(draft): telegram markdown v2 string builder

2026-04-30 13:56:36 +03:00
parent 269ccec007
commit 071fc2375e
34 changed files with 1227 additions and 385 deletions
@@ -0,0 +1,295 @@
+package tgmd
+
+import (
+	"strings"
+	"time"
+
+	"git.scuroneko.dev/scuroneko/extypes"
+	"git.scuroneko.dev/scuroneko/laniakea/tgapi"
+)
+
+//TODO GoDoc, tests. Maybe escape Markdown v2
+
+// MessageBuilder builds Telegram message text with explicit message entities.
+// MessageBuilder is not safe for concurrent use.
+type MessageBuilder struct {
+	str      string
+	offset   int
+	entities extypes.Slice[tgapi.MessageEntity]
+
+	entries extypes.Slice[*MessageBuilderEntry]
+	isDirty bool
+}
+
+// NewMessageBuilder returns an empty MessageBuilder.
+func NewMessageBuilder() *MessageBuilder {
+	return &MessageBuilder{
+		entities: make([]tgapi.MessageEntity, 0),
+		entries:  make(extypes.Slice[*MessageBuilderEntry], 0),
+		isDirty:  false,
+	}
+}
+
+// String returns the built message text.
+func (b *MessageBuilder) String() string {
+	if b.isDirty {
+		b.update()
+	}
+	return b.str
+}
+
+// Entities returns a copy of the built message entities.
+func (b *MessageBuilder) Entities() []tgapi.MessageEntity {
+	if b.isDirty {
+		b.update()
+	}
+	return append([]tgapi.MessageEntity(nil), b.entities...)
+}
+
+func (b *MessageBuilder) Build() (string, []tgapi.MessageEntity) {
+	if b.isDirty {
+		b.update()
+	}
+	return b.str, append([]tgapi.MessageEntity(nil), b.entities...)
+}
+
+func (b *MessageBuilder) Reset() {
+	b.str = ""
+	b.offset = 0
+	b.entities = b.entities[:0]
+	b.entries = b.entries[:0]
+	b.isDirty = false
+}
+
+func (b *MessageBuilder) update() *MessageBuilder {
+	b.offset = 0
+
+	var textLen int
+	var entitiesLen int
+	for _, e := range b.entries {
+		textLen += len(e.text) // bytes, для Grow нормально
+		entitiesLen += len(e.entities)
+	}
+
+	b.entities = make(extypes.Slice[tgapi.MessageEntity], 0, entitiesLen)
+
+	var sb strings.Builder
+	sb.Grow(textLen)
+
+	for _, e := range b.entries {
+		sb.WriteString(e.text)
+
+		for _, entity := range e.entities {
+			entity.Offset += b.offset
+			b.entities = append(b.entities, entity)
+		}
+
+		b.offset += e.length
+	}
+
+	b.str = sb.String()
+	b.isDirty = false
+	return b
+}
+func (b *MessageBuilder) markDirty() {
+	b.isDirty = true
+}
+
+type MessageBuilderEntry struct {
+	text   string
+	length int
+
+	b        *MessageBuilder
+	entities extypes.Slice[tgapi.MessageEntity]
+}
+
+// Add appends plain text to the message and returns its entry for formatting.
+func (b *MessageBuilder) Add(text string) *MessageBuilderEntry {
+	e := &MessageBuilderEntry{
+		b:        b,
+		entities: make(extypes.Slice[tgapi.MessageEntity], 0),
+
+		text:   text,
+		length: telegramTextLen(text),
+	}
+	b.entries = b.entries.Push(e)
+	b.markDirty()
+
+	return e
+}
+
+func (e *MessageBuilderEntry) Mention() *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityMention,
+		Offset: 0, Length: e.length,
+	})
+	return e
+}
+
+func (e *MessageBuilderEntry) Hashtag() *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityHashtag,
+		Offset: 0, Length: e.length,
+	})
+	return e
+}
+
+func (e *MessageBuilderEntry) Cashtag() *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityCashtag,
+		Offset: 0, Length: e.length,
+	})
+	return e
+}
+
+func (e *MessageBuilderEntry) BotCommand() *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityBotCommand,
+		Offset: 0, Length: e.length,
+	})
+	return e
+}
+
+func (e *MessageBuilderEntry) Email() *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityEmail,
+		Offset: 0, Length: e.length,
+	})
+	return e
+}
+
+func (e *MessageBuilderEntry) Phone() *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityPhoneNumber,
+		Offset: 0, Length: e.length,
+	})
+	return e
+}
+func (e *MessageBuilderEntry) Bold() *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityBold,
+		Offset: 0, Length: e.length,
+	})
+	return e
+}
+func (e *MessageBuilderEntry) Italic() *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityItalic,
+		Offset: 0, Length: e.length,
+	})
+	return e
+}
+func (e *MessageBuilderEntry) Underline() *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityUnderline,
+		Offset: 0, Length: e.length,
+	})
+	return e
+}
+func (e *MessageBuilderEntry) Strikethrough() *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityStrike,
+		Offset: 0, Length: e.length,
+	})
+	return e
+}
+func (e *MessageBuilderEntry) Spoiler() *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntitySpoiler,
+		Offset: 0, Length: e.length,
+	})
+	return e
+}
+func (e *MessageBuilderEntry) Quote() *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityBlockquote,
+		Offset: 0, Length: e.length,
+	})
+	return e
+}
+func (e *MessageBuilderEntry) ExpandableQuote() *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityExpandableBlockquote,
+		Offset: 0, Length: e.length,
+	})
+	return e
+}
+func (e *MessageBuilderEntry) InlineCode() *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityCode,
+		Offset: 0, Length: e.length,
+	})
+	return e
+}
+func (e *MessageBuilderEntry) CodeBlock() *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityPre,
+		Offset: 0, Length: e.length,
+	})
+	return e
+}
+func (e *MessageBuilderEntry) CodeBlockWithLanguage(lang string) *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityPre,
+		Offset: 0, Length: e.length, Language: lang,
+	})
+	return e
+}
+func (e *MessageBuilderEntry) Link(url string) *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityTextLink,
+		Offset: 0, Length: e.length, URL: url,
+	})
+	return e
+}
+func (e *MessageBuilderEntry) TextMention(user *tgapi.User) *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityTextMention,
+		Offset: 0, Length: e.length, User: user,
+	})
+	return e
+}
+func (e *MessageBuilderEntry) CustomEmoji(emojiID string) *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityCustomEmoji,
+		Offset: 0, Length: e.length, CustomEmojiID: emojiID,
+	})
+	return e
+}
+func (e *MessageBuilderEntry) DateTime(time time.Time) *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityDateTime,
+		Offset: 0, Length: e.length, UnixTime: time.Unix(),
+	})
+	return e
+}
+func (e *MessageBuilderEntry) DateTimeFormat(time time.Time, format string) *MessageBuilderEntry {
+	e.addEntity(tgapi.MessageEntity{
+		Type:   tgapi.MessageEntityDateTime,
+		Offset: 0, Length: e.length,
+		UnixTime: time.Unix(), DateTimeFormat: format,
+	})
+	return e
+}
+
+func telegramTextLen(text string) int {
+	n := 0
+	for _, r := range text {
+		if r <= 0xFFFF {
+			n++
+		} else {
+			n += 2
+		}
+	}
+	return n
+}
+
+func (e *MessageBuilderEntry) addEntity(entity tgapi.MessageEntity) {
+	if entity.Length <= 0 {
+		return
+	}
+	e.entities = append(e.entities, entity)
+	if e.b != nil {
+		e.b.markDirty()
+	}
+}