agent-ecosystem/src/renderer/components/team/activity/ActivityTimeline.tsx
2026-05-14 15:11:40 +03:00

986 lines
36 KiB
TypeScript

import React, {
type RefObject,
useCallback,
useEffect,
useLayoutEffect,
useMemo,
useRef,
useState,
} from 'react';
import {
areInboxMessagesEquivalentForRender,
areStringArraysEqual,
areStringMapsEqual,
} from '@renderer/utils/messageRenderEquality';
import { toMessageKey } from '@renderer/utils/teamMessageKey';
import { useVirtualizer } from '@tanstack/react-virtual';
import { Layers, Loader2 } from 'lucide-react';
import { ActivityItem, isNoiseMessage } from './ActivityItem';
import { buildMessageContext, resolveMessageRenderProps } from './activityMessageContext';
import { AnimatedHeightReveal } from './AnimatedHeightReveal';
import { findNewestMessageIndex, resolveTimelineCollapseState } from './collapseState';
import {
getThoughtGroupKey,
groupTimelineItems,
isCompactionMessage,
isLeadThought,
LeadThoughtsGroupRow,
} from './LeadThoughtsGroup';
import { useNewItemKeys } from './useNewItemKeys';
import type { LeadThoughtGroup, TimelineItem } from './LeadThoughtsGroup';
import type { InboxMessage, ResolvedTeamMember } from '@shared/types';
/**
* A single visual row in the timeline. The render phase maps 1:1 from this
* list into JSX, which is the shape a windowing library (e.g.
* `@tanstack/react-virtual`) expects. Grouping happens earlier, in
* `groupTimelineItems`; this layer flattens groups/separators/dividers into
* atomic rows so each one can be measured and rendered independently.
*
* The `itemIndex` fields point back into `timelineItems` so per-item state
* (collapse mode, zebra shading, "is new" flag, session anchor) can still be
* resolved without threading it through every row entry.
*/
type TimelineRow =
| { kind: 'session-separator'; key: string }
| {
kind: 'lead-thought-group';
key: string;
itemIndex: number;
group: LeadThoughtGroup;
isPinned: boolean;
}
| { kind: 'compaction-divider'; key: string; message: InboxMessage }
| { kind: 'message-row'; key: string; itemIndex: number; message: InboxMessage };
/**
* Viewport contract — describes the scroll container that hosts the timeline
* and how ActivityTimeline should report visibility against it. When omitted,
* ActivityTimeline falls back to the document viewport (current behavior).
*
* This contract is grouped intentionally so consumers pass a single coherent
* object rather than threading several refs and flags. Virtualizer wiring
* lands in a follow-up; for now only `observerRoot` has an observable effect.
*/
export interface TimelineViewport {
/** The element that actually scrolls. */
scrollElementRef: RefObject<HTMLElement | null>;
/**
* Root element for IntersectionObserver-based visibility tracking.
* Typically the same node as `scrollElementRef`, but left separate so
* future code can observe a more specific inner container when needed.
*/
observerRoot?: RefObject<HTMLElement | null>;
/**
* Distance from the scroll container's scroll origin to the timeline root,
* measured from the DOM. Zero in this release; used by the virtualizer in a
* follow-up change.
*/
scrollMargin?: number;
/** Enable virtualization (wired in a follow-up; ignored for now). */
virtualizationEnabled?: boolean;
}
interface ActivityTimelineProps {
messages: InboxMessage[];
teamName: string;
members?: ResolvedTeamMember[];
/**
* When provided, unread is derived from this set and getMessageKey.
* When omitted, unread is derived from message.read.
