import { describe, it, expect } from 'vitest';
import { extractCalendarId, getCalendarSubscribeUrl } from './google-calendar';

describe('extractCalendarId', () => {
	it('returns null for empty input', () => {
		expect(extractCalendarId('')).toBeNull();
	});

	it('returns email-style calendar ID as-is', () => {
		expect(extractCalendarId('user@gmail.com')).toBe('user@gmail.com');
	});

	it('trims whitespace from email-style IDs', () => {
		expect(extractCalendarId('  user@gmail.com  ')).toBe('user@gmail.com');
	});

	it('returns group calendar ID as-is', () => {
		const id = 'abc123@group.calendar.google.com';
		expect(extractCalendarId(id)).toBe(id);
	});

	it('extracts calendar ID from cid parameter (base64)', () => {
		const calId = 'user@gmail.com';
		const encoded = btoa(calId);
		const url = `https://calendar.google.com/calendar/u/0?cid=${encoded}`;
		expect(extractCalendarId(url)).toBe(calId);
	});

	it('extracts calendar ID from src parameter', () => {
		const url = 'https://calendar.google.com/calendar/embed?src=user@gmail.com';
		expect(extractCalendarId(url)).toBe('user@gmail.com');
	});

	it('extracts calendar ID from ical path', () => {
		const url = 'https://calendar.google.com/calendar/ical/user%40gmail.com/public/basic.ics';
		expect(extractCalendarId(url)).toBe('user@gmail.com');
	});

	it('returns null for non-URL non-email input', () => {
		expect(extractCalendarId('random-string')).toBeNull();
	});

	it('handles URL without recognized parameters', () => {
		expect(extractCalendarId('https://example.com/page')).toBeNull();
	});
});

describe('getCalendarSubscribeUrl', () => {
	it('generates a subscribe URL with base64-encoded calendar ID', () => {
		const calId = 'user@gmail.com';
		const url = getCalendarSubscribeUrl(calId);
		expect(url).toContain('https://calendar.google.com/calendar/u/0?cid=');
		expect(url).toContain(btoa(calId));
	});

	it('roundtrips with extractCalendarId', () => {
		const calId = 'test@group.calendar.google.com';
		const url = getCalendarSubscribeUrl(calId);
		expect(extractCalendarId(url)).toBe(calId);
	});
});