package authoritative

import (
	"testing"

	"github.com/miekg/dns"

	"github.com/owen/vibedns/internal/models"
)

// extendedIndex builds an "extended" zone that overrides a single name
// (www.example.com) and otherwise carries no data, mimicking a domain whose
// public records should still be resolved on the internet.
func extendedIndex(t *testing.T) *Index {
	t.Helper()
	zone := models.Zone{
		ID: 1, Name: "example.com.", Kind: models.ZoneExtended, Enabled: true,
		DefaultTTL: 3600, PrimaryNS: "ns1.example.com.", AdminEmail: "hostmaster@example.com",
	}
	recs := []models.Record{
		{ZoneID: 1, Name: "www", Type: "A", Data: "10.0.0.1", Enabled: true},
		{ZoneID: 1, Name: "www", Type: "AAAA", Data: "2001:db8::1", Enabled: true},
	}
	idx, problems := Build([]models.Zone{zone}, map[int64][]models.Record{1: recs})
	for _, p := range problems {
		t.Fatalf("unexpected build problem: %v", p)
	}
	return idx
}

func TestExtendedZoneOverridesLocalRecord(t *testing.T) {
	idx := extendedIndex(t)

	resp := query(t, idx, "www.example.com.", dns.TypeA)
	if resp == nil {
		t.Fatal("expected a local answer for the overridden name, got nil (fallthrough)")
	}
	if !resp.Authoritative {
		t.Error("expected the override answer to be authoritative")
	}
	if len(resp.Answer) != 1 {
		t.Fatalf("expected 1 answer, got %d", len(resp.Answer))
	}
	a, ok := resp.Answer[0].(*dns.A)
	if !ok || a.A.String() != "10.0.0.1" {
		t.Errorf("unexpected answer: %v", resp.Answer[0])
	}
}

func TestExtendedZoneFallsThroughForUnknownName(t *testing.T) {
	idx := extendedIndex(t)

	// No local record for mail.example.com at all: the caller must see nil
	// so it forwards the query upstream, instead of a synthesised NXDOMAIN.
	resp := query(t, idx, "mail.example.com.", dns.TypeA)
	if resp != nil {
		t.Fatalf("expected fallthrough (nil) for an unconfigured name, got %+v", resp)
	}
}

func TestExtendedZoneFallsThroughForApex(t *testing.T) {
	idx := extendedIndex(t)

	// The apex itself was never configured (no auto SOA/NS synthesis for an
	// extended zone), so even a query at the zone name falls through.
	resp := query(t, idx, "example.com.", dns.TypeMX)
	if resp != nil {
		t.Fatalf("expected fallthrough (nil) for the bare apex, got %+v", resp)
	}
}

func TestExtendedZoneNoDataForOverriddenNameOtherType(t *testing.T) {
	idx := extendedIndex(t)

	// www.example.com is locally overridden for A/AAAA; a query for a type
	// that was not configured there is answered locally as NODATA rather
	// than forwarded, since the name itself is under local management.
	resp := query(t, idx, "www.example.com.", dns.TypeTXT)
	if resp == nil {
		t.Fatal("expected a local NODATA answer, got nil (fallthrough)")
	}
	if len(resp.Answer) != 0 {
		t.Errorf("expected no answer records, got %d", len(resp.Answer))
	}
	if resp.Rcode != dns.RcodeSuccess {
		t.Errorf("expected NOERROR/NODATA, got %s", dns.RcodeToString[resp.Rcode])
	}
}