package de.banananetwork.dsa.currencies

import java.util.*
import kotlin.collections.ArrayList

class CurrencySet private constructor(private val currencies: Array<Currency>) {

    fun transferToSet(baseValue: Int): Map<Currency, Int> {
        var modBaseValue = baseValue
        val values = EnumMap<Currency, Int>(Currency::class.java)
        for (currency in currencies) {
            val value = currency.transferTo(modBaseValue)
            values[currency] = value
            modBaseValue -= currency.transferFrom(value)
        }
        if (modBaseValue != 0)
            throw RuntimeException() // TODO Change to ValueNotRepresentableException
        return values
    }

    class Builder {

        private val currencies = ArrayList<Currency>()

        fun add(currency: Currency): Builder {
            currencies.add(currency)
            return this
        }

        fun create(): CurrencySet {
            currencies.sortBy { it.multiplier }
            return CurrencySet(currencies.toTypedArray())
        }

    }

}