package ingest

import (
	"context"
	"fmt"
	"log"
	"net"
	"strings"

	"git.apinb.com/ops/logs/internal/config"
)

func StartSyslogUDP(ctx context.Context) error {
	addr := strings.TrimSpace(config.Spec.Ingest.SyslogListenAddr)
	if addr == "" {
		return nil
	}
	pc, err := net.ListenPacket("udp", addr)
	if err != nil {
		return fmt.Errorf("syslog UDP 监听 %s 失败: %w", addr, err)
	}
	startWorker("syslog_udp", func() error {
		defer pc.Close()
		go func() {
			<-ctx.Done()
			_ = pc.Close()
		}()
		log.Printf("logs: syslog listening UDP %s", addr)
		buf := make([]byte, 65536)
		for {
			n, remote, err := pc.ReadFrom(buf)
			if err != nil {
				if ctx.Err() != nil {
					return nil
				}
				markWorkerError("syslog_udp", err)
				log.Printf("logs: syslog read: %v", err)
				continue
			}
			udpAddr, _ := remote.(*net.UDPAddr)
			if udpAddr == nil {
				continue
			}
			p := make([]byte, n)
			copy(p, buf[:n])
			a := *udpAddr
			Global.HandleSyslog(&a, p)
			markWorkerSucceeded("syslog_udp")
		}
	})
	return nil
}