package xmpp

// Manages the stack of filters that can read and modify stanzas on

// their way from the remote to the application.

// Receive new filters on filterAdd; those new filters get added to

// the top of the stack. Receive stanzas at the bottom of the stack on

// input. Send stanzas out the top of the stack on output.

func filterMgr(filterAdd <-chan Filter, input <-chan Stanza, output chan<- Stanza) {

	defer close(output)

	for {

		select {

		case stan, ok := <-input:

			if !ok {

				return

			}

			output <- stan

		case filt := <-filterAdd:

			ch := make(chan Stanza)

			go filt(input, ch)

			input = ch

		}

	}

}

// AddRecvFilter adds a new filter to the top of the stack through which

// incoming stanzas travel on their way up to the client.

func (cl *Client) AddRecvFilter(filt Filter) {

	if filt == nil {

		return

	}

	cl.recvFilterAdd <- filt

}

// AddSendFilter adds a new filter to the top of the stack through

// which outgoing stanzas travel on their way down from the client to

// the network.

func (cl *Client) AddSendFilter(filt Filter) {

	if filt == nil {

		return

	}

	cl.sendFilterAdd <- filt

}