import { Client, GatewayIntentBits, Events } from 'discord.js';
import { getConfig } from './config.js';
import { BotNotReadyError, ConfigurationError } from '../utils/errors.js';
let clientInstance: Client | null = null;
let readyPromise: Promise<Client> | null = null;
let isInitializing = false;
/**
* Gets the Discord client singleton instance.
* Creates and logs in the client on first call, reuses the instance on subsequent calls.
*
* @returns Promise<Client> - The authenticated Discord client
* @throws {ConfigurationError} If bot token is missing or invalid
* @throws {BotNotReadyError} If bot fails to connect
*/
export async function getDiscordClient(): Promise<Client> {
// If client is ready, return immediately
if (clientInstance?.isReady()) {
return clientInstance;
}
// If already initializing, wait for the existing initialization
if (isInitializing && readyPromise) {
return readyPromise;
}
// Start new initialization
if (!clientInstance) {
isInitializing = true;
try {
// Create Discord client with required intents
clientInstance = new Client({
intents: [
GatewayIntentBits.Guilds, // Required for guild operations (channels, roles)
GatewayIntentBits.GuildMembers, // Required for role management
],
});
// Set up ready promise
readyPromise = new Promise<Client>((resolve, reject) => {
const timeout = setTimeout(() => {
reject(new BotNotReadyError('Bot connection timeout after 30 seconds'));
}, 30000);
clientInstance!.once(Events.ClientReady, (client) => {
clearTimeout(timeout);
console.error(`Discord bot ready as ${client.user.tag}`);
resolve(client);
});
clientInstance!.once(Events.Error, (error) => {
clearTimeout(timeout);
reject(new BotNotReadyError(`Bot connection failed: ${error.message}`));
});
});
// Get token from config
const config = getConfig();
if (!config.discordToken) {
throw new ConfigurationError('Discord bot token is required');
}
// Login to Discord
await clientInstance.login(config.discordToken);
// Wait for ready event
await readyPromise;
isInitializing = false;
return clientInstance;
} catch (error) {
// Clean up on error
isInitializing = false;
if (clientInstance) {
clientInstance.destroy();
clientInstance = null;
}
readyPromise = null;
if (error instanceof Error) {
if (error.message.includes('TOKEN_INVALID') || error.message.includes('Incorrect login')) {
throw new ConfigurationError('Invalid Discord bot token. Please check your DISCORD_BOT_TOKEN.');
}
}
throw error;
}
}
// Wait for existing client to be ready
if (readyPromise) {
return readyPromise;
}
throw new BotNotReadyError('Discord bot is not ready');
}
/**
* Closes the Discord client connection and cleans up resources.
* Should be called on MCP server shutdown.
*/
export async function closeDiscordClient(): Promise<void> {
if (clientInstance) {
console.error('Closing Discord client...');
clientInstance.destroy();
clientInstance = null;
readyPromise = null;
isInitializing = false;
}
}
/**
* Checks if the Discord client is currently ready and connected.
*
* @returns boolean - True if client is ready, false otherwise
*/
export function isClientReady(): boolean {
return clientInstance?.isReady() ?? false;
}
