import { Client, ok, simpleFetchHandler } from '@atcute/client';
import { AppBskyActorDefs } from '@atcute/bluesky';
import {
	configureOAuth,
	createAuthorizationUrl,
	finalizeAuthorization,
	getSession,
	listStoredSessions,
	OAuthUserAgent,
	type Session
} from '@atcute/oauth-browser-client';
import {
	CompositeDidDocumentResolver,
	LocalActorResolver,
	PlcDidDocumentResolver,
	WebDidDocumentResolver,
	XrpcHandleResolver
} from '@atcute/identity-resolver';

configureOAuth({
	metadata: {
		client_id: import.meta.env.VITE_OAUTH_CLIENT_ID,
		redirect_uri: import.meta.env.VITE_OAUTH_REDIRECT_URI
	},
	identityResolver: new LocalActorResolver({
		handleResolver: new XrpcHandleResolver({
			serviceUrl: 'https://public.api.bsky.app'
		}),
		didDocumentResolver: new CompositeDidDocumentResolver({
			methods: {
				plc: new PlcDidDocumentResolver(),
				web: new WebDidDocumentResolver()
			}
		})
	})
});

/** Public (unauthenticated) RPC client — always available */
export const publicClient = new Client({
	handler: simpleFetchHandler({ service: 'https://public.api.bsky.app' })
});

/** Authenticated RPC client — set after login, null otherwise */
export let rpc: Client | null = null;

/** Current OAuth session */
let currentSession: Session | null = null;

export async function getClient(): Promise<Client> {
	if (rpc === null) {
		await resumeSession();
	}
	return rpc ?? publicClient;
}

/** Try to resume an existing session from localStorage */
export async function resumeSession(): Promise<boolean> {
	const dids = listStoredSessions();
	if (dids.length === 0) return false;

	try {
		const session = await getSession(dids[0], { allowStale: true });
		setSession(session);
		return true;
	} catch {
		return false;
	}
}

/** Handle the OAuth callback — call this from the callback route */
export async function handleCallback(params: URLSearchParams): Promise<void> {
	const { session } = await finalizeAuthorization(params);
	setSession(session);
}

/** Start the login flow */
export async function login(handle: string): Promise<void> {
	const authUrl = await createAuthorizationUrl({
		target: { type: 'account', identifier: handle },
		scope: import.meta.env.VITE_OAUTH_SCOPE
	});
	await new Promise((r) => setTimeout(r, 200));
	window.location.assign(authUrl);
}

/** Check if a session is active */
export function isLoggedIn(): boolean {
	return rpc !== null;
}

/** Fetch the logged-in user's profile */
export async function getProfile(): Promise<AppBskyActorDefs.ProfileViewDetailed | null> {
	if (!rpc || !currentSession) return null;
	const data = await ok(rpc.get('app.bsky.actor.getProfile', {
		params: { actor: currentSession.info.sub }
	}));
	return data;
}

function setSession(session: Session): void {
	currentSession = session;
	const agent = new OAuthUserAgent(session);
	rpc = new Client({ handler: agent });
}