package checker

import (
	"reflect"
	"testing"
)

func TestDeriveView_Nil(t *testing.T) {
	deriveView(nil) // must not panic
}

func TestDeriveView_PicksMajoritySignature(t *testing.T) {
	key := "example.com./A"
	data := &ResolverPropagationData{
		Resolvers: map[string]*ResolverView{
			"a": mkResolver("a", "eu", false, true, map[string]*RRProbe{key: mkProbe("NOERROR", "1.1.1.1")}),
			"b": mkResolver("b", "global", false, true, map[string]*RRProbe{key: mkProbe("NOERROR", "1.1.1.1")}),
			"c": mkResolver("c", "na", false, true, map[string]*RRProbe{key: mkProbe("NOERROR", "9.9.9.9")}),
		},
		RRsets: map[string]*RRsetView{
			key: {Name: "example.com.", Type: "A"},
		},
	}
	deriveView(data)
	v := data.RRsets[key]
	if v.ConsensusSig != "1.1.1.1" {
		t.Errorf("consensus = %q", v.ConsensusSig)
	}
	if !reflect.DeepEqual(v.Agreeing, []string{"a", "b"}) {
		t.Errorf("agreeing = %v", v.Agreeing)
	}
	if !reflect.DeepEqual(v.Dissenting, []string{"c"}) {
		t.Errorf("dissenting = %v", v.Dissenting)
	}
	if data.Stats.UnfilteredAgreeing != 2 {
		t.Errorf("unfilteredAgreeing = %d", data.Stats.UnfilteredAgreeing)
	}
}

func TestDeriveView_FilteredResolverDoesNotVote(t *testing.T) {
	key := "example.com./A"
	data := &ResolverPropagationData{
		Resolvers: map[string]*ResolverView{
			"good":  mkResolver("good", "eu", false, true, map[string]*RRProbe{key: mkProbe("NOERROR", "1.1.1.1")}),
			"filt":  mkResolver("filt", "eu", true, true, map[string]*RRProbe{key: mkProbe("NOERROR", "0.0.0.0")}),
			"filt2": mkResolver("filt2", "eu", true, true, map[string]*RRProbe{key: mkProbe("NOERROR", "0.0.0.0")}),
			"filt3": mkResolver("filt3", "eu", true, true, map[string]*RRProbe{key: mkProbe("NOERROR", "0.0.0.0")}),
		},
		RRsets: map[string]*RRsetView{
			key: {Name: "example.com.", Type: "A"},
		},
	}
	deriveView(data)
	if data.RRsets[key].ConsensusSig != "1.1.1.1" {
		t.Errorf("filtered resolvers should not win: %q", data.RRsets[key].ConsensusSig)
	}
}

func TestDeriveView_ExpectedMatch(t *testing.T) {
	key := "example.com./A"
	data := &ResolverPropagationData{
		Resolvers: map[string]*ResolverView{
			"a": mkResolver("a", "eu", false, true, map[string]*RRProbe{key: mkProbe("NOERROR", "1.1.1.1")}),
		},
		RRsets: map[string]*RRsetView{
			key: {Name: "example.com.", Type: "A", Expected: "1.1.1.1"},
		},
	}
	deriveView(data)
	if !data.RRsets[key].MatchesExpected {
		t.Errorf("expected match should be true")
	}

	// Drift case.
	data.RRsets[key].Expected = "9.9.9.9"
	data.RRsets[key].MatchesExpected = false
	deriveView(data)
	if data.RRsets[key].MatchesExpected {
		t.Errorf("expected match should be false on drift")
	}
}

func TestDeriveView_Idempotent(t *testing.T) {
	key := "example.com./A"
	data := &ResolverPropagationData{
		Resolvers: map[string]*ResolverView{
			"a": mkResolver("a", "eu", false, true, map[string]*RRProbe{key: mkProbe("NOERROR", "1.1.1.1")}),
			"b": mkResolver("b", "eu", false, true, map[string]*RRProbe{key: mkProbe("NOERROR", "1.1.1.1")}),
		},
		RRsets: map[string]*RRsetView{key: {Name: "example.com.", Type: "A"}},
	}
	deriveView(data)
	first := *data.RRsets[key]
	deriveView(data)
	second := *data.RRsets[key]
	if !reflect.DeepEqual(first.Groups, second.Groups) ||
		first.ConsensusSig != second.ConsensusSig ||
		!reflect.DeepEqual(first.Agreeing, second.Agreeing) {
		t.Errorf("deriveView is not idempotent: %+v vs %+v", first, second)
	}
}

func TestDeriveView_SkipsErrorProbes(t *testing.T) {
	key := "example.com./A"
	data := &ResolverPropagationData{
		Resolvers: map[string]*ResolverView{
			"a": mkResolver("a", "eu", false, true, map[string]*RRProbe{key: {Error: "timeout", Transport: TransportUDP}}),
			"b": mkResolver("b", "eu", false, true, map[string]*RRProbe{key: mkProbe("NOERROR", "1.1.1.1")}),
		},
		RRsets: map[string]*RRsetView{key: {Name: "example.com.", Type: "A"}},
	}
	deriveView(data)
	if data.RRsets[key].ConsensusSig != "1.1.1.1" {
		t.Errorf("err probe shouldn't be counted: %q", data.RRsets[key].ConsensusSig)
	}
}

func TestDeriveView_DissenterDoesNotAgree(t *testing.T) {
	// Resolver "c" probes two RRsets and disagrees on one ⇒ should not be
	// counted in UnfilteredAgreeing.
	k1, k2 := "ex./A", "ex./MX"
	data := &ResolverPropagationData{
		Resolvers: map[string]*ResolverView{
			"a": mkResolver("a", "eu", false, true, map[string]*RRProbe{
				k1: mkProbe("NOERROR", "1.1.1.1"),
				k2: mkProbe("NOERROR", "10 mx."),
			}),
			"b": mkResolver("b", "eu", false, true, map[string]*RRProbe{
				k1: mkProbe("NOERROR", "1.1.1.1"),
				k2: mkProbe("NOERROR", "10 mx."),
			}),
			"c": mkResolver("c", "eu", false, true, map[string]*RRProbe{
				k1: mkProbe("NOERROR", "1.1.1.1"),
				k2: mkProbe("NOERROR", "20 nope."), // dissents
			}),
		},
		RRsets: map[string]*RRsetView{
			k1: {Name: "ex.", Type: "A"},
			k2: {Name: "ex.", Type: "MX"},
		},
	}
	deriveView(data)
	if data.Stats.UnfilteredAgreeing != 2 {
		t.Errorf("UnfilteredAgreeing = %d, want 2", data.Stats.UnfilteredAgreeing)
	}
}