//
// Copyright 2020-2022 Sean C Foley
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

package ipaddr

import (
	"strings"

	"github.com/seancfoley/ipaddress-go/ipaddr/addrerr"
	"github.com/seancfoley/ipaddress-go/ipaddr/addrstr"
)

// Note: For IPv6, translation from options to params is more complicated and requires the section, so it's done in IPv6AddressSection methods

func toNormalizedIPZonedString(opts addrstr.IPStringOptions, section AddressDivisionSeries, zone Zone) string {
	return toIPParams(opts).toZonedString(section, zone)
}

func toNormalizedIPString(opts addrstr.IPStringOptions, section AddressDivisionSeries) string {
	return toIPParams(opts).toString(section)
}

func toNormalizedZonedString(opts addrstr.StringOptions, section AddressDivisionSeries, zone Zone) string {
	return toParams(opts).toZonedString(section, zone)
}

func toNormalizedString(opts addrstr.StringOptions, section AddressDivisionSeries) string {
	return toParams(opts).toString(section)
}

func toIPParams(opts addrstr.IPStringOptions) *ipAddressStringParams {
	return &ipAddressStringParams{
		addressStringParams: addressStringParams{
			radix:            opts.GetRadix(),
			separator:        opts.GetSeparator(),
			hasSep:           opts.HasSeparator(),
			uppercase:        opts.IsUppercase(),
			expandSegments:   opts.IsExpandedSegments(),
			wildcards:        opts.GetWildcards(),
			segmentStrPrefix: opts.GetSegmentStrPrefix(),
			reverse:          opts.IsReverse(),
			addressLabel:     opts.GetAddressLabel(),
			zoneSeparator:    opts.GetZoneSeparator(),
		},
		wildcardOption: opts.GetWildcardOption(),
		addressSuffix:  opts.GetAddressSuffix(),
	}
}

func toParams(opts addrstr.StringOptions) *addressStringParams {
	return &addressStringParams{
		radix:            opts.GetRadix(),
		separator:        opts.GetSeparator(),
		hasSep:           opts.HasSeparator(),
		uppercase:        opts.IsUppercase(),
		expandSegments:   opts.IsExpandedSegments(),
		wildcards:        opts.GetWildcards(),
		segmentStrPrefix: opts.GetSegmentStrPrefix(),
		addressLabel:     opts.GetAddressLabel(),
		reverse:          opts.IsReverse(),
		// the options don't provide a zone separator (only IPStringOptions do), so we must specify what it is
		zoneSeparator: IPv6ZoneSeparatorStr,
	}
}

func from(opts addrstr.IPv6StringOptions, addr *IPv6AddressSection) (res *ipv6StringParams) {
	res = &ipv6StringParams{
		ipAddressStringParams: ipAddressStringParams{
			addressStringParams: addressStringParams{
				radix:            opts.GetRadix(),
				separator:        opts.GetSeparator(),
				hasSep:           opts.HasSeparator(),
				uppercase:        opts.IsUppercase(),
				expandSegments:   opts.IsExpandedSegments(),
				wildcards:        opts.GetWildcards(),
				segmentStrPrefix: opts.GetSegmentStrPrefix(),
				reverse:          opts.IsReverse(),
				splitDigits:      opts.IsSplitDigits(),
				addressLabel:     opts.GetAddressLabel(),
				zoneSeparator:    opts.GetZoneSeparator(),
			},
			wildcardOption: opts.GetWildcardOption(),
			addressSuffix:  opts.GetAddressSuffix(),
		},
	}
	if opts.GetCompressOptions() != nil {
		compressOptions := opts.GetCompressOptions()
		maxIndex, maxCount := addr.getCompressIndexAndCount(compressOptions, opts.IsMixed())
		if maxCount > 0 {
			res.firstCompressedSegmentIndex = maxIndex
			res.nextUncompressedIndex = maxIndex + maxCount
			res.hostCompressed = compressOptions.GetCompressionChoiceOptions().CompressHost() &&
				addr.IsPrefixed() &&
				(res.nextUncompressedIndex >
					getHostSegmentIndex(addr.getNetworkPrefixLen().bitCount(), IPv6BytesPerSegment, IPv6BitsPerSegment))
		}
	}
	return res
}

type divStringProvider interface {
	getLowerStringLength(radix int) int

	getUpperStringLength(radix int) int

	getLowerString(radix int, uppercase bool, appendable *strings.Builder)

	getLowerStringChopped(radix int, choppedDigits int, uppercase bool, appendable *strings.Builder)

	getUpperString(radix int, uppercase bool, appendable *strings.Builder)

	getUpperStringMasked(radix int, uppercase bool, appendable *strings.Builder)

	getSplitLowerString(radix int, choppedDigits int, uppercase bool,
		splitDigitSeparator byte, reverseSplitDigits bool, stringPrefix string, appendable *strings.Builder)

	getSplitRangeString(rangeSeparator string, wildcard string, radix int, uppercase bool,
		splitDigitSeparator byte, reverseSplitDigits bool, stringPrefix string, appendable *strings.Builder) addrerr.IncompatibleAddressError

	getSplitRangeStringLength(rangeSeparator string, wildcard string, leadingZeroCount int, radix int, uppercase bool,
		splitDigitSeparator byte, reverseSplitDigits bool, stringPrefix string) int

	getRangeDigitCount(radix int) int

	// if leadingZeroCount is -1, returns the number of leading zeros for maximum width, based on the width of the value
	adjustLowerLeadingZeroCount(leadingZeroCount int, radix int) int

	// if leadingZeroCount is -1, returns the number of leading zeros for maximum width, based on the width of the value
	adjustUpperLeadingZeroCount(leadingZeroCount int, radix int) int

	getMaxDigitCountRadix(radix int) int

	// returns the default radix for textual representations of addresses (10 for IPv4, 16 for IPv6)
	getDefaultTextualRadix() int // put this in divisionValues perhaps?  or use addrType

	// returns the number of digits for the maximum possible value of the division when using the default radix
	getMaxDigitCount() int

	// A simple string using just the lower value and the default radix.
	getDefaultLowerString() string

	// A simple string using just the lower and upper values and the default radix, separated by the default range character.
	getDefaultRangeString() string

	// This is the wildcard string to be used when producing the default strings with getString() or getWildcardString()
	//
	// Since no parameters for the string are provided, default settings are used, but they must be consistent with the address.
	//
	//For instance, generally the '-' is used as a range separator, but in some cases that character is used for a segment separator.
	//
	// Note that this only applies to "default" settings, there are additional string methods that allow you to specify these separator characters.
	// Those methods must be aware of the defaults as well, to know when they can defer to the defaults and when they cannot.
	getDefaultRangeSeparatorString() string
}

