'use strict';

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

const USAGE = 'usage: sporel-mapper encode <atlas_idx> <tile_id> [rotation]\n';

function parseIntStrict(s, field) {
  if (!/^-?\d+$/.test(s)) {
    throw new RangeError(`${field} '${s}' is not an integer`);
  }
  return parseInt(s, 10);
}

function run(args, { out, err }) {
  if (args.length < 2 || args.length > 3) {
    err.write(USAGE);
    return 1;
  }
  try {
    const atlas = parseIntStrict(args[0], 'atlas');
    const tile = parseIntStrict(args[1], 'tile');
    const rotation = args.length === 3 ? parseIntStrict(args[2], 'rotation') : 0;
    const gid = encodeGid(atlas, tile, rotation);
    out.write(`${gid}\n`);
    return 0;
  } catch (e) {
    err.write(`error: ${e.message}\n`);
    return 1;
  }
}

module.exports = { run };