feat: ReadBusinessMessage and TransferBusinessAccountStars

- ReadBusinessMessage: messages.readHistory over the business connection, marking
  a message and earlier ones as read.
- TransferBusinessAccountStars: getPaymentForm + sendStarsForm with
  inputInvoiceBusinessBotTransferStars{inputUserSelf, stars}, both over the
  business connection via businessRaw.

Mapping confirmed against telegram-bot-api 10.1. Hermetic tests; lint clean.

Author: ernado

business.go

@@ -236,6 +236,58 @@ func (b *Bot) DeleteBusinessMessages(ctx context.Context, businessConnectionID s
 	return nil
 }
 
+// ReadBusinessMessage marks a message and all earlier messages in the chat as
+// read on behalf of a managed business account. The bot must have the
+// can_read_messages business bot right.
+func (b *Bot) ReadBusinessMessage(ctx context.Context, businessConnectionID string, chat ChatID, messageID int) error {
+	peer, err := b.resolveInputPeer(ctx, chat)
+	if err != nil {
+		return err
+	}
+
+	var affected tg.MessagesAffectedMessages
+
+	if err := b.invokeBusiness(ctx, businessConnectionID, &tg.MessagesReadHistoryRequest{
+		Peer:  peer,
+		MaxID: messageID,
+	}, &affected); err != nil {
+		return asAPIError(err)
+	}
+
+	return nil
+}
+
+// TransferBusinessAccountStars transfers Telegram Stars from a managed business
+// account to the bot's own account. The bot must have the can_transfer_stars
+// business bot right.
+func (b *Bot) TransferBusinessAccountStars(ctx context.Context, businessConnectionID string, starCount int) error {
+	invoice := &tg.InputInvoiceBusinessBotTransferStars{
+		Bot:   &tg.InputUserSelf{},
+		Stars: int64(starCount),
+	}
+
+	raw := b.businessRaw(businessConnectionID)
+
+	form, err := raw.PaymentsGetPaymentForm(ctx, &tg.PaymentsGetPaymentFormRequest{Invoice: invoice})
+	if err != nil {
+		return asAPIError(err)
+	}
+
+	formID, err := starsFormID(form)
+	if err != nil {
+		return err
+	}
+
+	if _, err := raw.PaymentsSendStarsForm(ctx, &tg.PaymentsSendStarsFormRequest{
+		FormID:  formID,
+		Invoice: invoice,
+	}); err != nil {
+		return asAPIError(err)
+	}
+
+	return nil
+}
+
 // updatesAndUsers unpacks the update list and a user-by-id index from an
 // Updates response.
 func updatesAndUsers(resp tg.UpdatesClass) (updates []tg.UpdateClass, users map[int64]*tg.User) {

business_read_test.go

@@ -0,0 +1,75 @@
+package botapi
+
+import (
+	"context"
+	"testing"
+
+	"github.com/gotd/td/bin"
+	"github.com/gotd/td/tg"
+)
+
+func TestReadBusinessMessage(t *testing.T) {
+	inv := newMockInvoker()
+	inv.reply(tg.InvokeWithBusinessConnectionRequestTypeID, &tg.MessagesAffectedMessages{})
+
+	if err := newMockBot(inv).ReadBusinessMessage(context.Background(), "bc1", userRef(10, 20), 77); err != nil {
+		t.Fatalf("ReadBusinessMessage: %v", err)
+	}
+
+	wrapper := tg.InvokeWithBusinessConnectionRequest{Query: &tg.MessagesReadHistoryRequest{}}
+
+	inv.decode(t, tg.InvokeWithBusinessConnectionRequestTypeID, &wrapper)
+
+	if wrapper.ConnectionID != "bc1" {
+		t.Fatalf("connection id = %q", wrapper.ConnectionID)
+	}
+
+	rh, ok := wrapper.Query.(*tg.MessagesReadHistoryRequest)
+	if !ok || rh.MaxID != 77 {
+		t.Fatalf("query = %#v", wrapper.Query)
+	}
+}
+
+func TestTransferBusinessAccountStars(t *testing.T) {
+	inv := newMockInvoker()
+
+	// The transfer makes two business-wrapped calls under the same outer type:
+	// getPaymentForm then sendStarsForm. Respond by call order.
+	calls := 0
+
+	inv.handle(tg.InvokeWithBusinessConnectionRequestTypeID, func(*bin.Buffer) (bin.Encoder, error) {
+		calls++
+		if calls == 1 {
+			return &tg.PaymentsPaymentFormStars{FormID: 555, Invoice: tg.Invoice{Currency: "XTR"}}, nil
+		}
+
+		return &tg.PaymentsPaymentResult{Updates: &tg.Updates{}}, nil
+	})
+
+	if err := newMockBot(inv).TransferBusinessAccountStars(context.Background(), "bc2", 100); err != nil {
+		t.Fatalf("TransferBusinessAccountStars: %v", err)
+	}
+
+	// The last wrapped call is sendStarsForm.
+	wrapper := tg.InvokeWithBusinessConnectionRequest{Query: &tg.PaymentsSendStarsFormRequest{}}
+
+	inv.decode(t, tg.InvokeWithBusinessConnectionRequestTypeID, &wrapper)
+
+	if wrapper.ConnectionID != "bc2" {
+		t.Fatalf("connection id = %q", wrapper.ConnectionID)
+	}
+
+	send, ok := wrapper.Query.(*tg.PaymentsSendStarsFormRequest)
+	if !ok || send.FormID != 555 {
+		t.Fatalf("query = %#v", wrapper.Query)
+	}
+
+	invoice, ok := send.Invoice.(*tg.InputInvoiceBusinessBotTransferStars)
+	if !ok || invoice.Stars != 100 {
+		t.Fatalf("invoice = %#v", send.Invoice)
+	}
+
+	if _, ok := invoice.Bot.(*tg.InputUserSelf); !ok {
+		t.Fatalf("bot = %#v, want self", invoice.Bot)
+	}
+}