import { expect, test, type Download, type Locator, type Page } from '@playwright/test';
import { PDFDocument, StandardFonts, rgb } from 'pdf-lib';
import { zipSync } from 'fflate';
import { readFile } from 'node:fs/promises';

const createPdf = async (pageCount: number, label: string) => {
	const document = await PDFDocument.create();
	const font = await document.embedFont(StandardFonts.Helvetica);
	for (let pageNumber = 1; pageNumber <= pageCount; pageNumber += 1) {
		const page = document.addPage([420, 594]);
		page.drawText(`${label} – Seite ${pageNumber}`, {
			x: 40,
			y: 520,
			size: 20,
			font,
			color: rgb(0.1, 0.2, 0.4)
		});
	}
	return Buffer.from(await document.save());
};

const dropFiles = async (
	page: Page,
	target: Locator | 'window',
	files: Array<{ name: string; mimeType: string; buffer: Buffer }>
) => {
	await page.locator('[data-dropzone-ready="true"]').first().waitFor();
	const dataTransfer = await page.evaluateHandle(
		(droppedFiles) => {
			const transfer = new DataTransfer();
			for (const droppedFile of droppedFiles) {
				const bytes = Uint8Array.from(atob(droppedFile.base64), (character) =>
					character.charCodeAt(0)
				);
				transfer.items.add(
					new File([bytes], droppedFile.name, {
						type: droppedFile.mimeType,
						lastModified: Date.now()
					})
				);
			}
			return transfer;
		},
		files.map((file) => ({
			name: file.name,
			mimeType: file.mimeType,
			base64: file.buffer.toString('base64')
		}))
	);

	if (target === 'window') {
		await page.evaluate((transfer) => {
			window.dispatchEvent(
				new DragEvent('drop', { dataTransfer: transfer, bubbles: true, cancelable: true })
			);
		}, dataTransfer);
	} else {
		await target.dispatchEvent('drop', { dataTransfer });
	}
	await dataTransfer.dispose();
};

const expectPdfDownload = async (download: Download, name: RegExp) => {
	expect(download.suggestedFilename()).toMatch(name);
	const path = await download.path();
	expect(path).not.toBeNull();
	const bytes = await readFile(path!);
	expect(bytes.subarray(0, 5).toString()).toBe('%PDF-');
	return bytes;
};

const trackPageErrors = (page: Page) => {
	const errors: Error[] = [];
	page.on('pageerror', (error) => errors.push(error));
	return errors;
};

const pdfDropzone = (page: Page) => page.getByRole('button', { name: 'PDF-Dateien hinzufügen' });

test('start page exposes only working tools and forwards a dropped ZIP to beA', async ({
	page
}) => {
	const pageErrors = trackPageErrors(page);
	const pdf = await createPdf(1, 'beA');
	const zip = Buffer.from(zipSync({ 'anlage.pdf': pdf }));

	await page.goto('/');
	await expect(page.getByRole('heading', { name: 'PDF-Werkzeuge' })).toBeVisible();
	await expect(page.getByRole('link', { name: /Signieren/ })).toHaveCount(0);

	await dropFiles(page, 'window', [
		{ name: 'bea-archiv.zip', mimeType: 'application/zip', buffer: zip }
	]);

	await expect(page).toHaveURL(/\/tools\/bea$/);
	await expect(page.getByText('1 lose Datei')).toBeVisible({ timeout: 15_000 });
	expect(pageErrors).toEqual([]);
});

test('short tool pages keep the footer flush with the viewport bottom', async ({ page }) => {
	const expectFooterAtViewportBottom = async (viewport: { width: number; height: number }) => {
		await page.setViewportSize(viewport);
		await page.goto('/tools/watermark');

		const footerBottom = await page.locator('footer').evaluate((footer) => {
			return footer.getBoundingClientRect().bottom;
		});

		expect(Math.abs(footerBottom - viewport.height)).toBeLessThanOrEqual(1);
	};

	await expectFooterAtViewportBottom({ width: 1440, height: 900 });
	await expectFooterAtViewportBottom({ width: 390, height: 844 });
});

test('merge accepts dropped PDFs and downloads a merged PDF', async ({ page }) => {
	const pageErrors = trackPageErrors(page);
	await page.goto('/tools/merge');
	await dropFiles(page, pdfDropzone(page), [
		{ name: 'eins.pdf', mimeType: 'application/pdf', buffer: await createPdf(1, 'Eins') },
		{ name: 'zwei.pdf', mimeType: 'application/pdf', buffer: await createPdf(2, 'Zwei') }
	]);

	await expect(page.getByText('2 Dateien ausgewählt')).toBeVisible();
	const downloadPromise = page.waitForEvent('download');
	await page.getByRole('button', { name: 'PDFs zusammenfügen' }).click();
	await expectPdfDownload(await downloadPromise, /^zusammengefuegt\.pdf$/);
	expect(pageErrors).toEqual([]);
});

test('separate renders dropped PDF pages and removes a selected page', async ({ page }) => {
	const pageErrors = trackPageErrors(page);
	await page.goto('/tools/separate');
	await dropFiles(page, pdfDropzone(page), [
		{ name: 'seiten.pdf', mimeType: 'application/pdf', buffer: await createPdf(3, 'Trennen') }
	]);