// Each segment params has settings to write exactly one type of IP address part string segment.
type addressSegmentParams interface {
	getWildcards() addrstr.Wildcards

	preferWildcards() bool

	// returns -1 for as many leading zeros as needed to write the max number of characters per segment,
	// or 0, 1, 2, 3 to indicate the number of leading zeros
	getLeadingZeros(segmentIndex int) int

	getSegmentStrPrefix() string

	getRadix() int

	isUppercase() bool

	isSplitDigits() bool

	hasSeparator() bool

	getSplitDigitSeparator() byte

	isReverseSplitDigits() bool
}

type addressStringParams struct {
	wildcards      addrstr.Wildcards
	expandSegments bool //whether to expand 1 to 001 for IPv4 or 0001 for IPv6

	segmentStrPrefix string //eg for inet_aton style there is 0x for hex, 0 for octal

	radix int

	//the segment separator and in the case of split digits, the digit separator
	separator byte // default is ' '
	hasSep    bool // whether there is a separator at all
	uppercase bool //whether to print A or a

	//print the segments in reverse, and in the case of splitDigits, print the digits in reverse as well
	reverse bool

	//in each segment, split the digits with the separator, so that 123.456.1.1 becomes 1.2.3.4.5.6.1.1
	splitDigits   bool
	addressLabel  string
	zoneSeparator string
}

func (params *addressStringParams) getWildcards() addrstr.Wildcards {
	return params.wildcards
}

func (params *addressStringParams) preferWildcards() bool {
	return true
}

//returns -1 to expand
func (params *addressStringParams) getLeadingZeros(_ int) int {
	if params.expandSegments {
		return -1
	}
	return 0
}

func (params *addressStringParams) getSegmentStrPrefix() string {
	return params.segmentStrPrefix
}

func (params *addressStringParams) getRadix() int {
	return params.radix
}

func (params *addressStringParams) isUppercase() bool {
	return params.uppercase
}

func (params *addressStringParams) isSplitDigits() bool {
	return params.splitDigits
}

func (params *addressStringParams) hasSeparator() bool {
	return params.hasSep
}

func (params *addressStringParams) getSplitDigitSeparator() byte {
	return params.separator
}

func (params *addressStringParams) isReverseSplitDigits() bool {
	return params.reverse
}

func (params *addressStringParams) getSegmentsStringLength(part AddressDivisionSeries) int {
	count := 0
	divCount := part.GetDivisionCount()
	if divCount != 0 {
		for i := 0; i < divCount; i++ {
			count += params.appendSegment(i, nil, part)
		}
		//Character separator = getSeparator();
		if params.hasSep {
			count += divCount - 1 // the number of separators
		}
	}
	return count
}

func (params *addressStringParams) appendSegments(builder *strings.Builder, part AddressDivisionSeries) *strings.Builder {
	divCount := part.GetDivisionCount()
	if divCount != 0 {
		reverse := params.reverse
		i := 0
		hasSeparator := params.hasSep
		separator := params.separator
		for {
			segIndex := i
			if reverse {
				segIndex = divCount - i - 1
			}
			params.appendSegment(segIndex, builder, part)
			i++
			if i == divCount {
				break
			}
			if hasSeparator {
				builder.WriteByte(separator)
			}
		}
	}
	return builder
}

func (params *addressStringParams) appendSingleDivision(seg DivisionType, builder *strings.Builder) int {
	writer := stringWriter{seg}
	if builder == nil {
		result, _ := writer.getStandardString(0, params, nil)
		return result + params.getAddressLabelLength()
	}
	params.appendLabel(builder)
	_, _ = writer.getStandardString(0, params, builder)
	return 0
}

func (params *addressStringParams) getDivisionStringLength(seg DivisionType) int {
	return params.appendSingleDivision(seg, nil)
}

func (params *addressStringParams) appendDivision(builder *strings.Builder, seg DivisionType) *strings.Builder {
	params.appendSingleDivision(seg, builder)
	return builder
}

func (params *addressStringParams) appendSegment(segmentIndex int, builder *strings.Builder, part AddressDivisionSeries) int {
	div := part.GetGenericDivision(segmentIndex)
	writer := stringWriter{div}
	res, _ := writer.getStandardString(segmentIndex, params, builder)
	return res
}

func (params *addressStringParams) getZoneLength(zone Zone, sep string) int {
	if zone != NoZone {
		return len(zone) + len(sep) /* zone separator is one char */
	}
	return 0
}

func (params *addressStringParams) getZonedStringLength(addr AddressDivisionSeries, zone Zone) int {
	if addr.GetDivisionCount() > 0 {
		result := params.getStringLength(addr)
		if zone != NoZone {
			result += params.getZoneLength(zone, params.zoneSeparator)
		}
		return result
	}
	return 0
}

func (params *addressStringParams) getStringLength(addr AddressDivisionSeries) int {
	if addr.GetDivisionCount() > 0 {
		return params.getAddressLabelLength() + params.getSegmentsStringLength(addr)
	}
	return 0
}

func (params *addressStringParams) appendZone(builder *strings.Builder, zone Zone) *strings.Builder {
	if zone != NoZone {
		builder.WriteString(params.zoneSeparator)
		builder.WriteString(string(zone))
	}
	return builder
}

func (params *addressStringParams) appendZoned(builder *strings.Builder, addr AddressDivisionSeries, zone Zone) *strings.Builder {
	if addr.GetDivisionCount() > 0 {
		params.appendLabel(builder)
		params.appendSegments(builder, addr)
		params.appendZone(builder, zone)
	}
	return builder
}

func (params *addressStringParams) append(builder *strings.Builder, addr AddressDivisionSeries) *strings.Builder {
	return params.appendZoned(builder, addr, NoZone)
}

func (params *addressStringParams) toZonedString(addr AddressDivisionSeries, zone Zone) string {
	length := params.getZonedStringLength(addr, zone)
	builder := &strings.Builder{}
	builder.Grow(length)
	params.appendZoned(builder, addr, zone)
	checkLengths(length, builder)
	return builder.String()
}

func (params *addressStringParams) appendLabel(builder *strings.Builder) *strings.Builder {
	str := params.addressLabel
	if str != "" {
		builder.WriteString(str)
	}
	return builder
}

func (params *addressStringParams) getAddressLabelLength() int {
	return len(params.addressLabel)
}

func (params *addressStringParams) toString(addr AddressDivisionSeries) string {
	length := params.getStringLength(addr)
	builder := &strings.Builder{}
	builder.Grow(length)
	params.append(builder, addr)
	checkLengths(length, builder)
	return builder.String()
}

