package cdns

import (
	"fmt"
	"net"

	"github.com/miekg/dns"
)

func soaQuery(mychan chan SOAreply, zone string, name string, server string) {
	var result SOAreply
	var trials uint
	result.retrieved = false
	result.name = name
	result.address = server
	result.msg = "UNKNOWN"
	m := new(dns.Msg)
	if !noedns {
		m.SetEdns0(bufsize, !nodnssec)
	}
	m.Id = dns.Id()
	if recursion {
		m.RecursionDesired = true
	} else {
		m.RecursionDesired = false
	}
	m.Question = make([]dns.Question, 1)
	c := new(dns.Client)
	c.ReadTimeout = timeout // Seems ignored for TCP?
	if tcp {
		c.Net = "tcp"
	}
	m.Question[0] = dns.Question{Name: zone, Qtype: dns.TypeSOA, Qclass: dns.ClassINET}
	nsAddressPort := net.JoinHostPort(server, "53")
	if debug {
		fmt.Printf("DEBUG Querying SOA from %s\n", nsAddressPort)
	}
	for trials = 0; trials < uint(maxTrials); trials++ {
		soa, rtt, err := c.Exchange(m, nsAddressPort)
		if soa == nil {
			result.rtt = 0
			result.msg = err.Error()
		} else {
			result.rtt = rtt
			if soa.Rcode != dns.RcodeSuccess {
				result.msg = dns.RcodeToString[soa.Rcode]
				break
			}
			if len(soa.Answer) == 0 { /* May happen if the server is a recursor, not authoritative, since we query with RD=0 */
				result.msg = "0 answer"
				break
			} else { //nolint:revive // complex nested structure
				gotSoa := false
				for _, rsoa := range soa.Answer {
					switch r := rsoa.(type) {
					case *dns.SOA:
						if noauthrequired || soa.Authoritative {
							result.retrieved = true
							result.serial = r.Serial
							result.msg = "OK"
						} else {
							result.msg = "Not authoritative"
						}
						gotSoa = true
					case *dns.CNAME: /* Bad practice but common */
						result.msg = "Apparently not a zone but an alias"
					case *dns.RRSIG:
						/* Ignore them. See bug #8 */
					default:
						// TODO: a name server can send us other RR types.
						result.msg = fmt.Sprintf("Internal error when processing %s, unexpected record type\n", rsoa)
					}
				}
				if !gotSoa {
					result.msg = "No SOA record in reply"
				}
				break
			}
		}
	}
	mychan <- result
}