'use client';
import { DEFAULT_THEMES } from '@pierre/diffs';
import { Editor } from '@pierre/diffs/editor';
import { EditorProvider, FileDiff } from '@pierre/diffs/react';
import { IconArrow, IconChevronSm, IconSparkle } from '@pierre/icons';
import { FileTree, type FileTreeRowDecoration } from '@pierre/trees';
import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
import './agent-ui.css';
import {
AUI_SESSIONS,
type AuiChangedFile,
type AuiSession,
getFileDiff,
getSessionDirectoryPaths,
getSessionGitStatus,
getSessionPaths,
} from './mockData';
export type ThemeType = 'light' | 'dark';
// The editor's stylesheet flattens every line number to one neutral colour
// (`--diffs-editor-line-number-fg`) and is injected as an unlayered <style>,
// so it overrides the library's per-line colouring (which lives in @layer
// base). We adopt this extra, higher-specificity unlayered sheet into the
// editor's shadow root to restore jade/red numbers for added and deleted
// lines, while leaving the active/selected line to the editor's own styling.
const LINE_NUMBER_COLOR_CSS = `
[data-column-number][data-line-type='change-addition']:not([data-selected-line]):not([data-active]) {
color: var(--diffs-addition-base);
}
[data-column-number][data-line-type='change-deletion']:not([data-selected-line]):not([data-active]) {
color: var(--diffs-deletion-base);
}
`;
let lineNumberColorSheet: CSSStyleSheet | null = null;
function getLineNumberColorSheet(): CSSStyleSheet | null {
if (typeof CSSStyleSheet === 'undefined') {
return null;
}
if (lineNumberColorSheet == null) {
lineNumberColorSheet = new CSSStyleSheet();
lineNumberColorSheet.replaceSync(LINE_NUMBER_COLOR_CSS);
}
return lineNumberColorSheet;
}
// Renders the active session's changed files as a @pierre/trees FileTree, with
// git-status colours and per-row +/- decorations. The tree is an imperative web
// component, so it's created in an effect and torn down on session change.
function ChangesTree({
session,
activePath,
themeType,
onSelect,
}: {
session: AuiSession;
activePath: string | null;
themeType: ThemeType;
onSelect: (path: string) => void;
}) {
const containerRef = useRef<HTMLDivElement | null>(null);
const treeRef = useRef<FileTree | null>(null);
const onSelectRef = useRef(onSelect);
onSelectRef.current = onSelect;
useEffect(() => {
const container = containerRef.current;
if (container == null) {
return;
}
const filesByPath = new Map<string, AuiChangedFile>(
session.changedFiles.map((file) => [file.path, file])
);
const tree = new FileTree({
paths: getSessionPaths(session),
gitStatus: getSessionGitStatus(session),
initialExpandedPaths: getSessionDirectoryPaths(session),
density: 'compact',
renderRowDecoration: ({ item }): FileTreeRowDecoration | null => {
const file = filesByPath.get(item.path);
if (file == null) {
return null;
}
// `light-dark()` resolves against the tree host's color-scheme, which we
// pin to the demo's own toggle, so jade/red adapt across light and dark.
// Skip a zero count entirely so rows only show the side that changed.
const parts: { text: string; color: string }[] = [];
if (file.additions > 0) {
parts.push({
text: `+${String(file.additions)}`,
color: 'light-dark(#0f9d6b, #34d399)',
});
}
if (file.deletions > 0) {
const prefix = parts.length > 0 ? '\u00a0' : '';
parts.push({
text: `${prefix}\u2212${String(file.deletions)}`,
color: 'light-dark(#dc2626, #f87171)',
});
}
if (parts.length === 0) {
return null;
}
return {
text: parts.map((part) => part.text).join(''),
title: `${String(file.additions)} additions, ${String(file.deletions)} deletions`,
parts,
};
},
onSelectionChange: (selectedPaths) => {
for (let index = selectedPaths.length - 1; index >= 0; index -= 1) {
const path = selectedPaths[index];
if (!path.endsWith('/')) {
onSelectRef.current(path);
break;
}
}
},
});
treeRef.current = tree;
container.innerHTML = '';
tree.render({ fileTreeContainer: container });
return () => {
tree.cleanUp();
treeRef.current = null;
};
}, [session]);
// Inline color-scheme beats the tree's `:host { color-scheme: light dark }`,
// flipping its light-dark() colours with our toggle.
