package ipp

import (
	"bufio"
	"bytes"
	"encoding/binary"
	"fmt"

	log "github.com/sirupsen/logrus"
)

// Resolution represents a ipp resolution attribute
type Resolution struct {
	CrossFeedResolution int32
	FeedResolution      int32
	Unit                int8 // 3 seems to mean dpi (rfc3805)
}

// SetOfResolutions represents a set ipp resolution attributes
type SetOfResolutions struct {
	name string
	sor  []Resolution
}

// NewSetOfResolution creats a new set of ipp resolution attributes
func NewSetOfResolution(name string, resSet ...Resolution) *SetOfResolutions {
	r := new(SetOfResolutions)
	r.name = name
	r.sor = resSet
	return r
}

func (r *SetOfResolutions) unmarshal(byteStream *bufio.Reader) {
	var length uint16
	var res Resolution
	for {
		binary.Read(byteStream, binary.BigEndian, &length)
		attributeName := make([]byte, length)
		if length > 0 {
			binary.Read(byteStream, binary.BigEndian, attributeName)
			r.name = string(attributeName)
		}
		binary.Read(byteStream, binary.BigEndian, &length)
		if length != 9 {
			panic("Wrong length in resolution")
		}
		binary.Read(byteStream, binary.BigEndian, &res.CrossFeedResolution)
		binary.Read(byteStream, binary.BigEndian, &res.FeedResolution)
		binary.Read(byteStream, binary.BigEndian, &res.Unit)
		r.sor = append(r.sor, res)
		var t tag
		err := binary.Read(byteStream, binary.BigEndian, &t)
		if err != nil {
			log.Error(err.Error())
		}
		if t != resolutionValueTag {
			byteStream.UnreadByte()
			return
		}
	}
}

// Name returns the name of the attribute
func (r SetOfResolutions) Name() string {
	return r.name
}

func (r SetOfResolutions) String() string {
	return fmt.Sprintf("%v:%v", r.name, r.sor)
}

func (r *SetOfResolutions) marshal() []byte {

	b := make([]byte, 0, 14+len(r.name)+14*(len(r.sor)-1))
	buf := bytes.NewBuffer(b)

	for i, res := range r.sor {
		buf.WriteByte(byte(resolutionValueTag))
		if i == 0 {
			binary.Write(buf, binary.BigEndian, uint16(len(r.name)))
			buf.WriteString(r.name)
		} else {
			binary.Write(buf, binary.BigEndian, uint16(0))
		}
		binary.Write(buf, binary.BigEndian, uint16(9))
		binary.Write(buf, binary.BigEndian, int32(res.CrossFeedResolution))
		binary.Write(buf, binary.BigEndian, int32(res.FeedResolution))
		buf.WriteByte(byte(res.Unit))
	}
	return buf.Bytes()
}

func (r *SetOfResolutions) valueTag() tag {
	return resolutionValueTag
}