package main

import (
	"fmt"
	"log"
	"net"
	"net/http"

	"google.golang.org/grpc"
	"google.golang.org/grpc/reflection"
	// "server/api" // This would be the generated package
)

const version = "1.0.0"

// CoordinatorServer implements the Coordinator gRPC service
type CoordinatorServer struct {
	// In a full implementation, we would have a Redis client here
	// nodes map[string]*NodeInfo
}

func (s *CoordinatorServer) RegisterNode(ctx interface{}, req interface{}) (interface{}, error) {
	fmt.Println("RegisterNode called")
	return nil, nil // Placeholder for actual implementation
}

func (s *CoordinatorServer) Heartbeat(ctx interface{}, req interface{}) (interface{}, error) {
	fmt.Println("Heartbeat called")
	return nil, nil
}

func (s *CoordinatorServer) GetPeerEndpoint(ctx interface{}, req interface{}) (interface{}, error) {
	fmt.Println("GetPeerEndpoint called")
	return nil, nil
}

func (s *CoordinatorServer) SignalConnection(ctx interface{}, req interface{}) (interface{}, error) {
	fmt.Println("SignalConnection called")
	return nil, nil
}

// STUN server implementation
func startSTUNServer(port int) {
	addr := fmt.Sprintf(":%d", port)
	conn, err := net.ListenUDP("udp", &net.UDPAddr{Port: port})
	if err != nil {
		log.Fatalf("STUN server failed to start: %v", err)
	}
	defer conn.Close()

	fmt.Printf("STUN server listening on %s\n", addr)

	buf := make([]byte, 1024)
	for {
		n, remoteAddr, err := conn.ReadFromUDP(buf)
		if err != nil {
			log.Printf("STUN read error: %v", err)
			continue
		}

		fmt.Printf("Received STUN request from %s (size: %d)\n", remoteAddr, n)

		// Simplified STUN response: send the remote address back to the client
		// In a real STUN server, we would follow RFC 5389
		response := []byte(fmt.Sprintf("STUN_RESP:%s", remoteAddr.String()))
		_, err = conn.WriteToUDP(response, remoteAddr)
		if err != nil {
			log.Printf("STUN write error: %v", err)
		}
	}
}

func main() {
	// Start STUN server in a goroutine
	go startSTUNServer(3478)

	// Serve HTML Dashboard
	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		// Note: In a production app, we would use a template to inject the version
		// For this task, we serve the file and suggest using a template for dynamic injection
		http.ServeFile(w, r, "C:\\Users\\jadon\\Documents\\vscode\\tailscale-test\\meshvpn-dashboard\\index.html")
	})

	// Start HTTP server in a goroutine
	go func() {
		fmt.Printf("HTTP Dashboard listening on :8080 (Version: %s)\n", version)
		if err := http.ListenAndServe(":8080", nil); err != nil {
			log.Fatalf("HTTP server failed: %v", err)
		}
	}()

	// Start gRPC Coordinator server
	lis, err := net.Listen("tcp", ":50051")
	if err != nil {
		log.Fatalf("failed to listen: %v", err)
	}

	s := grpc.NewServer()
	// In a real setup, we'd register the generated server:
	// pb.RegisterCoordinatorServer(s, &CoordinatorServer{})

	reflection.Register(s)

	fmt.Println("Coordinator Server listening on :50051")
	if err := s.Serve(lis); err != nil {
		log.Fatalf("failed to serve: %v", err)
	}
}