//
func checkLengths(length int, builder *strings.Builder) {
	//Note: re-enable this when doing development
	//calcMatch := length == builder.Len()
	//capMatch := length == builder.Cap()
	//if !calcMatch || !capMatch {
	//	panic(fmt.Sprintf("length is %d, capacity is %d, expected length is %d", builder.Len(), builder.Cap(), length))
	//}
}

func (params *addressStringParams) clone() *addressStringParams {
	result := *params
	return &result
}

var _ addressSegmentParams = &addressStringParams{}

// Each StringParams has settings to write exactly one type of IP address part string.
type ipAddressStringParams struct {
	addressStringParams

	wildcardOption addrstr.WildcardOption
	expandSeg      []int //the same as expandSegments but for each segment
	addressSuffix  string
}

func (params *ipAddressStringParams) preferWildcards() bool {
	return params.wildcardOption == addrstr.WildcardsAll
}

func (params *ipAddressStringParams) getExpandedSegmentLength(segmentIndex int) int {
	expandSegment := params.expandSeg
	if expandSegment == nil || len(expandSegment) <= segmentIndex {
		return 0
	}
	return expandSegment[segmentIndex]
}

func (params *ipAddressStringParams) expandSegment(index, expansionLength, segmentCount int) {
	expandSegment := params.expandSeg
	if expandSegment == nil {
		expandSegment = make([]int, segmentCount)
		params.expandSeg = expandSegment
	}
	expandSegment[index] = expansionLength
}

//returns -1 for MAX, or 0, 1, 2, 3 to indicate the string prefix length
func (params *ipAddressStringParams) getLeadingZeros(segmentIndex int) int {
	expandSegment := params.expandSeg
	if params.expandSegments {
		return -1
	} else if expandSegment != nil && len(expandSegment) > segmentIndex {
		return expandSegment[segmentIndex]
	}
	return 0
}

func (params *ipAddressStringParams) getTrailingSegmentSeparator() byte {
	return params.separator
}

func (params *ipAddressStringParams) appendSuffix(builder *strings.Builder) *strings.Builder {
	suffix := params.addressSuffix
	if len(suffix) > 0 {
		builder.WriteString(suffix)
	}
	return builder
}

func (params *ipAddressStringParams) getAddressSuffixLength() int {
	suffix := params.addressSuffix
	return len(suffix)
}

func (params *ipAddressStringParams) getTrailingSeparatorCount(addr AddressDivisionSeries) int {
	count := addr.GetDivisionCount()
	if count > 0 {
		return count - 1
	}
	return 0
}

func getPrefixIndicatorStringLength(addr AddressDivisionSeries) int {
	if addr.IsPrefixed() {
		return toUnsignedStringLengthFast(uint16(addr.GetPrefixLen().bitCount()), 10) + 1
	}
	return 0
}

func (params *ipAddressStringParams) getSegmentsStringLength(part AddressDivisionSeries) int {
	count := 0
	divCount := part.GetDivisionCount()
	if divCount != 0 {
		prefLen := part.GetPrefixLen()
		for i := 0; i < divCount; i++ {
			div := part.GetGenericDivision(i)
			count += params.appendSegment(i, div, prefLen, nil, part)
			if prefLen != nil {
				bc := prefLen.bitCount()
				dc := div.GetBitCount()
				var bits BitCount
				if bc > dc {
					bits = bc - dc
				}
				prefLen = cacheBitCount(bits)
			}
		}
		if params.hasSep {
			count += divCount - 1 // the number of separators
		}
	}
	return count
}

func (params *ipAddressStringParams) getStringLength(series AddressDivisionSeries) int {
	count := params.getSegmentsStringLength(series)
	if !params.reverse && !params.preferWildcards() {
		count += getPrefixIndicatorStringLength(series)
	}
	return count + params.getAddressSuffixLength() + params.getAddressLabelLength()
}

func (params *ipAddressStringParams) appendPrefixIndicator(builder *strings.Builder, addr AddressDivisionSeries) *strings.Builder {
	if addr.IsPrefixed() {
		builder.WriteByte(PrefixLenSeparator)
		return toUnsignedStringCased(uint64(addr.GetPrefixLen().bitCount()), 10, 0, false, builder)
	}
	return builder
}

func (params *ipAddressStringParams) appendSegments(builder *strings.Builder, part AddressDivisionSeries) *strings.Builder {
	divCount := part.GetDivisionCount()
	if divCount != 0 {
		prefLen := part.GetPrefixLen()
		reverse := params.reverse
		i := 0
		hasSeparator := params.hasSep
		separator := params.separator
		for {
			segIndex := i
			if reverse {
				segIndex = divCount - i - 1
			}
			div := part.GetGenericDivision(segIndex)
			params.appendSegment(segIndex, div, prefLen, builder, part)
			if prefLen != nil {
				bc := prefLen.bitCount()
				dc := div.GetBitCount()
				var bits BitCount
				if bc > dc {
					bits = bc - dc
				}
				prefLen = cacheBitCount(bits)
			}
			i++
			if i == divCount {
				break
			}
			if hasSeparator {
				builder.WriteByte(separator)
			}
		}
	}
	return builder
}

func (params *ipAddressStringParams) append(builder *strings.Builder, addr AddressDivisionSeries, zone Zone) *strings.Builder {
	if addr.GetDivisionCount() > 0 {
		params.appendSuffix(params.appendZone(params.appendSegments(params.appendLabel(builder), addr), zone))
		if !params.reverse && !params.preferWildcards() {
			params.appendPrefixIndicator(builder, addr)
		}
	}
	return builder
}

func (params *ipAddressStringParams) appendSegment(segmentIndex int, div DivisionType, divPrefixLen PrefixLen, builder *strings.Builder, part AddressDivisionSeries) int {
	if params.isSplitDigits() {
		panic("split digits") // split digits restricted to IPv6, because we ignore the errors generated by split digits elsewhere.
	}
	writer := stringWriter{div}
	// consider all the cases in which we need not account for prefix length
	if params.preferWildcards() ||
		divPrefixLen == nil ||
		divPrefixLen.bitCount() >= div.GetBitCount() ||
		!part.IsPrefixBlock() /* || params.isSplitDigits() */ {
		count, _ := writer.getStandardString(segmentIndex, params, builder)
		return count
	}
	// prefix length will have an impact on the string - either we need not print the range at all
	// because it is equivalent to the prefix length, or we need to adjust the upper value of the
	// range so that the host is zero when printing the string
	if div.IsSinglePrefix(divPrefixLen.bitCount()) {
		//if div.ContainsSinglePrefixBlock(*divPrefixLen) {
		//xxx ContainsSinglePrefix xxxx // this could be slightly quicker since we know it is a prefix block (since the whole part is), all we need to know is that it is single prefix.  Add such a method to divStringProvider.
		return writer.getLowerStandardString(segmentIndex, params, builder)
	}
	return writer.getPrefixAdjustedRangeString(segmentIndex, params, builder)
}

func (params *ipAddressStringParams) getZonedStringLength(addr AddressDivisionSeries, zone Zone) int {
	if addr.GetDivisionCount() > 0 {
		result := params.getStringLength(addr)
		if zone != NoZone {
			result += params.getZoneLength(zone, params.zoneSeparator)
		}
		return result
	}
	return 0
}

func (params *ipAddressStringParams) toZonedString(series AddressDivisionSeries, zone Zone) string {
	length := params.getZonedStringLength(series, zone)
	builder := strings.Builder{}
	builder.Grow(length)
	params.append(&builder, series, zone)
	checkLengths(length, &builder)
	return builder.String()
}

func (params *ipAddressStringParams) toString(series AddressDivisionSeries) string {
	return params.toZonedString(series, NoZone)
}

func (params *ipAddressStringParams) clone() *ipAddressStringParams {
	result := *params
	expandSegment := params.expandSeg
	if expandSegment != nil {
		result.expandSeg = cloneInts(expandSegment)
	}
	return &result
}

