ward/platform/afreeca/chat_message.go

package afreeca

import (
	"bytes"
	"errors"
	"fmt"
	"git.beejay.kim/tool/service/ascii"
	"github.com/samber/lo"
	"strconv"
	"time"
)

type kind []byte

func newKind(category, index int) kind {
	return []byte(
		fmt.Sprintf("%04d%03d", category, index))
}

type kindList struct {
	Ping          kind
	Authorize     kind
	Authenticate  kind
	Authenticated kind
	Roster        struct {
		List   kind
		Change kind
		Status kind
	}

	Chat         kind
	ChatEmoticon kind

	Donation kind
}

var (
	Kind = &kindList{
		Ping:          newKind(0, 0),
		Authorize:     newKind(1, 0),
		Authenticate:  newKind(2, 0),
		Authenticated: newKind(94, 0),

		Chat:         newKind(5, 0),
		ChatEmoticon: newKind(109, 0),

		Donation: newKind(18, 0),

		Roster: struct {
			List   kind
			Change kind
			Status kind
		}{
			List:   newKind(4, 1),
			Change: newKind(4, 0),
			Status: newKind(13, 0),
		},
	}
)

type ChatMessage struct {
	raw []byte

	kind kind
	data []string
	at   time.Time
}

func (m *ChatMessage) Unmarshall(buf []byte) error {
	m.at = time.Now()
	m.raw = buf

	if buf == nil || len(buf) < 14 {
		return errors.New("empty data")
	}

	if buf[0] != ascii.Escape ||
		buf[1] != ascii.HorizontalTab ||
		buf[14] != ascii.FormFeed {
		return errors.New("illegal data format")
	}

	m.data = []string{}
	m.kind = buf[2:9]

	var (
		size = 0
		data bytes.Buffer
		err  error
	)

	if size, err = strconv.Atoi(string(buf[9:12])); err != nil {
		return errors.New("illegal data size")
	}

	for i := range buf[15:] {
		last := i == size-2
		b := buf[15+i : 16+i]

		if ascii.FormFeed == b[0] {
			m.data = append(m.data, data.String())
			data.Reset()
			continue
		}

		data.Write(b)
		if last {
			m.data = append(m.data, data.String())
		}
	}

	return nil
}

func (m *ChatMessage) Build() []byte {
	var (
		buf  bytes.Buffer
		size = lo.SumBy(m.data, func(item string) int {
			return len(item)
		})
	)

	buf.WriteByte(ascii.Escape)
	buf.WriteByte(ascii.HorizontalTab)
	buf.Write(m.kind)
	buf.WriteString(fmt.Sprintf("%03d00", size+len(m.data)))

	for i := range m.data {
		buf.WriteByte(ascii.FormFeed)
		buf.WriteString(m.data[i])
	}

	return buf.Bytes()
}

func (m ChatMessage) Is(k kind) bool {
	return bytes.Compare(m.kind, k) == 0
}

func (m ChatMessage) Kind() []byte {
	return m.kind
}

func (m ChatMessage) Data() []string {
	return m.data
}

func NewChatMessage(k kind, args ...string) *ChatMessage {
	return &ChatMessage{
		kind: k,
		data: args,
		at:   time.Now(),
	}
}

func NewChatAuthorizeMessage(token string, withQuickView bool) *ChatMessage {
	flag := "16"
	if withQuickView {
		flag = "524304"
	}

	return NewChatMessage(Kind.Authorize, token, "", flag, "")
}

func NewChatPingMessage() []byte {
	return NewChatMessage(Kind.Ping, "").Build()
}

func NewChatRosterRequestMessage() []byte {
	return NewChatMessage(Kind.Roster.Change, "").Build()
}