import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
import { CapsBlinkClient, defaultConnect } from "../src/client.ts";
import { checkPlatformSupport } from "../src/platform.ts";
import { resolveRuntimePaths } from "../src/runtime-paths.ts";
import {
	packageRootFrom,
	resolveDaemonScriptPath,
	spawnDaemon,
} from "../src/spawn.ts";

/**
 * Blink the built-in Caps Lock LED while this Pi session has an active agent.
 * Machine-wide coordination is via a shared Swift daemon lease socket.
 */
export default function capsBlinkExtension(pi: ExtensionAPI): void {
	const support = checkPlatformSupport();
	let client: CapsBlinkClient | null = null;
	let unsupportedWarned = false;

	const warn = (message: string): void => {
		console.warn(message);
	};

	pi.on("session_start", (_event, ctx) => {
		client?.dispose();
		client = null;

		if (!support.ok) {
			if (!unsupportedWarned) {
				unsupportedWarned = true;
				warn(`pi-caps-blink: disabled — ${support.reason}`);
			}
			return;
		}

		try {
			const paths = resolveRuntimePaths();
			const packageRoot = packageRootFrom(import.meta.url);
			client = new CapsBlinkClient({
				socketPath: paths.socketPath,
				runtimeDir: paths.runtimeDir,
				scriptPath: resolveDaemonScriptPath(packageRoot),
				connect: defaultConnect,
				spawnDaemon,
				setTimeout: (fn, ms) => setTimeout(fn, ms),
				clearTimeout: (id) => clearTimeout(id as NodeJS.Timeout),
				random: Math.random,
				now: () => Date.now(),
				warn,
			});
		} catch (err) {
			if (!unsupportedWarned) {
				unsupportedWarned = true;
				const detail = err instanceof Error ? err.message : String(err);
				warn(`pi-caps-blink: disabled — ${detail}`);
			}
			return;
		}

		if (!ctx.isIdle()) {
			client.setDesiredBusy(true);
		}
	});

	pi.on("agent_start", () => {
		client?.setDesiredBusy(true);
	});

	pi.on("agent_settled", (_event, ctx) => {
		if (ctx.isIdle()) {
			client?.setDesiredBusy(false);
		}
	});

	pi.on("session_shutdown", () => {
		client?.setDesiredBusy(false);
		client?.dispose();
		client = null;
	});
}