import { OAuthUserAgent, getSession, deleteStoredSession, listStoredSessions } from '@atcute/oauth-browser-client';
import type { Session } from '@atcute/oauth-browser-client';
import { getHandleFromDid } from './atproto.js';

export interface AuthState {
	agent: OAuthUserAgent | null;
	did: string | null;
	handle: string | null;
	pds: string | null;
	loading: boolean;
	error: string | null;
}

function createAuth() {
	let state = $state<AuthState>({
		agent: null,
		did: null,
		handle: null,
		pds: null,
		loading: false,
		error: null
	});

	return {
		get agent() { return state.agent; },
		get did() { return state.did; },
		get handle() { return state.handle; },
		get pds() { return state.pds; },
		get loading() { return state.loading; },
		get error() { return state.error; },
		get isLoggedIn() { return state.agent !== null; },

		async tryRestoreSession() {
			state.loading = true;
			state.error = null;
			try {
				const sessions = listStoredSessions();
				if (sessions.length > 0) {
					const did = sessions[0];
					const session = await getSession(did, { allowStale: true });
					const agent = new OAuthUserAgent(session);
					state.agent = agent;
					state.did = session.info.sub;
					state.pds = session.info.aud;
					// Resolve handle in the background — don't block session restore
					getHandleFromDid(session.info.sub).then((h) => {
						if (h) state.handle = h;
					}).catch(() => {});
				}
			} catch (_) {
				state.agent = null;
				state.did = null;
				state.handle = null;
				state.pds = null;
			} finally {
				state.loading = false;
			}
		},

		setFromSession(session: Session) {
			const agent = new OAuthUserAgent(session);
			state.agent = agent;
			state.did = session.info.sub;
			state.pds = session.info.aud;
		},

		setHandle(handle: string) {
			state.handle = handle;
		},

		async signOut() {
			if (state.agent) {
				try {
					await state.agent.signOut();
				} catch (_) {}
			}
			if (state.did) {
				try {
					deleteStoredSession(state.did as `did:${string}:${string}`);
				} catch (_) {}
			}
			state.agent = null;
			state.did = null;
			state.handle = null;
			state.pds = null;
		}
	};
}

export const auth = createAuth();