import { describe, expect, it, vi, beforeEach } from 'vitest';

vi.mock('$lib/api.server', () => ({ createApiClient: vi.fn() }));

import { load } from './+page.server';
import { createApiClient } from '$lib/api.server';

beforeEach(() => vi.clearAllMocks());

function makeUrl(params: Record<string, string | string[]> = {}) {
	const url = new URL('http://localhost/');
	for (const [key, value] of Object.entries(params)) {
		if (Array.isArray(value)) {
			value.forEach((v) => url.searchParams.append(key, v));
		} else {
			url.searchParams.set(key, value);
		}
	}
	return url;
}

// ─── happy path ───────────────────────────────────────────────────────────────

describe('home page load — happy path', () => {
	it('returns documents and persons on success', async () => {
		vi.mocked(createApiClient).mockReturnValue({
			GET: vi
				.fn()
				.mockResolvedValueOnce({
					response: { ok: true, status: 200 },
					data: [{ id: 'd1', title: 'Brief' }]
				})
				.mockResolvedValueOnce({
					response: { ok: true, status: 200 },
					data: [{ id: 'p1', firstName: 'Hans', lastName: 'Müller' }]
				})
				.mockResolvedValueOnce({ response: { ok: true }, data: { count: 3 } })
		} as ReturnType<typeof createApiClient>);

		const result = await load({ url: makeUrl(), fetch: vi.fn() as unknown as typeof fetch });

		expect(result.documents).toHaveLength(1);
		expect(result.incompleteCount).toBe(3);
		expect(result.error).toBeNull();
	});

	it('passes search params from the URL to the API', async () => {
		const mockGet = vi
			.fn()
			.mockResolvedValueOnce({ response: { ok: true, status: 200 }, data: [] })
			.mockResolvedValueOnce({ response: { ok: true, status: 200 }, data: [] })
			.mockResolvedValueOnce({ response: { ok: true }, data: { count: 0 } });
		vi.mocked(createApiClient).mockReturnValue({
			GET: mockGet
		} as ReturnType<typeof createApiClient>);

		await load({
			url: makeUrl({ q: 'Urlaub', from: '2020-01-01' }),
			fetch: vi.fn() as unknown as typeof fetch
		});

		const firstCall = mockGet.mock.calls[0];
		expect(firstCall[1].params.query.q).toBe('Urlaub');
		expect(firstCall[1].params.query.from).toBe('2020-01-01');
	});

	it('returns incompleteCount 0 when the incomplete-count API fails', async () => {
		vi.mocked(createApiClient).mockReturnValue({
			GET: vi
				.fn()
				.mockResolvedValueOnce({ response: { ok: true, status: 200 }, data: [] })
				.mockResolvedValueOnce({ response: { ok: true, status: 200 }, data: [] })
				.mockResolvedValueOnce({ response: { ok: false }, data: null })
		} as ReturnType<typeof createApiClient>);

		const result = await load({ url: makeUrl(), fetch: vi.fn() as unknown as typeof fetch });

		expect(result.incompleteCount).toBe(0);
	});
});

// ─── 401 redirect ─────────────────────────────────────────────────────────────

describe('home page load — auth redirect', () => {
	it('redirects to /login when documents API returns 401', async () => {
		vi.mocked(createApiClient).mockReturnValue({
			GET: vi
				.fn()
				.mockResolvedValueOnce({ response: { ok: false, status: 401 }, data: null })
				.mockResolvedValueOnce({ response: { ok: true, status: 200 }, data: [] })
				.mockResolvedValueOnce({ response: { ok: true }, data: { count: 0 } })
		} as ReturnType<typeof createApiClient>);

		await expect(
			load({ url: makeUrl(), fetch: vi.fn() as unknown as typeof fetch })
		).rejects.toMatchObject({ location: '/login' });
	});

	it('redirects to /login when persons API returns 401', async () => {
		vi.mocked(createApiClient).mockReturnValue({
			GET: vi
				.fn()
				.mockResolvedValueOnce({ response: { ok: true, status: 200 }, data: [] })
				.mockResolvedValueOnce({ response: { ok: false, status: 401 }, data: null })
				.mockResolvedValueOnce({ response: { ok: true }, data: { count: 0 } })
		} as ReturnType<typeof createApiClient>);

		await expect(
			load({ url: makeUrl(), fetch: vi.fn() as unknown as typeof fetch })
		).rejects.toMatchObject({ location: '/login' });
	});
});

// ─── network error fallback ───────────────────────────────────────────────────

describe('home page load — network error fallback', () => {
	it('returns error string instead of throwing when API call throws', async () => {
		vi.mocked(createApiClient).mockReturnValue({
			GET: vi.fn().mockRejectedValue(new Error('Network failure'))
		} as ReturnType<typeof createApiClient>);

		const result = await load({ url: makeUrl(), fetch: vi.fn() as unknown as typeof fetch });

		expect(result.error).toBe('Daten konnten nicht geladen werden.');
		expect(result.documents).toEqual([]);
		expect(result.incompleteCount).toBe(0);
	});
});