package inetcksum

import (
	`io`
)

// New returns a new initialized [InetChecksum]. It will never panic.
func New() (i *InetChecksum) {

	i = &InetChecksum{}
	_ = i.Aligned()

	return
}

/*
NewFromBytes returns a new [InetChecksum] initialized with explicit bytes.

b may be nil or 0-length; this will not cause an error.
*/
func NewFromBytes(b []byte) (i *InetChecksum, copied int, err error) {

	var cksum InetChecksum

	if b != nil && len(b) > 0 {
		if copied, err = cksum.Write(b); err != nil {
			return
		}
		_ = i.Aligned()
	} else {
		i = New()
		return
	}

	i = &cksum

	return
}

/*
NewFromBuf returns an [InetChecksum] from a specified [io.Reader].

buf may be nil. If it isn't, NewFromBuf will call [io.Copy] on buf.
Note that this may exhaust your passed buf or advance its current seek position/offset,
depending on its type.
*/
func NewFromBuf(buf io.Reader) (i *InetChecksum, copied int64, err error) {

	var cksum InetChecksum

	_ = i.Aligned()

	if buf != nil {
		if copied, err = io.Copy(&cksum, buf); err != nil {
			return
		}
	}

	i = &cksum

	return
}