package sprigx

import (
	`math`
	`net`
	`strconv`
)

// netExtractAddr calls net.ParseCIDR and returns the net.IP from it.
func netExtractAddr(s string) (addr net.IP, err error) {

	if addr, _, err = net.ParseCIDR(s); err != nil {
		return
	}

	return
}

// netExtractHost extracts the host component from hostPort.
func netExtractHost(hostPort string) (host string, err error) {

	if host, _, err = net.SplitHostPort(hostPort); err != nil {
		return
	}

	return
}

// netExtractIpnet calls net.ParseCIDR and returns the net.IPNet from it.
func netExtractIpnet(s string) (ipnet *net.IPNet, err error) {

	if _, ipnet, err = net.ParseCIDR(s); err != nil {
		return
	}

	return
}

// netExtractPort extracts the port component from hostPort.
func netExtractPort(hostPort string) (port uint16, err error) {

	var portStr string
	var u64 uint64

	if _, portStr, err = net.SplitHostPort(hostPort); err != nil {
		return
	}

	if u64, err = strconv.ParseUint(portStr, 10, 16); err != nil {
		return
	}
	port = uint16(u64)

	return
}

// netIp4Mask is a more flexible wrapper around net.IPv4Mask.
func netIp4Mask(a, b, c, d any) (mask net.IPMask, err error) {

	var idx int
	var elem any
	var elemInt int
	var mBytes [4]byte
	var orig [4]any = [4]any{a, b, c, d}

	for idx, elem = range orig {
		if elemInt, _, err = toPosInt(elem); err != nil {
			return
		}
		if elemInt > math.MaxUint8 {
			err = ErrOverflow
			return
		}
		mBytes[idx] = byte(uint8(elemInt))
	}

	mask = net.IPv4Mask(
		mBytes[0], mBytes[1], mBytes[2], mBytes[3],
	)

	return
}