package chat

// Code generated by the Holanet PDL compiler. DO NOT EDIT.
// The source file is located at <path>
// Please edit that file instead, and re-compile it to this location.
// HOPP, TAPE, METADAPT, PDL/0 (c) 2025 holanet.xyz

import "fmt"
import "git.tebibyte.media/sashakoshka/hopp"
import "git.tebibyte.media/sashakoshka/hopp/tape"

// Table is a KTV table with an undefined schema.
type Table = map[uint16] any

// Message is any message that can be sent along this protocol.
type Message interface {
	tape.Encodable
	tape.Decodable

	// Method returns the method code of the message.
	Method() uint16
}

// Send encodes a message and sends it along a transaction.
func Send(trans hopp.Trans, message Message) (n int, err error) {
	writer, err := trans.SendWriter(message.Method())
	if err != nil { return n, err }
	defer writer.Close()
	encoder := tape.NewEncoder(writer)
	n, err = message.Encode(encoder)
	if err != nil { return n, err }
	return n, encoder.Flush()
}

// canAssign determines if data from the given source tag can be assigned to
// a Go type represented by destination. It is designed to receive destination
// values from [generate.Generator.generateCanAssign]. The eventual Go type and
// the destination tag must come from the same (or hash-equivalent) PDL type.
func canAssign(destination, source tape.Tag) bool {
	if destination.Is(source) { return true }
	if (destination.Is(tape.SBA) || destination.Is(tape.LBA)) &&
		(source.Is(tape.SBA) || source.Is(tape.LBA)) {
		return true
	}
	return false
}

// boolInt converts a bool to an integer.
func boolInt(input bool) int {
	if input {
		return 1
	} else {
		return 0
	}
}

// ensure ucontainer is always imported
var _ hopp.Option[int]

// Error is sent by a party when the other party has done something erroneous. The
// valid error codes are:
// 
//   - 0: General, unspecified error 
// 
// The description field, if specified, determines a human-readable error to be
// shown to the user. The sending party must immediately close the transaction
// after this message is sent.
type MessageError struct {
	Code uint16
	Description hopp.Option[string]
}

// Method returns the message's method number.
func(this *MessageError) Method() uint16 { return 0x0000 }

// Encode encodes this message's tag and value.
func(this *MessageError) Encode(encoder *tape.Encoder) (n int, err error) {
	tag_1 := tape.KTV.WithCN(0)
	nn, err := encoder.WriteTag(tag_1)
	n += nn; if err != nil { return n, err }
	if 2 > tape.MaxStructureLength {
		return n, tape.ErrTooLong
	}
	nn, err = encoder.WriteUintN(2, tag_1.CN() + 1)
	n += nn; if err != nil { return n, err }
	{
		if value, ok := (*this).Description.Value(); ok {
			nn, err = encoder.WriteUint16(0x0001)
			n += nn; if err != nil { return n, err }
			tag_2 := tape.StringTag(string(value))
			nn, err = encoder.WriteUint8(uint8(tag_2))
			n += nn; if err != nil { return n, err }
			if len(value) > tape.MaxStructureLength {
				return n, tape.ErrTooLong
			}
			if tag_2.Is(tape.LBA) {
				nn, err = encoder.WriteUintN(uint64(len(value)), tag_2.CN())
				n += nn; if err != nil { return n, err }
			}
			nn, err = encoder.Write([]byte(value))
			n += nn; if err != nil { return n, err }
		}
		nn, err = encoder.WriteUint16(0x0000)
		n += nn; if err != nil { return n, err }
		tag_3 := tape.LI.WithCN(1)
		nn, err = encoder.WriteUint8(uint8(tag_3))
		n += nn; if err != nil { return n, err }
		nn, err = encoder.WriteUint16(uint16((*this).Code))
		n += nn; if err != nil { return n, err }
	}
	return n, nil
}

