package recon

import (
	"net"
	"strconv"
	"time"
)

// dialPortFn overrides TCP probes in tests (nil = live dial from server host).
var dialPortFn func(host string, port int, timeout time.Duration) bool

// ScanPorts TCP-dials common fleet ports on host with timeout from server host.
func ScanPorts(host string) []PortResult {
	out := make([]PortResult, 0, len(FleetPorts))
	for _, port := range FleetPorts {
		out = append(out, PortResult{Port: port, Open: dialPort(host, port, DefaultPortDialTimeout)})
	}
	return out
}

func dialPort(host string, port int, timeout time.Duration) bool {
	if dialPortFn != nil {
		return dialPortFn(host, port, timeout)
	}
	addr := net.JoinHostPort(host, strconv.Itoa(port))
	conn, err := net.DialTimeout("tcp", addr, timeout)
	if err != nil {
		return false
	}
	_ = conn.Close()
	return true
}