feat: add BusinessContext handle

Bot.Business(connectionID) returns a *BusinessContext that scopes the
business-account methods to a single connection, so the
business_connection_id no longer has to be threaded through every call:
Connection, SetName/SetBio/SetUsername, SetProfilePhoto/RemoveProfilePhoto,
StarBalance, DeleteMessages.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: ernado

business_context.go

@@ -0,0 +1,74 @@
+package botapi
+
+import "context"
+
+// BusinessContext is a handle scoped to a single business connection. It lets the
+// bot act on behalf of a connected business account without threading the
+// connection id through every call.
+//
+// Obtain one with Bot.Business, passing the business_connection_id received in
+// business updates (or returned by GetBusinessConnection). Its methods are thin
+// wrappers over the SetBusinessAccount* / GetBusinessAccount* / DeleteBusinessMessages
+// methods on *Bot, and require the same business bot rights.
+type BusinessContext struct {
+	bot          *Bot
+	connectionID string
+}
+
+// Business returns a handle that scopes business-account operations to the given
+// connection id.
+func (b *Bot) Business(connectionID string) *BusinessContext {
+	return &BusinessContext{bot: b, connectionID: connectionID}
+}
+
+// ConnectionID returns the business connection id this context is bound to.
+func (c *BusinessContext) ConnectionID() string { return c.connectionID }
+
+// Connection returns information about this business connection.
+func (c *BusinessContext) Connection(ctx context.Context) (*BusinessConnection, error) {
+	return c.bot.GetBusinessConnection(ctx, c.connectionID)
+}
+
+// SetName changes the first and last name of the connected business account. The
+// bot must have the can_edit_name business bot right.
+func (c *BusinessContext) SetName(ctx context.Context, firstName, lastName string) error {
+	return c.bot.SetBusinessAccountName(ctx, c.connectionID, firstName, lastName)
+}
+
+// SetBio changes the bio of the connected business account. The bot must have the
+// can_edit_bio business bot right.
+func (c *BusinessContext) SetBio(ctx context.Context, bio string) error {
+	return c.bot.SetBusinessAccountBio(ctx, c.connectionID, bio)
+}
+
+// SetUsername changes the username of the connected business account. The bot
+// must have the can_edit_username business bot right.
+func (c *BusinessContext) SetUsername(ctx context.Context, username string) error {
+	return c.bot.SetBusinessAccountUsername(ctx, c.connectionID, username)
+}
+
+// SetProfilePhoto changes the profile photo of the connected business account.
+// When isPublic is true the photo becomes the public (fallback) photo. The bot
+// must have the can_edit_profile_photo business bot right.
+func (c *BusinessContext) SetProfilePhoto(ctx context.Context, photo InputProfilePhoto, isPublic bool) error {
+	return c.bot.SetBusinessAccountProfilePhoto(ctx, c.connectionID, photo, isPublic)
+}
+
+// RemoveProfilePhoto removes the profile photo of the connected business account.
+// When isPublic is true the public (fallback) photo is removed. The bot must have
+// the can_edit_profile_photo business bot right.
+func (c *BusinessContext) RemoveProfilePhoto(ctx context.Context, isPublic bool) error {
+	return c.bot.RemoveBusinessAccountProfilePhoto(ctx, c.connectionID, isPublic)
+}
+
+// StarBalance returns the Telegram Stars balance of the connected business
+// account. The bot must have the can_view_gifts_and_stars business bot right.
+func (c *BusinessContext) StarBalance(ctx context.Context) (StarAmount, error) {
+	return c.bot.GetBusinessAccountStarBalance(ctx, c.connectionID)
+}
+
+// DeleteMessages deletes messages on behalf of the connected business account.
+// The messages must all belong to the same chat.
+func (c *BusinessContext) DeleteMessages(ctx context.Context, messageIDs []int) error {
+	return c.bot.DeleteBusinessMessages(ctx, c.connectionID, messageIDs)
+}

