import type { Config } from './config.ts';
import { SchulcloudClient } from './core/client.ts';
import type { SessionKeepalive } from './core/keepalive.ts';
import { FileManager } from './core/legacy-files.ts';
import { SessionToken } from './core/session-token.ts';
import { UntisClient } from './core/untis.ts';
import { Indexer } from './indexer/indexer.ts';
import { Store } from './store/store.ts';

/**
 * Process-wide singletons.
 *
 * The store and indexer are shared across MCP sessions — one index, one crawl
 * at a time — whereas each session gets its own `ServerContext`. Both are
 * optional: without `DATABASE_URL` the server runs in live-only mode, and
 * every feature that needs the index says so rather than failing.
 */
export interface Services {
	config: Config;
	client: SchulcloudClient;
	/**
	 * The "Dateien" file manager. Process-wide so its short listing cache is
	 * shared: an `ls` in one MCP session and a `schulcloud fs get` from the CLI
	 * then cost one page fetch between them, not two.
	 */
	files: FileManager;
	store: Store | undefined;
	indexer: Indexer | undefined;
	/** The Schulcloud token, which `/api/token` can replace without a restart. */
	session: SessionToken;
	/**
	 * WebUntis, when configured. Process-wide so its master data — 140 subjects,
	 * 216 teachers, every holiday of the school year — is fetched once rather
	 * than per MCP session.
	 */
	untis: UntisClient | undefined;
	/**
	 * Set by the entry point that runs one, for status reports. Created there
	 * rather than here because each entry point logs to a different stream.
	 */
	keepalive?: SessionKeepalive;
}

export async function createServices(config: Config): Promise<Services> {
	const client = new SchulcloudClient(config);
	// Before anything else reads config.jwt: a token replaced at runtime and
	// saved may be newer than the one in the environment.
	const session = new SessionToken(config, client, config.stateDir);
	await session.load();

	const files = new FileManager(client);
	const store = await Store.open(config.databaseUrl);
	const untis = config.untis ? new UntisClient(config.untis, config.requestTimeoutMs) : undefined;
	// The indexer gets the same client, so the class register is read with the
	// master data the untis_* tools have already paid for.
	const indexer = store ? new Indexer(client, store, config, { untis }) : undefined;

	if (!store) {
		console.warn(
			'[schulcloud-mcp] no index: search will crawl live on every call, and ' +
				'/files, /manifest and refresh_index are unavailable. Set DATABASE_URL to enable them.',
		);
	}
	return { config, client, files, store, indexer, session, untis };
}

export async function closeServices(services: Services): Promise<void> {
	await services.store?.close();
}