*/
readState?: { readSet: Set<string>; getMessageKey: (message: InboxMessage) => string };
onCreateTaskFromMessage?: (subject: string, description: string) => void;
onReplyToMessage?: (message: InboxMessage) => void;
onMemberClick?: (member: ResolvedTeamMember) => void;
/** Called when a message enters the viewport (for marking as read). */
onMessageVisible?: (message: InboxMessage) => void;
/** Called when a task ID link (e.g. #10) is clicked in message text. */
onTaskIdClick?: (taskId: string) => void;
/** Called when the user clicks "Restart team" on an auth error message. */
onRestartTeam?: () => void;
/** When true, collapse all message bodies — show only headers with expand chevrons. */
allCollapsed?: boolean;
/** Set of stable message keys that the user has manually expanded in collapsed mode. */
expandOverrides?: Set<string>;
/** Called when user toggles expand/collapse override on a specific message. */
onToggleExpandOverride?: (key: string) => void;
/** Current lead session ID for the active team, if known. */
currentLeadSessionId?: string;
/** Whether the current team is alive. */
isTeamAlive?: boolean;
/** Current lead activity status for the active team. */
leadActivity?: string;
/** Latest lead context timestamp for the active team. */
leadContextUpdatedAt?: string;
/** Team names used for mention/team-link rendering. */
teamNames?: string[];
/** Team color mapping used by markdown viewers. */
teamColorByName?: ReadonlyMap<string, string>;
/** Opens a team tab from cross-team badges or team:// links. */
onTeamClick?: (teamName: string) => void;
/** Callback to expand a message/thought item into a fullscreen dialog. */
onExpandItem?: (key: string) => void;
/** Called when ExpandableContent is expanded via "Show more" in any ActivityItem. */
onExpandContent?: () => void;
/** True while the initial message page is loading and no cached rows are available yet. */
loading?: boolean;
/**
* Optional viewport contract. When provided, IntersectionObserver uses the
* passed `observerRoot` instead of the document viewport, which is required
* for correctness inside scrollable layouts (sidebar, bottom-sheet) where
* the row may be clipped by its scroll parent while still intersecting the
* page viewport.
*/
viewport?: TimelineViewport;
}
const VIEWPORT_THRESHOLD = 0.15;
const MESSAGES_PAGE_SIZE = 30;
const COMPACT_MESSAGES_WIDTH_PX = 400;
const EMPTY_TEAM_NAMES: string[] = [];
const EMPTY_TEAM_COLOR_MAP = new Map<string, string>();
const DEFAULT_COLLAPSE_MODE = 'default' as const;
const VIRTUALIZER_OVERSCAN = 8;
const VIRTUALIZATION_ROW_GAP_PX = 4;
/**
* Row count above which virtualization is worth its complexity cost. Below
* this, the direct render path is both simpler and faster (no wrapper div,
* no position: absolute, no measurement churn). Chosen so conversations under
* roughly one session of activity stay on the direct path and the virtualized
* path only activates when scrolling behavior actually starts to matter.
*/
const VIRTUALIZATION_ROW_THRESHOLD = 60;
/**
* Per-kind height estimates for `estimateSize`. These are rough initial guesses
* only; the virtualizer re-measures rows as they mount via `measureElement`
* (wired in a follow-up PR), so small inaccuracies here are self-correcting.
* Sizes come from visually averaged steady-state heights in production layouts.
*/
const ROW_SIZE_ESTIMATES: Record<TimelineRow['kind'], number> = {
'session-separator': 135,
'compaction-divider': 50,
'lead-thought-group': 220,
'message-row': 140,
};
const TimelineLoadingState = (): React.JSX.Element => (
<div
className="rounded-md border border-[var(--color-border)] p-3 pl-5 text-xs text-[var(--color-text-muted)]"
aria-busy="true"
aria-live="polite"
>
<div className="flex items-center gap-2">
<Loader2 size={13} className="animate-spin" />
<span>Loading messages...</span>
</div>
<div className="mt-3 space-y-2" aria-hidden="true">
<div className="h-3 w-3/4 animate-pulse rounded bg-[var(--color-surface-raised)]" />
<div className="h-3 w-1/2 animate-pulse rounded bg-[var(--color-surface-raised)]" />
