import {expect, test} from 'bun:test';
import fs from 'fs';
import os from 'os';
import path from 'path';
import {RenderInternals} from '@remotion/renderer';
import execa from 'execa';
import {random} from 'remotion';
import sharp from 'sharp';

function selectColor(color: string, frame: number) {
	return Math.floor((random(`${color}-${frame}`) * 255) % 255);
}

const getMissedFramesforCodec = async () => {
	const outputDir = await fs.promises.mkdtemp(
		path.join(os.tmpdir(), 'remotion-'),
	);
	const outputPath = path.join(outputDir, 'vid.gif');

	// render the VideoTesting example (which contains the Framer composition embedded with <Html5Video>) to an image
	// sequence which can be checked for accuracy
	await execa(
		'bun',
		[
			'x',
			'remotion',
			'render',
			'build',
			`video-testing-mp4-offthread`,
			'--codec=gif',
			'--every-nth-frame=2',
			outputPath,
		],
		{
			cwd: path.join(process.cwd(), '..', 'example'),
		},
	);

	await RenderInternals.callFf({
		bin: 'ffmpeg',
		args: [
			'-i',
			outputPath,
			'-f',
			'image2',
			path.join(outputDir, 'out%2d.jpeg'),
			'-y',
		],
		indent: false,
		logLevel: 'info',
		binariesDirectory: null,
		cancelSignal: undefined,
	});

	let missedFrames = 0;

	for (let frame = 0; frame < 50; frame++) {
		// each frame of the embedded video contains a (deterministically) random color which should appear correctly
		// in the rendered output
		const expectedColor = {
			red: selectColor('red', frame * 2),
			green: selectColor('green', frame * 2),
			blue: selectColor('blue', frame * 2),
		};

		// extract the actual RGB color value of the top left pixel in the frame image that was generated by remotion
		const paddedIndex = String(frame + 1).padStart(2, '0');
		const filename = path.join(outputDir, `out${paddedIndex}.jpeg`);
		const img = await sharp(filename).raw().toBuffer();

		const actualColor = {
			red: img.readUInt8(0),
			green: img.readUInt8(1),
			blue: img.readUInt8(2),
		};

		const colorDistance = {
			red: Math.abs(expectedColor.red - actualColor.red),
			green: Math.abs(expectedColor.green - actualColor.green),
			blue: Math.abs(expectedColor.blue - actualColor.blue),
		};

		// encoding sometimes shifts the color slightly - so measure the distance between the expected and actual
		// colors and consider any frame not within an acceptable range to be wrong
		const highestDistance = Math.max(
			colorDistance.red,
			colorDistance.blue,
			colorDistance.green,
		);
		const threshold = 70;
		if (highestDistance > threshold) {
			missedFrames++;
		}
	}

	RenderInternals.deleteDirectory(outputDir);
	return missedFrames;
};

test(
	'should render correct frames from embedded videos - MP4 offthread',
	async () => {
		const missedFrames = await getMissedFramesforCodec();
		expect(missedFrames).toBe(0);
	},
	{
		retry: 2,
		timeout: 40000,
	},
);