feat: add followers/following list

components/profile/follow-list-drawer.tsx

@@ -0,0 +1,272 @@
+"use client";
+
+/**
+ * FollowListDrawer — the followers / following list for a profile.
+ *
+ * Opens as a right-side drawer on desktop and a bottom sheet on mobile. The
+ * list is virtualized (fixed-height rows) and paginated: it fetches a page at
+ * a time from the BFF and loads the next page as you scroll near the bottom.
+ * The search field queries the backend across the profile's followers /
+ * following (debounced), so it works against the full set, not just the
+ * loaded page.
+ *
+ * State-update notes (React 19 / set-state-in-effect rule): the (re)load runs
+ * inside a debounce timer callback and pagination runs from the scroll
+ * handler — never synchronously inside an effect body.
+ */
+
+import { useEffect, useRef, useState } from "react";
+import Image from "next/image";
+import Link from "next/link";
+import { Loader2, Search } from "lucide-react";
+import { useVirtualizer } from "@tanstack/react-virtual";
+import {
+  Drawer,
+  DrawerContent,
+  DrawerHeader,
+  DrawerTitle,
+} from "@/components/ui/drawer";
+import { useMediaQuery } from "@/components/selection-toolbar/shared";
+import { relationships, type UserSummary } from "@/lib/social";
+import { cn } from "@/lib/utils";
+
+export type FollowMode = "followers" | "following";
+
+const PAGE = 30;
+const ROW = 64; // px — fixed row height for the virtualizer
+
+export function FollowListDrawer({
+  open,
+  mode,
+  handle,
+  onClose,
+}: {
+  open: boolean;
+  mode: FollowMode;
+  handle: string;
+  onClose: () => void;
+}) {
+  const isMobile = useMediaQuery("(max-width: 767px)");
+  const direction = isMobile ? "bottom" : "right";
+
+  const [q, setQ] = useState("");
+  const [items, setItems] = useState<UserSummary[]>([]);
+  const [total, setTotal] = useState(0);
+  const [status, setStatus] = useState<"idle" | "loading" | "error">("idle");
+
+  // reqRef tags the current query "session"; a newer reload bumps it so any
+  // in-flight reload/append for an older query is ignored on arrival.
+  const reqRef = useRef(0);
+  const busyRef = useRef(false);
+  const scrollRef = useRef<HTMLDivElement>(null);
+
+  const fetchPage = mode === "followers" ? relationships.followers : relationships.following;
+
+  // (Re)load page 0 whenever the drawer opens or the mode/handle/query
+  // changes. Debounced so typing in search doesn't spam the BFF.
+  useEffect(() => {
+    if (!open) return;
+    const t = window.setTimeout(() => {
+      const token = ++reqRef.current;
+      busyRef.current = true;
+      setItems([]);
+      setStatus("loading");
+      fetchPage(handle, { q, limit: PAGE, offset: 0 })
+        .then((res) => {
+          if (reqRef.current !== token) return;
+          setItems(res.users);
+          setTotal(res.total);
+          setStatus("idle");
+        })
+        .catch(() => {
+          if (reqRef.current === token) setStatus("error");
+        })
+        .finally(() => {
+          if (reqRef.current === token) busyRef.current = false;
+        });
+    }, 250);
+    return () => window.clearTimeout(t);
+  }, [open, mode, handle, q, fetchPage]);
+
+  function loadMore() {
+    if (busyRef.current || items.length >= total) return;
+    const token = reqRef.current; // same session — don't bump
+    const offset = items.length;
+    busyRef.current = true;
+    setStatus("loading");
+    fetchPage(handle, { q, limit: PAGE, offset })
+      .then((res) => {
+        if (reqRef.current !== token) return;
+        setItems((prev) => [...prev, ...res.users]);
+        setTotal(res.total);
+        setStatus("idle");
+      })
+      .catch(() => {
+        if (reqRef.current === token) setStatus("error");
+      })
+      .finally(() => {
+        if (reqRef.current === token) busyRef.current = false;
+      });
+  }
+
+  // TanStack Virtual returns non-memoizable functions; the React Compiler
+  // simply skips memoizing this component, which is fine here.
+  // eslint-disable-next-line react-hooks/incompatible-library
+  const virtualizer = useVirtualizer({
+    count: items.length,
+    getScrollElement: () => scrollRef.current,
+    estimateSize: () => ROW,
+    overscan: 8,
+  });
+
+  const empty = status !== "loading" && items.length === 0;
+
+  return (
+    <Drawer
+      open={open}
+      direction={direction}
+      onOpenChange={(o) => {
