package test

import (
	"testing"

	"github.com/coredns/coredns/plugin/test"

	"github.com/miekg/dns"
)

func TestFileUpstream(t *testing.T) {
	name, rm, err := test.TempFile(".", `$ORIGIN example.org.
@	3600 IN	SOA   sns.dns.icann.org. noc.dns.icann.org. (
        2017042745 ; serial
        7200       ; refresh (2 hours)
        3600       ; retry (1 hour)
        1209600    ; expire (2 weeks)
        3600       ; minimum (1 hour)
)

    3600 IN NS    a.iana-servers.net.
    3600 IN NS    b.iana-servers.net.

www 3600 IN CNAME www.example.net.
`)
	if err != nil {
		t.Fatalf("Failed to create zone: %s", err)
	}
	defer rm()

	corefile := `.:0 {
		file ` + name + ` example.org
		hosts {
			10.0.0.1 www.example.net.
			fallthrough
		}
	}`

	i, udp, _, err := CoreDNSServerAndPorts(corefile)
	if err != nil {
		t.Fatalf("Could not get CoreDNS serving instance: %s", err)
	}
	defer i.Stop()

	m := new(dns.Msg)
	m.SetQuestion("www.example.org.", dns.TypeA)
	m.SetEdns0(4096, true)

	r, err := dns.Exchange(m, udp)
	if err != nil {
		t.Fatalf("Could not exchange msg: %s", err)
	}
	if r.Rcode == dns.RcodeServerFailure {
		t.Fatalf("Rcode should not be dns.RcodeServerFailure")
	}
	if x := r.Answer[1].(*dns.A).A.String(); x != "10.0.0.1" {
		t.Errorf("Failed to get address for CNAME, expected 10.0.0.1 got %s", x)
	}
}

func TestFileUpstreamError(t *testing.T) {
	cases := map[string]test.Case{
		"nxdomain": {
			Qname: "nxdomain.example.org.", Qtype: dns.TypeA,
			Answer: []dns.RR{
				test.CNAME("nxdomain.example.org.	3600	IN	CNAME	nxdomain.example.net"),
			},
			Rcode: dns.RcodeNameError,
		},
		"nxdomain-chain": {
			Qname: "chain1.example.org.", Qtype: dns.TypeA,
			Answer: []dns.RR{
				test.CNAME("chain1.example.org.	3600	IN	CNAME	nxdomain.example.org"),
				test.CNAME("nxdomain.example.org.	3600	IN	CNAME	nxdomain.example.net"),
			},
			Rcode: dns.RcodeNameError,
		},
		"srvfail": {
			Qname: "srvfail.example.org.", Qtype: dns.TypeA,
			Answer: []dns.RR{
				test.CNAME("srvfail.example.org.	3600	IN	CNAME	srvfail.example.net."),
			},
			Rcode: dns.RcodeServerFailure,
		},
		"srvfail-chain": {
			Qname: "chain2.example.org.", Qtype: dns.TypeA,
			Answer: []dns.RR{
				test.CNAME("chain2.example.org.	3600	IN	CNAME	srvfail.example.org."),
				test.CNAME("srvfail.example.org.	3600	IN	CNAME	srvfail.example.net."),
			},
			Rcode: dns.RcodeServerFailure,
		},
		"nodata": {
			Qname: "nodata.example.org.", Qtype: dns.TypeA,
			Answer: []dns.RR{
				test.CNAME("nodata.example.org.	3600	IN	CNAME	nodata.example.net"),
			},
			Rcode: dns.RcodeSuccess,
		},
		"nodata-chain": {
			Qname: "chain3.example.org.", Qtype: dns.TypeA,
			Answer: []dns.RR{
				test.CNAME("chain3.example.org.	3600	IN	CNAME	nodata.example.org"),
				test.CNAME("nodata.example.org.	3600	IN	CNAME	nodata.example.net"),
			},
			Rcode: dns.RcodeSuccess,
		},
	}
	name, rm, err := test.TempFile(".", `$ORIGIN example.org.
@	3600 IN	SOA   sns.dns.icann.org. noc.dns.icann.org. (
        2017042745 ; serial
        7200       ; refresh (2 hours)
        3600       ; retry (1 hour)
        1209600    ; expire (2 weeks)
        3600       ; minimum (1 hour)
)

    3600 IN NS    a.iana-servers.net.
    3600 IN NS    b.iana-servers.net.

chain1   3600 IN CNAME nxdomain
nxdomain 3600 IN CNAME nxdomain.example.net.
chain2   3600 IN CNAME srvfail
srvfail  3600 IN CNAME srvfail.example.net.
chain3   3600 IN CNAME nodata
nodata   3600 IN CNAME nodata.example.net.

