package ipp

import (
	"bytes"
	"encoding/binary"
	"fmt"
	"io"
)

type Integer struct {
	name   string
	values []int32
}

func NewInteger(name string, values ...int32) *Integer {
	e := new(Integer)
	e.name = name
	e.values = values
	return e
}

func (i Integer) Name() string {
	return i.name
}

func (i Integer) String() string {
	return i.name + ":" + fmt.Sprint(i.values)
}

func (i *Integer) valueTag() tag {
	return integerValueTag
}

func (i *Integer) size() int {
	return 9 + len(i.name) // The attribute tag + 2 lengths
}

func (i *Integer) addValue(v interface{}) {
	i.values = append(i.values, v.(int32))
}

func (i *Integer) marshal() []byte {
	return marshalInteger(integerValueTag, i.name, i.values)
}

func marshalInteger(t tag, name string, values []int32) []byte {
	l := 9 + len(name) + 9*(len(values)-1)
	b := make([]byte, 0, l)
	buf := bytes.NewBuffer(b)
	buf.WriteByte(byte(t))
	binary.Write(buf, binary.BigEndian, uint16(len(name)))
	buf.WriteString(name)
	binary.Write(buf, binary.BigEndian, uint16(4))
	binary.Write(buf, binary.BigEndian, values[0])
	for _, v := range values[1:] {
		buf.WriteByte(byte(t))
		binary.Write(buf, binary.BigEndian, uint16(0))
		binary.Write(buf, binary.BigEndian, uint16(4))
		binary.Write(buf, binary.BigEndian, v)
	}
	return buf.Bytes()
}

func unmarshalSingleInteger(byteStream io.Reader) (string, int32) {
	name, data := unmarshalSingleAttribute(byteStream)
	return name, int32(binary.BigEndian.Uint32(data))
}