import { afterEach, describe, expect, it, vi } from 'vitest';
import { cleanup, render } from 'vitest-browser-svelte';
import { page } from 'vitest/browser';
import Page from './+page.svelte';

const tick = () => new Promise((r) => setTimeout(r, 0));

vi.mock('$app/navigation', () => ({ goto: vi.fn() }));

// Silence fetch calls from PersonTypeahead when advanced filters are open
vi.stubGlobal(
	'fetch',
	vi.fn().mockResolvedValue({ ok: true, json: vi.fn().mockResolvedValue([]) })
);

afterEach(cleanup);

// ─── Test data ────────────────────────────────────────────────────────────────

const emptyData = {
	user: undefined,
	canWrite: true,
	canAnnotate: false,
	filters: { q: '', from: '', to: '', senderId: '', receiverId: '', tags: [] },
	documents: [],
	initialValues: { senderName: '', receiverName: '' },
	error: null
};

const makeDoc = (overrides = {}) => ({
	id: '1',
	title: 'Testbrief',
	originalFilename: 'testbrief.pdf',
	status: 'UPLOADED' as const,
	documentDate: '2024-03-15',
	location: 'Berlin',
	sender: { id: 'p1', firstName: 'Max', lastName: 'Mustermann' },
	receivers: [{ id: 'p2', firstName: 'Anna', lastName: 'Musterfrau' }],
	tags: [{ id: 't1', name: 'Familie' }],
	filePath: '/files/testbrief.pdf',
	createdAt: '2024-03-15T10:00:00Z',
	updatedAt: '2024-03-15T10:00:00Z',
	...overrides
});

const dataWithDocs = { ...emptyData, documents: [makeDoc()] };

// ─── Search bar ───────────────────────────────────────────────────────────────

describe('Home page – search bar', () => {
	it('renders the full-text search input', async () => {
		render(Page, { data: emptyData });
		await expect
			.element(page.getByPlaceholder('Suche in Titel, Inhalt, Ort...'))
			.toBeInTheDocument();
		await page.screenshot({ path: 'test-results/screenshots/home-default.png' });
	});

	it('renders the filter toggle button', async () => {
		render(Page, { data: emptyData });
		// Use exact match to avoid collision with the empty-state "Alle Filter löschen" button
		await expect
			.element(page.getByRole('button', { name: 'Filter', exact: true }))
			.toBeInTheDocument();
	});

	it('renders the reset link pointing to /', async () => {
		render(Page, { data: emptyData });
		const resetLink = page.getByTitle('Filter zurücksetzen');
		await expect.element(resetLink).toBeInTheDocument();
		await expect.element(resetLink).toHaveAttribute('href', '/');
	});

	it('pre-fills the search input from filters.q', async () => {
		render(Page, { data: { ...emptyData, filters: { ...emptyData.filters, q: 'Urlaub' } } });
		await expect
			.element(page.getByPlaceholder('Suche in Titel, Inhalt, Ort...'))
			.toHaveValue('Urlaub');
	});
});

// ─── Advanced filters ─────────────────────────────────────────────────────────

describe('Home page – advanced filters', () => {
	it('hides the advanced filters by default', async () => {
		render(Page, { data: emptyData });
		// Date inputs are inside the {#if showAdvanced} block → not in DOM
		await tick();
		expect(document.querySelector('input[id="from"]')).toBeNull();
		expect(document.querySelector('input[id="to"]')).toBeNull();
	});

	it('toggles the advanced filter panel open on button click', async () => {
		render(Page, { data: emptyData });
		await page.getByRole('button', { name: 'Filter', exact: true }).click();
		await tick();
		expect(document.querySelector('input[id="from"]')).not.toBeNull();
		expect(document.querySelector('input[id="to"]')).not.toBeNull();
		await page.screenshot({ path: 'test-results/screenshots/home-filters-open.png' });
	});

	it('collapses the advanced filter panel on second click', async () => {
		render(Page, { data: emptyData });
		const btn = page.getByRole('button', { name: 'Filter', exact: true });
		await btn.click();
		// Wait for the input to appear before clicking again
		await expect.element(page.getByText('Schlagworte')).toBeInTheDocument();
		await btn.click();
		// Wait for slide transition to finish
		await expect.element(page.getByText('Schlagworte')).not.toBeInTheDocument();
	});

	it('renders the tag filter section when filters are open', async () => {
		render(Page, { data: emptyData });
		await page.getByRole('button', { name: 'Filter', exact: true }).click();
		await expect.element(page.getByText('Schlagworte')).toBeInTheDocument();
	});
});