`)
	if err != nil {
		t.Fatalf("Failed to create zone: %s", err)
	}
	defer rm()

	corefile := `.:0 {
	template ANY A nxdomain.example.net. {
		rcode NXDOMAIN
	}
	template ANY A srvfail.example.net. {
		rcode SERVFAIL
	}
	template ANY A nodata.example.net. {
	}
	file ` + name + ` example.org
}`

	i, udp, _, err := CoreDNSServerAndPorts(corefile)
	if err != nil {
		t.Fatalf("Could not get CoreDNS serving instance: %s", err)
	}
	defer i.Stop()

	for n, tc := range cases {
		t.Run(n, func(t *testing.T) {
			m := new(dns.Msg)
			m.SetQuestion(tc.Qname, tc.Qtype)
			m.SetEdns0(4096, true)

			r, err := dns.Exchange(m, udp)
			if err != nil {
				t.Fatalf("Could not exchange msg: %s", err)
			}
			if r.Rcode != tc.Rcode {
				t.Fatalf("expected rcode %v, got %v", tc.Rcode, r.Rcode)
			}
			if n := len(r.Answer); n != len(tc.Answer) {
				t.Fatalf("Expected %v answers, got %v", len(tc.Answer), n)
			}
			if err := test.Section(tc, test.Answer, r.Answer); err != nil {
				t.Error(err)
			}
		})
	}
}

// TestFileUpstreamAdditional runs two CoreDNS servers that serve example.org and foo.example.org.
// example.org contains a cname to foo.example.org; this should be resolved via upstream.Self.
func TestFileUpstreamAdditional(t *testing.T) {
	name, rm, err := test.TempFile(".", `$ORIGIN example.org.
@	3600 IN	SOA   sns.dns.icann.org. noc.dns.icann.org. 2017042745 7200 3600 1209600 3600

    3600 IN NS    b.iana-servers.net.

www 3600 IN CNAME www.foo
`)
	if err != nil {
		t.Fatalf("Failed to create zone: %s", err)
	}
	defer rm()

	name2, rm2, err2 := test.TempFile(".", `$ORIGIN foo.example.org.
@	3600 IN	SOA sns.dns.icann.org. noc.dns.icann.org. 2017042745 7200 3600 1209600 3600

    3600 IN NS  b.iana-servers.net.

www 3600 IN A   127.0.0.53
`)
	if err2 != nil {
		t.Fatalf("Failed to create zone: %s", err2)
	}
	defer rm2()

	corefile := `.:0 {
		file ` + name + ` example.org
		file ` + name2 + ` foo.example.org
	}`

	i, udp, _, err := CoreDNSServerAndPorts(corefile)
	if err != nil {
		t.Fatalf("Could not get CoreDNS serving instance: %s", err)
	}
	defer i.Stop()

	m := new(dns.Msg)
	m.SetQuestion("www.example.org.", dns.TypeA)

	r, err := dns.Exchange(m, udp)
	if err != nil {
		t.Fatalf("Could not exchange msg: %s", err)
	}
	if r.Rcode == dns.RcodeServerFailure {
		t.Fatalf("Rcode should not be dns.RcodeServerFailure")
	}
	if x := len(r.Answer); x != 2 {
		t.Errorf("Expected 2 RR in reply, got %d", x)
	}
	if x := r.Answer[1].(*dns.A).A.String(); x != "127.0.0.53" {
		t.Errorf("Failed to get address for CNAME, expected 127.0.0.53, got %s", x)
	}
}

// TestFileCnameOrigin tests that CNAMEs pointing to origin are correctly resolved
func TestFileCnameOrigin(t *testing.T) {
	cases := map[string]uint16{
		"A":   dns.TypeA,
		"SOA": dns.TypeSOA,
		"NS":  dns.TypeNS,
	}

	name, rm, err := test.TempFile(".", exampleOrg)
	if err != nil {
		t.Fatalf("Failed to create zone: %s", err)
	}
	defer rm()

	// Corefile with for example without proxy section.
	corefile := `example.org:0 {
		file ` + name + `
	}`
	i, udp, _, err := CoreDNSServerAndPorts(corefile)
	if err != nil {
		t.Fatalf("Could not get CoreDNS serving instance: %s", err)
	}
	defer i.Stop()

	for name, qtype := range cases {
		t.Run(name, func(t *testing.T) {
			m := new(dns.Msg)
			m.SetQuestion("cname-origin.example.org.", qtype)

			resp, err := dns.Exchange(m, udp)
			if err != nil {
				t.Fatalf("Expected to receive reply, but didn't: %s", err)
			}

			// Check minimum answer count (CNAME + target record)
			if len(resp.Answer) < 2 {
				t.Fatalf("Expected at least 2 RRs in answer section, got %d", len(resp.Answer))
			}

			// Verify first record is CNAME
			if len(resp.Answer) > 0 && resp.Answer[0].Header().Rrtype != dns.TypeCNAME {
				t.Errorf("Expected first RR to be CNAME, got %s", dns.TypeToString[resp.Answer[0].Header().Rrtype])
			}

			// Verify we have the queried type in the response
			if len(resp.Answer) > 1 {
				found := false
				for _, rr := range resp.Answer[1:] {
					if rr.Header().Rrtype == qtype {
						found = true
						break
					}
				}
				if !found {
					t.Errorf("Expected to find %s record in answer section", dns.TypeToString[qtype])
				}
			}
		})
	}
}
