package mdns

import (
	"bytes"
	"net"
	"reflect"
	"testing"

	"github.com/miekg/dns"
)

func makeService(t *testing.T) *MDNSService {
	return makeServiceWithServiceName(t, "_http._tcp")
}

func makeServiceWithServiceName(t *testing.T, service string) *MDNSService {
	m, err := NewMDNSService(
		"hostname",
		service,
		"local.",
		"testhost.",
		80, // port
		[]net.IP{net.IP([]byte{192, 168, 0, 42}), net.ParseIP("2620:0:1000:1900:b0c2:d0b2:c411:18bc")},
		[]string{"Local web server"}) // TXT

	if err != nil {
		t.Fatalf("err: %v", err)
	}

	return m
}

func TestNewMDNSService_BadParams(t *testing.T) {
	for _, test := range []struct {
		testName string
		hostName string
		domain   string
	}{
		{
			"NewMDNSService should fail when passed hostName that is not a legal fully-qualified domain name",
			"hostname", // not legal FQDN - should be "hostname." or "hostname.local.", etc.
			"local.",   // legal
		},
		{
			"NewMDNSService should fail when passed domain that is not a legal fully-qualified domain name",
			"hostname.", // legal
			"local",     // should be "local."
		},
	} {
		_, err := NewMDNSService(
			"instance name",
			"_http._tcp",
			test.Domain,
			test.hostName,
			80, // port
			[]net.IP{net.IP([]byte{192, 168, 0, 42})},
			[]string{"Local web server"}) // TXT
		if err == nil {
			t.Fatalf("%s: error expected, but got none", test.testName)
		}
	}
}

func TestMDNSService_BadAddr(t *testing.T) {
	s := makeService(t)
	q := dns.Question{
		Name:  "random",
		Qtype: dns.TypeANY,
	}
	recs := s.Records(q)
	if len(recs) != 0 {
		t.Fatalf("bad: %v", recs)
	}
}

func TestMDNSService_ServiceAddr(t *testing.T) {
	s := makeService(t)
	q := dns.Question{
		Name:  "_http._tcp.local.",
		Qtype: dns.TypeANY,
	}
	recs := s.Records(q)
	if got, want := len(recs), 5; got != want {
		t.Fatalf("got %d records, want %d: %v", got, want, recs)
	}

	if ptr, ok := recs[0].(*dns.PTR); !ok {
		t.Errorf("recs[0] should be PTR record, got: %v, all records: %v", recs[0], recs)
	} else if got, want := ptr.Ptr, "hostname._http._tcp.local."; got != want {
		t.Fatalf("bad PTR record %v: got %v, want %v", ptr, got, want)
	}

	if _, ok := recs[1].(*dns.SRV); !ok {
		t.Errorf("recs[1] should be SRV record, got: %v, all reccords: %v", recs[1], recs)
	}
	if _, ok := recs[2].(*dns.A); !ok {
		t.Errorf("recs[2] should be A record, got: %v, all records: %v", recs[2], recs)
	}
	if _, ok := recs[3].(*dns.AAAA); !ok {
		t.Errorf("recs[3] should be AAAA record, got: %v, all records: %v", recs[3], recs)
	}
	if _, ok := recs[4].(*dns.TXT); !ok {
		t.Errorf("recs[4] should be TXT record, got: %v, all records: %v", recs[4], recs)
	}

	q.Qtype = dns.TypePTR
	if recs2 := s.Records(q); !reflect.DeepEqual(recs, recs2) {
		t.Fatalf("PTR question should return same result as ANY question: ANY => %v, PTR => %v", recs, recs2)
	}
}

func TestMDNSService_InstanceAddr_ANY(t *testing.T) {
	s := makeService(t)
	q := dns.Question{
		Name:  "hostname._http._tcp.local.",
		Qtype: dns.TypeANY,
	}
	recs := s.Records(q)
	if len(recs) != 4 {
		t.Fatalf("bad: %v", recs)
	}
	if _, ok := recs[0].(*dns.SRV); !ok {
		t.Fatalf("bad: %v", recs[0])
	}
	if _, ok := recs[1].(*dns.A); !ok {
		t.Fatalf("bad: %v", recs[1])
	}
	if _, ok := recs[2].(*dns.AAAA); !ok {
		t.Fatalf("bad: %v", recs[2])
	}
	if _, ok := recs[3].(*dns.TXT); !ok {
		t.Fatalf("bad: %v", recs[3])
	}
}

func TestMDNSService_InstanceAddr_SRV(t *testing.T) {
	s := makeService(t)
	q := dns.Question{
		Name:  "hostname._http._tcp.local.",
		Qtype: dns.TypeSRV,
	}
	recs := s.Records(q)
	if len(recs) != 3 {
		t.Fatalf("bad: %v", recs)
	}
	srv, ok := recs[0].(*dns.SRV)
	if !ok {
		t.Fatalf("bad: %v", recs[0])
	}
	if _, ok := recs[1].(*dns.A); !ok {
		t.Fatalf("bad: %v", recs[1])
	}
	if _, ok := recs[2].(*dns.AAAA); !ok {
		t.Fatalf("bad: %v", recs[2])
	}

	if srv.Port != uint16(s.Port) {
		t.Fatalf("bad: %v", recs[0])
	}
}

func TestMDNSService_InstanceAddr_A(t *testing.T) {
	s := makeService(t)
	q := dns.Question{
		Name:  "hostname._http._tcp.local.",
		Qtype: dns.TypeA,
	}
	recs := s.Records(q)
	if len(recs) != 1 {
		t.Fatalf("bad: %v", recs)
	}
	a, ok := recs[0].(*dns.A)
	if !ok {
		t.Fatalf("bad: %v", recs[0])
	}
	if !bytes.Equal(a.A, []byte{192, 168, 0, 42}) {
		t.Fatalf("bad: %v", recs[0])
	}
}

func TestMDNSService_InstanceAddr_AAAA(t *testing.T) {
	s := makeService(t)
	q := dns.Question{
		Name:  "hostname._http._tcp.local.",
		Qtype: dns.TypeAAAA,
	}
	recs := s.Records(q)
	if len(recs) != 1 {
		t.Fatalf("bad: %v", recs)
	}
	a4, ok := recs[0].(*dns.AAAA)
	if !ok {
		t.Fatalf("bad: %v", recs[0])
	}
	ip6 := net.ParseIP("2620:0:1000:1900:b0c2:d0b2:c411:18bc")
	if got := len(ip6); got != net.IPv6len {
		t.Fatalf("test IP failed to parse (len = %d, want %d)", got, net.IPv6len)
	}
	if !bytes.Equal(a4.AAAA, ip6) {
		t.Fatalf("bad: %v", recs[0])
	}
}

func TestMDNSService_InstanceAddr_TXT(t *testing.T) {
	s := makeService(t)
	q := dns.Question{
		Name:  "hostname._http._tcp.local.",
		Qtype: dns.TypeTXT,
	}
	recs := s.Records(q)
	if len(recs) != 1 {
		t.Fatalf("bad: %v", recs)
	}
	txt, ok := recs[0].(*dns.TXT)
	if !ok {
		t.Fatalf("bad: %v", recs[0])
	}
	if got, want := txt.Txt, s.TXT; !reflect.DeepEqual(got, want) {
		t.Fatalf("TXT record mismatch for %v: got %v, want %v", recs[0], got, want)
	}
}