package combat

import "math/rand"

func PlayerEffective(level, styleBonus int) int {
	return level + styleBonus + 8
}

func NPCEffective(level int) int {
	return level + 9
}

// ScienceEffective is the effective-level formula for science attacks. It is
// intentionally the same as NPCEffective (level + 9) and is applied to BOTH the
// attacker and defender of a science-mod exchange (see scienceAttack), giving a
// symmetric science-vs-science model with no attack styles. It is kept as a
// distinct function to document that intent independently of NPCEffective.
func ScienceEffective(level int) int {
	return level + 9
}

func AttackRoll(effective, equipBonus int) int {
	return effective * (equipBonus + 64)
}

func HitChance(attackRoll, defenseRoll int) float64 {
	a := float64(attackRoll)
	d := float64(defenseRoll)
	if a > d {
		return 1.0 - (d+2.0)/(2.0*(a+1.0))
	}
	return a / (2.0 * (d + 1.0))
}

func HitCheck(attackRoll, defenseRoll int) bool {
	return rand.Float64() < HitChance(attackRoll, defenseRoll)
}

func MaxHit(effective, equipStrBonus int) int {
	hit := (effective*(equipStrBonus+64) + 320) / 640
	if hit < 1 {
		hit = 1
	}
	return hit
}

func RollDamage(maxHit int) int {
	if maxHit <= 0 {
		return 0
	}
	d := rand.Intn(maxHit + 1)
	if d < 1 {
		d = 1
	}
	return d
}

func AttackStyleBonus(style string) (attack, strength, defense int) {
	switch style {
	case "accurate":
		return 3, 0, 0
	case "aggressive":
		return 0, 3, 0
	case "defensive":
		return 0, 0, 3
	case "balanced":
		return 1, 1, 1
	default:
		return 0, 0, 0
	}
}

func RangedStyleBonus(style string) (ranged, defense int) {
	switch style {
	case "accurate":
		return 3, 0
	case "aggressive":
		return 3, 0
	case "defensive":
		return 0, 3
	case "balanced":
		return 1, 1
	default:
		return 0, 0
	}
}

func SelectBonus(attackType string, stab, slash, crush, science, ranged int) int {
	switch attackType {
	case AttackStab:
		return stab
	case AttackSlash:
		return slash
	case AttackCrush:
		return crush
	case AttackScience:
		return science
	case AttackRanged:
		return ranged
	default:
		return crush
	}
}