package weightedrandom

import (
	"crypto/rand"
	"math"
	"math/big"
)

type ordered interface {
	int | int8 | int16 | int32 | int64 |
		uint | uint8 | uint16 | uint32 | uint64 |
		float32 | float64 |
		string
}

// RandomFunc is the Type for random values required for this
type RandomFunc func(int) int

// AdjustFunc is the function that returns an adjusted value for the weighting
type AdjustFunc func(itemweight int, totalWeight int) int

// AccessModifier is executed before an item is returned and returns the modified weight of an item.
type AccessModifier func(oldweight int) int

// RandInt is the standard function for returning random numbers. It returns an random number between 0 and max
func RandInt(max int) int {
	out, err := rand.Int(rand.Reader, big.NewInt(int64(max)))
	if err != nil {
		panic(err)
	}
	return int(out.Int64())
}

// StandardAdjustFunc returns the normal weight for the adjustment
func StandardAdjustFunc(standardweight, _ int) int {
	return standardweight
}

// ReverseWeightAdjustFunc returns the value relative to the total weight
func ReverseWeightAdjustFunc(weight, totalWeight int) int {
	return totalWeight / weight
}

// Addone adds one until the max value is reached, after that it returns only the max value
func Addone(oldweight int) int {
	if oldweight != math.MaxInt {
		return oldweight + 1
	}
	return oldweight
}

type weightitem[T any] struct {
	weight   int
	adjusted int
	value    T
}