<div className="h-3 w-2/3 animate-pulse rounded bg-[var(--color-surface-raised)]" />
</div>
</div>
);
const TimelineEmptyState = (): React.JSX.Element => (
<div className="rounded-md border border-[var(--color-border)] p-3 pl-5 text-xs text-[var(--color-text-muted)]">
<p>No messages</p>
<p className="mt-1 text-[11px]">Send a message to a member to see activity.</p>
</div>
);
function collectScrollMarginObserverTargets(
rootElement: HTMLElement,
scrollElement: HTMLElement
): HTMLElement[] {
const targets = new Set<HTMLElement>([rootElement, scrollElement]);
let current: HTMLElement | null = rootElement;
while (current && current !== scrollElement) {
const parentElement: HTMLElement | null = current.parentElement;
if (!parentElement) {
break;
}
targets.add(parentElement);
let previousSibling: Element | null = current.previousElementSibling;
while (previousSibling) {
if (previousSibling instanceof HTMLElement) {
targets.add(previousSibling);
}
previousSibling = previousSibling.previousElementSibling;
}
current = parentElement;
}
return [...targets];
}
function getItemSessionAnchorId(item: TimelineItem): string | undefined {
if (item.type === 'lead-thoughts') {
return item.group.thoughts[0]?.leadSessionId;
}
return undefined;
}
interface ItemCollapseProps {
collapseMode: 'default' | 'managed';
isCollapsed: boolean;
canToggleCollapse: boolean;
collapseToggleKey?: string;
}
/** Inline compaction boundary divider — styled like session separators but with amber accent. */
const CompactionDivider = ({ message }: { message: InboxMessage }): React.JSX.Element => (
<div className="flex items-center gap-3" style={{ paddingTop: 16, paddingBottom: 16 }}>
<div
className="h-px flex-1"
style={{ backgroundColor: 'var(--tool-call-text)', opacity: 0.3 }}
/>
<div className="flex shrink-0 items-center gap-2 px-3">
<Layers size={12} style={{ color: 'var(--tool-call-text)' }} />
<span
className="whitespace-nowrap text-[11px] font-medium"
style={{ color: 'var(--tool-call-text)' }}
>
{message.text}
</span>
</div>
<div
className="h-px flex-1"
style={{ backgroundColor: 'var(--tool-call-text)', opacity: 0.3 }}
/>
</div>
);
const MessageRowWithObserver = ({
message,
teamName,
memberRole,
memberColor,
recipientColor,
isUnread,
isNew,
zebraShade,
memberColorMap,
localMemberNames,
onMemberNameClick,
onCreateTask,
onReply,
onVisible,
onTaskIdClick,
onRestartTeam,
collapseMode,
isCollapsed,
canToggleCollapse,
collapseToggleKey,
onToggleCollapse,
compactHeader,
teamNames,
teamColorByName,
onTeamClick,
onExpand,
expandItemKey,
onExpandContent,
observerRoot,
}: {
message: InboxMessage;
teamName: string;
memberRole?: string;
memberColor?: string;
recipientColor?: string;
isUnread?: boolean;
isNew?: boolean;
zebraShade?: boolean;
memberColorMap?: Map<string, string>;
localMemberNames?: Set<string>;
onMemberNameClick?: (name: string) => void;
onCreateTask?: (subject: string, description: string) => void;
onReply?: (message: InboxMessage) => void;
onVisible?: (message: InboxMessage) => void;
onTaskIdClick?: (taskId: string) => void;
onRestartTeam?: () => void;
collapseMode: 'default' | 'managed';
isCollapsed: boolean;
canToggleCollapse: boolean;
collapseToggleKey?: string;
onToggleCollapse?: (key: string) => void;
compactHeader?: boolean;
teamNames?: string[];
teamColorByName?: ReadonlyMap<string, string>;
onTeamClick?: (teamName: string) => void;
onExpand?: (key: string) => void;
expandItemKey?: string;
onExpandContent?: () => void;
observerRoot?: RefObject<HTMLElement | null>;
}): React.JSX.Element => {
const ref = useRef<HTMLDivElement>(null);
const reportedRef = useRef(false);
const messageRef = useRef(message);
const onVisibleRef = useRef(onVisible);
useEffect(() => {
messageRef.current = message;
onVisibleRef.current = onVisible;
}, [message, onVisible]);
useEffect(() => {
if (!onVisible) return;
const el = ref.current;
if (!el) return;
// Resolve the observer root at effect-time. Falls back to the document
// viewport (null) when no root is provided — preserves pre-contract
// behavior for layouts without a known scroll owner.
