import { describe, it, expect } from 'vitest';
import { makeInitialReviewRows } from '../src/lib/reviews.ts';

describe('makeInitialReviewRows', () => {
	it('creates one row per subIndex', () => {
		const now = new Date('2025-01-01T00:00:00Z');
		const rows = makeInitialReviewRows({
			userId: 'u-1',
			cardId: 'c-1',
			subIndices: [0, 1, 2],
			now,
		});
		expect(rows).toHaveLength(3);
		expect(rows[0].subIndex).toBe(0);
		expect(rows[1].subIndex).toBe(1);
		expect(rows[2].subIndex).toBe(2);
	});

	it('sets correct userId and cardId on each row', () => {
		const now = new Date();
		const rows = makeInitialReviewRows({
			userId: 'u-test',
			cardId: 'c-test',
			subIndices: [0],
			now,
		});
		expect(rows[0].userId).toBe('u-test');
		expect(rows[0].cardId).toBe('c-test');
	});

	it('returns empty array for empty subIndices', () => {
		const rows = makeInitialReviewRows({
			userId: 'u-1',
			cardId: 'c-1',
			subIndices: [],
			now: new Date(),
		});
		expect(rows).toHaveLength(0);
	});

	it('initial state has reps=0 and lapses=0', () => {
		const rows = makeInitialReviewRows({
			userId: 'u-1',
			cardId: 'c-1',
			subIndices: [0],
			now: new Date(),
		});
		expect(rows[0].reps).toBe(0);
		expect(rows[0].lapses).toBe(0);
	});

	it('due date is a Date instance', () => {
		const now = new Date();
		const rows = makeInitialReviewRows({
			userId: 'u-1',
			cardId: 'c-1',
			subIndices: [0],
			now,
		});
		expect(rows[0].due).toBeInstanceOf(Date);
	});
});