    <Comment depth={depth + 1} key={item.id} item={item} />
+                    <>
-                  ))
+                      {item.comments.comments.map((item) => (
+                        <Comment depth={depth + 1} key={item.id} item={item} />
+                      ))}
+                      {item.comments.comments.length < item.nDirectComments && <ViewAllReplies id={item.id} nshown={item.comments.comments.length} nhas={item.nDirectComments} />}
+                    </>
+                    )
                   : null}
+                {/* TODO: add link to more comments if they're limited */}
               </div>
             </div>
             )
@@ -267,6 +273,18 @@ export default function Comment ({
   )
 }
 
+export function ViewAllReplies ({ id, nshown, nhas }) {
+  const text = `view all ${nhas} replies`
+
+  return (
+    <div className={`d-block fw-bold ${styles.comment} pb-2 ps-3`}>
+      <Link href={`/items/${id}`} as={`/items/${id}`} className='text-muted'>
+        {text}
+      </Link>
+    </div>
+  )
+}
+
 export function CommentSkeleton ({ skeletonChildren }) {
   return (
     <div className={styles.comment}>

components/comments.js

@@ -1,4 +1,4 @@
-import { Fragment } from 'react'
+import { Fragment, useMemo } from 'react'
 import Comment, { CommentSkeleton } from './comment'
 import styles from './header.module.css'
 import Nav from 'react-bootstrap/Nav'
@@ -6,6 +6,8 @@ import Navbar from 'react-bootstrap/Navbar'
 import { numWithUnits } from '@/lib/format'
 import { defaultCommentSort } from '@/lib/item'
 import { useRouter } from 'next/router'
+import MoreFooter from './more-footer'
+import { FULL_COMMENTS_THRESHOLD } from '@/lib/constants'
 
 export function CommentsHeader ({ handleSort, pinned, bio, parentCreatedAt, commentSats }) {
   const router = useRouter()
@@ -60,10 +62,13 @@ export function CommentsHeader ({ handleSort, pinned, bio, parentCreatedAt, comm
   )
 }
 
-export default function Comments ({ parentId, pinned, bio, parentCreatedAt, commentSats, comments, ...props }) {
+export default function Comments ({
+  parentId, pinned, bio, parentCreatedAt,
+  commentSats, comments, commentsCursor, fetchMoreComments, ncomments, ...props
+}) {
   const router = useRouter()
 
-  const pins = comments?.filter(({ position }) => !!position).sort((a, b) => a.position - b.position)
+  const pins = useMemo(() => comments?.filter(({ position }) => !!position).sort((a, b) => a.position - b.position), [comments])
 
   return (
     <>
@@ -91,6 +96,12 @@ export default function Comments ({ parentId, pinned, bio, parentCreatedAt, comm
       {comments.filter(({ position }) => !position).map(item => (
         <Comment depth={1} key={item.id} item={item} {...props} />
       ))}
+      {ncomments > FULL_COMMENTS_THRESHOLD &&
+        <MoreFooter
+          cursor={commentsCursor} fetchMore={fetchMoreComments} noMoreText=' '
+          count={comments?.length}
+          Skeleton={CommentsSkeleton}
+        />}
     </>
   )
 }

components/item-full.js

@@ -160,7 +160,7 @@ function ItemText ({ item }) {
     : <Text itemId={item.id} topLevel rel={item.rel ?? UNKNOWN_LINK_REL} outlawed={item.outlawed} imgproxyUrls={item.imgproxyUrls}>{item.text}</Text>
 }
 
