classname.ts

interface ClassObject {
  [className: string]: boolean | undefined
}

const addClass = (
  collection: string,
  className?: string,
  statement: boolean = false
): string => {
  if (className === undefined || className === '' || !statement) {
    return collection
  }
  if (collection === '') {
    return className
  }
  return `${collection} ${className}`
}

/**
 * Function for classnames concatenation
 * @param args string or objects to conatenate
 * @returns string with all truely classnames
 */
const cx = (...args: Array<string | ClassObject | undefined>): string => {
  return args.reduce<string>((computedClassName, currentArgument) => {
    if (typeof currentArgument === 'object') {
      return addClass(
        computedClassName,
        Object.entries(currentArgument).reduce(
          (objectClassName, classObjectArray) => {
            return addClass(objectClassName, ...classObjectArray)
          },
          ''
        ),
        true
      )
    }

    return addClass(computedClassName, currentArgument, true)
  }, '')
}

export default cx