const fs = require('node:fs/promises');
const path = require('node:path');
const { createHash } = require('node:crypto');
const sharp = require('sharp');
const esbuild = require('esbuild');
const { textToAscii, POPULAR_FONTS } = require('../lib/text-core.ts');
const { StandardMode } = require('../lib/modes/standard.ts');
const root = path.join(__dirname, '..');
const directory = path.join(root, 'public', 'research', '2026-11-08');
const hash = bytes => createHash('sha256').update(bytes).digest('hex');
const json = value => JSON.stringify(value, null, 2) + '\n';
const baseline = '90dfd52964bf937786a61af2ac30442e78daa051';

function fontMeasurements() {
  const version = require('../package-lock.json').packages['node_modules/figlet'].version;
  const phrases = ['HELLO', 'BUILD OK', 'ASCII ART'];
  const figlet = require('figlet');
  const records = POPULAR_FONTS.flatMap(({ value: font }) => phrases.map(text => {
    const output = textToAscii(text, { font, width: 200, horizontalLayout: 'default', verticalLayout: 'default' });
    if (/[^\x20-\x7e\n]/.test(output)) throw new Error(`Non-ASCII banner: ${font}`);
    const lines = output.split('\n');
    if (lines.length > figlet.figFonts[font].options.height) throw new Error(`Wrapped banner: ${font}`);
    return { font, phrase: text, columns: Math.max(...lines.map(line => line.length)), rows: lines.length,
      fits80: lines.every(line => line.length <= 80), text: output, sha256: hash(output) };
  }));
  return { schemaVersion: 1, baseline, figletVersion: version, phrases,
    settings: { width: 200, horizontalLayout: 'default', verticalLayout: 'default' },
    method: 'Unwrapped output; maximum ASCII characters per row, including trailing spaces. No terminal emulator measured.',
    records };
}

async function prepare() {
  await fs.mkdir(directory, { recursive: true });
  await fs.writeFile(path.join(directory, 'figlet-widths.json'), json(fontMeasurements()));
  for (const name of ['gradient', 'checkerboard', 'disk']) {
    const pixels = Buffer.alloc(320 * 180 * 4);
    for (let y = 0; y < 180; y++) for (let x = 0; x < 320; x++) {
      const value = name === 'gradient' ? Math.round(x / 319 * 255) :
        name === 'checkerboard' ? (Math.floor(x / 20) + Math.floor(y / 20)) % 2 * 255 :
          ((x - 159.5) ** 2 + (y - 89.5) ** 2 <= 70 ** 2 ? 0 : 255);
      const i = (y * 320 + x) * 4;
      pixels[i] = pixels[i + 1] = pixels[i + 2] = value;
      pixels[i + 3] = 255;
    }
    await fs.writeFile(path.join(directory, `${name}.png`), await sharp(pixels, { raw: { width: 320, height: 180, channels: 4 } }).png().toBuffer());
  }
  const script = await fs.readFile(path.join(__dirname, 'research-browser.ts'), 'utf8');
  await fs.writeFile(path.join(directory, 'method.txt'), script.replace(/\r\n?/g, '\n'));
  await fs.writeFile(path.join(directory, 'figlet-method.txt'), (await fs.readFile(__filename, 'utf8')).replace(/\r\n?/g, '\n'));
  await esbuild.build({ entryPoints: [path.join(__dirname, 'research-browser.ts')], bundle: true, format: 'esm',
    platform: 'browser', target: 'chrome116', outfile: path.join(directory, 'capture.js') });
  const html = '<!doctype html><html lang="en"><meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1"><title>ASCII research capture</title><style>body{font:16px system-ui;max-width:70ch;margin:3rem auto;padding:1rem}a{display:inline-block;padding:1rem}a[hidden]{display:none}pre{white-space:pre-wrap}</style><h1>ASCII research capture</h1><p>Local synthetic fixtures only. No analytics, external requests or automatic submission. Canvas results depend on the browser and installed fonts.</p><pre>Measuring...</pre><a hidden>Download measurements JSON</a><script type="module" src="./capture.js"></script></html>\n';
  await fs.writeFile(path.join(directory, 'capture.html'), html);
  await fs.writeFile(path.join(directory, 'capture-page.txt'), html);
}

async function importCapture(file) {
  const capture = JSON.parse(await fs.readFile(file, 'utf8'));
  if (capture.schemaVersion !== 1 || capture.exports.length !== 9 || capture.fonts.length !== 4) throw new Error('Unexpected capture schema');
  for (const item of capture.exports) {
    const png = Buffer.from(item.png, 'base64');
    const rgba = Buffer.from(item.rgba, 'base64');
    const source = await fs.readFile(path.join(directory, `${item.source}.png`));
    const text = new StandardMode().convertToAscii(new Uint8ClampedArray(rgba), item.columns, item.rows, capture.ramp, capture.options).replace(/\n$/, '');
    const metadata = await sharp(png).metadata();
    if (text !== item.text || hash(item.text) !== item.txtSha256 || Buffer.byteLength(item.text) !== item.txtBytes ||
      png.length !== item.pngBytes || hash(png) !== item.pngSha256 || hash(rgba) !== item.rasterSha256 ||
      hash(source) !== item.sourceSha256 || metadata.width !== item.pngWidth || metadata.height !== item.pngHeight) throw new Error(`Unverified export: ${item.source}/${item.columns}`);
    await fs.writeFile(path.join(directory, `${item.source}-${item.columns}.txt`), item.text);
    await fs.writeFile(path.join(directory, `${item.source}-${item.columns}.png`), png);
  }
  const common = { schemaVersion: 1, baseline, capturedAt: capture.capturedAt, userAgent: capture.userAgent,
    platform: capture.platform, captureSha256: hash(await fs.readFile(path.join(directory, 'capture.js'))) };
  await fs.writeFile(path.join(directory, 'export-sizes.json'), json({ ...common, sourceWidth: capture.sourceWidth,
    sourceHeight: capture.sourceHeight, ramp: capture.ramp, options: capture.options, pngSettings: capture.pngSettings,
    records: capture.exports.map(({ png: _png, ...record }) => record) }));
  await fs.writeFile(path.join(directory, 'character-widths.json'), json({ ...common, settings: capture.glyphSettings, fonts: capture.fonts }));
  await fs.unlink(path.join(directory, 'capture.html'));
}

if (require.main === module) {
  const command = process.argv[2];
  const job = command === '--prepare' ? prepare() : command === '--import' && process.argv[3] ? importCapture(process.argv[3]) : Promise.reject(new Error('Use --prepare or --import <capture.json>'));
  job.catch(error => { console.error(error); process.exitCode = 1; });
}
module.exports = { fontMeasurements };