-export default function ItemFull ({ item, bio, rank, ...props }) {
+export default function ItemFull ({ item, fetchMoreComments, bio, rank, ...props }) {
   useEffect(() => {
     commentsViewed(item)
   }, [item.lastCommentAt])
@@ -186,7 +186,11 @@ export default function ItemFull ({ item, bio, rank, ...props }) {
             <div className={styles.comments}>
               <Comments
                 parentId={item.id} parentCreatedAt={item.createdAt}
-                pinned={item.position} bio={bio} commentSats={item.commentSats} comments={item.comments}
+                pinned={item.position} bio={bio} commentSats={item.commentSats}
+                ncomments={item.ncomments}
+                comments={item.comments.comments}
+                commentsCursor={item.comments.cursor}
+                fetchMoreComments={fetchMoreComments}
               />
             </div>}
         </CarouselProvider>

components/reply.js

@@ -55,9 +55,9 @@ export default forwardRef(function Reply ({
 
   const placeholder = useMemo(() => {
     return [
-      'comment for currency?',
+      'comment for currency',
       'fractions of a penny for your thoughts?',
-      'put your money where your mouth is?'
+      'put your money where your mouth is'
     ][parentId % 3]
   }, [parentId])
 
@@ -70,13 +70,16 @@ export default forwardRef(function Reply ({
         cache.modify({
           id: `Item:${parentId}`,
           fields: {
-            comments (existingCommentRefs = []) {
+            comments (existingComments = {}) {
               const newCommentRef = cache.writeFragment({
                 data: result,
                 fragment: COMMENTS,
                 fragmentName: 'CommentsRecursive'
               })
-              return [newCommentRef, ...existingCommentRefs]
+              return {
+                cursor: existingComments.cursor,
+                comments: [newCommentRef, ...(existingComments?.comments || [])]
+              }
             }
           },
           optimistic: true

fragments/comments.js

@@ -46,6 +46,7 @@ export const COMMENT_FIELDS = gql`
     mine
     otsHash
     ncomments
+    nDirectComments
     imgproxyUrls
     rel
     apiKey
@@ -66,6 +67,7 @@ export const COMMENTS_ITEM_EXT_FIELDS = gql`
       id
       title
       bounty
+      ncomments
       bountyPaidTo
       subName
       sub {
@@ -89,19 +91,23 @@ export const COMMENTS = gql`
   fragment CommentsRecursive on Item {
     ...CommentFields
     comments {
-      ...CommentFields
       comments {
         ...CommentFields
         comments {
-          ...CommentFields
           comments {
             ...CommentFields
             comments {
-              ...CommentFields
               comments {
                 ...CommentFields
                 comments {
-                  ...CommentFields
+                  comments {
+                    ...CommentFields
+                    comments {
+                      comments {
+                        ...CommentFields
+                      }
+                    }
+                  }
                 }
               }
             }

fragments/items.js

@@ -57,6 +57,7 @@ export const ITEM_FIELDS = gql`
     freebie
     bio
     ncomments
+    nDirectComments
     commentSats
     commentCredits
     lastCommentAt
@@ -94,6 +95,7 @@ export const ITEM_FULL_FIELDS = gql`
       bountyPaidTo
       subName
       mine
+      ncomments
       user {
         id
         name
@@ -166,13 +168,16 @@ export const ITEM_FULL = gql`
   ${ITEM_FULL_FIELDS}
   ${POLL_FIELDS}
   ${COMMENTS}
-  query Item($id: ID!, $sort: String) {
+  query Item($id: ID!, $sort: String, $cursor: String) {
     item(id: $id) {
       ...ItemFullFields
       prior
       ...PollFields
-      comments(sort: $sort) {
+      comments(sort: $sort, cursor: $cursor) {
-        ...CommentsRecursive
+        cursor
+        comments {
+          ...CommentsRecursive
+        }
       }
     }
   }`

fragments/paidAction.js

@@ -25,7 +25,9 @@ const ITEM_PAID_ACTION_FIELDS = gql`
       reminderScheduledAt
       ...CommentFields
       comments {
-        ...CommentsRecursive
+        comments {
+          ...CommentsRecursive
+        }
       }
     }
   }`

