import { describe, expect, it } from 'vitest';
import { capImageDataURLSize } from '$lib/utils/cap-img-size';
import { getJpegOrientationFromDataURL } from '$lib/utils/jpeg-orientation';

// Real 64x32 jpegs generated with Pillow, quality 90. The upright picture is
// four solid quadrants: top left red, top right green, bottom left blue,
// bottom right yellow. For each exif value the stored pixels are inverse
// transposed so a conforming decoder shows the upright picture, exactly like
// a rotated smartphone photo.
const EXIF1 = `data:image/jpeg;base64,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`;
const EXIF3 = `data:image/jpeg;base64,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`;
const EXIF5 = `data:image/jpeg;base64,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`;
const EXIF6 = `data:image/jpeg;base64,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`;
const EXIF8 = `data:image/jpeg;base64,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`;
const NOEXIF = `data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAAD/2wBDAAMCAgMCAgMDAwMEAwMEBQgFBQQEBQoHBwYIDAoMDAsKCwsNDhIQDQ4RDgsLEBYQERMUFRUVDA8XGBYUGBIUFRT/2wBDAQMEBAUEBQkFBQkUDQsNFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBT/wAARCAAgAEADASIAAhEBAxEB/8QAHwAAAQUBAQEBAQEAAAAAAAAAAAECAwQFBgcICQoL/8QAtRAAAgEDAwIEAwUFBAQAAAF9AQIDAAQRBRIhMUEGE1FhByJxFDKBkaEII0KxwRVS0fAkM2JyggkKFhcYGRolJicoKSo0NTY3ODk6Q0RFRkdISUpTVFVWV1hZWmNkZWZnaGlqc3R1dnd4eXqDhIWGh4iJipKTlJWWl5iZmqKjpKWmp6ipqrKztLW2t7i5usLDxMXGx8jJytLT1NXW19jZ2uHi4+Tl5ufo6erx8vP09fb3+Pn6/8QAHwEAAwEBAQEBAQEBAQAAAAAAAAECAwQFBgcICQoL/8QAtREAAgECBAQDBAcFBAQAAQJ3AAECAxEEBSExBhJBUQdhcRMiMoEIFEKRobHBCSMzUvAVYnLRChYkNOEl8RcYGRomJygpKjU2Nzg5OkNERUZHSElKU1RVVldYWVpjZGVmZ2hpanN0dXZ3eHl6goOEhYaHiImKkpOUlZaXmJmaoqOkpaanqKmqsrO0tba3uLm6wsPExcbHyMnK0tPU1dbX2Nna4uPk5ebn6Onq8vP09fb3+Pn6/9oADAMBAAIRAxEAPwD50ooor8MP9UwooooA9uooor4I/wCcwKKKKAPhSiiiv+gM/qgKKKKAP3Vooor/AJdz+lQooooA/9k=`;

const RED: Rgb = [255, 0, 0];
const GREEN: Rgb = [0, 200, 0];
const BLUE: Rgb = [0, 0, 255];
const YELLOW: Rgb = [255, 220, 0];

// Wide tolerance per channel, jpeg compression shifts solid colors a bit
const COLOR_TOLERANCE = 70;

// 0.000512 megapixels is 512 pixels, a quarter of the area of the 2048 pixel fixtures
const QUARTER_AREA_MEGAPIXELS = 0.000512;

type Rgb = [number, number, number];

function loadImage(dataUrl: string): Promise<HTMLImageElement> {
	return new Promise((resolve, reject) => {
		const img = new Image();
		img.onload = () => resolve(img);
		img.onerror = () => reject(new Error('Failed to decode image.'));
		img.src = dataUrl;
	});
}

// Decodes a data URL and samples the center of each quadrant of the picture
async function quadrantColors(dataUrl: string): Promise<Rgb[]> {
	const img = await loadImage(dataUrl);
	const canvas = document.createElement('canvas');
	canvas.width = img.naturalWidth;
	canvas.height = img.naturalHeight;
	const ctx = canvas.getContext('2d')!;
	ctx.drawImage(img, 0, 0);
	const points = [
		[0.25, 0.25],
		[0.75, 0.25],
		[0.25, 0.75],
		[0.75, 0.75]
	];
	return points.map(([fx, fy]) => {
		const d = ctx.getImageData(
			Math.floor(canvas.width * fx),
			Math.floor(canvas.height * fy),
			1,
			1
		).data;
		return [d[0], d[1], d[2]];
	});
}

function expectUpright(colors: Rgb[]) {
	const targets = [RED, GREEN, BLUE, YELLOW];
	for (let i = 0; i < 4; i++) {
		for (let c = 0; c < 3; c++) {
			expect(Math.abs(colors[i][c] - targets[i][c])).toBeLessThan(COLOR_TOLERANCE);
		}
	}
}

describe('capImageDataURLSize orientation and capping', () => {
	it('passes upright jpegs through untouched when capping is disabled', async () => {
		expect(await capImageDataURLSize(EXIF1, 0)).toBe(EXIF1);
		expect(await capImageDataURLSize(NOEXIF, 0)).toBe(NOEXIF);
	});

	it('passes upright jpegs through untouched when under the cap threshold', async () => {
		expect(await capImageDataURLSize(EXIF1, 1)).toBe(EXIF1);
	});

	it.each([
		['orientation 3', EXIF3],
		['orientation 5', EXIF5],
		['orientation 6', EXIF6],
		['orientation 8', EXIF8]
	])('bakes %s into upright pixels without capping', async (_label, fixture) => {
		const result = await capImageDataURLSize(fixture, 0);

		expect(result).not.toBe(fixture);

		const img = await loadImage(result);

		expect(img.naturalWidth).toBe(64);
		expect(img.naturalHeight).toBe(32);
		expectUpright(await quadrantColors(result));

		// The re-encoded jpeg carries no orientation tag anymore
		expect(getJpegOrientationFromDataURL(result)).toBe(1);
	});

	it('caps and bakes the orientation in a single output', async () => {
		const result = await capImageDataURLSize(EXIF6, QUARTER_AREA_MEGAPIXELS);
		const img = await loadImage(result);

		expect(img.naturalWidth).toBe(32);
		expect(img.naturalHeight).toBe(16);
		expectUpright(await quadrantColors(result));
		expect(getJpegOrientationFromDataURL(result)).toBe(1);
	});

	it('caps upright jpegs without disturbing the picture', async () => {
		const result = await capImageDataURLSize(EXIF1, QUARTER_AREA_MEGAPIXELS);
		const img = await loadImage(result);

		expect(img.naturalWidth).toBe(32);
		expect(img.naturalHeight).toBe(16);
		expectUpright(await quadrantColors(result));
	});
});