// Decode decodes this message's tag and value.
func(this *MessageError) Decode(decoder *tape.Decoder) (n int, err error) {
	tag, nn, err := decoder.ReadTag()
	n += nn; if err != nil { return n, err }
	if !(canAssign(tape.KTV, tag)) {
		nn, err = tape.Skim(decoder, tag)
		n += nn; if err != nil { return n, err }
		return n, nil
	}
	nn, err = decodeBranch_1d505103df99c95e6bed0800d0ea881a_MessageError(this, decoder, tag)
	n += nn; if err != nil { return n, err }
	return n, nil
}

// Success is sent by a party when it has successfully completed a task given to it
// by the other party. The sending party must immediately close the transaction
// after this message is sent.
type MessageSuccess struct {
}

// Method returns the message's method number.
func(this *MessageSuccess) Method() uint16 { return 0x0001 }

// Encode encodes this message's tag and value.
func(this *MessageSuccess) Encode(encoder *tape.Encoder) (n int, err error) {
	tag_4 := tape.KTV.WithCN(0)
	nn, err := encoder.WriteTag(tag_4)
	n += nn; if err != nil { return n, err }
	if 0 > tape.MaxStructureLength {
		return n, tape.ErrTooLong
	}
	nn, err = encoder.WriteUintN(0, tag_4.CN() + 1)
	n += nn; if err != nil { return n, err }
	{
	}
	return n, nil
}

// Decode decodes this message's tag and value.
func(this *MessageSuccess) Decode(decoder *tape.Decoder) (n int, err error) {
	tag, nn, err := decoder.ReadTag()
	n += nn; if err != nil { return n, err }
	if !(canAssign(tape.KTV, tag)) {
		nn, err = tape.Skim(decoder, tag)
		n += nn; if err != nil { return n, err }
		return n, nil
	}
	nn, err = decodeBranch_99914b932bd37a50b983c5e7c90ae93b_MessageSuccess(this, decoder, tag)
	n += nn; if err != nil { return n, err }
	return n, nil
}

// Join is sent by the client when it wishes to join a room. It must begin a new
// transaction, and that transaction will persist while the user is in that room.
// Messages having to do with the room will be sent along this transaction. To
// leave the room, the client must close the transaction.
type MessageJoin struct {
	Room string
	Nickname string
}

// Method returns the message's method number.
func(this *MessageJoin) Method() uint16 { return 0x0200 }

// Encode encodes this message's tag and value.
func(this *MessageJoin) Encode(encoder *tape.Encoder) (n int, err error) {
	tag_5 := tape.KTV.WithCN(0)
	nn, err := encoder.WriteTag(tag_5)
	n += nn; if err != nil { return n, err }
	if 2 > tape.MaxStructureLength {
		return n, tape.ErrTooLong
	}
	nn, err = encoder.WriteUintN(2, tag_5.CN() + 1)
	n += nn; if err != nil { return n, err }
	{
		nn, err = encoder.WriteUint16(0x0000)
		n += nn; if err != nil { return n, err }
		tag_6 := tape.StringTag(string((*this).Room))
		nn, err = encoder.WriteUint8(uint8(tag_6))
		n += nn; if err != nil { return n, err }
		if len((*this).Room) > tape.MaxStructureLength {
			return n, tape.ErrTooLong
		}
		if tag_6.Is(tape.LBA) {
			nn, err = encoder.WriteUintN(uint64(len((*this).Room)), tag_6.CN())
			n += nn; if err != nil { return n, err }
		}
		nn, err = encoder.Write([]byte((*this).Room))
		n += nn; if err != nil { return n, err }
		nn, err = encoder.WriteUint16(0x0001)
		n += nn; if err != nil { return n, err }
		tag_7 := tape.StringTag(string((*this).Nickname))
		nn, err = encoder.WriteUint8(uint8(tag_7))
		n += nn; if err != nil { return n, err }
		if len((*this).Nickname) > tape.MaxStructureLength {
			return n, tape.ErrTooLong
		}
		if tag_7.Is(tape.LBA) {
			nn, err = encoder.WriteUintN(uint64(len((*this).Nickname)), tag_7.CN())
			n += nn; if err != nil { return n, err }
		}
		nn, err = encoder.Write([]byte((*this).Nickname))
		n += nn; if err != nil { return n, err }
	}
	return n, nil
}

