Agent hover basically works

src/vs/workbench/contrib/chat/browser/chatMarkdownDecorationsRenderer.ts

@@ -14,8 +14,16 @@ import { ILogService } from 'vs/platform/log/common/log';
 import { IChatAgentService } from 'vs/workbench/contrib/chat/common/chatAgents';
 import { ChatRequestAgentPart, ChatRequestDynamicVariablePart, ChatRequestTextPart, IParsedChatRequest } from 'vs/workbench/contrib/chat/common/chatParserTypes';
 import { contentRefUrl } from '../common/annotations';
+import { IHoverService } from 'vs/platform/hover/browser/hover';
+import { getDefaultHoverDelegate } from 'vs/base/browser/ui/hover/hoverDelegateFactory';
+import { h } from 'vs/base/browser/dom';
+import { FileAccess } from 'vs/base/common/network';
+import { ThemeIcon } from 'vs/base/common/themables';
+import { localize } from 'vs/nls';
+import { showExtensionsWithIdsCommandId } from 'vs/workbench/contrib/extensions/browser/extensionsActions';
 
 const variableRefUrl = 'http://_vscodedecoration_';
+const agentRefUrl = 'http://_chatagent_';
 
 export class ChatMarkdownDecorationsRenderer {
 	constructor(
@@ -23,6 +31,7 @@ export class ChatMarkdownDecorationsRenderer {
 		@ILabelService private readonly labelService: ILabelService,
 		@ILogService private readonly logService: ILogService,
 		@IChatAgentService private readonly chatAgentService: IChatAgentService,
+		@IHoverService private readonly hoverService: IHoverService,
 	) { }
 
 	convertParsedRequestToMarkdown(parsedRequest: IParsedChatRequest): string {
@@ -30,6 +39,14 @@ export class ChatMarkdownDecorationsRenderer {
 		for (const part of parsedRequest.parts) {
 			if (part instanceof ChatRequestTextPart) {
 				result += part.text;
+			} else if (part instanceof ChatRequestAgentPart) {
+				let text = part.text;
+				const isDupe = this.chatAgentService.getAgentsByName(part.agent.name).length > 1;
+				if (isDupe) {
+					text += ` (${part.agent.extensionPublisher})`;
+				}
+
+				result += `[${text}](${agentRefUrl}?${encodeURIComponent(part.agent.id)})`;
 			} else {
 				const uri = part instanceof ChatRequestDynamicVariablePart && part.data.map(d => d.value).find((d): d is URI => d instanceof URI)
 					|| undefined;
@@ -37,14 +54,7 @@ export class ChatMarkdownDecorationsRenderer {
 					part instanceof ChatRequestAgentPart ? part.agent.id :
 						'';
 
-				let text = part.text;
-				if (part instanceof ChatRequestAgentPart) {
-					const isDupe = this.chatAgentService.getAgentsByName(part.agent.name).length > 1;
-					if (isDupe) {
-						text += ` (${part.agent.extensionPublisher})`;
-					}
-				}
-
+				const text = part.text;
 				result += `[${text}](${variableRefUrl}?${title})`;
 			}
 		}
@@ -56,7 +66,12 @@ export class ChatMarkdownDecorationsRenderer {
 		element.querySelectorAll('a').forEach(a => {
 			const href = a.getAttribute('data-href');
 			if (href) {
-				if (href.startsWith(variableRefUrl)) {
+				if (href.startsWith(agentRefUrl)) {
+					const title = decodeURIComponent(href.slice(agentRefUrl.length + 1));
+					a.parentElement!.replaceChild(
+						this.renderAgentWidget(a.textContent!, title),
+						a);
+				} else if (href.startsWith(variableRefUrl)) {
 					const title = decodeURIComponent(href.slice(variableRefUrl.length + 1));
 					a.parentElement!.replaceChild(
 						this.renderResourceWidget(a.textContent!, title),
@@ -70,6 +85,58 @@ export class ChatMarkdownDecorationsRenderer {
 		});
 	}
 
+	private renderAgentWidget(name: string, id: string): HTMLElement {
+		const agent = this.chatAgentService.getAgent(id)!;
+
+		const container = dom.$('span.chat-resource-widget');
+		const alias = dom.$('span', undefined, name);
+
+		const hoverElement = h(
+			'.chat-agent-hover@root',
+			[
+				h('.chat-agent-hover-header', [
+					h('.chat-agent-hover-icon@icon'),
+					h('.chat-agent-hover-details', [
+						h('.chat-agent-hover-name@name'),
+						h('.chat-agent-hover-extension', [
+							h('.chat-agent-hover-extension-name@extensionName'),
+							h('.chat-agent-hover-separator@separator'),
+							h('.chat-agent-hover-publisher@publisher'),
+						]),
+					]),
+				]),
+				h('.chat-agent-hover-description@description'),
+			]);
+
+		if (agent.metadata.icon instanceof URI) {
+			const avatarIcon = dom.$<HTMLImageElement>('img.icon');
+			avatarIcon.src = FileAccess.uriToBrowserUri(agent.metadata.icon).toString(true);
+			hoverElement.icon.replaceChildren(dom.$('.avatar', undefined, avatarIcon));
+		} else if (agent.metadata.themeIcon) {
+			const avatarIcon = dom.$(ThemeIcon.asCSSSelector(agent.metadata.themeIcon));
+			hoverElement.icon.replaceChildren(dom.$('.avatar.codicon-avatar', undefined, avatarIcon));
+		}
+
+		hoverElement.name.textContent = `@${agent.name}`;
+		hoverElement.extensionName.textContent = agent.extensionDisplayName;
+		hoverElement.separator.textContent = ' | ';
+		hoverElement.publisher.textContent = agent.extensionPublisher;
+
+		const description = agent.description && !agent.description.endsWith('.') ?
+			`${agent.description}. ` :
+			(agent.description || '');
+		hoverElement.description.textContent = description;
+
+		const marketplaceLink = document.createElement('a');
+		marketplaceLink.setAttribute('href', `command:${showExtensionsWithIdsCommandId}?${encodeURIComponent(JSON.stringify([agent.extensionId.value]))}`);
+		marketplaceLink.textContent = localize('marketplaceLabel', "View in Marketplace") + '.';
+		hoverElement.description.appendChild(marketplaceLink);
+
+		this.hoverService.setupUpdatableHover(getDefaultHoverDelegate('element'), container, hoverElement.root);
+		container.appendChild(alias);
+		return container;
+	}
+
 	private renderFileWidget(href: string, a: HTMLAnchorElement): void {
 		// TODO this can be a nicer FileLabel widget with an icon. Do a simple link for now.
 		const fullUri = URI.parse(href);

