import { mkdir, mkdtemp, rm, writeFile } from 'node:fs/promises';
import { spawn } from 'node:child_process';
import { once } from 'node:events';
import { tmpdir } from 'node:os';
import { dirname, join, resolve } from 'node:path';

const root = resolve(import.meta.dirname, '..');
const outputPath = resolve(root, 'media/hdr-wordmark.png');
const width = 2200;
const height = 500;

function run(command, args, options = {}) {
  const child = spawn(command, args, options);
  return once(child, 'close').then(([code]) => {
    if (code !== 0) throw new Error(`${command} exited with code ${code}`);
  });
}

function capture(command, args) {
  return new Promise((resolveBuffer, reject) => {
    const child = spawn(command, args, { stdio: ['ignore', 'pipe', 'inherit'] });
    const chunks = [];
    child.stdout.on('data', (chunk) => chunks.push(chunk));
    child.on('error', reject);
    child.on('close', (code) => {
      if (code !== 0) {
        reject(new Error(`${command} exited with code ${code}`));
        return;
      }
      resolveBuffer(Buffer.concat(chunks));
    });
  });
}

const tempDir = await mkdtemp(join(tmpdir(), 'hdr-wordmark-'));
const svgPath = join(tempDir, 'wordmark.svg');
const maskPath = join(tempDir, 'wordmark-mask.png');

const svg = `<?xml version="1.0" encoding="UTF-8"?>
<svg xmlns="http://www.w3.org/2000/svg" width="${width}" height="${height}" viewBox="0 0 ${width} ${height}">
  <defs>
    <filter id="blur-strong" x="-20%" y="-70%" width="140%" height="240%">
      <feGaussianBlur stdDeviation="38"/>
    </filter>
    <filter id="blur-soft" x="-20%" y="-70%" width="140%" height="240%">
      <feGaussianBlur stdDeviation="16"/>
    </filter>
  </defs>
  <g font-family="Arial Black, Helvetica, Arial, sans-serif" font-size="220" font-weight="900" letter-spacing="-9" text-anchor="middle">
    <text x="1100" y="326" fill="#00faff" stroke="#00faff" stroke-width="48" opacity="0.96" filter="url(#blur-strong)">HDR Web Plugin</text>
    <text x="1114" y="336" fill="#ff31ef" stroke="#ff31ef" stroke-width="30" opacity="0.74" filter="url(#blur-strong)">HDR Web Plugin</text>
    <text x="1086" y="316" fill="#2f76ff" stroke="#2f76ff" stroke-width="22" opacity="0.62" filter="url(#blur-soft)">HDR Web Plugin</text>
    <text x="1100" y="326" fill="#ffffff" stroke="#ffffff" stroke-width="18" opacity="0.72" filter="url(#blur-soft)">HDR Web Plugin</text>
    <text x="1094" y="322" fill="#eaffff" stroke="#00faff" stroke-width="12" opacity="1" filter="url(#blur-soft)">HDR Web Plugin</text>
    <text x="1100" y="326" fill="#ffffff" stroke="#ffffff" stroke-width="7">HDR Web Plugin</text>
  </g>
</svg>`;

await mkdir(dirname(outputPath), { recursive: true });
await writeFile(svgPath, svg, 'utf8');

await run('/usr/bin/sips', [
  '-s',
  'format',
  'png',
  svgPath,
  '--out',
  maskPath
], { stdio: ['ignore', 'inherit', 'inherit'] });

const rgba = await capture('ffmpeg', [
  '-hide_banner',
  '-loglevel',
  'error',
  '-i',
  maskPath,
  '-f',
  'rawvideo',
  '-pix_fmt',
  'rgba',
  'pipe:1'
]);

const frame = Buffer.alloc(width * height * 8);
for (let index = 0; index < width * height; index += 1) {
  const src = index * 4;
  const dst = index * 8;
  const alpha = rgba[src + 3] / 255;
  const red = alpha === 0 ? 0 : rgba[src] / 255;
  const green = alpha === 0 ? 0 : rgba[src + 1] / 255;
  const blue = alpha === 0 ? 0 : rgba[src + 2] / 255;
  const channels = [red, green, blue];

  for (let channel = 0; channel < 3; channel += 1) {
    const lifted = Math.pow(channels[channel], 0.42);
    const value = Math.min(65535, Math.round(lifted * 65535));
    frame.writeUInt16LE(value, dst + channel * 2);
  }

  const alphaValue = Math.min(65535, Math.round(Math.pow(alpha, 0.42) * 65535));
  frame.writeUInt16LE(alphaValue, dst + 6);
}

const encode = spawn('ffmpeg', [
  '-y',
  '-f',
  'rawvideo',
  '-pix_fmt',
  'rgba64le',
  '-s:v',
  `${width}x${height}`,
  '-i',
  'pipe:0',
  '-vf',
  'setparams=range=full:color_primaries=bt2020:color_trc=smpte2084:colorspace=gbr',
  '-frames:v',
  '1',
  '-update',
  '1',
  '-c:v',
  'png',
  '-pix_fmt',
  'rgba64be',
  '-pred',
  'mixed',
  '-color_primaries',
  'bt2020',
  '-color_trc',
  'smpte2084',
  outputPath
], { stdio: ['pipe', 'inherit', 'inherit'] });

encode.stdin.end(frame);
const [encodeCode] = await once(encode, 'close');
await rm(tempDir, { recursive: true, force: true });
if (encodeCode !== 0) throw new Error(`ffmpeg png exited with code ${encodeCode}`);

console.log(`Wrote ${outputPath}`);