// Decode decodes this message's tag and value.
func(this *MessageJoin) Decode(decoder *tape.Decoder) (n int, err error) {
	tag, nn, err := decoder.ReadTag()
	n += nn; if err != nil { return n, err }
	if !(canAssign(tape.KTV, tag)) {
		nn, err = tape.Skim(decoder, tag)
		n += nn; if err != nil { return n, err }
		return n, nil
	}
	nn, err = decodeBranch_2c5f22d9503118676b4c5584211a4a95_MessageJoin(this, decoder, tag)
	n += nn; if err != nil { return n, err }
	return n, nil
}

// Chat is sent by the client when it wishes to post a message to the room. It is
// also relayed by the server to other clients to notify them of the message. It
// must be sent within a room transaction.
type MessageChat struct {
	Content string
	Nickname string
}

// Method returns the message's method number.
func(this *MessageChat) Method() uint16 { return 0x0300 }

// Encode encodes this message's tag and value.
func(this *MessageChat) Encode(encoder *tape.Encoder) (n int, err error) {
	tag_8 := tape.KTV.WithCN(0)
	nn, err := encoder.WriteTag(tag_8)
	n += nn; if err != nil { return n, err }
	if 2 > tape.MaxStructureLength {
		return n, tape.ErrTooLong
	}
	nn, err = encoder.WriteUintN(2, tag_8.CN() + 1)
	n += nn; if err != nil { return n, err }
	{
		nn, err = encoder.WriteUint16(0x0000)
		n += nn; if err != nil { return n, err }
		tag_9 := tape.StringTag(string((*this).Content))
		nn, err = encoder.WriteUint8(uint8(tag_9))
		n += nn; if err != nil { return n, err }
		if len((*this).Content) > tape.MaxStructureLength {
			return n, tape.ErrTooLong
		}
		if tag_9.Is(tape.LBA) {
			nn, err = encoder.WriteUintN(uint64(len((*this).Content)), tag_9.CN())
			n += nn; if err != nil { return n, err }
		}
		nn, err = encoder.Write([]byte((*this).Content))
		n += nn; if err != nil { return n, err }
		nn, err = encoder.WriteUint16(0x0001)
		n += nn; if err != nil { return n, err }
		tag_10 := tape.StringTag(string((*this).Nickname))
		nn, err = encoder.WriteUint8(uint8(tag_10))
		n += nn; if err != nil { return n, err }
		if len((*this).Nickname) > tape.MaxStructureLength {
			return n, tape.ErrTooLong
		}
		if tag_10.Is(tape.LBA) {
			nn, err = encoder.WriteUintN(uint64(len((*this).Nickname)), tag_10.CN())
			n += nn; if err != nil { return n, err }
		}
		nn, err = encoder.Write([]byte((*this).Nickname))
		n += nn; if err != nil { return n, err }
	}
	return n, nil
}

// Decode decodes this message's tag and value.
func(this *MessageChat) Decode(decoder *tape.Decoder) (n int, err error) {
	tag, nn, err := decoder.ReadTag()
	n += nn; if err != nil { return n, err }
	if !(canAssign(tape.KTV, tag)) {
		nn, err = tape.Skim(decoder, tag)
		n += nn; if err != nil { return n, err }
		return n, nil
	}
	nn, err = decodeBranch_5c1cf9347bb6d9f41cee64b186392d24_MessageChat(this, decoder, tag)
	n += nn; if err != nil { return n, err }
	return n, nil
}

// JoinNotify is sent by the server when another client joins the room. It must be
// sent within a room transaction.
type MessageJoinNotify struct {
	Nickname string
}

// Method returns the message's method number.
func(this *MessageJoinNotify) Method() uint16 { return 0x0400 }