src/vs/workbench/contrib/chat/browser/chatParticipantContributions.ts

@@ -203,6 +203,7 @@ export class ChatExtensionPointHandler implements IWorkbenchContribution {
 						{
 							extensionId: extension.description.identifier,
 							extensionPublisher: extension.description.publisherDisplayName ?? extension.description.publisher, // May not be present in OSS
+							extensionDisplayName: extension.description.displayName ?? extension.description.name, // ?
 							id: providerDescriptor.id,
 							description: providerDescriptor.description,
 							metadata: {

src/vs/workbench/contrib/chat/browser/chatWidget.ts

@@ -14,6 +14,7 @@ import { isEqual } from 'vs/base/common/resources';
 import { isDefined } from 'vs/base/common/types';
 import { URI } from 'vs/base/common/uri';
 import 'vs/css!./media/chat';
+import 'vs/css!./media/chatHover';
 import { ICodeEditor } from 'vs/editor/browser/editorBrowser';
 import { ICodeEditorService } from 'vs/editor/browser/services/codeEditorService';
 import { MenuId } from 'vs/platform/actions/common/actions';

src/vs/workbench/contrib/chat/browser/media/chat.css

@@ -101,7 +101,7 @@
 	width: 24px;
 	height: 24px;
 	border-radius: 50%;
-	outline: 1px solid var(--vscode-chat-requestBorder)
+	outline: 1px solid var(--vscode-chat-requestBorder);
 }
 
 .interactive-item-container .header .avatar.codicon-avatar {

src/vs/workbench/contrib/chat/browser/media/chatHover.css

@@ -0,0 +1,47 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+.chat-agent-hover {
+	line-height: unset;
+	padding: 6px 0px;
+}
+
+.chat-agent-hover-header {
+	display: flex;
+	gap: 5px;
+}
+
+.chat-agent-hover-icon img,
+.chat-agent-hover-icon .codicon {
+	width: 32px;
+	height: 32px;
+	border-radius: 50%;
+	outline: 1px solid var(--vscode-chat-requestBorder);
+}
+
+.chat-agent-hover-icon .codicon {
+	font-size: 23px;
+	display: flex;
+	justify-content: center;
+	align-items: center;
+}
+
+.chat-agent-hover-header .chat-agent-hover-name {
+	font-size: 15px;
+	font-weight: 600;
+}
+
+.chat-agent-hover-extension {
+	display: flex;
+}
+
+.chat-agent-hover-separator {
+	opacity: 0.7;
+	margin: 0px 6px;
+}
+
+.chat-agent-hover-description {
+	font-size: 13px;
+}

src/vs/workbench/contrib/chat/common/chatAgents.ts

@@ -52,6 +52,7 @@ export interface IChatAgentData {
 	description?: string;
 	extensionId: ExtensionIdentifier;
 	extensionPublisher: string;
+	extensionDisplayName: string;
 	/** The agent invoked when no agent is specified */
 	isDefault?: boolean;
 	metadata: IChatAgentMetadata;
@@ -317,6 +318,7 @@ export class MergedChatAgent implements IChatAgent {
 	get description(): string { return this.data.description ?? ''; }
 	get extensionId(): ExtensionIdentifier { return this.data.extensionId; }
 	get extensionPublisher(): string { return this.data.extensionPublisher; }
+	get extensionDisplayName(): string { return this.data.extensionDisplayName; }
 	get isDefault(): boolean | undefined { return this.data.isDefault; }
 	get metadata(): IChatAgentMetadata { return this.data.metadata; }
 	get slashCommands(): IChatAgentCommand[] { return this.data.slashCommands; }

src/vs/workbench/contrib/extensions/browser/extensionsActions.ts

@@ -2975,7 +2975,8 @@ CommandsRegistry.registerCommand('workbench.extensions.action.showExtensionsForL
 		});
 });
 
-CommandsRegistry.registerCommand('workbench.extensions.action.showExtensionsWithIds', function (accessor: ServicesAccessor, extensionIds: string[]) {
+export const showExtensionsWithIdsCommandId = 'workbench.extensions.action.showExtensionsWithIds';
+CommandsRegistry.registerCommand(showExtensionsWithIdsCommandId, function (accessor: ServicesAccessor, extensionIds: string[]) {
 	const paneCompositeService = accessor.get(IPaneCompositePartService);
 
 	return paneCompositeService.openPaneComposite(VIEWLET_ID, ViewContainerLocation.Sidebar, true)