// Compose one cast figure from atoms, per the rig table in cast.md ("Build from ATOMS").
// usage: yarn node - <kind> <poseOrBody> <head> <face> <out.svg> < compose-peep.cjs
//   kind = standing | sitting | bust
//
// Composing from Separate Atoms/ rather than Templates/ is the whole point: a template has to
// be REJECTED for printed text, sunglasses or a Rage face, whereas a composed triple can
// never contain one. Atom names are the curated local set, not upstream.
//
// Every head is 473x567 and every face 289x293, so one set of offsets serves any combination.
// Layer order is body/pose first, then the head group with the face nested inside it.
const fs = require('node:fs');
const path = require('node:path');
const ATOMS = '/home/ubuntu/generated-images/character-moodboard/cast/atoms';

const RIG = {
  standing: { viewBox: '0 0 1179 3291', base: 'translate(-121,634)', head: 'translate(404,180)', dir: 'pose-standing' },
  sitting:  { viewBox: '0 0 1647 2500', base: 'translate(-81,637)',  head: 'translate(345,180)', dir: 'pose-sitting'  },
  bust:     { viewBox: '0 0 1136 1533', base: 'translate(147,639)',  head: 'translate(372,180)', dir: 'body'          },
};
const FACE_OFFSET = 'translate(159,186)';

// The atom files are Sketch exports; everything between the svg tags is the drawing.
const inner = (file) => {
  const s = fs.readFileSync(file, 'utf8');
  const open = s.indexOf('>', s.indexOf('<svg'));
  return s.slice(open + 1, s.lastIndexOf('</svg>')).trim();
};

function compose({ kind, base, head, face }) {
  const rig = RIG[kind];
  if (!rig) throw new Error(`kind must be one of ${Object.keys(RIG).join(', ')}`);
  const baseFile = path.join(ATOMS, rig.dir, base + '.svg');
  const headFile = path.join(ATOMS, 'head', head + '.svg');
  const faceFile = path.join(ATOMS, 'face', face + '.svg');
  for (const f of [baseFile, headFile, faceFile]) {
    if (!fs.existsSync(f)) throw new Error(`no such atom: ${f}`);
  }
  return [
    // xmlns:xlink is required, not decorative: some atoms use <use xlink:href> and rendering
    // fails with a namespace error without it.
    `<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="${rig.viewBox}" fill="none" fill-rule="evenodd">`,
    `<g transform="${rig.base}">`, inner(baseFile), `</g>`,
    `<g transform="${rig.head}">`, inner(headFile),
    `  <g transform="${FACE_OFFSET}">`, inner(faceFile), `  </g>`,
    `</g>`,
    `</svg>`, '',
  ].join('\n');
}

module.exports = { compose, RIG };

// Checked on argv, not `require.main === module`: these scripts are piped in on stdin so Yarn
// PnP can resolve from the workspace, and under stdin `require.main` is not this module, so a
// require.main guard silently does nothing.
{
  const [kind, base, head, face, out] = process.argv.slice(2);
  if (!out) {
    console.error('usage: compose-peep.cjs <kind> <poseOrBody> <head> <face> <out.svg>');
    process.exit(1);
  }
  fs.mkdirSync(path.dirname(out), { recursive: true });
  fs.writeFileSync(out, compose({ kind, base, head, face }));
  console.log(`  ${path.basename(out).padEnd(34)} ${kind}/${base} + ${head} + ${face}`);
}