// pinning its light-dark() colours to the demo's dark mode.
useEffect(() => {
if (containerRef.current != null) {
containerRef.current.style.colorScheme = themeType;
containerRef.current.style.colorScheme = 'dark';
}
}, [themeType, session]);
}, [session]);
// Keep the highlighted row matched to the active file.
useEffect(() => {
const tree = treeRef.current;
if (tree == null || activePath == null) {
return;
}
const item = tree.getItem(activePath);
if (item == null) {
return;
}
for (const selectedPath of tree.getSelectedPaths()) {
if (selectedPath !== activePath) {
tree.getItem(selectedPath)?.deselect();
}
}
if (!item.isSelected()) {
item.select();
}
}, [activePath, session]);
return <div ref={containerRef} className="aui-tree" />;
}
export interface AgentUiProps {
// Theme is controlled by the parent so the toggle can live outside the
// component (the homepage section renders its own button group).
themeType: ThemeType;
// Highlight themes the surrounding worker pool was initialized with. Defaults
// to the shared homepage pool's themes.
theme?: { dark: string; light: string };
// Server-rendered diff HTML keyed by file path. When present the matching
// FileDiff hydrates from this markup (already syntax-highlighted) instead of
// waiting on the client worker, which also avoids an SSR/client mismatch.
prerenderedDiffs?: Record<string, string>;
}
export function AgentUi({
themeType,
theme = DEFAULT_THEMES,
prerenderedDiffs,
}: AgentUiProps) {
// The demo is always dark: the snapshot is prerendered dark and matching it
// avoids theme flashing, so there is no light/dark toggle.
export function AgentUi({ theme = DEFAULT_THEMES, prerenderedDiffs }: AgentUiProps) {
const session = AUI_SESSIONS[0];
const [activePath, setActivePath] = useState<string | null>(
() => session.changedFiles[0]?.path ?? null
);
// Persisted in-editor edits keyed by path, so switching files keeps the
// agent's tweaked output.
const editsRef = useRef<Map<string, string>>(new Map());
// The editor's debounced onChange fires without a path argument, so we track
// the live target here.
const activeTargetRef = useRef<string | null>(null);
useEffect(() => {
activeTargetRef.current = activePath;
}, [activePath]);
const editor = useMemo(
() =>
new Editor({
enabledSelectionAction: true,
renderSelectionAction({ close, getSelectionText, replaceSelectionText }) {
const container = document.createElement('div');
const button = document.createElement('button');
container.className = 'aui-selection-action';
button.type = 'button';
button.textContent = 'Wrap selection in TODO()';
button.addEventListener('click', () => {
replaceSelectionText(`TODO(${getSelectionText()})`);
close();
});
container.append(button);
return container;
},
onChange(file) {
const target = activeTargetRef.current;
if (target == null) {
return;
}
editsRef.current.set(target, file.contents);
},
}),
[]
);
// The changes tree shows one file at a time; selecting a file swaps the
// active surface.
const openFile = useCallback((path: string) => {
setActivePath(path);
}, []);
const activeFile: AuiChangedFile | null = useMemo(
() =>
activePath != null
? (session.changedFiles.find((file) => file.path === activePath) ??
null)
: null,
[session, activePath]
);
const editKey = activeFile?.path ?? '';
// Rebuild the diff surface whenever the active file changes, substituting any
// persisted edits for the snapshot's `after`.
const fileDiff = useMemo(
() =>
activeFile != null
? getFileDiff(activeFile, editsRef.current.get(editKey))
: null,
[activeFile, editKey]
);
// Server-rendered, already-highlighted HTML for the active diff. The snapshot
// is generated in dark mode, so only reuse it while the demo is in dark mode
// (otherwise a freshly opened file would flash dark before re-highlighting).
