package types

import (
	"encoding/binary"
)

var NO = binary.BigEndian

const MIN_BUFFER_SIZE = 256

type LuxBuffer struct {
	data   []byte
	offset int
	len    int
}

func NewLuxBuffer(cap int) *LuxBuffer {
	return &LuxBuffer{
		data:   make([]byte, cap),
		offset: 0,
		len:    0,
	}
}

func FromSlice(bytes []byte) *LuxBuffer {
	return &LuxBuffer{
		data:   bytes,
		offset: 0,
		len:    len(bytes),
	}
}

func (buf *LuxBuffer) Capacity() int {
	return len(buf.data)
}

func (buf *LuxBuffer) Offset() int {
	return buf.offset
}

func (buf *LuxBuffer) Length() int {
	return buf.len
}

func (buf *LuxBuffer) Available() int {
	return buf.Capacity() - buf.Length()
}

func (buf *LuxBuffer) Grow(grow int) {
	ocap, ncap := buf.Capacity(), (buf.Capacity()*2 + grow)
	odata := buf.data

	buf.data = make([]byte, ncap)
	copy(buf.data[:ocap], odata[:])
}

// will return byte buffer, sliced to real length
func (buf *LuxBuffer) AllBytes() []byte {
	return buf.data[:buf.len]
}

// ensure capacity for new write, return slice pointing to a place of a new write
func (buf *LuxBuffer) WriteNext(size int) []byte {
	if buf.Available() < size {
		buf.Grow(size)
	}

	next := buf.data[buf.len : buf.len+size]
	buf.len += size

	return next
}

func (buf *LuxBuffer) WriteBytes(bytes []byte) {
	copy(buf.WriteNext(len(bytes)), bytes)
}