	await expect(page.getByRole('button', { name: /Seite 1/ })).toBeVisible({ timeout: 15_000 });
	await page.getByRole('button', { name: /Seite 2/ }).click();
	const downloadPromise = page.waitForEvent('download');
	await page.getByRole('button', { name: 'Seiten entfernen & herunterladen' }).click();
	await expectPdfDownload(await downloadPromise, /^seiten_ohne_seiten\.pdf$/);
	expect(pageErrors).toEqual([]);
});

test('watermark accepts numeric controls and downloads text and image watermarks', async ({
	page
}) => {
	const pageErrors = trackPageErrors(page);
	await page.goto('/tools/watermark');
	await dropFiles(page, pdfDropzone(page), [
		{ name: 'marke.pdf', mimeType: 'application/pdf', buffer: await createPdf(1, 'Marke') }
	]);

	await expect(page.getByRole('heading', { name: 'Wasserzeichen-Einstellungen' })).toBeVisible({
		timeout: 15_000
	});
	await page.locator('#watermark-color').fill('#00ff00');
	await page.locator('#watermark-opacity').fill('0.45');
	const downloadPromise = page.waitForEvent('download');
	await page.getByRole('button', { name: 'Wasserzeichen anwenden & herunterladen' }).click();
	await expectPdfDownload(await downloadPromise, /^marke_wasserzeichen\.pdf$/);

	await page.getByLabel('Bild', { exact: true }).check();
	await dropFiles(page, page.getByRole('button', { name: 'Wasserzeichenbild hinzufügen' }), [
		{
			name: 'logo.png',
			mimeType: 'image/png',
			buffer: Buffer.from(
				'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAusB9Y9Z5rAAAAAASUVORK5CYII=',
				'base64'
			)
		}
	]);
	const imageDownloadPromise = page.waitForEvent('download');
	await page.getByRole('button', { name: 'Wasserzeichen anwenden & herunterladen' }).click();
	await expectPdfDownload(await imageDownloadPromise, /^marke_wasserzeichen\.pdf$/);

	await expect(page.getByText('Fehler beim Anwenden')).toHaveCount(0);
	expect(pageErrors).toEqual([]);
});

test('encrypt creates a protected PDF and decrypt rebuilds it with the password', async ({
	page
}) => {
	const pageErrors = trackPageErrors(page);
	await page.goto('/tools/encrypt');
	await dropFiles(page, pdfDropzone(page), [
		{ name: 'geheim.pdf', mimeType: 'application/pdf', buffer: await createPdf(1, 'Geheim') }
	]);

	await page.locator('#encrypt-password').fill('test-passwort');
	await page.locator('#encrypt-password-confirmation').fill('test-passwort');
	const encryptedDownloadPromise = page.waitForEvent('download');
	await page.getByRole('button', { name: 'Passwort setzen & herunterladen' }).click();
	const encryptedDownload = await encryptedDownloadPromise;
	const encryptedBytes = await expectPdfDownload(encryptedDownload, /^geheim_geschuetzt\.pdf$/);

	await page.goto('/tools/decrypt');
	await dropFiles(page, pdfDropzone(page), [
		{
			name: 'geheim_geschuetzt.pdf',
			mimeType: 'application/pdf',
			buffer: encryptedBytes
		}
	]);
	await page.locator('#decrypt-password').fill('test-passwort');
	const decryptedDownloadPromise = page.waitForEvent('download');
	await page.getByRole('button', { name: 'Passwort entfernen & herunterladen' }).click();
	await expectPdfDownload(await decryptedDownloadPromise, /^geheim_geschuetzt_entsperrt\.pdf$/);
	expect(pageErrors).toEqual([]);
});

test('compress previews result size before downloading', async ({ page }) => {
	const pageErrors = trackPageErrors(page);
	await page.goto('/tools/compress');
	await dropFiles(page, pdfDropzone(page), [
		{ name: 'gross.pdf', mimeType: 'application/pdf', buffer: await createPdf(2, 'Komprimieren') }
	]);

	await page.getByRole('button', { name: 'Komprimieren', exact: true }).click();
	await expect(page.getByText(/Ergebnisgröße:/)).toBeVisible({ timeout: 20_000 });
	const downloadPromise = page.waitForEvent('download');
	await page.getByRole('button', { name: 'PDF herunterladen' }).click();
	await expectPdfDownload(await downloadPromise, /^gross_komprimiert\.pdf$/);
	expect(pageErrors).toEqual([]);
});

test('convert bundles a multi-page PDF as a correctly named ZIP', async ({ page }) => {
	const pageErrors = trackPageErrors(page);
	await page.goto('/tools/convert');
	await dropFiles(page, pdfDropzone(page), [
		{ name: 'bilder.pdf', mimeType: 'application/pdf', buffer: await createPdf(2, 'Bilder') }
	]);

	const downloadPromise = page.waitForEvent('download');
	await page.getByRole('button', { name: 'Konvertieren & herunterladen' }).click();
	const download = await downloadPromise;
	expect(download.suggestedFilename()).toBe('bilder_bilder.zip');
	expect(download.suggestedFilename()).not.toContain('.pdf');
	expect(pageErrors).toEqual([]);
});