package function.builtin.math

import function.ArgumentValidator
import function.FunctionNames
import function.LispFunction
import sexpression.Cons
import sexpression.LispNumber
import sexpression.LispNumber.Companion.ONE

@FunctionNames("*")
class Multiply(name: String) : LispFunction() {

    private val argumentValidator = ArgumentValidator(name).apply {
        setEveryArgumentExpectedType(LispNumber::class.java)
    }

    private val mathFunction: MathFunction = MathFunction({ it }, this::multiply)

    override fun call(argumentList: Cons): LispNumber {
        argumentValidator.validate(argumentList)

        return mathFunction.callTailRecursive(Cons(ONE, argumentList))
    }

    private fun multiply(number1: LispNumber, number2: LispNumber) =
        LispNumber(number1.value * number2.value)
}