fragments/users.js

@@ -297,17 +297,20 @@ export const USER_FULL = gql`
   ${USER_FIELDS}
   ${ITEM_FULL_FIELDS}
   ${COMMENTS}
-  query User($name: String!, $sort: String) {
+  query User($name: String!, $sort: String, $cursor: String) {
     user(name: $name) {
       ...UserFields
       bio {
         ...ItemFullFields
-        comments(sort: $sort) {
+        comments(sort: $sort, cursor: $cursor) {
-          ...CommentsRecursive
+          cursor
+          comments {
+            ...CommentsRecursive
+          }
         }
       }
-  }
+    }
-}`
+  }`
 
 export const USER = gql`
   ${USER_FIELDS}

lib/apollo.js

@@ -1,7 +1,7 @@
 import { ApolloClient, InMemoryCache, HttpLink, makeVar, split } from '@apollo/client'
 import { BatchHttpLink } from '@apollo/client/link/batch-http'
 import { decodeCursor, LIMIT } from './cursor'
-import { SSR } from './constants'
+import { COMMENTS_LIMIT, SSR } from './constants'
 
 function isFirstPage (cursor, existingThings, limit = LIMIT) {
   if (cursor) {
@@ -201,12 +201,6 @@ function getClient (uri) {
                 }
               }
             },
-            comments: {
-              keyArgs: ['id', 'sort'],
-              merge (existing, incoming) {
-                return incoming
-              }
-            },
             related: {
               keyArgs: ['id', 'title', 'minMatch', 'limit'],
               merge (existing, incoming, { args }) {
@@ -277,6 +271,19 @@ function getClient (uri) {
         },
         Item: {
           fields: {
+            comments: {
+              keyArgs: ['sort'],
+              merge (existing, incoming) {
+                if (isFirstPage(incoming.cursor, existing?.comments, COMMENTS_LIMIT)) {
+                  return incoming
+                }
+
+                return {
+                  cursor: incoming.cursor,
+                  comments: [...(existing?.comments || []), ...incoming.comments]
+                }
+              }
+            },
             meAnonSats: {
               read (existingAmount, { readField }) {
                 if (SSR) return null

lib/constants.js

@@ -40,7 +40,10 @@ export const BOUNTY_MAX = 10000000
 export const POST_TYPES = ['LINK', 'DISCUSSION', 'BOUNTY', 'POLL']
 export const TERRITORY_BILLING_TYPES = ['MONTHLY', 'YEARLY', 'ONCE']
 export const TERRITORY_GRACE_DAYS = 5
-export const COMMENT_DEPTH_LIMIT = 8
+export const COMMENT_DEPTH_LIMIT = 6
+export const COMMENTS_LIMIT = 50
+export const FULL_COMMENTS_THRESHOLD = 200
+export const COMMENTS_OF_COMMENT_LIMIT = 2
 export const MAX_TITLE_LENGTH = 80
 export const MIN_TITLE_LENGTH = 5
 export const MAX_POST_TEXT_LENGTH = 100000 // 100k

lib/cursor.js

@@ -5,6 +5,7 @@ export function decodeCursor (cursor) {
     return { offset: 0, time: new Date() }
   } else {
     const res = JSON.parse(Buffer.from(cursor, 'base64'))
+    res.offset = Number(res.offset)
     res.time = new Date(res.time)
     return res
   }

lib/item.js

@@ -1,4 +1,4 @@
-import { COMMENT_DEPTH_LIMIT, OLD_ITEM_DAYS } from './constants'
+import { COMMENT_DEPTH_LIMIT, FULL_COMMENTS_THRESHOLD, OLD_ITEM_DAYS } from './constants'
 import { datePivot } from './time'
 
 export const defaultCommentSort = (pinned, bio, createdAt) => {
@@ -106,6 +106,10 @@ export const deleteReminders = async ({ id, userId, models }) => {
 }
 
 export const commentSubTreeRootId = (item) => {
+  if (item.root?.ncomments > FULL_COMMENTS_THRESHOLD) {
+    return item.id
+  }
+
   const path = item.path.split('.')
   return path.slice(-(COMMENT_DEPTH_LIMIT - 1))[0]
 }

pages/items/[id]/index.js

@@ -14,15 +14,19 @@ export const getServerSideProps = getGetServerSideProps({
 export default function Item ({ ssrData }) {
   const router = useRouter()
 