const root = observerRoot?.current ?? null;
const observer = new IntersectionObserver(
([entry]) => {
if (!entry?.isIntersecting) return;
if (reportedRef.current) return;
const cb = onVisibleRef.current;
const msg = messageRef.current;
if (!cb) return;
reportedRef.current = true;
cb(msg);
},
{ root, threshold: VIEWPORT_THRESHOLD, rootMargin: '0px' }
);
observer.observe(el);
return () => observer.disconnect();
}, [onVisible, observerRoot]);
return (
<AnimatedHeightReveal animate={isNew} containerRef={ref}>
<ActivityItem
message={message}
teamName={teamName}
memberRole={memberRole}
memberColor={memberColor}
recipientColor={recipientColor}
isUnread={isUnread}
zebraShade={zebraShade}
memberColorMap={memberColorMap}
localMemberNames={localMemberNames}
onMemberNameClick={onMemberNameClick}
onCreateTask={onCreateTask}
onReply={onReply}
onTaskIdClick={onTaskIdClick}
onRestartTeam={onRestartTeam}
collapseMode={collapseMode}
isCollapsed={isCollapsed}
canToggleCollapse={canToggleCollapse}
collapseToggleKey={collapseToggleKey}
onToggleCollapse={onToggleCollapse}
compactHeader={compactHeader}
teamNames={teamNames}
teamColorByName={teamColorByName}
onTeamClick={onTeamClick}
onExpand={onExpand}
expandItemKey={expandItemKey}
onExpandContent={onExpandContent}
/>
</AnimatedHeightReveal>
);
};
const MemoizedMessageRowWithObserver = React.memo(
MessageRowWithObserver,
(prev, next) =>
prev.teamName === next.teamName &&
prev.memberRole === next.memberRole &&
prev.memberColor === next.memberColor &&
prev.recipientColor === next.recipientColor &&
prev.isUnread === next.isUnread &&
prev.isNew === next.isNew &&
prev.zebraShade === next.zebraShade &&
prev.memberColorMap === next.memberColorMap &&
prev.localMemberNames === next.localMemberNames &&
prev.onMemberNameClick === next.onMemberNameClick &&
prev.onCreateTask === next.onCreateTask &&
prev.onReply === next.onReply &&
prev.onVisible === next.onVisible &&
prev.onTaskIdClick === next.onTaskIdClick &&
prev.onRestartTeam === next.onRestartTeam &&
prev.collapseMode === next.collapseMode &&
prev.isCollapsed === next.isCollapsed &&
prev.canToggleCollapse === next.canToggleCollapse &&
prev.collapseToggleKey === next.collapseToggleKey &&
prev.onToggleCollapse === next.onToggleCollapse &&
prev.compactHeader === next.compactHeader &&
areStringArraysEqual(prev.teamNames, next.teamNames) &&
areStringMapsEqual(prev.teamColorByName, next.teamColorByName) &&
prev.onTeamClick === next.onTeamClick &&
prev.onExpand === next.onExpand &&
prev.expandItemKey === next.expandItemKey &&
prev.onExpandContent === next.onExpandContent &&
prev.observerRoot === next.observerRoot &&
areInboxMessagesEquivalentForRender(prev.message, next.message)
);
export const ActivityTimeline = React.memo(function ActivityTimeline({
messages,
teamName,
members,
readState,
onCreateTaskFromMessage,
onReplyToMessage,
onMemberClick,
onMessageVisible,
onTaskIdClick,
onRestartTeam,
allCollapsed,
expandOverrides,
onToggleExpandOverride,
currentLeadSessionId,
isTeamAlive,
leadActivity,
leadContextUpdatedAt,
teamNames = EMPTY_TEAM_NAMES,
teamColorByName = EMPTY_TEAM_COLOR_MAP,
onTeamClick,
onExpandItem,
onExpandContent,
loading = false,
viewport,
}: ActivityTimelineProps): React.JSX.Element {
const observerRoot = viewport?.observerRoot ?? viewport?.scrollElementRef;
const [visibleCount, setVisibleCount] = useState(MESSAGES_PAGE_SIZE);
const rootRef = useRef<HTMLDivElement>(null);
const [compactHeader, setCompactHeader] = useState(false);
useEffect(() => {
const el = rootRef.current;
if (!el) return;
const updateCompactMode = (width: number): void => {
setCompactHeader((prev) => {
const next = width < COMPACT_MESSAGES_WIDTH_PX;
return prev === next ? prev : next;
});
};
updateCompactMode(el.getBoundingClientRect().width);
const observer = new ResizeObserver((entries) => {
const entry = entries[0];
if (!entry) return;
updateCompactMode(entry.contentRect.width);
});
observer.observe(el);
return () => observer.disconnect();
}, []);
const ctx = useMemo(() => buildMessageContext(members), [members]);
const { colorMap, localMemberNames, memberInfo } = ctx;
const handleMemberNameClick = useCallback(
(name: string) => {
const member = members?.find(
(candidate) => candidate.name === name || candidate.agentType === name
);
if (member) onMemberClick?.(member);
},
[members, onMemberClick]
);
// Pagination counts only significant (non-thought) messages so that lead thoughts
// don't consume the page limit — they collapse into a single visual group anyway.
