import { writable } from 'svelte/store';
import { api, type MeResponse } from './api';

interface SessionState {
	loading: boolean;
	me: MeResponse | null;
	error: string | null;
}

export const session = writable<SessionState>({
	loading: true,
	me: null,
	error: null,
});

export async function loadSession(): Promise<void> {
	session.update((s) => ({ ...s, loading: true, error: null }));
	try {
		const me = await api.me();
		session.set({ loading: false, me, error: null });
	} catch (err) {
		const status = (err as { status?: number }).status;
		if (status === 401) {
			redirectToLogin();
			return;
		}
		session.set({
			loading: false,
			me: null,
			error: err instanceof Error ? err.message : String(err),
		});
	}
}

/**
 * Resolve org slug for org-scoped Feishu OAuth (`GET /auth/feishu/:orgSlug`).
 * Unscoped `/auth/feishu` is disabled unless allowLegacyFeishuOAuth is on.
 * Path no longer carries tenancy: prefer hostname silo slug, then ?org=.
 */
export function resolveLoginOrgSlug(): string | null {
	const q = new URLSearchParams(window.location.search).get('org');
	if (q && q.trim() !== '') return q.trim();

	// Alpha Silo public host: <slug>.educraft.paradigm-edu.net (or educraft-dev)
	const host = window.location.hostname.toLowerCase();
	const m = host.match(/^([a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?)\.educraft(?:-dev)?\./);
	if (m?.[1]) return m[1];

	// Legacy path while old bookmarks still land briefly before redirect.
	const path = window.location.pathname.split('/').filter(Boolean);
	if (path[0] === 'admin' && path[1] === 'org' && path[2]) {
		return decodeURIComponent(path[2]);
	}
	return null;
}

export function redirectToLogin(): void {
	if (window.location.pathname === '/admin/login') return;
	const ret = encodeURIComponent(
		window.location.pathname + window.location.search + window.location.hash,
	);
	const slug = resolveLoginOrgSlug();
	if (slug === null) {
		// Need an org slug for scoped OAuth — backend login helper can prompt.
		window.location.href = `/admin/login?returnTo=${ret}`;
		return;
	}
	window.location.href = `/auth/feishu/${encodeURIComponent(slug)}?returnTo=${ret}`;
}

export async function logout(): Promise<void> {
	await api.logout();
	redirectToLogin();
}