import { Arity4, Curry4 } from '../types'

import { curry2 } from './curry2'
import { curry3 } from './curry3'

export function curry4<A, B, C, D, E>(fn: Arity4<A, B, C, D, E>): Curry4<A, B, C, D, E>
export function curry4(fn: Arity4<any, any, any, any, any>): Curry4<any, any, any, any, any>

export function curry4<A, B, C, D, E>(fn: Arity4<A, B, C, D, E>): Curry4<A, B, C, D, E> {
  function curried(a: A, b: B, c: C, d: D): any {
    switch (arguments.length) {
      case 1:
        return curry3<B, C, D, E>((b: B, c: C, d: D) => fn(a, b, c, d))
      case 2:
        return curry2<C, D, E>((c: C, d: D) => fn(a, b, c, d))
      case 3:
        return (d: D) => fn(a, b, c, d)
      default:
        return fn(a, b, c, d)
    }
  }

  return curried as Curry4<A, B, C, D, E>
}