package event

import (
	"git.openprivacy.ca/openprivacy/libricochet-go/log"
	"sync"
)

// IPCMessage is a wrapper for a regular eventMessage with a destination (onion|AppDest) so the other side of the bridge can route appropriately
type IPCMessage struct {
	Dest    string
	Message Event
}

type pipeBridge struct {
	in         chan IPCMessage
	out        chan IPCMessage
	closedChan chan bool
	closed     bool
	lock       sync.Mutex
}

// IPCBridge is an interface to a IPC construct used to communicate IPCMessages
type IPCBridge interface {
	Read() (IPCMessage, bool)
	Write(message *IPCMessage)
	Shutdown()
}

// MakePipeBridge returns a simple testing IPCBridge made from inprocess go channels
func MakePipeBridge() (b1, b2 IPCBridge) {
	chan1 := make(chan IPCMessage)
	chan2 := make(chan IPCMessage)
	closed := make(chan bool)

	a := &pipeBridge{in: chan1, out: chan2, closedChan: closed, closed: false}
	b := &pipeBridge{in: chan2, out: chan1, closedChan: closed, closed: false}

	go monitor(a, b)

	return a, b
}

func monitor(a, b *pipeBridge) {
	<-a.closedChan
	a.closed = true
	b.closed = true
	a.closedChan <- true
}

func (pb *pipeBridge) Read() (message IPCMessage, ok bool) {
	message, ok = <-pb.in
	return
}

func (pb *pipeBridge) Write(message *IPCMessage) {
	pb.lock.Lock()
	defer pb.lock.Unlock()
	log.Infof("pb.Write: %v\n", message)
	if !pb.closed {
		pb.out <- *message
	}
}

func (pb *pipeBridge) Shutdown() {
	if !pb.closed {
		close(pb.in)
		close(pb.out)
		pb.closedChan <- true
		<-pb.closedChan
	}
}