channel

type Channel interface {
	// ID returns the channel identifier (e.g. "wechat").
	ID() string
	// State returns the current lifecycle state.
	State() State
	// Login initiates the authentication flow (e.g. QR scan).
	// Returns a login session that can be waited on.
	Login() (*LoginSession, error)
	// Logout clears credentials and stops the channel.
	Logout() error
	// Enable starts push notifications and inbound message polling.
	Enable() error
	// Disable stops push notifications and polling but keeps credentials.
	Disable() error
	// SendText sends a text message to the connected user.
	SendText(text string) error
}

type LoginSession struct {
	// QRCodeURL is a URL that renders a QR code image for scanning.
	QRCodeURL string
	// QRCodeContent is the raw content to encode as a QR code in terminal.
	QRCodeContent string
	// SessionKey identifies this login attempt.
	SessionKey string
	// WaitFunc blocks until login completes or times out. Returns nil on success.
	WaitFunc func() error
}

type State int