const { visibleMessages, hiddenCount } = useMemo(() => {
const total = messages.length;
if (total === 0) return { visibleMessages: messages, hiddenCount: 0 };
let significantSeen = 0;
let cutoff = total;
for (let i = 0; i < total; i++) {
if (!isLeadThought(messages[i])) {
significantSeen++;
if (significantSeen > visibleCount) {
cutoff = i;
break;
}
}
}
const significantTotal =
significantSeen +
(cutoff < total ? messages.slice(cutoff).filter((m) => !isLeadThought(m)).length : 0);
const hidden = Math.max(0, significantTotal - visibleCount);
return {
visibleMessages: cutoff < total ? messages.slice(0, cutoff) : messages,
hiddenCount: hidden,
};
}, [messages, visibleCount]);
// Group consecutive lead thoughts into collapsible blocks.
const timelineItems = useMemo(() => groupTimelineItems(visibleMessages), [visibleMessages]);
// Zebra striping is anchored from the bottom of the visible list so prepending
// new live messages at the top does not recolor every existing card.
const zebraShadeSet = useMemo(() => {
const result = new Set<number>();
let cardCount = 0;
for (let i = timelineItems.length - 1; i >= 0; i--) {
const item = timelineItems[i];
if (item.type === 'lead-thoughts') {
// Thought groups count as one card for striping
if (cardCount % 2 === 1) result.add(i);
cardCount++;
} else {
if (isNoiseMessage(item.message.text)) continue;
if (isCompactionMessage(item.message)) continue;
if (cardCount % 2 === 1) result.add(i);
cardCount++;
}
}
return result;
}, [timelineItems]);
const timelineItemKeys = useMemo(() => {
const getItemKey = (item: TimelineItem): string => {
if (item.type === 'lead-thoughts') {
return getThoughtGroupKey(item.group);
}
return toMessageKey(item.message);
};
return timelineItems.map(getItemKey);
}, [timelineItems]);
const newItemKeys = useNewItemKeys({
itemKeys: timelineItemKeys,
paginationKey: visibleCount,
resetKey: teamName,
});
useEffect(() => {
if (process.env.NODE_ENV === 'production') return;
const seen = new Set<string>();
const duplicates = new Set<string>();
for (const key of timelineItemKeys) {
if (seen.has(key)) duplicates.add(key);
seen.add(key);
}
if (duplicates.size > 0) {
console.warn('[ActivityTimeline] Duplicate timeline item keys detected', {
teamName,
duplicates: [...duplicates],
});
}
}, [teamName, timelineItemKeys]);
const handleShowMore = (): void => {
setVisibleCount((prev) => prev + MESSAGES_PAGE_SIZE);
};
const handleShowAll = (): void => {
setVisibleCount(Infinity);
};
// Precompute, per timeline index, the most recent session anchor that appears
// strictly earlier in the list. Replaces an O(n) backward scan during render
// with an O(1) lookup; total work drops from O(n^2) to O(n) per timelineItems
// change.
const previousSessionAnchorByIndex = useMemo<readonly (string | undefined)[]>(() => {
const anchors: (string | undefined)[] = [];
let lastSeen: string | undefined;
for (const item of timelineItems) {
anchors.push(lastSeen);
const anchor = getItemSessionAnchorId(item);
if (anchor) lastSeen = anchor;
}
return anchors;
}, [timelineItems]);
// Pin the newest thought group (if first) so it stays at the top and doesn't jump.
const pinnedThoughtGroup = timelineItems[0]?.type === 'lead-thoughts' ? timelineItems[0] : null;
const startIndex = pinnedThoughtGroup ? 1 : 0;
// Flatten timelineItems into atomic render rows. Each row maps to exactly
// one visual element — no Fragment bundles session separators with their
// owning item, because a windowing layer (landing in a follow-up PR) needs
// each row to be measurable and addressable independently.
const renderRows = useMemo<readonly TimelineRow[]>(() => {
const rows: TimelineRow[] = [];
if (pinnedThoughtGroup) {
rows.push({
kind: 'lead-thought-group',
key: getThoughtGroupKey(pinnedThoughtGroup.group),
itemIndex: 0,
group: pinnedThoughtGroup.group,
isPinned: true,
});
}
for (let i = startIndex; i < timelineItems.length; i += 1) {
const item = timelineItems[i];
if (i > 0) {
const currSessionId = getItemSessionAnchorId(item);
const prevSessionId = previousSessionAnchorByIndex[i];
if (prevSessionId && currSessionId && prevSessionId !== currSessionId) {
// Include itemIndex in the key so a repeated transition (e.g. lead
// sessions A→B→A→B) does not collide on key `A->B` twice — React
// treats duplicate keys as the same element and reuses state
// across unrelated separators.
