package simulation.dice

import java.util.*

/**
 * Interface for objects that can modify a value with a bonus.
 *
 * Implementations will generate a bonus value based on their internal logic.
 *
 * A [Random] object is provided if the bonus is variable.
 */
interface DiceModifier<T> {

    /**
     * Generates a bonus integer, potentially using the provided Random instance if needs be.
     *
     * @param r Random instance to use for random number generation
     * @return a generated bonus integer
     */
    fun getBonus(r: Random, crit: Boolean): T
}

/**
 * A [DiceModifier] that generates a random bonus integer based on a provided [DiceRoller].
 *
 * On each call to [getBonus], it will roll the given [DiceRoller] using the passed [Random]
 * instance and return the result as a positive bonus amount.
 *
 * @param dice The [DiceRoller] instance to use for generating bonus values.
 */
class DiceBonusModifier(private val dice: DiceRoller) : DiceModifier<Int> {

    constructor(diceString: String):this(Dice.regular(diceString))

    override fun getBonus(r: Random, crit: Boolean): Int {
        return if (crit){
            dice.roll(r).result + dice.roll(r).result
        }else{
            dice.roll(r).result
        }
    }

}

/**
 * A [DiceModifier] that applies a random penalty based on a [DiceRoller].
 *
 * On each call to [getBonus], it will roll the provided [DiceRoller] object and return the
 * result as a negative number.
 *
 * @param dice The [DiceRoller] to use for generating penalty values.
 */
class DicePenaltyModifier(private val dice: DiceRoller): DiceModifier<Int> {
    override fun getBonus(r: Random, crit: Boolean): Int {//can penalties ever crit?
        return -dice.roll(r).result
    }
}

/**
 * A [DiceModifier] that applies a fixed bonus amount.
 *
 * The bonus value is set on construction and does not vary.
 *
 * @param bonus The fixed bonus amount to apply.
 */
class FlatModifier(private val bonus: Int) : DiceModifier<Int> {
    override fun getBonus(r: Random, crit: Boolean): Int {
        return bonus
    }
}