// Each IPv6StringParams has settings to write exactly one IPv6 address section string
type ipv6StringParams struct {
	ipAddressStringParams

	firstCompressedSegmentIndex, nextUncompressedIndex int //the start and end of any compressed section

	hostCompressed bool //whether the host was compressed, which with some prefix configurations means we must print the network prefix to indicate that the host is full range
}

func (params *ipv6StringParams) endIsCompressed(addr IPAddressSegmentSeries) bool {
	return params.nextUncompressedIndex >= addr.GetDivisionCount()
}

func (params *ipv6StringParams) isCompressed(_ IPAddressSegmentSeries) bool {
	return params.firstCompressedSegmentIndex >= 0
}

func (params *ipv6StringParams) getTrailingSeparatorCount(addr *IPv6AddressSection) int {
	return params.getTrailingSepCount(addr)
}

func (params *ipv6StringParams) getTrailingSepCount(addr IPAddressSegmentSeries) int {
	divisionCount := addr.GetDivisionCount()
	if divisionCount == 0 {
		return 0
	}
	count := divisionCount - 1 //separators with no compression
	if params.isCompressed(addr) {
		firstCompressedSegmentIndex := params.firstCompressedSegmentIndex
		nextUncompressedIndex := params.nextUncompressedIndex
		count -= (nextUncompressedIndex - firstCompressedSegmentIndex) - 1 //missing seps
		if firstCompressedSegmentIndex == 0 /* additional separator at front */ ||
			nextUncompressedIndex >= divisionCount /* additional separator at end */ {
			count++
		}
	}
	return count
}

func (params *ipv6StringParams) append(builder *strings.Builder, addr *IPv6AddressSection, zone Zone) (err addrerr.IncompatibleAddressError) {
	if addr.GetDivisionCount() > 0 {
		// Our order is label, then segments, then zone, then suffix, then prefix length.
		err = params.appendSegments(params.appendLabel(builder), addr)
		if err != nil {
			return
		}
		params.appendSuffix(params.appendZone(builder, zone))
		if !params.reverse && (!params.preferWildcards() || params.hostCompressed) {
			params.appendPrefixIndicator(builder, addr)
		}
	}
	return
}

func (params *ipv6StringParams) appendSegment(segmentIndex int, div DivisionType, divPrefixLen PrefixLen, builder *strings.Builder, part AddressDivisionSeries) (count int, err addrerr.IncompatibleAddressError) {
	if params.isSplitDigits() {
		writer := stringWriter{div}
		count, err = writer.getStandardString(segmentIndex, params, builder)
		return
	}
	count = params.ipAddressStringParams.appendSegment(segmentIndex, div, divPrefixLen, builder, part)
	return
}

func (params *ipv6StringParams) appendSegments(builder *strings.Builder, addr IPv6AddressSegmentSeries) (err addrerr.IncompatibleAddressError) {
	divisionCount := addr.GetDivisionCount()
	if divisionCount <= 0 {
		return nil
	}
	lastIndex := divisionCount - 1
	separator := params.separator
	reverse := params.reverse
	i := 0
	firstCompressedSegmentIndex := params.firstCompressedSegmentIndex
	nextUncompressedIndex := params.nextUncompressedIndex
	hasSep := params.hasSeparator()
	for {
		segIndex := i
		if reverse {
			segIndex = lastIndex - i
		}
		if segIndex < firstCompressedSegmentIndex || segIndex >= nextUncompressedIndex {
			div := addr.GetSegment(segIndex)
			prefLen := div.getDivisionPrefixLength() // Needs to be DivisionType
			_, err = params.appendSegment(segIndex, div, prefLen, builder, addr)
			i++
			if i > lastIndex {
				break
			}
			if hasSep {
				builder.WriteByte(separator)
			}
		} else {
			firstCompressed := firstCompressedSegmentIndex
			if reverse {
				firstCompressed = nextUncompressedIndex - 1
			}
			if segIndex == firstCompressed && hasSep { //the segment is compressed
				builder.WriteByte(separator)
				if i == 0 { //when compressing the front we use two separators
					builder.WriteByte(separator)
				}
			} //else we are in the middle of a compressed set of segments, so nothing to write
			i++
			if i > lastIndex {
				break
			}
		}
	}
	return
}

func (params *ipv6StringParams) getSegmentsStringLength(part IPv6AddressSegmentSeries) int {
	count := 0
	divCount := part.GetDivisionCount()
	if divCount != 0 {
		i := 0
		firstCompressedSegmentIndex := params.firstCompressedSegmentIndex
		nextUncompressedIndex := params.nextUncompressedIndex
		for {
			if i < firstCompressedSegmentIndex || i >= nextUncompressedIndex {
				div := part.GetSegment(i)
				prefLen := div.GetSegmentPrefixLen()
				additionalCount, _ := params.appendSegment(i, div, prefLen, nil, part)
				count += additionalCount
				i++
				if i >= divCount {
					break
				}
				if params.hasSeparator() {
					count++
				}
			} else {
				if i == firstCompressedSegmentIndex && params.hasSeparator() { //the segment is compressed
					count++
					if i == 0 { //when compressing the front we use two separators
						count++
					}
				} //else we are in the middle of a compressed set of segments, so nothing to write
				i++
				if i >= divCount {
					break
				}
			}
		}
	}
	return count
}

func (params *ipv6StringParams) getStringLength(addr *IPv6AddressSection) int {
	count := params.getSegmentsStringLength(addr)
	if !params.reverse && (!params.preferWildcards() || params.hostCompressed) {
		count += getPrefixIndicatorStringLength(addr)
	}
	return count + params.getAddressSuffixLength() + params.getAddressLabelLength()
}

func (params *ipv6StringParams) getZonedStringLength(addr *IPv6AddressSection, zone Zone) int {
	if addr.GetDivisionCount() > 0 {
		result := params.getStringLength(addr)
		if zone != NoZone {
			result += params.getZoneLength(zone, params.zoneSeparator)
		}
		return result
	}
	return 0
}

func (params *ipv6StringParams) toZonedSplitString(addr *IPv6AddressSection, zone Zone) (str string, err addrerr.IncompatibleAddressError) {
	length := params.getZonedStringLength(addr, zone)
	builder := strings.Builder{}
	builder.Grow(length)
	if err = params.append(&builder, addr, zone); err != nil {
		return
	}
	checkLengths(length, &builder)
	str = builder.String()
	return
}

func (params *ipv6StringParams) toZonedString(addr *IPv6AddressSection, zone Zone) string {
	length := params.getZonedStringLength(addr, zone)
	builder := strings.Builder{}
	builder.Grow(length)
	_ = params.append(&builder, addr, zone) // only split strings produce errors
	checkLengths(length, &builder)
	return builder.String()
}

func (params *ipv6StringParams) toString(addr *IPv6AddressSection) string {
	return params.toZonedString(addr, NoZone)
}

func (params *ipv6StringParams) clone() *ipv6StringParams {
	res := *params
	res.ipAddressStringParams = *res.ipAddressStringParams.clone()
	return &res
}

