//go:generate ../../../tools/readme_config_includer/generator
package netstat

import (
	_ "embed"
	"fmt"
	"syscall"

	"github.com/influxdata/telegraf"
	"github.com/influxdata/telegraf/plugins/common/psutil"
	"github.com/influxdata/telegraf/plugins/inputs"
)

//go:embed sample.conf
var sampleConfig string

type NetStat struct {
	ps psutil.PS
}

func (*NetStat) SampleConfig() string {
	return sampleConfig
}

func (ns *NetStat) Gather(acc telegraf.Accumulator) error {
	netconns, err := ns.ps.NetConnections()
	if err != nil {
		return fmt.Errorf("error getting net connections info: %w", err)
	}
	counts := make(map[string]int)
	counts["UDP"] = 0

	// TODO: add family to tags or else
	tags := make(map[string]string)
	for _, netcon := range netconns {
		if netcon.Type == syscall.SOCK_DGRAM {
			counts["UDP"]++
			continue // UDP has no status
		}
		c, ok := counts[netcon.Status]
		if !ok {
			counts[netcon.Status] = 0
		}
		counts[netcon.Status] = c + 1
	}

	fields := map[string]interface{}{
		"tcp_established": counts["ESTABLISHED"],
		"tcp_syn_sent":    counts["SYN_SENT"],
		"tcp_syn_recv":    counts["SYN_RECV"],
		"tcp_fin_wait1":   counts["FIN_WAIT1"],
		"tcp_fin_wait2":   counts["FIN_WAIT2"],
		"tcp_time_wait":   counts["TIME_WAIT"],
		"tcp_close":       counts["CLOSE"],
		"tcp_close_wait":  counts["CLOSE_WAIT"],
		"tcp_last_ack":    counts["LAST_ACK"],
		"tcp_listen":      counts["LISTEN"],
		"tcp_closing":     counts["CLOSING"],
		"tcp_none":        counts["NONE"],
		"udp_socket":      counts["UDP"],
	}
	acc.AddFields("netstat", fields, tags)

	return nil
}

func init() {
	inputs.Add("netstat", func() telegraf.Input {
		return &NetStat{ps: psutil.NewSystemPS()}
	})
}