// ─── Document list ────────────────────────────────────────────────────────────

describe('Home page – document list', () => {
	it('shows empty state when there are no documents', async () => {
		render(Page, { data: emptyData });
		await expect.element(page.getByText('Keine Dokumente gefunden')).toBeInTheDocument();
		await page.screenshot({ path: 'test-results/screenshots/home-empty-state.png' });
	});

	it('renders a document with title, date, location, sender and receiver', async () => {
		render(Page, { data: dataWithDocs });
		await expect.element(page.getByText('Testbrief')).toBeInTheDocument();
		await expect.element(page.getByText('15. März 2024')).toBeInTheDocument();
		await expect.element(page.getByText('Berlin')).toBeInTheDocument();
		await expect.element(page.getByText('Max Mustermann')).toBeInTheDocument();
		await expect.element(page.getByText('Anna Musterfrau')).toBeInTheDocument();
		await page.screenshot({ path: 'test-results/screenshots/home-with-documents.png' });
	});

	it('renders a tag chip for each document tag', async () => {
		render(Page, { data: dataWithDocs });
		await expect.element(page.getByRole('button', { name: 'Familie' })).toBeInTheDocument();
	});

	it('renders "Unbekannt" for sender when sender is null', async () => {
		const data = { ...emptyData, documents: [makeDoc({ sender: null })] };
		render(Page, { data });
		await expect.element(page.getByText('Unbekannt')).toBeInTheDocument();
	});

	it('renders original filename when title is empty', async () => {
		const data = { ...emptyData, documents: [makeDoc({ title: null })] };
		render(Page, { data });
		await expect.element(page.getByText('testbrief.pdf')).toBeInTheDocument();
	});

	it('links each document to its detail page', async () => {
		render(Page, { data: dataWithDocs });
		const link = page.getByRole('link', { name: /Testbrief/ });
		await expect.element(link).toHaveAttribute('href', '/documents/1');
	});

	it('renders the "Neues Dokument" link', async () => {
		render(Page, { data: emptyData });
		const link = page.getByRole('link', { name: /Neues Dokument/i });
		await expect.element(link).toBeInTheDocument();
		await expect.element(link).toHaveAttribute('href', '/documents/new');
	});
});

// ─── Keystroke preservation (issue #34) ──────────────────────────────────────

describe('Home page – search input keystroke preservation', () => {
	it('does not overwrite the search input while the user is focused and stale data arrives', async () => {
		const { rerender } = render(Page, { data: emptyData });

		const input = page.getByPlaceholder('Suche in Titel, Inhalt, Ort...');

		// User types "abc" — input is focused
		await input.click();
		await input.fill('abc');

		// Simulate a navigation completing with stale data (q='a') while the user is still typing
		await rerender({ data: { ...emptyData, filters: { ...emptyData.filters, q: 'a' } } });
		await tick();

		// Input must still show what the user typed, not the stale URL value
		await expect.element(input).toHaveValue('abc');
	});
});

// ─── Error state ──────────────────────────────────────────────────────────────

describe('Home page – error state', () => {
	it('shows the error message when data.error is set', async () => {
		const data = { ...emptyData, error: 'Daten konnten nicht geladen werden.' };
		render(Page, { data });
		await expect.element(page.getByText('Daten konnten nicht geladen werden.')).toBeInTheDocument();
		await page.screenshot({ path: 'test-results/screenshots/home-error.png' });
	});
});