package ipp

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

// References
// https://tools.ietf.org/html/rfc8010
// https://tools.ietf.org/html/rfc8011

// Defined value tags
// from rfc8010
type tag uint8

const (
	// attribute group tags
	beginAttribute        tag = 0x00
	operationAttributes   tag = 0x01
	jobAttributes         tag = 0x02
	endOfAttributes       tag = 0x03
	printerAttributes     tag = 0x04
	unsupportedAttributes tag = 0x05
	// Out of band
	unsupportedValueTag tag = 0x10
	unknownValueTag     tag = 0x12
	noValueValueTag     tag = 0x13

	// Integer values
	integerValueTag tag = 0x21
	booleanValueTag tag = 0x22
	enumValueTag    tag = 0x23

	// octetString Tags
	octetStringValueTag      tag = 0x30
	dateTimeValueTag         tag = 0x31
	resolutionValueTag       tag = 0x32
	rangeOfIntegerValueTag   tag = 0x33
	begCollectionValueTag    tag = 0x34
	textWithLanguageValueTag tag = 0x35
	nameWithLanguageValueTag tag = 0x36
	endCollectionValueTag    tag = 0x37

	// Character string values
	textWithoutLanguageValueTag tag = 0x41
	nameWithoutLanguageValueTag tag = 0x42
	keyWordValueTag             tag = 0x44
	uriValueTag                 tag = 0x45
	uriSchemeValueTag           tag = 0x46
	charsetValueTag             tag = 0x47
	naturalLanguageValueTag     tag = 0x48
	mimeMediaTypeValueTag       tag = 0x49
	memberAttrNameValueTag      tag = 0x4a
)

// Operation-id, defined in rfc8011
type OperationId uint16

const (
	PrintJob             OperationId = 0x0002
	PrintURI             OperationId = 0x0003
	ValidateJob          OperationId = 0x0004
	CreateJob            OperationId = 0x0005
	SendDocument         OperationId = 0x0006
	SendURI              OperationId = 0x0007
	CancelJob            OperationId = 0x0008
	GetJobAttributes     OperationId = 0x0009
	GetJobs              OperationId = 0x000a
	GetPrinterAttributes OperationId = 0x000b
	HoldJob              OperationId = 0x000c
	ReleaseJob           OperationId = 0x000d
	RestartJob           OperationId = 0x000e
	PausePrinter         OperationId = 0x0010
	ResumePrinter        OperationId = 0x0011
	PurgeJobs            OperationId = 0x0012
)

type printerState int32

const (
	Idle       printerState = 3
	Processing printerState = 4
	Stopped    printerState = 5
)

type statusCode uint16

const (
	SuccessfulOk          statusCode = 0x0000
	ClientErrorBadRequest statusCode = 0x0400
)

type versionNumber uint16

func (v versionNumber) String() string {
	vn := uint16(v)
	return fmt.Sprintf("%x.%x", vn&0xff00>>8, vn&0x00ff)
}

func unmarshalSingleValue(byteStream io.Reader) (string, string) {
	var length uint16
	binary.Read(byteStream, binary.BigEndian, &length)
	attributeName := make([]byte, length)
	if length > 0 {
		binary.Read(byteStream, binary.BigEndian, attributeName)
	}
	binary.Read(byteStream, binary.BigEndian, &length)
	attributeValue := make([]byte, length)
	binary.Read(byteStream, binary.BigEndian, attributeValue)
	return string(attributeName), string(attributeValue)
}

func marshalNameValue(name, value string, b []byte) {
	p := 0
	binary.BigEndian.PutUint16(b[p:p+2], uint16(len(name)))
	p += 2
	copy(b[p:], []byte(name))
	p += len(name)
	binary.BigEndian.PutUint16(b[p:p+2], uint16(len(value)))
	p += 2
	copy(b[p:], []byte(value))
}