package kubeedit

import (
	"context"
	"errors"
	"strings"
	"testing"

	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/runtime/schema"
	dynfake "k8s.io/client-go/dynamic/fake"

	"git.k8s-git-k6n.net/mats/fancy-dns/internal/config"
	"git.k8s-git-k6n.net/mats/fancy-dns/internal/kubesource"
)

func newEditor() *Editor {
	c := dynfake.NewSimpleDynamicClientWithCustomListKinds(runtime.NewScheme(),
		map[schema.GroupVersionResource]string{
			kubesource.ZoneGVR:  "DNSZoneList",
			kubesource.GroupGVR: "ClientGroupList",
			kubesource.ListGVR:  "BlockListList",
		})
	return New(c, "dns")
}

var ctx = context.Background()

func grp(name, policy string) config.Group {
	return config.Group{Name: name, Policy: policy, Match: config.Match{CIDRs: []string{"10.0.0.0/8"}}}
}

func TestSyncGroupsCreatesUpdatesDeletesAndOrders(t *testing.T) {
	e := newEditor()
	res, err := e.SyncGroups(ctx, []config.Group{grp("a", "allow"), grp("b", "deny")}, nil, "alice")
	if err != nil || len(res.Created) != 2 {
		t.Fatalf("create: %+v %v", res, err)
	}
	// Nothing changed: nothing written.
	res, err = e.SyncGroups(ctx, []config.Group{grp("a", "allow"), grp("b", "deny")}, nil, "alice")
	if err != nil || len(res.Created)+len(res.Updated)+len(res.Deleted) != 0 {
		t.Fatalf("idempotent: %+v %v", res, err)
	}
	// Reorder, change one, drop none.
	res, err = e.SyncGroups(ctx, []config.Group{grp("b", "deny"), grp("a", "block_only")}, nil, "alice")
	if err != nil || len(res.Updated) != 2 {
		t.Fatalf("reorder: %+v %v", res, err)
	}
	got, _ := e.Groups(ctx)
	if got[0].Name != "b" || got[1].Name != "a" || got[1].Spec.Policy != "block_only" {
		t.Fatalf("groups = %+v", got)
	}
	res, err = e.SyncGroups(ctx, []config.Group{grp("b", "deny")}, nil, "alice")
	if err != nil || len(res.Deleted) != 1 || res.Deleted[0] != "a" {
		t.Fatalf("delete: %+v %v", res, err)
	}
}

func TestSyncGroupsLeavesForeignGroupsAlone(t *testing.T) {
	e := newEditor()
	yaml := func(n string) bool { return n == "from-yaml" }
	res, err := e.SyncGroups(ctx, []config.Group{grp("from-yaml", "allow"), grp("mine", "deny")}, yaml, "alice")
	if err != nil || len(res.Created) != 1 || res.Created[0] != "mine" {
		t.Fatalf("%+v %v", res, err)
	}
}

func TestSyncGroupsValidatesBeforeWriting(t *testing.T) {
	e := newEditor()
	_, err := e.SyncGroups(ctx, []config.Group{grp("ok", "allow"), grp("bad", "maybe")}, nil, "alice")
	if err == nil || !strings.Contains(err.Error(), "bad") {
		t.Fatalf("err = %v", err)
	}
	if got, _ := e.Groups(ctx); len(got) != 0 {
		t.Fatalf("a rejected save wrote %+v", got)
	}
	if _, err := e.SyncGroups(ctx, []config.Group{grp("Kids Room", "allow")}, nil, "alice"); err == nil {
		t.Fatal("a name that is not a Kubernetes object name must be refused")
	}
}

func TestActorIsRecorded(t *testing.T) {
	e := newEditor()
	if _, err := e.SyncGroups(ctx, []config.Group{grp("a", "allow")}, nil, "alice@example.com"); err != nil {
		t.Fatal(err)
	}
	u, err := e.res(kubesource.GroupGVR).Get(ctx, "a", getOpts)
	if err != nil {
		t.Fatal(err)
	}
	if u.GetAnnotations()[ActorAnnotation] != "alice@example.com" {
		t.Fatalf("annotations = %v", u.GetAnnotations())
	}
}

func TestZoneRecordLifecycle(t *testing.T) {
	e := newEditor()
	const apex = "home.example.com."

	// A zone starts with its servers: without an NS the runtime cannot answer
	// NXDOMAIN and the editor says so rather than storing a dead zone.
	if _, err := e.AddRecord(ctx, apex, RecordInput{Name: "nas", Type: "A", Value: "10.0.0.2"}, "a"); err == nil {
		t.Fatal("a zone with no NS must be refused")
	}
	if zs, _ := e.Zones(ctx); len(zs) != 0 {
		t.Fatal("the refused zone was stored")
	}