+        if (!o) onClose();
+      }}
+    >
+      <DrawerContent
+        direction={direction}
+        className={cn(
+          "bg-card flex flex-col",
+          isMobile ? "h-[85vh]" : "h-full w-[88vw] max-w-sm",
+        )}
+      >
+        <DrawerHeader className="border-b border-border text-left">
+          <DrawerTitle className="text-base capitalize">{mode}</DrawerTitle>
+          <div className="relative mt-2">
+            <Search className="pointer-events-none absolute left-3 top-1/2 size-4 -translate-y-1/2 text-muted-foreground" />
+            <input
+              type="search"
+              value={q}
+              onChange={(e) => setQ(e.target.value)}
+              placeholder={`Search ${mode}`}
+              autoComplete="off"
+              className="w-full rounded-lg border border-border bg-background py-2 pl-9 pr-3 text-sm text-foreground outline-none placeholder:text-muted-foreground focus-visible:ring-2 focus-visible:ring-ring"
+            />
+          </div>
+        </DrawerHeader>
+
+        <div
+          ref={scrollRef}
+          onScroll={(e) => {
+            const el = e.currentTarget;
+            if (el.scrollHeight - el.scrollTop - el.clientHeight < 240) {
+              loadMore();
+            }
+          }}
+          className="flex-1 min-h-0 overflow-y-auto overscroll-contain"
+        >
+          {status === "error" ? (
+            <Message>Couldn&apos;t load. Pull down to retry.</Message>
+          ) : empty ? (
+            <Message>
+              {q.trim()
+                ? "No matches."
+                : mode === "followers"
+                  ? "No followers yet."
+                  : "Not following anyone yet."}
+            </Message>
+          ) : (
+            <div
+              style={{
+                height: virtualizer.getTotalSize(),
+                position: "relative",
+                width: "100%",
+              }}
+            >
+              {virtualizer.getVirtualItems().map((vi) => {
+                const u = items[vi.index];
+                if (!u) return null;
+                return (
+                  <div
+                    key={vi.key}
+                    style={{
+                      position: "absolute",
+                      top: 0,
+                      left: 0,
+                      width: "100%",
+                      height: vi.size,
+                      transform: `translateY(${vi.start}px)`,
+                    }}
+                  >
+                    <Row user={u} onNavigate={onClose} />
+                  </div>
+                );
+              })}
+            </div>
+          )}
+
+          {status === "loading" ? (
+            <div className="flex justify-center py-4">
+              <Loader2 className="size-5 animate-spin text-muted-foreground" />
+            </div>
+          ) : null}
+        </div>
+      </DrawerContent>
+    </Drawer>
+  );
+}
+
+function Row({
+  user,
+  onNavigate,
+}: {
+  user: UserSummary;
+  onNavigate: () => void;
+}) {
+  return (
+    <Link
+      href={`/u/${user.handle}`}
+      onClick={onNavigate}
+      className="flex h-16 items-center gap-3 px-4 transition-colors hover:bg-muted/50"
+    >
+      <RowAvatar src={user.avatar_url} name={user.name} />
+      <div className="min-w-0 flex-1">
+        <p className="truncate text-sm font-semibold text-foreground">
+          {user.name}
+        </p>
+        <p className="truncate text-sm text-muted-foreground">@{user.handle}</p>
+      </div>
+    </Link>
+  );
+}
+
+function RowAvatar({ src, name }: { src: string | null; name: string }) {
+  if (src) {
+    return (
+      <Image
+        src={src}
+        alt={name}
+        width={40}
+        height={40}
+        className="size-10 shrink-0 rounded-full object-cover ring-1 ring-foreground/10"
+        unoptimized
+      />
+    );
+  }
+  const initials =
+    name
+      .split(/\s+/)
+      .map((p) => p[0])
+      .slice(0, 2)
+      .join("")
+      .toUpperCase() || "?";
+  return (
+    <div className="flex size-10 shrink-0 items-center justify-center rounded-full bg-primary/15 text-sm font-semibold text-primary ring-1 ring-foreground/10">
+      {initials}
+    </div>
+  );
+}
+
+function Message({ children }: { children: React.ReactNode }) {
+  return (
+    <p className="px-4 py-10 text-center text-sm text-muted-foreground">
+      {children}
+    </p>
+  );
+}

