import * as _ from 'lodash';
import * as inflection from 'inflection';

function applyHelperToStringWithSeparator(str: string, helper: (str: string) => string): string {
  str = str.toString();
  const separators = _.uniq(str.match(/[^a-z_0-9]+/gi) || []);

  if (separators.length === 1) {
    return str.split(separators[0]).map(s => helper(s)).join(separators[0]);
  } else {
    return helper(str);
  }
}

export function underscore(str: string): string {
  return applyHelperToStringWithSeparator(str, inflection.underscore);
}

export function upperCamel(str: string): string {
  return applyHelperToStringWithSeparator(str, inflection.camelize);
}

export function upperCamelCase(str: string): string {
  return upperCamel(str);
}

export function lowerCamelCase(str: string): string {
  return lowerCamel(str);
}

export function lowerCamel(str: string): string {
  return applyHelperToStringWithSeparator(str, s => {
    return inflection.camelize(s, true);
  });
}

export function pluralize(str: string): string {
  return inflection.pluralize(str);
}

export function singularize(str: string): string {
  return inflection.singularize(str);
}