	// An apex NS on its own is a valid zone.
	if _, err := e.AddRecord(ctx, apex, RecordInput{Name: "@", Type: "NS", Value: "ns1.home.example.com."}, "a"); err != nil {
		t.Fatal(err)
	}
	res, err := e.AddRecord(ctx, apex, RecordInput{Name: "nas", Type: "A", TTL: 60, Value: "10.0.0.2"}, "a")
	if err != nil || res.Serial < 1 {
		t.Fatalf("add: %+v %v", res, err)
	}
	// Names are stored the way an operator writes them.
	zs, _ := e.Zones(ctx)
	if len(zs) != 1 || zs[0].Name != "home.example.com" {
		t.Fatalf("zones = %+v", zs)
	}
	var names []string
	for _, r := range zs[0].Spec.Records {
		names = append(names, r.Name)
	}
	if strings.Join(names, ",") != "@,nas" {
		t.Fatalf("stored names = %v", names)
	}

	// The same record, spelled differently, is a duplicate.
	if _, err := e.AddRecord(ctx, apex, RecordInput{Name: "nas.home.example.com.", Type: "A", Value: "10.0.0.2"}, "a"); err == nil {
		t.Fatal("duplicate accepted")
	}
	// Put replaces the RRset.
	if _, err := e.PutRecord(ctx, apex, RecordInput{Name: "nas", Type: "A", Value: "10.0.0.9"}, "a"); err != nil {
		t.Fatal(err)
	}
	zs, _ = e.Zones(ctx)
	if n := countType(zs[0].Spec, "A"); n != 1 || zs[0].Spec.Records[len(zs[0].Spec.Records)-1].Value != "10.0.0.9" {
		t.Fatalf("after put = %+v", zs[0].Spec.Records)
	}
	// Delete one record, then one that is not there.
	if _, err := e.DeleteRecord(ctx, apex, "nas", "A", "10.0.0.9", "a"); err != nil {
		t.Fatal(err)
	}
	if _, err := e.DeleteRecord(ctx, apex, "nas", "A", "", "a"); !errors.Is(err, ErrNotFound) {
		t.Fatalf("err = %v, want not found", err)
	}
	// An edit that would leave the zone invalid is refused and changes nothing.
	if _, err := e.DeleteRecord(ctx, apex, "@", "NS", "", "a"); err == nil {
		t.Fatal("removing the last apex NS must be refused")
	}
	if zs, _ = e.Zones(ctx); countType(zs[0].Spec, "NS") != 1 {
		t.Fatal("the refused delete changed the zone")
	}
}

func countType(s kubesource.DNSZoneSpec, typ string) int {
	n := 0
	for _, r := range s.Records {
		if r.Type == typ {
			n++
		}
	}
	return n
}

func TestDelegationsAndZoneDelete(t *testing.T) {
	e := newEditor()
	const apex = "lab.example.com."
	// A delegation in a brand new zone also gives the zone its own servers.
	if _, err := e.SetDelegation(ctx, apex, "sub", []string{"ns.sub.lab.example.com.", "ns2.sub.lab.example.com."}, 300, "a"); err != nil {
		t.Fatal(err)
	}
	zs, _ := e.Zones(ctx)
	if got := countType(zs[0].Spec, "NS"); got != 4 {
		t.Fatalf("NS records = %d, want 2 for the cut and 2 for the apex: %+v", got, zs[0].Spec.Records)
	}
	// Data under the cut is refused, as in the file-based writer.
	if _, err := e.AddRecord(ctx, apex, RecordInput{Name: "x.sub", Type: "A", Value: "10.0.0.1"}, "a"); err == nil {
		t.Fatal("a record below a delegation was accepted")
	}
	if _, err := e.RemoveDelegation(ctx, apex, "sub", "a"); err != nil {
		t.Fatal(err)
	}
	if _, err := e.RemoveDelegation(ctx, apex, "sub", "a"); !errors.Is(err, ErrNotFound) {
		t.Fatalf("err = %v", err)
	}
	if err := e.DeleteZone(ctx, apex); err != nil {
		t.Fatal(err)
	}
	if err := e.DeleteZone(ctx, apex); !errors.Is(err, ErrNotFound) {
		t.Fatalf("err = %v", err)
	}
}

func TestListEditing(t *testing.T) {
	e := newEditor()
	if err := e.PutList(ctx, "ads", kubesource.BlockListSpec{URL: "https://e.com/hosts", Format: "hosts"}, "a"); err != nil {
		t.Fatal(err)
	}
	if err := e.PutList(ctx, "evil", kubesource.BlockListSpec{URL: "file:///etc/passwd"}, "a"); err == nil {
		t.Fatal("file:// accepted")
	}
	if err := e.SetListDisabled(ctx, "ads", true, "a"); err != nil {
		t.Fatal(err)
	}
	ls, _ := e.Lists(ctx)
	if len(ls) != 1 || !ls[0].Spec.Disabled || ls[0].Spec.Format != "hosts" {
		t.Fatalf("lists = %+v", ls)
	}
	if err := e.SetListDisabled(ctx, "nope", true, "a"); !errors.Is(err, ErrNotFound) {
		t.Fatalf("err = %v", err)
	}
	if err := e.DeleteList(ctx, "ads"); err != nil {
		t.Fatal(err)
	}
}