'use strict';

const { decodeGid } = require('../gid');

const USAGE = 'usage: sporel-mapper decode <gid>\n';

function parseGid(s) {
  let n;
  if (/^0x[0-9a-fA-F]+$/.test(s)) {
    n = parseInt(s, 16);
  } else if (/^\d+$/.test(s)) {
    n = parseInt(s, 10);
  } else {
    throw new RangeError(`gid '${s}' is not a decimal or 0x-hex integer`);
  }
  return n;
}

function run(args, { out, err }) {
  if (args.length !== 1) {
    err.write(USAGE);
    return 1;
  }
  try {
    const gid = parseGid(args[0]);
    if (gid === 0) {
      out.write('empty\n');
      return 0;
    }
    const { atlas, tile, rotation } = decodeGid(gid);
    out.write(`atlas=${atlas} tile=${tile} rotation=${rotation}\n`);
    return 0;
  } catch (e) {
    err.write(`error: ${e.message}\n`);
    return 1;
  }
}

module.exports = { run };