package cdns

import (
	"fmt"
	"time"

	"github.com/miekg/dns"
)

// Results provides functionality.
type Results map[string]nameServer

func masterTask(zone string, nameservers map[string]nameServer) (uint, uint, bool, Results) {
	var numRequests uint
	success := true
	addressChannel := make(chan DNSreply)
	soaChannel := make(chan SOAreply)
	numNS := uint(0)
	numAddrNS := uint(0)
	results := make(Results)
	for name := range nameservers {
		if !v6only {
			go localQuery(addressChannel, name, dns.TypeA)
		}
		if !v4only {
			go localQuery(addressChannel, name, dns.TypeAAAA)
		}
		numNS++
	}
	if v6only || v4only {
		numRequests = numNS
	} else {
		numRequests = numNS * 2
	}
	for i := uint(0); i < numRequests; i++ {
		addrResult := <-addressChannel
		addrFamily := "IPv6"
		if addrResult.qtype == dns.TypeA {
			addrFamily = "IPv4"
		}
		if addrResult.r == nil {
			// TODO We may have different globalErrMsg is it
			// works with IPv4 but not IPv6 (it should not happen but it does)
			nameservers[addrResult.qname] = nameServer{
				name:         addrResult.qname,
				ips:          nil,
				globalErrMsg: fmt.Sprintf("Cannot get the %s address: %s", addrFamily, addrResult.err),
			}
			success = false
		} else {
			if addrResult.r.Rcode != dns.RcodeSuccess {
				nameservers[addrResult.qname] = nameServer{
					name:         addrResult.qname,
					ips:          nil,
					globalErrMsg: fmt.Sprintf("Cannot get the %s address: %s", addrFamily, dns.RcodeToString[addrResult.r.Rcode]),
				}
				success = false
			} else {
				for j := range addrResult.r.Answer {
					ansa := addrResult.r.Answer[j]
					var ns string
					switch a := ansa.(type) {
					case *dns.A:
						ns = a.A.String()
						existing := nameservers[addrResult.qname]
						nameservers[addrResult.qname] = nameServer{name: addrResult.qname, ips: append(existing.ips, ns)}
						numAddrNS++
						go soaQuery(soaChannel, zone, addrResult.qname, ns)
					case *dns.AAAA:
						ns = a.AAAA.String()
						existing2 := nameservers[addrResult.qname]
						nameservers[addrResult.qname] = nameServer{name: addrResult.qname, ips: append(existing2.ips, ns)}
						numAddrNS++
						go soaQuery(soaChannel, zone, addrResult.qname, ns)
					}
				}
			}
		}
	}
	for i := uint(0); i < numAddrNS; i++ {
		if debug {
			fmt.Printf("DEBUG Getting result for ns #%d/%d\n", i+1, numAddrNS)
		}
		soaResult := <-soaChannel
		_, present := results[soaResult.name]
		if !present {
			results[soaResult.name] = nameServer{
				name:    soaResult.name,
				ips:     make([]string, 0),
				success: make([]bool, 0),
				errMsg:  make([]string, 0),
				serial:  make([]uint32, 0),
				rtts:    make([]time.Duration, 0),
			}
		}
		if !soaResult.retrieved {
			results[soaResult.name] = nameServer{
				name:    soaResult.name,
				ips:     append(results[soaResult.name].ips, soaResult.address),
				success: append(results[soaResult.name].success, false),
				errMsg:  append(results[soaResult.name].errMsg, soaResult.msg),
				serial:  append(results[soaResult.name].serial, 0),
				rtts:    append(results[soaResult.name].rtts, soaResult.rtt),
			}
			success = false
		} else {
			results[soaResult.name] = nameServer{
				name:    soaResult.name,
				ips:     append(results[soaResult.name].ips, soaResult.address),
				success: append(results[soaResult.name].success, true),
				errMsg:  append(results[soaResult.name].errMsg, ""),
				serial:  append(results[soaResult.name].serial, soaResult.serial),
				rtts:    append(results[soaResult.name].rtts, soaResult.rtt),
			}
		}
	}
	for name := range nameservers {
		if nameservers[name].ips == nil {
			results[name] = nameservers[name]
		}
	}
	return numNS, numAddrNS, success, results
}