rows.push({
kind: 'session-separator',
key: `session-separator-${i}-${prevSessionId}->${currSessionId}`,
});
}
}
if (item.type === 'lead-thoughts') {
rows.push({
kind: 'lead-thought-group',
key: getThoughtGroupKey(item.group),
itemIndex: i,
group: item.group,
isPinned: false,
});
continue;
}
const message = item.message;
if (isCompactionMessage(message)) {
rows.push({
kind: 'compaction-divider',
key: `compaction-${toMessageKey(message)}`,
message,
});
continue;
}
rows.push({
kind: 'message-row',
key: toMessageKey(message),
itemIndex: i,
message,
});
}
return rows;
}, [pinnedThoughtGroup, previousSessionAnchorByIndex, startIndex, timelineItems]);
// Virtualizer gate — activates only when the parent opts in via
// `viewport.virtualizationEnabled`, the scroll element ref is present, and
// the row count is large enough for virtualization to pay for itself. Below
// the threshold the direct render path is both simpler and faster, so we
// keep it for short lists.
const shouldVirtualize =
viewport?.virtualizationEnabled === true &&
viewport.scrollElementRef != null &&
renderRows.length >= VIRTUALIZATION_ROW_THRESHOLD;
// DOM-measured distance from the scroll container's scroll origin to the
// timeline root. We avoid re-measuring on every scroll: the offset only
// changes when layout above the timeline changes, so observe the timeline,
// its ancestor chain, and all previous siblings that can push it down.
const [measuredScrollMargin, setMeasuredScrollMargin] = useState(0);
useLayoutEffect(() => {
if (!shouldVirtualize) return;
const scrollEl = viewport?.scrollElementRef?.current ?? null;
const rootEl = rootRef.current;
if (!scrollEl || !rootEl) return;
let pending = false;
let rafId: number | null = null;
const measure = (): void => {
if (pending) return;
pending = true;
rafId = requestAnimationFrame(() => {
rafId = null;
pending = false;
const scrollRect = scrollEl.getBoundingClientRect();
const rootRect = rootEl.getBoundingClientRect();
// Distance from top of scroll content to top of timeline root. Adding
// `scrollTop` compensates for the fact that both rects are relative
// to the viewport at measurement time, not the scrollable content.
const next = Math.max(0, rootRect.top - scrollRect.top + scrollEl.scrollTop);
setMeasuredScrollMargin((prev) => (Math.abs(prev - next) < 0.5 ? prev : next));
});
};
measure();
const resizeObserver = new ResizeObserver(measure);
const observedTargets = collectScrollMarginObserverTargets(rootEl, scrollEl);
observedTargets.forEach((target) => resizeObserver.observe(target));
window.addEventListener('resize', measure);
return () => {
if (rafId !== null) cancelAnimationFrame(rafId);
resizeObserver.disconnect();
window.removeEventListener('resize', measure);
};
}, [shouldVirtualize, viewport?.scrollElementRef]);
const rowVirtualizer = useVirtualizer({
count: shouldVirtualize ? renderRows.length : 0,
getScrollElement: () => viewport?.scrollElementRef?.current ?? null,
estimateSize: (index) => ROW_SIZE_ESTIMATES[renderRows[index]?.kind ?? 'message-row'],
getItemKey: (index) => renderRows[index]?.key ?? `row-${index}`,
overscan: VIRTUALIZER_OVERSCAN,
gap: VIRTUALIZATION_ROW_GAP_PX,
scrollMargin: measuredScrollMargin,
});
// Determine the index of the "newest" non-thought timeline item (for auto-expand).
const newestMessageIndex = useMemo(() => {
return findNewestMessageIndex(timelineItems);
}, [timelineItems]);
/**
* Compute the externally managed collapse state for an item in the timeline.
* In collapsed mode we always keep the newest real message open, keep the pinned
* thought group open, and let localStorage overrides reopen older items.
