push

type ChannelReq struct {
	// Uid is the ID of the user making request.
	Uid t.Uid
	// DeviceID is the device-provided token in case a single device is being subscribed to all channels.
	DeviceID string
	// Channel to subscribe to or unsubscribe from.
	Channel string
	// Unsub is set to true to unsubscribe devices, otherwise subscribe them.
	Unsub bool
}

type Handler interface {
	// Init initializes the handler.
	Init(jsonconf string) error

	// IsReady сhecks if the handler is initialized.
	IsReady() bool

	// Push returns a channel that the server will use to send messages to.
	// The message will be dropped if the channel blocks.
	Push() chan<- *Receipt

	// Subscribe/unsubscribe device from FCM topic (channel).
	Channel() chan<- *ChannelReq

	// Stop terminates the handler's worker and stops sending pushes.
	Stop()
}

type Payload struct {
	// Action type of the push: new message (msg), new subscription (sub), etc.
	What string `json:"what"`
	// If this is a silent push: perform action but do not show a notification to the user.
	Silent bool `json:"silent"`
	// Topic which was affected by the action.
	Topic string `json:"topic"`
	// Timestamp of the action.
	Timestamp time.Time `json:"ts"`

	// Message sender 'usrXXX'
	From string `json:"from"`
	// Sequential ID of the message.
	SeqId int `json:"seq"`
	// MIME-Type of the message content, text/x-drafty or text/plain
	ContentType string `json:"mime"`
	// Actual Data.Content of the message, if requested
	Content interface{} `json:"content,omitempty"`

	// New access mode when notifying of a subscription change.
	// ModeNone for both means the subscription is removed.
	ModeWant  t.AccessMode `json:"want,omitempty"`
	ModeGiven t.AccessMode `json:"given,omitempty"`
}

type Receipt struct {
	// List of individual recipients, including those who did not receive the message.
	To map[t.Uid]Recipient `json:"to"`
	// Push topic for group notifications.
	Channel string `json:"channel"`
	// Actual content to be delivered to the client.
	Payload Payload `json:"payload"`
}

type Recipient struct {
	// Count of user's connections that were live when the packet was dispatched from the server
	Delivered int `json:"delivered"`
	// List of user's devices that the packet was delivered to (if known). Len(Devices) >= Delivered
	Devices []string `json:"devices,omitempty"`
	// Unread count to include in the push
	Unread int `json:"unread"`
}