-  const { data } = useQuery(ITEM_FULL, { variables: { ...router.query } })
+  const { data, fetchMore } = useQuery(ITEM_FULL, { variables: { ...router.query } })
   if (!data && !ssrData) return <PageLoading />
 
   const { item } = data || ssrData
   const sub = item.subName || item.root?.subName
 
+  const fetchMoreComments = async () => {
+    await fetchMore({ variables: { ...router.query, cursor: item.comments.cursor } })
+  }
+
   return (
     <Layout sub={sub} item={item}>
-      <ItemFull item={item} />
+      <ItemFull item={item} fetchMoreComments={fetchMoreComments} />
     </Layout>
   )
 }

prisma/migrations/20250118010433_comment_pages/migration.sql

@@ -0,0 +1,147 @@
+-- AlterTable
+ALTER TABLE "Item" ADD COLUMN "nDirectComments" INTEGER NOT NULL DEFAULT 0;
+
+-- Update nDirectComments
+UPDATE "Item"
+SET "nDirectComments" = "DirectComments"."nDirectComments"
+FROM (
+    SELECT "Item"."parentId" AS "id", COUNT(*) AS "nDirectComments"
+    FROM "Item"
+    WHERE "Item"."parentId" IS NOT NULL
+    GROUP BY "Item"."parentId"
+) AS "DirectComments"
+WHERE "Item"."id" = "DirectComments"."id";
+
+-- add limit and offset
+CREATE OR REPLACE FUNCTION item_comments_zaprank_with_me_limited(
+    _item_id int, _global_seed int, _me_id int, _limit int, _offset int, _grandchild_limit int,
+    _level int, _where text, _order_by text)
+  RETURNS jsonb
+  LANGUAGE plpgsql VOLATILE PARALLEL SAFE AS
+$$
+DECLARE
+    result  jsonb;
+BEGIN
+    IF _level < 1 THEN
+        RETURN '[]'::jsonb;
+    END IF;
+
+    EXECUTE 'CREATE TEMP TABLE IF NOT EXISTS t_item ON COMMIT DROP AS '
+    || 'WITH RECURSIVE base AS ( '
+    || '    (SELECT "Item".*, 1 as level, ROW_NUMBER() OVER () as rn, '
+    || '        GREATEST(g.tf_hot_score, l.tf_hot_score) AS personal_hot_score, '
+    || '        GREATEST(g.tf_top_score, l.tf_top_score) AS personal_top_score '
+    || '    FROM "Item" '
+    || '    LEFT JOIN zap_rank_personal_view g ON g."viewerId" = $2 AND g.id = "Item".id '
+    || '    LEFT JOIN zap_rank_personal_view l ON l."viewerId" = $3 AND l.id = g.id '
+    || '    WHERE "Item"."parentId" = $1 '
+    ||      _order_by || ' '
+    || '    LIMIT $4 '
+    || '    OFFSET $5) '
+    || '    UNION ALL '
+    || '    (SELECT "Item".*, b.level + 1, ROW_NUMBER() OVER (PARTITION BY "Item"."parentId" ' || _order_by || ') as rn, '
+    || '        GREATEST(g.tf_hot_score, l.tf_hot_score) AS personal_hot_score, '
+    || '        GREATEST(g.tf_top_score, l.tf_top_score) AS personal_top_score '
+    || '    FROM "Item" '
+    || '    JOIN base b ON "Item"."parentId" = b.id '
+    || '    LEFT JOIN zap_rank_personal_view g ON g."viewerId" = $2 AND g.id = "Item".id '
+    || '    LEFT JOIN zap_rank_personal_view l ON l."viewerId" = $3 AND l.id = g.id '
+    || '    WHERE b.level < $7 AND (b.level = 1 OR b.rn <= $6)) '
+    || ') '
+    || 'SELECT "Item".*, '