// Encode encodes this message's tag and value.
func(this *MessageJoinNotify) Encode(encoder *tape.Encoder) (n int, err error) {
	tag_11 := tape.KTV.WithCN(0)
	nn, err := encoder.WriteTag(tag_11)
	n += nn; if err != nil { return n, err }
	if 1 > tape.MaxStructureLength {
		return n, tape.ErrTooLong
	}
	nn, err = encoder.WriteUintN(1, tag_11.CN() + 1)
	n += nn; if err != nil { return n, err }
	{
		nn, err = encoder.WriteUint16(0x0000)
		n += nn; if err != nil { return n, err }
		tag_12 := tape.StringTag(string((*this).Nickname))
		nn, err = encoder.WriteUint8(uint8(tag_12))
		n += nn; if err != nil { return n, err }
		if len((*this).Nickname) > tape.MaxStructureLength {
			return n, tape.ErrTooLong
		}
		if tag_12.Is(tape.LBA) {
			nn, err = encoder.WriteUintN(uint64(len((*this).Nickname)), tag_12.CN())
			n += nn; if err != nil { return n, err }
		}
		nn, err = encoder.Write([]byte((*this).Nickname))
		n += nn; if err != nil { return n, err }
	}
	return n, nil
}

// Decode decodes this message's tag and value.
func(this *MessageJoinNotify) Decode(decoder *tape.Decoder) (n int, err error) {
	tag, nn, err := decoder.ReadTag()
	n += nn; if err != nil { return n, err }
	if !(canAssign(tape.KTV, tag)) {
		nn, err = tape.Skim(decoder, tag)
		n += nn; if err != nil { return n, err }
		return n, nil
	}
	nn, err = decodeBranch_68c536511e6d598462efc482144438e9_MessageJoinNotify(this, decoder, tag)
	n += nn; if err != nil { return n, err }
	return n, nil
}

// LeaveNotify is sent by the server when another client leaves the room. It must
// be sent within a room transaction.
type MessageLeaveNotify struct {
	Nickname string
}

// Method returns the message's method number.
func(this *MessageLeaveNotify) Method() uint16 { return 0x0401 }

// Encode encodes this message's tag and value.
func(this *MessageLeaveNotify) Encode(encoder *tape.Encoder) (n int, err error) {
	tag_13 := tape.KTV.WithCN(0)
	nn, err := encoder.WriteTag(tag_13)
	n += nn; if err != nil { return n, err }
	if 1 > tape.MaxStructureLength {
		return n, tape.ErrTooLong
	}
	nn, err = encoder.WriteUintN(1, tag_13.CN() + 1)
	n += nn; if err != nil { return n, err }
	{
		nn, err = encoder.WriteUint16(0x0000)
		n += nn; if err != nil { return n, err }
		tag_14 := tape.StringTag(string((*this).Nickname))
		nn, err = encoder.WriteUint8(uint8(tag_14))
		n += nn; if err != nil { return n, err }
		if len((*this).Nickname) > tape.MaxStructureLength {
			return n, tape.ErrTooLong
		}
		if tag_14.Is(tape.LBA) {
			nn, err = encoder.WriteUintN(uint64(len((*this).Nickname)), tag_14.CN())
			n += nn; if err != nil { return n, err }
		}
		nn, err = encoder.Write([]byte((*this).Nickname))
		n += nn; if err != nil { return n, err }
	}
	return n, nil
}

// Decode decodes this message's tag and value.
func(this *MessageLeaveNotify) Decode(decoder *tape.Decoder) (n int, err error) {
	tag, nn, err := decoder.ReadTag()
	n += nn; if err != nil { return n, err }
	if !(canAssign(tape.KTV, tag)) {
		nn, err = tape.Skim(decoder, tag)
		n += nn; if err != nil { return n, err }
		return n, nil
	}
	nn, err = decodeBranch_68c536511e6d598462efc482144438e9_MessageLeaveNotify(this, decoder, tag)
	n += nn; if err != nil { return n, err }
	return n, nil
}

