"use strict";

const keys = require("../util/keys");

const isObj = require("../is/obj");

const isFunction = require("../is/function");

const isClass = require("../is/class");

const construct = require("../fp/construct");

const always = require("../fp/always");
/**
 * @name toFunction
 * @since 5.0.0-beta.6
 * @memberOf cast
 *
 * @param  {Class|Object|*} x class or object to wrap
 * @param  {Function|*} [onCall=null] not implemented, would be onConstruct/call
 * @return {Function}
 *
 * @see fp/construct
 * @see is/class
 *
 * @example
 *
 *    class Eh {}
 *    const eh = toFunction(Eh)
 *
 *    isInstanceOf(eh(), Eh)
 *    //=> true
 *
 */


function toFunction(x, onCall = null) {
  if (isClass(x)) {
    return construct(x);
  } else if (isFunction(x)) {
    return construct(x.length, x);
  } else if (isObj(x)) {
    // could bind
    const first = keys(x).filter(key => isFunction(x[key]))[0];
    if (isFunction(first)) return first;else return always(x);
  } // else if (isObj(x)) return construct(x)
  else {
      return always(x);
    }
}

module.exports = toFunction;