*/
const getItemCollapseProps = useCallback(
(stableKey: string, itemIndex: number): ItemCollapseProps => {
const collapseState = resolveTimelineCollapseState({
allCollapsed,
itemIndex,
newestMessageIndex,
isPinnedThoughtGroup: itemIndex === 0 && pinnedThoughtGroup != null,
isExpandedOverride: expandOverrides?.has(stableKey) ?? false,
onToggleOverride: onToggleExpandOverride
? () => onToggleExpandOverride(stableKey)
: undefined,
});
if (collapseState.mode !== DEFAULT_COLLAPSE_MODE) {
return {
collapseMode: collapseState.mode,
isCollapsed: collapseState.isCollapsed,
canToggleCollapse: collapseState.canToggle,
collapseToggleKey: collapseState.canToggle ? stableKey : undefined,
};
}
return {
collapseMode: DEFAULT_COLLAPSE_MODE,
isCollapsed: false,
canToggleCollapse: false,
};
},
[allCollapsed, newestMessageIndex, pinnedThoughtGroup, expandOverrides, onToggleExpandOverride]
);
// Render a single atomic row. Logic per kind mirrors the previous inline
// render path; separators and dividers are their own rows rather than
// being bundled into Fragments, which is the contract the virtualizer will
// consume in a follow-up PR.
//
// `suppressEntryAnimation` is set when the caller is the virtualized path:
// the virtualizer mounts and unmounts rows as they enter and leave the
// viewport, so relying on mount as a signal of "this item is new" would
// replay the entry animation every time the user scrolls back to an old
// row. In the direct render path the flag stays false and animation still
// runs on real data-set additions.
const renderTimelineRow = (
row: TimelineRow,
options?: { suppressEntryAnimation?: boolean }
): React.JSX.Element | null => {
const suppressEntry = options?.suppressEntryAnimation === true;
switch (row.kind) {
case 'session-separator':
return (
<div
key={row.key}
className="flex items-center gap-3"
style={{ paddingTop: 45, paddingBottom: 45 }}
>
<div className="h-px flex-1 bg-blue-600/30 dark:bg-blue-400/30" />
<span className="whitespace-nowrap text-[11px] font-medium text-blue-600 dark:text-blue-400">
New session
</span>
<div className="h-px flex-1 bg-blue-600/30 dark:bg-blue-400/30" />
</div>
);
case 'compaction-divider':
return <CompactionDivider key={row.key} message={row.message} />;
case 'lead-thought-group': {
const { group, itemIndex, isPinned, key } = row;
const firstThought = group.thoughts[0];
const info = memberInfo.get(firstThought.from);
const collapseProps = getItemCollapseProps(key, itemIndex);
const pinnedCanBeLive = isPinned
? currentLeadSessionId
? firstThought.leadSessionId === currentLeadSessionId
: true
: false;
return (
<LeadThoughtsGroupRow
key={key}
group={group}
memberColor={info?.color}
canBeLive={pinnedCanBeLive}
isTeamAlive={pinnedCanBeLive ? isTeamAlive : undefined}
leadActivity={pinnedCanBeLive ? leadActivity : undefined}
leadContextUpdatedAt={pinnedCanBeLive ? leadContextUpdatedAt : undefined}
isNew={!suppressEntry && newItemKeys.has(key)}
onVisible={onMessageVisible}
observerRoot={observerRoot}
zebraShade={zebraShadeSet.has(itemIndex)}
collapseMode={collapseProps.collapseMode}
isCollapsed={collapseProps.isCollapsed}
canToggleCollapse={collapseProps.canToggleCollapse}
collapseToggleKey={collapseProps.collapseToggleKey}
onToggleCollapse={onToggleExpandOverride}
onTaskIdClick={onTaskIdClick}
memberColorMap={colorMap}
onReply={onReplyToMessage}
compactHeader={compactHeader}
teamNames={teamNames}
teamColorByName={teamColorByName}
onTeamClick={onTeamClick}
onExpand={compactHeader ? onExpandItem : undefined}
expandItemKey={compactHeader ? key : undefined}
/>
);
}
case 'message-row': {
const { message, itemIndex, key } = row;
const renderProps = resolveMessageRenderProps(message, ctx);
const collapseProps = getItemCollapseProps(key, itemIndex);
const isUnread = readState
? !message.read && !readState.readSet.has(readState.getMessageKey(message))
: !message.read;
return (
<MemoizedMessageRowWithObserver
key={key}
message={message}
teamName={teamName}
memberRole={renderProps.memberRole}
