package sfu

import (
	"errors"
	"g365sfu/logger"
	"os"

	"github.com/pion/interceptor"
	"github.com/pion/webrtc/v4"
)

var (
	api      *webrtc.API
	pcConfig webrtc.Configuration
)

// Коллбек для обработки новых SDP офферов от сервера для конкретного пира (при renegotiation)
var OnServerOffer func(roomID string, peerID string, offer webrtc.SessionDescription)

// Коллбек для обработки новых ICE кандидатов
var OnLocalICECandidate func(roomID, peerID string, candidate webrtc.ICECandidateInit)

// Ошибки
var (
	ErrRoomNotFound = errors.New("room not found")
	ErrPeerNotFound = errors.New("peer not found")
)

func InitWebRTCEngines() {
	publicIP := os.Getenv("PUBLIC_IP")
	fromPort := os.Getenv("PORT_RANGE_FROM")
	toPort := os.Getenv("PORT_RANGE_TO")
	if publicIP == "" || fromPort == "" || toPort == "" {
		// Если не указаны необходимые переменные окружения, логируем ошибку и завершаем процесс сервера
		logger.LogErrorMessage("PUBLIC_IP, PORT_RANGE_FROM and PORT_RANGE_TO environment variables must be set")
		os.Exit(-1)
		return
	}
	m := &webrtc.MediaEngine{}
	_ = m.RegisterDefaultCodecs()

	i := &interceptor.Registry{}
	_ = webrtc.RegisterDefaultInterceptors(m, i)

	se := webrtc.SettingEngine{}
	_ = se.SetEphemeralUDPPortRange(40000, 50000)

	if publicIP := os.Getenv("PUBLIC_IP"); publicIP != "" {
		se.SetICEAddressRewriteRules(webrtc.ICEAddressRewriteRule{
			External:        []string{publicIP},
			AsCandidateType: webrtc.ICECandidateTypeHost,
			Mode:            webrtc.ICEAddressRewriteReplace,
		})
	}

	api = webrtc.NewAPI(
		webrtc.WithMediaEngine(m),
		webrtc.WithInterceptorRegistry(i),
		webrtc.WithSettingEngine(se),
	)

	pcConfig = webrtc.Configuration{
		ICEServers: []webrtc.ICEServer{
			{URLs: []string{"stun:stun.l.google.com:19302"}},
		},
	}
}