// Each IPv6StringParams has settings to write exactly one IPv6 address section string
type ipv6v4MixedParams struct {
	ipv6Params *ipv6StringParams
	ipv4Params *ipAddressStringParams
}

func (params *ipv6v4MixedParams) getTrailingSegmentSeparator() byte {
	return params.ipv4Params.getTrailingSegmentSeparator()
}

func (params *ipv6v4MixedParams) getTrailingSeparatorCount(addr *IPv6v4MixedAddressGrouping) int {
	return params.ipv4Params.getTrailingSeparatorCount(addr.GetIPv4AddressSection())
}

func (params *ipv6v4MixedParams) getStringLength(addr *IPv6v4MixedAddressGrouping, zone Zone) int {
	if addr.GetDivisionCount() > 0 {
		ipv6Params := params.ipv6Params
		ipv6length := ipv6Params.getSegmentsStringLength(addr.GetIPv6AddressSection())
		ipv4length := params.ipv4Params.getSegmentsStringLength(addr.GetIPv4AddressSection())
		length := ipv6length + ipv4length
		if ipv6Params.nextUncompressedIndex < addr.GetIPv6AddressSection().GetSegmentCount() {
			length++
		}
		length += params.getPrefixStringLength(addr)
		length += ipv6Params.getZoneLength(zone, ipv6Params.zoneSeparator)
		length += ipv6Params.getAddressSuffixLength()
		length += ipv6Params.getAddressLabelLength()
		return length
	}
	return 0
}

func (params *ipv6v4MixedParams) toString(addr *IPv6v4MixedAddressGrouping) string {
	return params.toZonedString(addr, NoZone)
}

func (params *ipv6v4MixedParams) toZonedString(addr *IPv6v4MixedAddressGrouping, zone Zone) string {
	length := params.getStringLength(addr, zone)
	builder := &strings.Builder{}
	builder.Grow(length)
	params.append(builder, addr, zone)
	checkLengths(length, builder)
	return builder.String()
}

func (params *ipv6v4MixedParams) getDivisionStringLength(seg *AddressDivision) int {
	return params.ipv6Params.getDivisionStringLength(seg)
}

func (params *ipv6v4MixedParams) appendDivision(builder *strings.Builder, seg *AddressDivision) *strings.Builder {
	return params.ipv6Params.appendDivision(builder, seg)
}

func (params *ipv6v4MixedParams) append(builder *strings.Builder, addr *IPv6v4MixedAddressGrouping, zone Zone) *strings.Builder {
	if addr.GetDivisionCount() > 0 {
		ipv6Params := params.ipv6Params
		ipv6Params.appendLabel(builder)
		_ = ipv6Params.appendSegments(builder, addr.GetIPv6AddressSection())
		if ipv6Params.nextUncompressedIndex < addr.GetIPv6AddressSection().GetSegmentCount() {
			builder.WriteByte(ipv6Params.getTrailingSegmentSeparator())
		}
		params.ipv4Params.appendSegments(builder, addr.GetIPv4AddressSection())

		/*
		 * RFC 4038: for bracketed addresses, zone is inside and prefix outside, putting prefix after zone.
		 *
		 * Suffixes are things like .in-addr.arpa, .ip6.arpa, .ipv6-literal.net
		 * which generally convert an address string to a host
		 * As with our HostName, we support host/prefix in which case the prefix is applied
		 * to the resolved address.
		 *
		 * So in summary, our order is zone, then suffix, then prefix length.
		 */
		ipv6Params.appendZone(builder, zone)
		ipv6Params.appendSuffix(builder)
		params.appendPrefixIndicator(builder, addr)
	}
	return builder
}

func (params *ipv6v4MixedParams) getPrefixStringLength(addr *IPv6v4MixedAddressGrouping) int {
	if params.requiresPrefixIndicatorIPv6(addr.GetIPv6AddressSection()) || params.requiresPrefixIndicatorIPv4(addr.GetIPv4AddressSection()) {
		return getPrefixIndicatorStringLength(addr)
	}
	return 0
}

func (params *ipv6v4MixedParams) appendPrefixIndicator(builder *strings.Builder, addr *IPv6v4MixedAddressGrouping) {
	if params.requiresPrefixIndicatorIPv6(addr.GetIPv6AddressSection()) || params.requiresPrefixIndicatorIPv4(addr.GetIPv4AddressSection()) {
		params.ipv6Params.appendPrefixIndicator(builder, addr)
	}
}

func (params *ipv6v4MixedParams) requiresPrefixIndicatorIPv4(ipv4Section *IPv4AddressSection) bool {
	return ipv4Section.IsPrefixed() && !params.ipv4Params.preferWildcards()
}

func (params *ipv6v4MixedParams) requiresPrefixIndicatorIPv6(ipv6Section IPv6AddressSegmentSeries) bool {
	//func (params *ipv6v4MixedParams) requiresPrefixIndicatorIPv6(ipv6Section *IPv6AddressSection) bool {
	ipv6Params := params.ipv6Params
	return ipv6Section.IsPrefixed() && (!ipv6Params.preferWildcards() || ipv6Params.hostCompressed)
}

func (params *ipv6v4MixedParams) clone() *ipv6v4MixedParams {
	ipv6Params := *params.ipv6Params
	ipv4Params := *params.ipv4Params
	return &ipv6v4MixedParams{
		ipv6Params: &ipv6Params,
		ipv4Params: &ipv4Params,
	}
}

