import merge from './util/merge';
import assertString from './util/assertString';

function currencyRegex(options) {
  var decimal_digits = "\\d{".concat(options.digits_after_decimal[0], "}");
  options.digits_after_decimal.forEach(function (digit, index) {
    if (index !== 0) decimal_digits = "".concat(decimal_digits, "|\\d{").concat(digit, "}");
  });
  var symbol = "(".concat(options.symbol.replace(/\W/, function (m) {
    return "\\".concat(m);
  }), ")").concat(options.require_symbol ? '' : '?'),
      negative = '-?',
      whole_dollar_amount_without_sep = '[1-9]\\d*',
      whole_dollar_amount_with_sep = "[1-9]\\d{0,2}(\\".concat(options.thousands_separator, "\\d{3})*"),
      valid_whole_dollar_amounts = ['0', whole_dollar_amount_without_sep, whole_dollar_amount_with_sep],
      whole_dollar_amount = "(".concat(valid_whole_dollar_amounts.join('|'), ")?"),
      decimal_amount = "(\\".concat(options.decimal_separator, "(").concat(decimal_digits, "))").concat(options.require_decimal ? '' : '?');
  var pattern = whole_dollar_amount + (options.allow_decimal || options.require_decimal ? decimal_amount : ''); // default is negative sign before symbol, but there are two other options (besides parens)

  if (options.allow_negatives && !options.parens_for_negatives) {
    if (options.negative_sign_after_digits) {
      pattern += negative;
    } else if (options.negative_sign_before_digits) {
      pattern = negative + pattern;
    }
  } // South African Rand, for example, uses R 123 (space) and R-123 (no space)


  if (options.allow_negative_sign_placeholder) {
    pattern = "( (?!\\-))?".concat(pattern);
  } else if (options.allow_space_after_symbol) {
    pattern = " ?".concat(pattern);
  } else if (options.allow_space_after_digits) {
    pattern += '( (?!$))?';
  }

  if (options.symbol_after_digits) {
    pattern += symbol;
  } else {
    pattern = symbol + pattern;
  }

  if (options.allow_negatives) {
    if (options.parens_for_negatives) {
      pattern = "(\\(".concat(pattern, "\\)|").concat(pattern, ")");
    } else if (!(options.negative_sign_before_digits || options.negative_sign_after_digits)) {
      pattern = negative + pattern;
    }
  } // ensure there's a dollar and/or decimal amount, and that
  // it doesn't start with a space or a negative sign followed by a space


  return new RegExp("^(?!-? )(?=.*\\d)".concat(pattern, "$"));
}

var default_currency_options = {
  symbol: '$',
  require_symbol: false,
  allow_space_after_symbol: false,
  symbol_after_digits: false,
  allow_negatives: true,
  parens_for_negatives: false,
  negative_sign_before_digits: false,
  negative_sign_after_digits: false,
  allow_negative_sign_placeholder: false,
  thousands_separator: ',',
  decimal_separator: '.',
  allow_decimal: true,
  require_decimal: false,
  digits_after_decimal: [2],
  allow_space_after_digits: false
};
export default function isCurrency(str, options) {
  assertString(str);
  options = merge(options, default_currency_options);
  return currencyRegex(options).test(str);
}