func decodeBranch_1d505103df99c95e6bed0800d0ea881a_MessageError(this *MessageError, decoder *tape.Decoder, tag tape.Tag) (n int, err error) {
	var nn int
	var length_15 uint64
	if length_15 > uint64(tape.MaxStructureLength) {
		return n, tape.ErrTooLong
	}
	length_15, nn, err = decoder.ReadUintN(int(tag.CN()) + 1)
	n += nn; if err != nil { return n, err }
	for _ = range length_15 {
		var fieldKey_16 uint16
		fieldKey_16, nn, err = decoder.ReadUint16()
		n += nn; if err != nil { return n, err }
		var fieldTag_17 tape.Tag
		fieldTag_17, nn, err = decoder.ReadTag()
		n += nn; if err != nil { return n, err }
		switch fieldKey_16 {
		case 0x0000:
			if !(canAssign(tape.LI, fieldTag_17)) {
				tape.Skim(decoder, fieldTag_17)
				continue
			}
			destination_18, nn, err := decoder.ReadUint16()
			n += nn; if err != nil { return n, err }
			*(&(this.Code)) = destination_18
		case 0x0001:
			if !(canAssign(tape.LBA, fieldTag_17)) {
				tape.Skim(decoder, fieldTag_17)
				continue
			}
			var destination_19 string
			var length_20 uint64
			if fieldTag_17.Is(tape.LBA) {
				length_20, nn, err = decoder.ReadUintN(int(fieldTag_17.CN()))
				n += nn; if err != nil { return n, err }
			} else {
				length_20 = uint64(fieldTag_17.CN())
			}
			if length_20 > uint64(tape.MaxStructureLength) {
				return n, tape.ErrTooLong
			}
			buffer := make([]byte, length_20)
			nn, err = decoder.Read(buffer)
			n += nn; if err != nil { return n, err }
			*(&destination_19) = string(buffer)
			this.Description = hopp.O(destination_19)
		default:
			tape.Skim(decoder, fieldTag_17)
			continue
		}
	}
	return n, nil
}

func decodeBranch_99914b932bd37a50b983c5e7c90ae93b_MessageSuccess(this *MessageSuccess, decoder *tape.Decoder, tag tape.Tag) (n int, err error) {
	var nn int
	var length_21 uint64
	if length_21 > uint64(tape.MaxStructureLength) {
		return n, tape.ErrTooLong
	}
	length_21, nn, err = decoder.ReadUintN(int(tag.CN()) + 1)
	n += nn; if err != nil { return n, err }
	for _ = range length_21 {
		var fieldKey_22 uint16
		fieldKey_22, nn, err = decoder.ReadUint16()
		n += nn; if err != nil { return n, err }
		var fieldTag_23 tape.Tag
		fieldTag_23, nn, err = decoder.ReadTag()
		n += nn; if err != nil { return n, err }
		switch fieldKey_22 {
		default:
			tape.Skim(decoder, fieldTag_23)
			continue
		}
	}
	return n, nil
}

func decodeBranch_2c5f22d9503118676b4c5584211a4a95_MessageJoin(this *MessageJoin, decoder *tape.Decoder, tag tape.Tag) (n int, err error) {
	var nn int
	var length_24 uint64
	if length_24 > uint64(tape.MaxStructureLength) {
		return n, tape.ErrTooLong
	}
	length_24, nn, err = decoder.ReadUintN(int(tag.CN()) + 1)
	n += nn; if err != nil { return n, err }
	for _ = range length_24 {
		var fieldKey_25 uint16
		fieldKey_25, nn, err = decoder.ReadUint16()
		n += nn; if err != nil { return n, err }
		var fieldTag_26 tape.Tag
		fieldTag_26, nn, err = decoder.ReadTag()
		n += nn; if err != nil { return n, err }
		switch fieldKey_25 {
		case 0x0000:
			if !(canAssign(tape.LBA, fieldTag_26)) {
				tape.Skim(decoder, fieldTag_26)
				continue
			}
			var length_27 uint64
			if fieldTag_26.Is(tape.LBA) {
				length_27, nn, err = decoder.ReadUintN(int(fieldTag_26.CN()))
				n += nn; if err != nil { return n, err }
			} else {
				length_27 = uint64(fieldTag_26.CN())
			}
			if length_27 > uint64(tape.MaxStructureLength) {
				return n, tape.ErrTooLong
			}
			buffer := make([]byte, length_27)
			nn, err = decoder.Read(buffer)
			n += nn; if err != nil { return n, err }
			*(&(this.Room)) = string(buffer)
		case 0x0001:
			if !(canAssign(tape.LBA, fieldTag_26)) {
				tape.Skim(decoder, fieldTag_26)
				continue
			}
			var length_28 uint64
			if fieldTag_26.Is(tape.LBA) {
				length_28, nn, err = decoder.ReadUintN(int(fieldTag_26.CN()))
				n += nn; if err != nil { return n, err }
			} else {
				length_28 = uint64(fieldTag_26.CN())
			}
			if length_28 > uint64(tape.MaxStructureLength) {
				return n, tape.ErrTooLong
			}
			buffer := make([]byte, length_28)
			nn, err = decoder.Read(buffer)
			n += nn; if err != nil { return n, err }
			*(&(this.Nickname)) = string(buffer)
		default:
			tape.Skim(decoder, fieldTag_26)
			continue
		}
	}
	return n, nil
}