type stringWriter struct {
	DivisionType
}

// Produces a string to represent the segment, using wildcards and range characters.
// Use this instead of getWildcardString() if you have a customized wildcard or range separator or you have a non-zero leadingZeroCount,
func (writer stringWriter) getStandardString(segmentIndex int, params addressSegmentParams, appendable *strings.Builder) (digitCount int, err addrerr.IncompatibleAddressError) {
	//div := writer.div
	if !writer.IsMultiple() {
		splitDigits := params.isSplitDigits()
		if splitDigits {
			radix := params.getRadix()
			leadingZeroCount := params.getLeadingZeros(segmentIndex)
			leadingZeroCount = writer.adjustLowerLeadingZeroCount(leadingZeroCount, radix)
			stringPrefix := params.getSegmentStrPrefix()
			prefLen := len(stringPrefix)
			if appendable == nil {
				var length int
				if leadingZeroCount != 0 {
					if leadingZeroCount < 0 {
						length = writer.getMaxDigitCountRadix(radix)
					} else {
						length = writer.getLowerStringLength(radix) + leadingZeroCount
					}
				} else {
					length = writer.getLowerStringLength(radix)
				}
				count := (length << 1) - 1
				if prefLen > 0 {
					count += length * prefLen
				}
				return count, nil
			} else {
				var splitDigitSeparator byte = ' '
				if params.hasSeparator() {
					splitDigitSeparator = params.getSplitDigitSeparator()
				}
				reverseSplitDigits := params.isReverseSplitDigits()
				uppercase := params.isUppercase()
				if reverseSplitDigits {
					writer.getSplitLowerString(radix, 0, uppercase, splitDigitSeparator, reverseSplitDigits, stringPrefix, appendable)
					if leadingZeroCount != 0 {
						appendable.WriteByte(splitDigitSeparator)
						getSplitLeadingZeros(leadingZeroCount, splitDigitSeparator, stringPrefix, appendable)
					}
				} else {
					if leadingZeroCount != 0 {
						getSplitLeadingZeros(leadingZeroCount, splitDigitSeparator, stringPrefix, appendable)
						appendable.WriteByte(splitDigitSeparator)
					}
					writer.getSplitLowerString(radix, 0, uppercase, splitDigitSeparator, reverseSplitDigits, stringPrefix, appendable)
				}
				return
			}
		}
		return writer.getLowerStandardString(segmentIndex, params, appendable), nil
	} else if writer.IsFullRange() {
		wildcard := params.getWildcards().GetWildcard()
		if len(wildcard) > 0 {
			splitDigits := params.isSplitDigits()
			if splitDigits {
				radix := params.getRadix()
				if appendable == nil {
					length := writer.getMaxDigitCountRadix(radix)
					count := length*(len(wildcard)+1) - 1
					return count, nil
				}
				var splitDigitSeparator byte = ' '
				if params.hasSeparator() {
					splitDigitSeparator = params.getSplitDigitSeparator()
				}
				dg := writer.getMaxDigitCountRadix(radix)
				getSplitCharStr(dg, splitDigitSeparator, wildcard, "", appendable)
				return
			}
			return getFullRangeString(wildcard, appendable), nil
		}
	}
	return writer.getRangeString(segmentIndex, params, appendable)
}

func (writer stringWriter) getPrefixAdjustedRangeString(segmentIndex int, params addressSegmentParams, appendable *strings.Builder) int {
	leadingZeroCount := params.getLeadingZeros(segmentIndex)
	radix := params.getRadix()
	lowerLeadingZeroCount := writer.adjustLowerLeadingZeroCount(leadingZeroCount, radix)
	upperLeadingZeroCount := writer.adjustUpperLeadingZeroCount(leadingZeroCount, radix)

	//if the wildcards match those in use by getString(), and there is no character prefix, let's defer to getString() so that it is cached
	wildcards := params.getWildcards()
	rangeSeparator := wildcards.GetRangeSeparator()
	rangeDigitCount := 0
	if len(wildcards.GetSingleWildcard()) != 0 {
		rangeDigitCount = writer.getRangeDigitCount(radix)
	}

	//If we can, we reuse the standard string to construct this string (must have the same radix and no chopped digits)
	//We can insert leading zeros, string prefix, and a different separator string if necessary
	//Also, we cannot in the case of full range (in which case we are only here because we do not want '*')
	if rangeDigitCount == 0 && radix == writer.getDefaultTextualRadix() && !writer.IsFullRange() {
		//we call getString() to cache the result, and we call getString instead of getWildcardString() because it will also mask with the segment prefix length
		str := writer.GetString()
		rangeSep := writer.getDefaultRangeSeparatorString()
		stringPrefix := params.getSegmentStrPrefix()
		prefLen := len(stringPrefix)
		if lowerLeadingZeroCount == 0 && upperLeadingZeroCount == 0 && rangeSep == rangeSeparator && prefLen == 0 {
			if appendable == nil {
				return len(str)
			} else {
				if params.isUppercase() {
					appendUppercase(str, radix, appendable)
				} else {
					appendable.WriteString(str)
				}
				return 0
			}
		} else {
			if appendable == nil {
				count := len(str) + (len(rangeSeparator) - len(rangeSep)) +
					lowerLeadingZeroCount + upperLeadingZeroCount
				if prefLen > 0 {
					count += prefLen << 1
				}
				return count
			} else {
				firstEnd := strings.Index(str, rangeSep)
				if prefLen > 0 {
					appendable.WriteString(stringPrefix)
				}
				if lowerLeadingZeroCount > 0 {
					getLeadingZeros(lowerLeadingZeroCount, appendable)
				}
				appendable.WriteString(str[0:firstEnd])
				appendable.WriteString(rangeSeparator)
				if prefLen > 0 {
					appendable.WriteString(stringPrefix)
				}
				if upperLeadingZeroCount > 0 {
					getLeadingZeros(upperLeadingZeroCount, appendable)
				}
				appendable.WriteString(str[firstEnd+len(rangeSep):])
				return 0
			}
		}
	}
	rangeDigitCount = writer.adjustRangeDigits(rangeDigitCount)
	if leadingZeroCount < 0 && appendable == nil {
		charLength := writer.getMaxDigitCountRadix(radix)
		stringPrefix := params.getSegmentStrPrefix()
		prefLen := len(stringPrefix)
		if rangeDigitCount != 0 {
			count := charLength
			if prefLen > 0 {
				count += prefLen
			}
			return count
		}
		count := charLength << 1
		if prefLen > 0 {
			count += prefLen << 1
		}
		count += len(rangeSeparator)
		return count
	}
	if rangeDigitCount != 0 {
		return writer.getRangeDigitString(segmentIndex, params, appendable)
	}
	return writer.getRangeStringWithCounts(segmentIndex, params, lowerLeadingZeroCount, upperLeadingZeroCount, true, appendable)
}

func (writer stringWriter) getLowerStandardString(segmentIndex int, params addressSegmentParams, appendable *strings.Builder) int {
	count := 0
	stringPrefix := params.getSegmentStrPrefix()
	prefLen := len(stringPrefix)
	if prefLen > 0 {
		if appendable == nil {
			count += prefLen
		} else {
			appendable.WriteString(stringPrefix)
		}
	}
	radix := params.getRadix()
	leadingZeroCount := params.getLeadingZeros(segmentIndex)
	if leadingZeroCount != 0 {
		if appendable == nil {
			if leadingZeroCount < 0 {
				return count + writer.getMaxDigitCountRadix(radix)
			} else {
				count += leadingZeroCount
			}
		} else {
			leadingZeroCount = writer.adjustLowerLeadingZeroCount(leadingZeroCount, radix)
			getLeadingZeros(leadingZeroCount, appendable)
		}
	}
	uppercase := params.isUppercase()
	if radix == writer.getDefaultTextualRadix() {
		// Equivalent to GetString for ip addresses but not GetWildcardString.
		// For other addresses, equivalent to either one.
		str := writer.getStringAsLower()
		if appendable == nil {
			return count + len(str)
		} else if uppercase {
			appendUppercase(str, radix, appendable)
		} else {
			appendable.WriteString(str)
		}
	} else {
		if appendable == nil {
			return count + writer.getLowerStringLength(radix)
		} else {
			writer.getLowerString(radix, uppercase, appendable)
		}
	}
	return 0
}

