message

type Message struct {
	// UID of sender.
	SenderID string
	// UID of the receiver. If IsGroup, ReceiverID is bot's ID
	ReceiverID string

	// Whether it is a group message.
	IsGroup bool
	// If the message contains @at_bot
	IsToMe bool
	// Group ID
	GroupID string

	// Message segments
	Segments []MessageSegment

	// Raw message if you want to decode yourself.
	RawMessage string
}

type MessageSegment struct {
	// Type: text,image,video,sound,action.
	Type string
	// Content of the message.
	Content string
}