import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
import { resolveToken } from "../auth/token.js";
import type { ExtensionState } from "../state.js";
import { TickTickMcpClient } from "./client.js";
import { toTickTickAuthError } from "./errors.js";
import { registerMcpTools } from "./register-tools.js";

type ConnectUi = {
	setStatus: (key: string, value: string) => void;
	notify?: (message: string, level: "info" | "warning" | "error") => void;
};

let mcpClient: TickTickMcpClient | null = null;
let connectPromise: Promise<TickTickMcpClient | null> | null = null;

export function getMcpClient(): TickTickMcpClient | null {
	return mcpClient;
}

export async function closeMcpClient(): Promise<void> {
	await mcpClient?.close();
	mcpClient = null;
	connectPromise = null;
}

export async function ensureMcpConnected(
	pi: ExtensionAPI,
	state: ExtensionState,
	ui: ConnectUi,
): Promise<TickTickMcpClient | null> {
	if (mcpClient?.isConnected()) {
		return mcpClient;
	}

	if (connectPromise) {
		return connectPromise;
	}

	connectPromise = connectInternal(pi, state, ui);
	try {
		return await connectPromise;
	} finally {
		connectPromise = null;
	}
}

async function connectInternal(
	pi: ExtensionAPI,
	state: ExtensionState,
	ui: ConnectUi,
): Promise<TickTickMcpClient | null> {
	const token = await resolveToken();
	if (!token) {
		ui.setStatus("ticktick", "not configured");
		return null;
	}

	state.lastError = null;
	ui.setStatus("ticktick", "connecting…");

	try {
		await mcpClient?.close();
		mcpClient = new TickTickMcpClient(token);
		await mcpClient.connect();

		if (!state.toolsRegistered) {
			state.toolCount = registerMcpTools(pi, mcpClient, () =>
				ensureMcpConnected(pi, state, ui),
			);
			state.toolsRegistered = true;
		}

		state.connected = true;
		ui.setStatus("ticktick", `connected (${state.toolCount} tools)`);
		return mcpClient;
	} catch (error) {
		const normalized = toTickTickAuthError(error);
		const message = normalized.message;
		state.lastError = message;
		state.connected = false;
		ui.setStatus("ticktick", "error");
		ui.notify?.(`TickTick MCP connect failed: ${message}`, "error");
		await mcpClient?.close();
		mcpClient = null;
		return null;
	}
}