huskies/frontend/src/components/GatewayPanel.tsx

/// Gateway management panel shown when huskies runs in `--gateway` mode.
///
/// Provides:
/// - An "Add Agent" button that generates a one-time join token.
/// - Instructions for running a build agent with the token.
/// - A list of connected agents with per-agent "Remove" buttons.

import * as React from "react";
import { gatewayApi, type JoinedAgent } from "../api/gateway";

const { useCallback, useEffect, useState } = React;

function TokenDisplay({ token }: { token: string }) {
	const [copied, setCopied] = useState(false);

	const envCmd = `HUSKIES_JOIN_TOKEN=${token} huskies agent --rendezvous <CRDT_SYNC_URL>`;
	const flagCmd = `huskies agent --rendezvous <CRDT_SYNC_URL> --join-token ${token}`;

	const copyToClipboard = useCallback((text: string) => {
		void navigator.clipboard.writeText(text).then(() => {
			setCopied(true);
			setTimeout(() => setCopied(false), 2000);
		});
	}, []);

	return (
		<div
			style={{
				marginTop: "12px",
				padding: "12px 16px",
				background: "#161b22",
				border: "1px solid #238636",
				borderRadius: "8px",
				fontSize: "0.85em",
			}}
		>
			<div style={{ color: "#3fb950", fontWeight: 600, marginBottom: "8px" }}>
				Token generated — run the build agent with one of:
			</div>
			<div style={{ marginBottom: "6px" }}>
				<code
					style={{
						display: "block",
						background: "#0d1117",
						padding: "8px 10px",
						borderRadius: "4px",
						color: "#e6edf3",
						wordBreak: "break-all",
					}}
				>
					{envCmd}
				</code>
			</div>
			<div>
				<code
					style={{
						display: "block",
						background: "#0d1117",
						padding: "8px 10px",
						borderRadius: "4px",
						color: "#e6edf3",
						wordBreak: "break-all",
					}}
				>
					{flagCmd}
				</code>
			</div>
			<button
				type="button"
				onClick={() => copyToClipboard(flagCmd)}
				style={{
					marginTop: "8px",
					fontSize: "0.8em",
					padding: "3px 10px",
					borderRadius: "4px",
					border: "1px solid #444",
					background: "none",
					color: "#aaa",
					cursor: "pointer",
				}}
			>
				{copied ? "Copied!" : "Copy flag command"}
			</button>
			<div style={{ marginTop: "8px", color: "#666", fontSize: "0.85em" }}>
				This token is single-use. Generate a new one for each agent.
			</div>
		</div>
	);
}

function AgentRow({
	agent,
	onRemove,
}: {
	agent: JoinedAgent;
	onRemove: (id: string) => void;
}) {
	const registeredAt = new Date(agent.registered_at * 1000).toLocaleString();

	return (
		<div
			data-testid={`agent-row-${agent.id}`}
			style={{
				display: "flex",
				alignItems: "center",
				gap: "12px",
				padding: "10px 14px",
				background: "#161b22",
				border: "1px solid #30363d",
				borderRadius: "8px",
				marginBottom: "8px",
			}}
		>
			<div
				style={{
					width: "8px",
					height: "8px",
					borderRadius: "50%",
					background: "#3fb950",
					flexShrink: 0,
				}}
			/>
			<div style={{ flex: 1 }}>
				<div style={{ fontWeight: 600, color: "#e6edf3" }}>{agent.label}</div>
				<div style={{ fontSize: "0.8em", color: "#8b949e" }}>
					{agent.address}
				</div>
				<div style={{ fontSize: "0.75em", color: "#6e7681" }}>
					Registered {registeredAt}
				</div>
			</div>
			<button
				type="button"
				data-testid={`remove-agent-${agent.id}`}
				onClick={() => onRemove(agent.id)}
				style={{
					fontSize: "0.8em",
					padding: "4px 10px",
					borderRadius: "4px",
					border: "1px solid #f85149",
					background: "none",
					color: "#f85149",
					cursor: "pointer",
				}}
			>
				Remove
			</button>
		</div>
	);
}