func (writer stringWriter) getRangeString(segmentIndex int, params addressSegmentParams, appendable *strings.Builder) (digitCount int, err addrerr.IncompatibleAddressError) {
	splitDigits := params.isSplitDigits()
	radix := params.getRadix()
	leadingZeroCount := params.getLeadingZeros(segmentIndex)
	wildcards := params.getWildcards()
	rangeSeparator := wildcards.GetRangeSeparator()
	singleWC := wildcards.GetSingleWildcard()
	rangeDigitCount := 0
	if singleWC != "" {
		rangeDigitCount = writer.getRangeDigitCount(radix)
	}
	lowerLeadingZeroCount := writer.adjustLowerLeadingZeroCount(leadingZeroCount, radix)
	upperLeadingZeroCount := writer.adjustUpperLeadingZeroCount(leadingZeroCount, radix)
	//check the case where we can use the result of getWildcardString which is cached.
	//It must have same radix and no chopped digits, and no splitting or reversal of digits.
	//We can insert leading zeros, string prefix, and a different separator string if necessary.
	//Also, we cannot in the case of full range (in which case we are only here because we do not want '*')
	if rangeDigitCount == 0 &&
		radix == writer.getDefaultTextualRadix() &&
		!splitDigits &&
		!writer.IsFullRange() {
		str := writer.GetWildcardString()
		rangeSep := writer.getDefaultRangeSeparatorString()
		stringPrefix := params.getSegmentStrPrefix()
		prefLen := len(stringPrefix)
		if lowerLeadingZeroCount == 0 && upperLeadingZeroCount == 0 &&
			prefLen == 0 &&
			rangeSeparator == rangeSep {
			if appendable == nil {
				return len(str), nil
			}
			appendable.WriteString(str)
			return
		} else {
			if appendable == nil {
				count := len(str) + (len(rangeSeparator) - len(rangeSep)) + lowerLeadingZeroCount + upperLeadingZeroCount
				if prefLen > 0 {
					count += prefLen << 1
				}
				return count, nil
			} else {
				firstEnd := strings.Index(str, rangeSep)
				if prefLen > 0 {
					appendable.WriteString(stringPrefix)
				}
				if lowerLeadingZeroCount > 0 {
					getLeadingZeros(lowerLeadingZeroCount, appendable)
				}
				appendable.WriteString(str[0:firstEnd])
				appendable.WriteString(rangeSeparator)
				if prefLen > 0 {
					appendable.WriteString(stringPrefix)
				}
				if upperLeadingZeroCount > 0 {
					getLeadingZeros(upperLeadingZeroCount, appendable)
				}
				appendable.WriteString(str[firstEnd+len(rangeSep):])
				return
			}
		}
	}
	/*
	 split digits that result in digit ranges of * are similar to range digits range digits
	 eg f00-fff is both f__ and f.*.*
	 One difference is that for decimal last range digit is 0-5 (ie 255) but for split we only check full range (0-9)
	 eg 200-255 is 2__  but not 2.*.*
	 another difference: when calculating range digits, the count is 0 unless the entire range can be written as range digits
	 eg f10-fff has no range digits but is f.1-f.*
	*/
	if !splitDigits && leadingZeroCount < 0 && appendable == nil {
		stringPrefix := params.getSegmentStrPrefix()
		prefLen := len(stringPrefix)
		charLength := writer.getMaxDigitCountRadix(radix)
		if rangeDigitCount != 0 {
			count := charLength
			if prefLen > 0 {
				count += prefLen
			}
			return count, nil
		}
		count := charLength << 1
		if prefLen > 0 {
			count += prefLen << 1
		}
		count += len(rangeSeparator)
		return count, nil
	}
	rangeDigitCount = writer.adjustRangeDigits(rangeDigitCount)
	if rangeDigitCount != 0 { // wildcards like _
		if splitDigits {
			return writer.getSplitRangeDigitString(segmentIndex, params, appendable), nil
		} else {
			return writer.getRangeDigitString(segmentIndex, params, appendable), nil
		}
	}
	if splitDigits {
		return writer.writeSplitRangeString(segmentIndex, params, appendable)
	}
	return writer.getRangeStringWithCounts(segmentIndex, params, lowerLeadingZeroCount, upperLeadingZeroCount, false, appendable), nil
}

func (writer stringWriter) getSplitRangeDigitString(segmentIndex int, params addressSegmentParams, appendable *strings.Builder) int {
	radix := params.getRadix()
	leadingZerosCount := params.getLeadingZeros(segmentIndex)
	leadingZerosCount = writer.adjustLowerLeadingZeroCount(leadingZerosCount, radix)
	stringPrefix := params.getSegmentStrPrefix()
	if appendable == nil {
		length := writer.getLowerStringLength(radix) + leadingZerosCount
		count := (length << 1) - 1
		prefLen := len(stringPrefix)
		if prefLen > 0 {
			count += length * prefLen
		}
		return count
	} else {
		wildcards := params.getWildcards()
		dc := writer.getRangeDigitCount(radix)
		rangeDigits := writer.adjustRangeDigits(dc)
		var splitDigitSeparator byte = ' '
		if params.hasSeparator() {
			splitDigitSeparator = params.getSplitDigitSeparator()
		}
		reverseSplitDigits := params.isReverseSplitDigits()
		uppercase := params.isUppercase()
		if reverseSplitDigits {
			getSplitCharStr(rangeDigits, splitDigitSeparator, wildcards.GetSingleWildcard(), stringPrefix, appendable)
			appendable.WriteByte(splitDigitSeparator)
			writer.getSplitLowerString(radix, rangeDigits, uppercase, splitDigitSeparator, reverseSplitDigits, stringPrefix, appendable)
			if leadingZerosCount > 0 {
				appendable.WriteByte(splitDigitSeparator)
				getSplitLeadingZeros(leadingZerosCount, splitDigitSeparator, stringPrefix, appendable)
			}
		} else {
			if leadingZerosCount != 0 {
				getSplitLeadingZeros(leadingZerosCount, splitDigitSeparator, stringPrefix, appendable)
				appendable.WriteByte(splitDigitSeparator)
			}
			writer.getSplitLowerString(radix, rangeDigits, uppercase, splitDigitSeparator, reverseSplitDigits, stringPrefix, appendable)
			appendable.WriteByte(splitDigitSeparator)
			getSplitCharStr(rangeDigits, splitDigitSeparator, wildcards.GetSingleWildcard(), stringPrefix, appendable)
		}
	}
	return 0
}