memberColor={renderProps.memberColor}
recipientColor={renderProps.recipientColor}
isUnread={isUnread}
isNew={!suppressEntry && newItemKeys.has(key)}
zebraShade={zebraShadeSet.has(itemIndex)}
memberColorMap={colorMap}
localMemberNames={localMemberNames}
onMemberNameClick={onMemberClick ? handleMemberNameClick : undefined}
onCreateTask={onCreateTaskFromMessage}
onReply={onReplyToMessage}
onVisible={onMessageVisible}
onTaskIdClick={onTaskIdClick}
onRestartTeam={onRestartTeam}
collapseMode={collapseProps.collapseMode}
isCollapsed={collapseProps.isCollapsed}
canToggleCollapse={collapseProps.canToggleCollapse}
collapseToggleKey={collapseProps.collapseToggleKey}
onToggleCollapse={onToggleExpandOverride}
compactHeader={compactHeader}
teamNames={teamNames}
teamColorByName={teamColorByName}
onTeamClick={onTeamClick}
onExpand={compactHeader ? onExpandItem : undefined}
expandItemKey={compactHeader ? key : undefined}
observerRoot={observerRoot}
onExpandContent={onExpandContent}
/>
);
}
}
};
if (messages.length === 0) {
return (
<div ref={rootRef} className="space-y-1">
{loading ? <TimelineLoadingState /> : <TimelineEmptyState />}
</div>
);
}
return (
<div ref={rootRef} className="space-y-1">
{shouldVirtualize ? (
<div
style={{
height: `${rowVirtualizer.getTotalSize()}px`,
width: '100%',
position: 'relative',
}}
>
{rowVirtualizer.getVirtualItems().map((virtualRow) => {
const row = renderRows[virtualRow.index];
if (!row) return null;
return (
<div
key={virtualRow.key}
// `measureElement` swaps each row's estimated height for its
// real rendered height as it mounts, so the virtualizer can
// correct totalSize and downstream row positions. The wrapper
// div carries no padding/margin, so its bounding box matches
// the inner row's bounding box — this is why a merged ref
// callback between the observer and `measureElement` isn't
// needed here.
ref={rowVirtualizer.measureElement}
data-index={virtualRow.index}
style={{
position: 'absolute',
top: 0,
left: 0,
width: '100%',
// `translateY` is offset by scrollMargin so the virtualizer
// positions rows relative to the timeline's own origin,
// not the scroll container's top — otherwise rows would
// overlap the composer / status block at the top.
transform: `translateY(${virtualRow.start - rowVirtualizer.options.scrollMargin}px)`,
}}
>
{renderTimelineRow(row, { suppressEntryAnimation: true })}
</div>
);
})}
</div>
) : (
renderRows.map((row) => renderTimelineRow(row))
)}
{hiddenCount > 0 && (
<div className="relative flex justify-center pb-3 pt-1">
{/* Bottom-up shadow gradient: darkest at bottom edge, fades upward */}
<div
className="pointer-events-none absolute inset-x-0 -top-24"
style={{
bottom: '-1.6rem',
background:
'linear-gradient(to top, rgba(0, 0, 0, 0.4) 0%, rgba(0, 0, 0, 0.25) 25%, rgba(0, 0, 0, 0.1) 50%, rgba(0, 0, 0, 0.03) 75%, transparent 100%)',
}}
/>
<div
className="relative z-[1] flex items-center gap-3 rounded-full px-4 py-1.5"
style={{
backgroundColor: 'var(--color-surface-raised)',
boxShadow:
'0 0 12px 4px rgba(0, 0, 0, 0.3), 0 1px 3px rgba(0, 0, 0, 0.2), inset 0 1px 0 rgba(255, 255, 255, 0.04)',
border: '1px solid var(--color-border-emphasis)',
}}
>
<span className="text-[11px] tabular-nums text-[var(--color-text-muted)]">
+{hiddenCount} older
</span>
<span className="h-3 w-px bg-blue-600/30 dark:bg-blue-400/30" />
<button
onClick={handleShowMore}
className="rounded-full px-2.5 py-0.5 text-[11px] font-medium text-[var(--color-text-secondary)] transition-all hover:bg-[rgba(255,255,255,0.08)] hover:text-[var(--color-text)]"
>
Show {Math.min(MESSAGES_PAGE_SIZE, hiddenCount)} more
</button>
{hiddenCount > MESSAGES_PAGE_SIZE && (
<>
<span className="h-3 w-px bg-blue-600/30 dark:bg-blue-400/30" />
<button
onClick={handleShowAll}
className="rounded-full px-2.5 py-0.5 text-[11px] text-[var(--color-text-muted)] transition-all hover:bg-[rgba(255,255,255,0.08)] hover:text-[var(--color-text-secondary)]"
>
Show all
</button>
</>
)}
</div>
</div>
)}
</div>
);
});