/// Gateway management panel — rendered when running in `--gateway` mode.
export function GatewayPanel() {
	const [agents, setAgents] = useState<JoinedAgent[]>([]);
	const [token, setToken] = useState<string | null>(null);
	const [generating, setGenerating] = useState(false);
	const [error, setError] = useState<string | null>(null);

	useEffect(() => {
		gatewayApi
			.listAgents()
			.then(setAgents)
			.catch(() => setAgents([]));
	}, []);

	const handleAddAgent = useCallback(async () => {
		setGenerating(true);
		setError(null);
		setToken(null);
		try {
			const result = await gatewayApi.generateToken();
			setToken(result.token);
		} catch (e) {
			setError(e instanceof Error ? e.message : String(e));
		} finally {
			setGenerating(false);
		}
	}, []);

	const handleRemoveAgent = useCallback(async (id: string) => {
		try {
			await gatewayApi.removeAgent(id);
			setAgents((prev) => prev.filter((a) => a.id !== id));
		} catch (e) {
			setError(e instanceof Error ? e.message : String(e));
		}
	}, []);

	return (
		<div
			style={{
				minHeight: "100vh",
				background: "#0d1117",
				color: "#e6edf3",
				padding: "32px",
				fontFamily: "-apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif",
			}}
		>
			<div style={{ maxWidth: "720px", margin: "0 auto" }}>
				<h1 style={{ fontSize: "1.5em", fontWeight: 700, marginBottom: "4px" }}>
					Huskies Gateway
				</h1>
				<p style={{ color: "#8b949e", marginBottom: "32px" }}>
					Manage build agents connected to this gateway.
				</p>

				{/* Add Agent */}
				<section style={{ marginBottom: "32px" }}>
					<h2
						style={{
							fontSize: "1.1em",
							fontWeight: 600,
							marginBottom: "12px",
							borderBottom: "1px solid #21262d",
							paddingBottom: "8px",
						}}
					>
						Add Agent
					</h2>
					<button
						type="button"
						data-testid="add-agent-button"
						onClick={handleAddAgent}
						disabled={generating}
						style={{
							padding: "8px 18px",
							borderRadius: "6px",
							border: "1px solid #238636",
							background: generating ? "#1a2f1a" : "#238636",
							color: "#fff",
							cursor: generating ? "not-allowed" : "pointer",
							fontWeight: 600,
							fontSize: "0.9em",
						}}
					>
						{generating ? "Generating…" : "Add Agent"}
					</button>
					{token && <TokenDisplay token={token} />}
				</section>

				{/* Agent list */}
				<section>
					<h2
						style={{
							fontSize: "1.1em",
							fontWeight: 600,
							marginBottom: "12px",
							borderBottom: "1px solid #21262d",
							paddingBottom: "8px",
						}}
					>
						Connected Agents{" "}
						{agents.length > 0 && (
							<span
								style={{
									fontSize: "0.8em",
									color: "#8b949e",
									fontWeight: 400,
								}}
							>
								({agents.length})
							</span>
						)}
					</h2>
					{agents.length === 0 ? (
						<p style={{ color: "#6e7681" }}>
							No agents connected yet. Click "Add Agent" to generate a join
							token.
						</p>
					) : (
						<div>
							{agents.map((agent) => (
								<AgentRow
									key={agent.id}
									agent={agent}
									onRemove={handleRemoveAgent}
								/>
							))}
						</div>
					)}
				</section>

				{error && (
					<div
						style={{
							marginTop: "16px",
							padding: "10px 14px",
							background: "#f8514911",
							border: "1px solid #f85149",
							borderRadius: "6px",
							color: "#f85149",
							fontSize: "0.875em",
						}}
					>
						{error}
					</div>
				)}
			</div>
		</div>
	);
}