package yggdrasil

import (
	"sync"

	"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
)

type awdl struct {
	core       *Core
	mutex      sync.RWMutex // protects interfaces below
	interfaces map[string]*awdlInterface
}

type awdlInterface struct {
	awdl     *awdl
	recv     <-chan []byte // traffic received from the network
	send     chan<- []byte // traffic to send to the network
	shutdown chan bool
	peer     *peer
}

func (l *awdl) init(c *Core) error {
	l.core = c
	l.mutex.Lock()
	l.interfaces = make(map[string]*awdlInterface)
	l.mutex.Unlock()

	return nil
}

func (l *awdl) create(boxPubKey *crypto.BoxPubKey, sigPubKey *crypto.SigPubKey, name string) *awdlInterface {
	shared := crypto.GetSharedKey(&l.core.boxPriv, boxPubKey)
	intf := awdlInterface{
		recv:     make(<-chan []byte),
		send:     make(chan<- []byte),
		shutdown: make(chan bool),
		peer:     l.core.peers.newPeer(boxPubKey, sigPubKey, shared, name),
	}
	if intf.peer != nil {
		l.mutex.Lock()
		l.interfaces[name] = &intf
		l.mutex.Unlock()
		intf.peer.linkOut = make(chan []byte, 1)
		intf.peer.out = func(msg []byte) {
			defer func() { recover() }()
			intf.send <- msg
		}
		go intf.handler()
		l.core.switchTable.idleIn <- intf.peer.port
		return &intf
	}
	return nil
}

func (l *awdl) getInterface(identity string) *awdlInterface {
	l.mutex.RLock()
	defer l.mutex.RUnlock()
	if intf, ok := l.interfaces[identity]; ok {
		return intf
	}
	return nil
}

func (l *awdl) shutdown(identity string) {
	if intf, ok := l.interfaces[identity]; ok {
		intf.shutdown <- true
		l.core.peers.removePeer(intf.peer.port)
		l.mutex.Lock()
		delete(l.interfaces, identity)
		l.mutex.Unlock()
	}
}

func (ai *awdlInterface) handler() {
	for {
		select {
		case p := <-ai.peer.linkOut:
			ai.send <- p
		case r := <-ai.recv: // traffic received from AWDL
			ai.peer.handlePacket(r)
		case <-ai.shutdown:
			return
		default:
		}
	}
}