'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = varValueConvert;

var _isWindows = require('is-windows');

var _isWindows2 = _interopRequireDefault(_isWindows);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

var pathLikeEnvVarWhitelist = new Set(['PATH', 'NODE_PATH']);

/**
 * This will transform UNIX-style list values to Windows-style.
 * For example, the value of the $PATH variable "/usr/bin:/usr/local/bin:."
 * will become "/usr/bin;/usr/local/bin;." on Windows.
 * @param {String} varValue Original value of the env variable
 * @param {String} varName Original name of the env variable
 * @returns {String} Converted value
 */
function replaceListDelimiters(varValue) {
  var varName = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : '';

  var targetSeparator = (0, _isWindows2.default)() ? ';' : ':';
  if (!pathLikeEnvVarWhitelist.has(varName)) {
    return varValue;
  }

  return varValue.replace(/(\\*):/g, function (match, backslashes) {
    if (backslashes.length % 2) {
      // Odd number of backslashes preceding it means it's escaped,
      // remove 1 backslash and return the rest as-is
      return match.substr(1);
    }
    return backslashes + targetSeparator;
  });
}

/**
 * This will attempt to resolve the value of any env variables that are inside
 * this string. For example, it will transform this:
 * cross-env FOO=$NODE_ENV BAR=\\$NODE_ENV echo $FOO $BAR
 * Into this:
 * FOO=development BAR=$NODE_ENV echo $FOO
 * (Or whatever value the variable NODE_ENV has)
 * Note that this function is only called with the right-side portion of the
 * env var assignment, so in that example, this function would transform
 * the string "$NODE_ENV" into "development"
 * @param {String} varValue Original value of the env variable
 * @returns {String} Converted value
 */
function resolveEnvVars(varValue) {
  var envUnixRegex = /(\\*)(\$(\w+)|\${(\w+)})/g; // $my_var or ${my_var} or \$my_var
  return varValue.replace(envUnixRegex, function (_, escapeChars, varNameWithDollarSign, varName, altVarName) {
    // do not replace things preceded by a odd number of \
    if (escapeChars.length % 2 === 1) {
      return varNameWithDollarSign;
    }
    return escapeChars.substr(0, escapeChars.length / 2) + (process.env[varName || altVarName] || '');
  });
}

/**
 * Converts an environment variable value to be appropriate for the current OS.
 * @param {String} originalValue Original value of the env variable
 * @param {String} originalName Original name of the env variable
 * @returns {String} Converted value
 */
function varValueConvert(originalValue, originalName) {
  return resolveEnvVars(replaceListDelimiters(originalValue, originalName));
}