/**
 * Composes single-argument functions from right to left. The rightmost
 * function can take multiple arguments as it provides the signature for the
 * resulting composite function.
 *
 * References：https://github.com/reduxjs/redux/blob/master/src/compose.ts
 *
 * @param funcs The functions to compose.
 * @returns A function obtained by composing the argument functions from right
 *   to left. For example, `compose(f, g, h)` is identical to doing
 *   `(...args) => f(g(h(...args)))`.
 */
const compose = <T extends Function>(...funcs: Array<(a: T) => T>) => {
  if (funcs.length === 0) {
    // infer the argument type so it is usable in inference down the line
    return <T>(arg: T) => arg
  }

  if (funcs.length === 1) {
    return funcs[0]
  }

  return funcs.reduce(
    (a, b) =>
      (...args) =>
        a(b(...args))
  )
}

export default compose