utils.js

var fs = require('fs');
var objectAssign = require('object-assign');

/**
 * Merge a configuration with tileset objects and
 * set 'smart' defaults based on these sources, e.g. center, zoom
 * @param {object} config passed to the mbview server
 * @param {array} tilesets of objects extracted from the mbtiles
 * @return {object} updated config object with sources appended
 */
module.exports.mergeConfigurations = function (config, tilesets) {
  var tilehash = tilesets.reduce(function (prev, curr) {
    var c = {};
    c[curr.basename] = curr;
    return objectAssign({}, prev, c);
  }, {});
  var smart = objectAssign({}, config, tilesets[0]);
  var centerZoom = smart.center.pop();
  smart.zoom = smart.zoom || centerZoom;
  smart.center.push(smart.zoom);
  return objectAssign({}, smart, {
    sources: tilehash
  });
};

/**
 * Get usage instructions
 * @return {String} the instructions to run this thing
 */
module.exports.usage = function () {
  var u = [];
  u.push('usage: mbview [options] [files]');
  u.push('');
  u.push(' --port sets port to use (default: 3000)');
  u.push(' --quiet or -q supress all logging except the address to visit');
  u.push(' -n don\'t automatically open the browser on start');
  u.push(' --basemap, --base or --map sets the basemap style (default: dark)');
  u.push(' --version returns module version');
  u.push(' --help prints this message');
  u.push('');
  return u.join('\n');
};

/**
 * Get module version from the package.json file
 * @return {String} version number
 */
module.exports.version = function () {
  var data = fs.readFileSync(__dirname + '/package.json');
  return JSON.parse(data).version;
};