func (writer stringWriter) getRangeDigitString(segmentIndex int, params addressSegmentParams, appendable *strings.Builder) int {
	radix := params.getRadix()
	leadingZerosCount := params.getLeadingZeros(segmentIndex)
	leadingZerosCount = writer.adjustLowerLeadingZeroCount(leadingZerosCount, radix)
	stringPrefix := params.getSegmentStrPrefix()
	prefLen := len(stringPrefix)
	wildcards := params.getWildcards()
	dc := writer.getRangeDigitCount(radix)
	rangeDigits := writer.adjustRangeDigits(dc)
	if appendable == nil {
		return writer.getLowerStringLength(radix) + leadingZerosCount + prefLen
	} else {
		if prefLen > 0 {
			appendable.WriteString(stringPrefix)
		}
		if leadingZerosCount > 0 {
			getLeadingZeros(leadingZerosCount, appendable)
		}
		uppercase := params.isUppercase()
		writer.getLowerStringChopped(radix, rangeDigits, uppercase, appendable)
		for i := 0; i < rangeDigits; i++ {
			appendable.WriteString(wildcards.GetSingleWildcard())
		}
	}
	return 0
}

func (writer stringWriter) adjustRangeDigits(rangeDigits int) int {
	if rangeDigits != 0 {
		//Note: ranges like ___ intended to represent 0-fff cannot work because the range does not include 2 digit and 1 digit numbers
		//This only happens when the lower value is 0 and there is more than 1 range digit
		//That's because you can then omit any leading zeros.
		//Ranges like f___ representing f000-ffff are fine.
		if !writer.IncludesZero() || rangeDigits == 1 {
			return rangeDigits
		}
	}
	return 0
}

func (writer stringWriter) getRangeStringWithCounts(
	segmentIndex int,
	params addressSegmentParams,
	lowerLeadingZerosCount int,
	upperLeadingZerosCount int,
	maskUpper bool,
	appendable *strings.Builder) int {
	_ = segmentIndex
	stringPrefix := params.getSegmentStrPrefix()
	radix := params.getRadix()
	rangeSeparator := params.getWildcards().GetRangeSeparator()
	uppercase := params.isUppercase()
	return getRangeString(writer.DivisionType, rangeSeparator, lowerLeadingZerosCount, upperLeadingZerosCount, stringPrefix, radix, uppercase, maskUpper, appendable)
}

func (writer stringWriter) writeSplitRangeString(
	segmentIndex int,
	params addressSegmentParams,
	appendable *strings.Builder) (int, addrerr.IncompatibleAddressError) {
	stringPrefix := params.getSegmentStrPrefix()
	radix := params.getRadix()
	leadingZeroCount := params.getLeadingZeros(segmentIndex)
	//for split ranges, it is the leading zeros of the upper value that matters
	leadingZeroCount = writer.adjustUpperLeadingZeroCount(leadingZeroCount, radix)
	wildcards := params.getWildcards()
	uppercase := params.isUppercase()
	var splitDigitSeparator byte = ' '
	if params.hasSeparator() {
		splitDigitSeparator = params.getSplitDigitSeparator()
	}
	reverseSplitDigits := params.isReverseSplitDigits()
	rangeSeparator := wildcards.GetRangeSeparator()
	if appendable == nil {
		return writer.getSplitRangeStringLength(
			rangeSeparator,
			wildcards.GetWildcard(),
			leadingZeroCount,
			radix,
			uppercase,
			splitDigitSeparator,
			reverseSplitDigits,
			stringPrefix), nil
	} else {
		hasLeadingZeros := leadingZeroCount != 0
		if hasLeadingZeros && !reverseSplitDigits {
			getSplitLeadingZeros(leadingZeroCount, splitDigitSeparator, stringPrefix, appendable)
			appendable.WriteByte(splitDigitSeparator)
			hasLeadingZeros = false
		}
		if err := writer.getSplitRangeString(
			rangeSeparator,
			wildcards.GetWildcard(),
			radix,
			uppercase,
			splitDigitSeparator,
			reverseSplitDigits,
			stringPrefix,
			appendable); err != nil {
			return 0, err
		}
		if hasLeadingZeros {
			appendable.WriteByte(splitDigitSeparator)
			getSplitLeadingZeros(leadingZeroCount, splitDigitSeparator, stringPrefix, appendable)
		}
	}
	return 0, nil
}

func getSplitCharStr(count int, splitDigitSeparator byte, characters string, stringPrefix string, builder *strings.Builder) {
	prefLen := len(stringPrefix)
	if count > 0 {
		for {
			if prefLen > 0 {
				builder.WriteString(stringPrefix)
			}
			builder.WriteString(characters)
			count--
			if count <= 0 {
				break
			}
			builder.WriteByte(splitDigitSeparator)
		}
	}
}

func getSplitChar(count int, splitDigitSeparator, character byte, stringPrefix string, builder *strings.Builder) {
	prefLen := len(stringPrefix)
	if count > 0 {
		for {
			if prefLen > 0 {
				builder.WriteString(stringPrefix)
			}
			builder.WriteByte(character)
			count--
			if count <= 0 {
				break
			}
			builder.WriteByte(splitDigitSeparator)
		}
	}
}

func getSplitLeadingZeros(leadingZeroCount int, splitDigitSeparator byte, stringPrefix string, builder *strings.Builder) {
	getSplitChar(leadingZeroCount, splitDigitSeparator, '0', stringPrefix, builder)
}

func appendUppercase(str string, radix int, appendable *strings.Builder) {
	if radix > 10 {
		for i := 0; i < len(str); i++ {
			c := str[i]
			if c >= 'a' && c <= 'z' {
				c -= byte('a') - byte('A')
			}
			appendable.WriteByte(c)
		}
	} else {
		appendable.WriteString(str)
	}
}

func getFullRangeString(wildcard string, appendable *strings.Builder) int {
	if appendable == nil {
		return len(wildcard)
	}
	appendable.WriteString(wildcard)
	return 0
}

func getLeadingZeros(leadingZeroCount int, builder *strings.Builder) {
	if leadingZeroCount > 0 {
		stringArray := zeros
		increment := len(stringArray)
		if leadingZeroCount > increment {
			for leadingZeroCount > increment {
				builder.WriteString(stringArray)
				leadingZeroCount -= increment
			}
		}
		builder.WriteString(stringArray[:leadingZeroCount])
	}
}

const zeros = "00000000000000000000"

func toNormalizedStringRange(params *addressStringParams, lower, upper AddressDivisionSeries, zone Zone) string {
	if lower.GetDivisionCount() > 0 {
		var builder strings.Builder
		length := params.getStringLength(lower) + params.getZonedStringLength(upper, zone)
		separator := params.getWildcards().GetRangeSeparator()
		if separator != "" {
			length += len(separator)
			builder.Grow(length)
			params.append(&builder, lower).WriteString(separator)
			params.appendZoned(&builder, upper, zone)

		} else {
			builder.Grow(length)
			params.appendZoned(params.append(&builder, lower), upper, zone)
		}
		checkLengths(length, &builder)
		return builder.String()
	}
	return ""
}