business_context_test.go

@@ -0,0 +1,120 @@
+package botapi
+
+import (
+	"context"
+	"testing"
+
+	"github.com/gotd/td/tg"
+)
+
+func TestBusinessContextConnectionID(t *testing.T) {
+	bc := newMockBot(newMockInvoker()).Business("bc9")
+
+	if bc.ConnectionID() != "bc9" {
+		t.Fatalf("connection id = %q", bc.ConnectionID())
+	}
+}
+
+func TestBusinessContextSetNameScopesConnection(t *testing.T) {
+	inv := newMockInvoker()
+	inv.reply(tg.InvokeWithBusinessConnectionRequestTypeID, &tg.User{ID: 10})
+
+	if err := newMockBot(inv).Business("bc9").SetName(context.Background(), "First", "Last"); err != nil {
+		t.Fatalf("SetName: %v", err)
+	}
+
+	wrapper := tg.InvokeWithBusinessConnectionRequest{Query: &tg.AccountUpdateProfileRequest{}}
+
+	inv.decode(t, tg.InvokeWithBusinessConnectionRequestTypeID, &wrapper)
+
+	if wrapper.ConnectionID != "bc9" {
+		t.Fatalf("connection id = %q", wrapper.ConnectionID)
+	}
+
+	profile, ok := wrapper.Query.(*tg.AccountUpdateProfileRequest)
+	if !ok {
+		t.Fatalf("query = %#v", wrapper.Query)
+	}
+
+	if first, _ := profile.GetFirstName(); first != "First" {
+		t.Fatalf("first name = %q", first)
+	}
+}
+
+func TestBusinessContextStarBalance(t *testing.T) {
+	inv := newMockInvoker()
+	inv.reply(tg.InvokeWithBusinessConnectionRequestTypeID, &tg.PaymentsStarsStatus{
+		Balance: &tg.StarsAmount{Amount: 7},
+	})
+
+	got, err := newMockBot(inv).Business("bc9").StarBalance(context.Background())
+	if err != nil {
+		t.Fatalf("StarBalance: %v", err)
+	}
+
+	if got.Amount != 7 {
+		t.Fatalf("balance = %#v", got)
+	}
+}
+
+func TestBusinessContextDeleteMessages(t *testing.T) {
+	inv := newMockInvoker()
+	inv.reply(tg.InvokeWithBusinessConnectionRequestTypeID, &tg.MessagesAffectedMessages{})
+
+	if err := newMockBot(inv).Business("bc9").DeleteMessages(context.Background(), []int{1, 2}); err != nil {
+		t.Fatalf("DeleteMessages: %v", err)
+	}
+
+	wrapper := tg.InvokeWithBusinessConnectionRequest{Query: &tg.MessagesDeleteMessagesRequest{}}
+
+	inv.decode(t, tg.InvokeWithBusinessConnectionRequestTypeID, &wrapper)
+
+	del, ok := wrapper.Query.(*tg.MessagesDeleteMessagesRequest)
+	if !ok || len(del.ID) != 2 {
+		t.Fatalf("query = %#v", wrapper.Query)
+	}
+}
+
+func TestBusinessContextConnection(t *testing.T) {
+	inv := newMockInvoker()
+	inv.reply(tg.AccountGetBotBusinessConnectionRequestTypeID, &tg.Updates{
+		Updates: []tg.UpdateClass{
+			&tg.UpdateBotBusinessConnect{Connection: tg.BotBusinessConnection{ConnectionID: "bc9", UserID: 10}},
+		},
+		Users: []tg.UserClass{&tg.User{ID: 10, FirstName: "Biz"}},
+	})
+
+	conn, err := newMockBot(inv).Business("bc9").Connection(context.Background())
+	if err != nil {
+		t.Fatalf("Connection: %v", err)
+	}
+
+	if conn.ID != "bc9" {
+		t.Fatalf("conn = %#v", conn)
+	}
+
+	var req tg.AccountGetBotBusinessConnectionRequest
+
+	inv.decode(t, tg.AccountGetBotBusinessConnectionRequestTypeID, &req)
+
+	if req.ConnectionID != "bc9" {
+		t.Fatalf("requested connection id = %q", req.ConnectionID)
+	}
+}
+
+func TestBusinessContextRemoveProfilePhoto(t *testing.T) {
+	inv := newMockInvoker()
+	inv.reply(tg.InvokeWithBusinessConnectionRequestTypeID, &tg.PhotosPhoto{Photo: &tg.PhotoEmpty{}})
+
+	if err := newMockBot(inv).Business("bc9").RemoveProfilePhoto(context.Background(), false); err != nil {
+		t.Fatalf("RemoveProfilePhoto: %v", err)
+	}
+
+	wrapper := tg.InvokeWithBusinessConnectionRequest{Query: &tg.PhotosUpdateProfilePhotoRequest{}}
+
+	inv.decode(t, tg.InvokeWithBusinessConnectionRequestTypeID, &wrapper)
+
+	if wrapper.ConnectionID != "bc9" {
+		t.Fatalf("connection id = %q", wrapper.ConnectionID)
+	}
+}