+    || '    "Item".created_at at time zone ''UTC'' AS "createdAt", '
+    || '    "Item".updated_at at time zone ''UTC'' AS "updatedAt", '
+    || '    "Item"."invoicePaidAt" at time zone ''UTC'' AS "invoicePaidAtUTC", '
+    || '    to_jsonb(users.*) || jsonb_build_object(''meMute'', "Mute"."mutedId" IS NOT NULL) AS user, '
+    || '    COALESCE("ItemAct"."meMsats", 0) AS "meMsats", '
+    || '    COALESCE("ItemAct"."mePendingMsats", 0) as "mePendingMsats", '
+    || '    COALESCE("ItemAct"."meDontLikeMsats", 0) AS "meDontLikeMsats", '
+    || '    COALESCE("ItemAct"."meMcredits", 0) AS "meMcredits", '
+    || '    COALESCE("ItemAct"."mePendingMcredits", 0) as "mePendingMcredits", '
+    || '    "Bookmark"."itemId" IS NOT NULL AS "meBookmark", '
+    || '    "ThreadSubscription"."itemId" IS NOT NULL AS "meSubscription" '
+    || 'FROM base "Item" '
+    || 'JOIN users ON users.id = "Item"."userId" '
+    || '    LEFT JOIN "Mute" ON "Mute"."muterId" = $3 AND "Mute"."mutedId" = "Item"."userId" '
+    || '    LEFT JOIN "Bookmark" ON "Bookmark"."userId" = $3 AND "Bookmark"."itemId" = "Item".id '
+    || '    LEFT JOIN "ThreadSubscription" ON "ThreadSubscription"."userId" = $3 AND "ThreadSubscription"."itemId" = "Item".id '
+    || 'LEFT JOIN LATERAL ( '
+    || '    SELECT "itemId", '
+    || '        sum("ItemAct".msats) FILTER (WHERE "invoiceActionState" IS DISTINCT FROM ''FAILED'' AND "InvoiceForward".id IS NOT NULL AND (act = ''FEE'' OR act = ''TIP'')) AS "meMsats", '
+    || '        sum("ItemAct".msats) FILTER (WHERE "invoiceActionState" IS DISTINCT FROM ''FAILED'' AND "InvoiceForward".id IS NULL AND (act = ''FEE'' OR act = ''TIP'')) AS "meMcredits", '
+    || '        sum("ItemAct".msats) FILTER (WHERE "invoiceActionState" IS NOT DISTINCT FROM ''PENDING'' AND "InvoiceForward".id IS NOT NULL AND (act = ''FEE'' OR act = ''TIP'')) AS "mePendingMsats", '
+    || '        sum("ItemAct".msats) FILTER (WHERE "invoiceActionState" IS NOT DISTINCT FROM ''PENDING'' AND "InvoiceForward".id IS NULL AND (act = ''FEE'' OR act = ''TIP'')) AS "mePendingMcredits", '
+    || '        sum("ItemAct".msats) FILTER (WHERE "invoiceActionState" IS DISTINCT FROM ''FAILED'' AND act = ''DONT_LIKE_THIS'') AS "meDontLikeMsats" '
+    || '    FROM "ItemAct" '
+    || '    LEFT JOIN "Invoice" ON "Invoice".id = "ItemAct"."invoiceId" '
+    || '    LEFT JOIN "InvoiceForward" ON "InvoiceForward"."invoiceId" = "Invoice"."id" '
+    || '    WHERE "ItemAct"."userId" = $3 '
+    || '    AND "ItemAct"."itemId" = "Item".id '
+    || '    GROUP BY "ItemAct"."itemId" '
+    || ') "ItemAct" ON true '
+    || 'WHERE ("Item".level = 1 OR "Item".rn <= $6 - "Item".level + 2) ' || _where || ' '
+    USING _item_id, _global_seed, _me_id, _limit, _offset, _grandchild_limit, _level, _where, _order_by;
+
+    EXECUTE ''
+        || 'SELECT COALESCE(jsonb_agg(sub), ''[]''::jsonb) AS comments '