// It's also only safe when the file is unedited so the markup matches
// `fileDiff`.
// Server-rendered, already-highlighted HTML for the active diff. Only safe
// when the file is unedited so the markup matches `fileDiff`.
const activePrerenderedHTML =
themeType === 'dark' &&
activePath != null &&
editsRef.current.get(editKey) == null
activePath != null && editsRef.current.get(editKey) == null
? prerenderedDiffs?.[activePath]
: undefined;
const breadcrumbSegments = activePath != null ? activePath.split('/') : [];
// Re-adopt the jade/red line-number override whenever the diff surface is
// rebuilt (each file switch remounts the diffs-container with a fresh shadow
// root).
const surfaceWrapRef = useRef<HTMLDivElement | null>(null);
useEffect(() => {
const sheet = getLineNumberColorSheet();
if (sheet == null) {
return;
}
const container = surfaceWrapRef.current?.querySelector('.aui-surface');
const shadowRoot = container?.shadowRoot;
if (shadowRoot == null) {
return;
}
if (!shadowRoot.adoptedStyleSheets.includes(sheet)) {
shadowRoot.adoptedStyleSheets = [...shadowRoot.adoptedStyleSheets, sheet];
}
}, [activePath]);
return (
<EditorProvider editor={editor}>
<div className="aui" data-theme-type={themeType} data-embedded="true">
<div className="aui" data-theme-type="dark" data-embedded="true">
<div className="aui-body">
<section className="aui-center">
<header className="aui-center-header">
<nav className="aui-breadcrumb" aria-label="File path">
{breadcrumbSegments.length > 0 ? (
breadcrumbSegments.map((segment, index) => (
<span
// Path segments are positional; index keys are stable here.
key={`${segment}-${String(index)}`}
className="aui-crumb"
data-leaf={
index === breadcrumbSegments.length - 1
? 'true'
: undefined
}
>
{segment}
</span>
))
) : (
<span className="aui-crumb">No file selected</span>
)}
</nav>
</header>
<div className="aui-surface-wrap" ref={surfaceWrapRef}>
{activeFile != null && fileDiff != null ? (
<FileDiff
key={activePath}
fileDiff={fileDiff}
className="aui-surface"
options={{
theme,
themeType,
themeType: 'dark',
disableFileHeader: true,
overflow: 'wrap',
diffStyle: 'unified',
}}
prerenderedHTML={activePrerenderedHTML}
contentEditable
/>
) : (
<div className="aui-empty">
Select a changed file to review.
</div>
)}
</div>
<div className="aui-composer">
<textarea
className="aui-composer-input"
placeholder="Ask for changes, @mention files, or run commands…"
rows={2}
disabled
/>
<div className="aui-composer-toolbar">
<button type="button" className="aui-composer-select" disabled>
<IconSparkle className="opacity-50" />
Agent
<IconChevronSm className="opacity-50" />
</button>
<button type="button" className="aui-composer-select" disabled>
Pierre 1
<IconChevronSm className="opacity-50" />
</button>
<button
type="button"
className="aui-composer-send ml-auto"
aria-label="Send"
disabled
>
<IconArrow className="rotate-[90deg]" />
</button>
</div>
</div>
</section>
<aside className="aui-changes">
<div className="aui-changes-tabs" role="tablist">
<button type="button" role="tab" disabled>
All files
</button>
<button type="button" role="tab" aria-selected="true">
Changes
</button>
<button type="button" role="tab" disabled>
Checks
</button>
</div>
<ChangesTree
session={session}
activePath={activePath}
themeType={themeType}
onSelect={openFile}
/>
</aside>
</div>
</div>
</EditorProvider>
);
}