package sync

import (
	"fmt"
	"net"
	"time"

	"vpnem/internal/models"
)

// HealthCheck tests if a server's proxy port is reachable.
func HealthCheck(server models.Server, timeout time.Duration) error {
	addr := fmt.Sprintf("%s:%d", server.Server, server.ServerPort)
	conn, err := net.DialTimeout("tcp", addr, timeout)
	if err != nil {
		return fmt.Errorf("server %s unreachable: %w", server.Tag, err)
	}
	conn.Close()
	return nil
}

// FindHealthyServer returns the first healthy non-RU server from the list.
func FindHealthyServer(servers []models.Server, timeout time.Duration) *models.Server {
	for _, s := range servers {
		if s.Region == "RU" {
			continue
		}
		if err := HealthCheck(s, timeout); err == nil {
			return &s
		}
	}
	return nil
}