func decodeBranch_5c1cf9347bb6d9f41cee64b186392d24_MessageChat(this *MessageChat, decoder *tape.Decoder, tag tape.Tag) (n int, err error) {
	var nn int
	var length_29 uint64
	if length_29 > uint64(tape.MaxStructureLength) {
		return n, tape.ErrTooLong
	}
	length_29, nn, err = decoder.ReadUintN(int(tag.CN()) + 1)
	n += nn; if err != nil { return n, err }
	for _ = range length_29 {
		var fieldKey_30 uint16
		fieldKey_30, nn, err = decoder.ReadUint16()
		n += nn; if err != nil { return n, err }
		var fieldTag_31 tape.Tag
		fieldTag_31, nn, err = decoder.ReadTag()
		n += nn; if err != nil { return n, err }
		switch fieldKey_30 {
		case 0x0000:
			if !(canAssign(tape.LBA, fieldTag_31)) {
				tape.Skim(decoder, fieldTag_31)
				continue
			}
			var length_32 uint64
			if fieldTag_31.Is(tape.LBA) {
				length_32, nn, err = decoder.ReadUintN(int(fieldTag_31.CN()))
				n += nn; if err != nil { return n, err }
			} else {
				length_32 = uint64(fieldTag_31.CN())
			}
			if length_32 > uint64(tape.MaxStructureLength) {
				return n, tape.ErrTooLong
			}
			buffer := make([]byte, length_32)
			nn, err = decoder.Read(buffer)
			n += nn; if err != nil { return n, err }
			*(&(this.Content)) = string(buffer)
		case 0x0001:
			if !(canAssign(tape.LBA, fieldTag_31)) {
				tape.Skim(decoder, fieldTag_31)
				continue
			}
			var length_33 uint64
			if fieldTag_31.Is(tape.LBA) {
				length_33, nn, err = decoder.ReadUintN(int(fieldTag_31.CN()))
				n += nn; if err != nil { return n, err }
			} else {
				length_33 = uint64(fieldTag_31.CN())
			}
			if length_33 > uint64(tape.MaxStructureLength) {
				return n, tape.ErrTooLong
			}
			buffer := make([]byte, length_33)
			nn, err = decoder.Read(buffer)
			n += nn; if err != nil { return n, err }
			*(&(this.Nickname)) = string(buffer)
		default:
			tape.Skim(decoder, fieldTag_31)
			continue
		}
	}
	return n, nil
}