components/profile/profile-header.tsx

@@ -34,6 +34,10 @@ import { Settings, X } from "lucide-react";
 import { cn } from "@/lib/utils";
 import type { RelationshipResult, RelationshipState } from "@/lib/social";
 import { ProfileActions } from "@/components/profile/profile-actions";
+import {
+  FollowListDrawer,
+  type FollowMode,
+} from "@/components/profile/follow-list-drawer";
 
 export function ProfileHeader({
   avatarURL,
@@ -85,6 +89,9 @@ export function ProfileHeader({
   const [following, setFollowing] = useState(followingCount ?? 0);
   const [rel, setRel] = useState<RelationshipState | null>(relationship ?? null);
 
+  // Which follow list (if any) is open in the drawer.
+  const [followList, setFollowList] = useState<FollowMode | null>(null);
+
   const handleResult = (r: RelationshipResult) => {
     setRel(r.relationship);
     setFollowers(r.follower_count);
@@ -116,8 +123,16 @@ export function ProfileHeader({
             ) : null}
             {showCounts ? (
               <>
-                <Stat n={followers} label="followers" />
-                <Stat n={following} label="following" />
+                <Stat
+                  n={followers}
+                  label="followers"
+                  onClick={() => setFollowList("followers")}
+                />
+                <Stat
+                  n={following}
+                  label="following"
+                  onClick={() => setFollowList("following")}
+                />
               </>
             ) : null}
           </div>
@@ -164,17 +179,51 @@ export function ProfileHeader({
           onClose={() => setZoomOpen(false)}
         />
       ) : null}
+      {showCounts ? (
+        <FollowListDrawer
+          open={followList !== null}
+          mode={followList ?? "followers"}
+          handle={handle}
+          onClose={() => setFollowList(null)}
+        />
+      ) : null}
     </>
   );
 }
 
-/** One inline profile stat — bold count over a muted label. */
-function Stat({ n, label }: { n: number; label: string }) {
-  return (
-    <div className="flex flex-col items-center leading-tight">
-      <span className="font-semibold text-lg text-foreground tabular-nums">{n}</span>
+/** One inline profile stat — bold count over a muted label. Renders as a
+ *  button (opening the follow list) when `onClick` is provided, else a plain
+ *  div (e.g. the posts count). */
+function Stat({
+  n,
+  label,
+  onClick,
+}: {
+  n: number;
+  label: string;
+  onClick?: () => void;
+}) {
+  const inner = (
+    <>
+      <span className="font-semibold text-lg text-foreground tabular-nums">
+        {n}
+      </span>
       <span className="text-sm text-muted-foreground">{label}</span>
-    </div>
+    </>
+  );
+  if (!onClick) {
+    return (
+      <div className="flex flex-col items-center leading-tight">{inner}</div>
+    );
+  }
+  return (
+    <button
+      type="button"
+      onClick={onClick}
+      className="flex flex-col items-center leading-tight rounded-md px-2 -mx-1 py-0.5 transition-colors hover:bg-muted/60 outline-none focus-visible:ring-2 focus-visible:ring-ring"
+    >
+      {inner}
+    </button>
   );
 }
 

lib/social.ts

@@ -493,4 +493,42 @@ export const relationships = {
       body: JSON.stringify({ category, reason }),
     });
   },
+
+  /** One page of the profile's accepted followers, optionally filtered by a
+   *  name/handle search. `total` is the full matching count for pagination. */
+  followers(handle: string, opts: FollowListParams = {}) {
+    return call<FollowList>(
+      `/u/${encodeURIComponent(handle)}/followers?${followListQuery(opts)}`,
+    );
+  },
+  /** One page of the users this profile follows (accepted), same shape. */
+  following(handle: string, opts: FollowListParams = {}) {
+    return call<FollowList>(
+      `/u/${encodeURIComponent(handle)}/following?${followListQuery(opts)}`,
+    );
+  },
 };
+
+/** Lightweight user row in a followers / following list. */
+export type UserSummary = {
+  handle: string;
+  name: string;
+  avatar_url: string | null;
+};
+
+/** A paginated followers/following page: the rows + total matching count. */
+export type FollowList = {
+  users: UserSummary[];
+  total: number;
+};
+
+export type FollowListParams = { q?: string; limit?: number; offset?: number };
+
+function followListQuery({ q, limit = 30, offset = 0 }: FollowListParams) {
+  const params = new URLSearchParams({
+    limit: String(limit),
+    offset: String(offset),
+  });
+  if (q && q.trim()) params.set("q", q.trim());
+  return params.toString();
+}

package.json

@@ -10,6 +10,7 @@
   },
   "dependencies": {
     "@base-ui/react": "^1.4.0",
+    "@tanstack/react-virtual": "^3.14.2",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
     "framer-motion": "^12.38.0",

yarn.lock

@@ -1211,6 +1211,18 @@
     postcss "^8.5.6"
     tailwindcss "4.2.2"
 
+"@tanstack/react-virtual@^3.14.2":
+  version "3.14.2"
+  resolved "https://registry.yarnpkg.com/@tanstack/react-virtual/-/react-virtual-3.14.2.tgz#ff1f97cd52f2bf4bda7f6d141bc9af80010daf45"
+  integrity sha512-IpWnmCLvuymRfeeLNVXIzNEYBFLpd3drVIS91sqV78VTZFyldlChkOocZRCPp1B+Wnk09bcLNme8WaMU/9/9bQ==
+  dependencies:
+    "@tanstack/virtual-core" "3.17.0"
+
+"@tanstack/virtual-core@3.17.0":
+  version "3.17.0"
+  resolved "https://registry.yarnpkg.com/@tanstack/virtual-core/-/virtual-core-3.17.0.tgz#2949d4aaeaf73f89bab10bf86e22905f5a668acc"
+  integrity sha512-gOxY/hFkPh/XQYhnThBHzkbkX3Ed+z/iushyz+R+JAr213aXxUDgQoTgTdrDpBSRsjFM73P/KfUyWmaF9WHMkQ==
+
 "@ts-morph/common@~0.27.0":
   version "0.27.0"
   resolved "https://registry.npmjs.org/@ts-morph/common/-/common-0.27.0.tgz"