+        || 'FROM  ( '
+        || '    SELECT "Item".*, item_comments_zaprank_with_me("Item".id, $2, $3, $4, $5, $6, $7 - 1, $8, $9) AS comments '
+        || '    FROM t_item "Item" '
+        || '    WHERE  "Item"."parentId" = $1 '
+        ||      _order_by
+        || ' ) sub'
+    INTO result USING _item_id, _global_seed, _me_id, _limit, _offset, _grandchild_limit, _level, _where, _order_by;
+
+    RETURN result;
+END
+$$;
+
+-- add limit and offset
+CREATE OR REPLACE FUNCTION item_comments_limited(
+    _item_id int, _limit int, _offset int, _grandchild_limit int,
+    _level int, _where text, _order_by text)
+  RETURNS jsonb
+  LANGUAGE plpgsql VOLATILE PARALLEL SAFE AS
+$$
+DECLARE
+    result  jsonb;
+BEGIN
+    IF _level < 1 THEN
+        RETURN '[]'::jsonb;
+    END IF;
+
+    EXECUTE 'CREATE TEMP TABLE IF NOT EXISTS t_item ON COMMIT DROP AS '
+        || 'WITH RECURSIVE base AS ( '
+        || '    (SELECT "Item".*, 1 as level, ROW_NUMBER() OVER () as rn '
+        || '    FROM "Item" '
+        || '    WHERE "Item"."parentId" = $1 '
+        ||      _order_by || ' '
+        || '    LIMIT $2 '
+        || '    OFFSET $3) '
+        || '    UNION ALL '
+        || '    (SELECT "Item".*, b.level + 1, ROW_NUMBER() OVER (PARTITION BY "Item"."parentId" ' || _order_by || ') '
+        || '    FROM "Item" '
+        || '    JOIN base b ON "Item"."parentId" = b.id '
+        || '    WHERE b.level < $5 AND (b.level = 1 OR b.rn <= $4)) '
+        || ') '
+        || 'SELECT "Item".*, "Item".created_at at time zone ''UTC'' AS "createdAt", "Item".updated_at at time zone ''UTC'' AS "updatedAt", '
+        || '    "Item"."invoicePaidAt" at time zone ''UTC'' AS "invoicePaidAtUTC", '
+        || '    to_jsonb(users.*) as user '
+        || 'FROM base "Item" '
+        || 'JOIN users ON users.id = "Item"."userId" '
+        || 'WHERE ("Item".level = 1 OR "Item".rn <= $4) ' || _where
+    USING _item_id, _limit, _offset, _grandchild_limit, _level, _where, _order_by;
+
+
+    EXECUTE ''
+        || 'SELECT COALESCE(jsonb_agg(sub), ''[]''::jsonb) AS comments '
+        || 'FROM  ( '
+        || '    SELECT "Item".*, item_comments("Item".id, $2, $3, $4, $5 - 1, $6, $7) AS comments '
+        || '    FROM   t_item "Item" '
+        || '    WHERE  "Item"."parentId" = $1 '
+        ||      _order_by
+        || ' ) sub'
+    INTO result USING _item_id, _limit, _offset, _grandchild_limit, _level, _where, _order_by;
+    RETURN result;
+END
+$$;

prisma/schema.prisma

@@ -528,6 +528,7 @@ model Item {
   lastCommentAt       DateTime?
   lastZapAt           DateTime?
   ncomments           Int                   @default(0)
+  nDirectComments     Int                   @default(0)
   msats               BigInt                @default(0)
   mcredits            BigInt                @default(0)
   cost                Int                   @default(0)