func decodeBranch_68c536511e6d598462efc482144438e9_MessageJoinNotify(this *MessageJoinNotify, decoder *tape.Decoder, tag tape.Tag) (n int, err error) {
	var nn int
	var length_34 uint64
	if length_34 > uint64(tape.MaxStructureLength) {
		return n, tape.ErrTooLong
	}
	length_34, nn, err = decoder.ReadUintN(int(tag.CN()) + 1)
	n += nn; if err != nil { return n, err }
	for _ = range length_34 {
		var fieldKey_35 uint16
		fieldKey_35, nn, err = decoder.ReadUint16()
		n += nn; if err != nil { return n, err }
		var fieldTag_36 tape.Tag
		fieldTag_36, nn, err = decoder.ReadTag()
		n += nn; if err != nil { return n, err }
		switch fieldKey_35 {
		case 0x0000:
			if !(canAssign(tape.LBA, fieldTag_36)) {
				tape.Skim(decoder, fieldTag_36)
				continue
			}
			var length_37 uint64
			if fieldTag_36.Is(tape.LBA) {
				length_37, nn, err = decoder.ReadUintN(int(fieldTag_36.CN()))
				n += nn; if err != nil { return n, err }
			} else {
				length_37 = uint64(fieldTag_36.CN())
			}
			if length_37 > uint64(tape.MaxStructureLength) {
				return n, tape.ErrTooLong
			}
			buffer := make([]byte, length_37)
			nn, err = decoder.Read(buffer)
			n += nn; if err != nil { return n, err }
			*(&(this.Nickname)) = string(buffer)
		default:
			tape.Skim(decoder, fieldTag_36)
			continue
		}
	}
	return n, nil
}

func decodeBranch_68c536511e6d598462efc482144438e9_MessageLeaveNotify(this *MessageLeaveNotify, decoder *tape.Decoder, tag tape.Tag) (n int, err error) {
	var nn int
	var length_38 uint64
	if length_38 > uint64(tape.MaxStructureLength) {
		return n, tape.ErrTooLong
	}
	length_38, nn, err = decoder.ReadUintN(int(tag.CN()) + 1)
	n += nn; if err != nil { return n, err }
	for _ = range length_38 {
		var fieldKey_39 uint16
		fieldKey_39, nn, err = decoder.ReadUint16()
		n += nn; if err != nil { return n, err }
		var fieldTag_40 tape.Tag
		fieldTag_40, nn, err = decoder.ReadTag()
		n += nn; if err != nil { return n, err }
		switch fieldKey_39 {
		case 0x0000:
			if !(canAssign(tape.LBA, fieldTag_40)) {
				tape.Skim(decoder, fieldTag_40)
				continue
			}
			var length_41 uint64
			if fieldTag_40.Is(tape.LBA) {
				length_41, nn, err = decoder.ReadUintN(int(fieldTag_40.CN()))
				n += nn; if err != nil { return n, err }
			} else {
				length_41 = uint64(fieldTag_40.CN())
			}
			if length_41 > uint64(tape.MaxStructureLength) {
				return n, tape.ErrTooLong
			}
			buffer := make([]byte, length_41)
			nn, err = decoder.Read(buffer)
			n += nn; if err != nil { return n, err }
			*(&(this.Nickname)) = string(buffer)
		default:
			tape.Skim(decoder, fieldTag_40)
			continue
		}
	}
	return n, nil
}

// Receive decodes a message from a transaction and returns it as a value.
// Use a type switch to determine what type of message it is.
func Receive(trans hopp.Trans) (message any, n int, err error) {
	method, reader, err := trans.ReceiveReader()
	decoder := tape.NewDecoder(reader)
	if err != nil { return nil, n, err }
	switch method {
	case 0x0401:
		var message MessageLeaveNotify
		nn, err := message.Decode(decoder)
		n += nn; if err != nil { return nil, n, err }
		return message, n, nil
	case 0x0000:
		var message MessageError
		nn, err := message.Decode(decoder)
		n += nn; if err != nil { return nil, n, err }
		return message, n, nil
	case 0x0001:
		var message MessageSuccess
		nn, err := message.Decode(decoder)
		n += nn; if err != nil { return nil, n, err }
		return message, n, nil
	case 0x0200:
		var message MessageJoin
		nn, err := message.Decode(decoder)
		n += nn; if err != nil { return nil, n, err }
		return message, n, nil
	case 0x0300:
		var message MessageChat
		nn, err := message.Decode(decoder)
		n += nn; if err != nil { return nil, n, err }
		return message, n, nil
	case 0x0400:
		var message MessageJoinNotify
		nn, err := message.Decode(decoder)
		n += nn; if err != nil { return nil, n, err }
		return message, n, nil
	}
	return nil, n, fmt.Errorf("%w: M%04X", hopp.ErrUnknownMethod, method)
}