package engine

import (
	"slices"
	"strings"
	"testing"

	"jarl/internal/auth"
	"jarl/internal/model"
	"jarl/internal/validate"
)

// linkedEnv has views internal and external and zone example.com in
// internal with a few records.
func linkedEnv(t *testing.T) *testEnv {
	env := newEnv(t)
	env.submit(env.admin, NewRequest(OpSettingsUpdate, 0, SettingsInput{Nameservers: &[]string{"ns1.example.net."}}))
	env.submit(env.admin,
		NewRequest(OpViewCreate, 0, ViewInput{Name: model.Ptr("internal"), MatchClients: &[]string{"10.0.0.0/8"}}),
		NewRequest(OpViewCreate, 0, ViewInput{Name: model.Ptr("external"), MatchClients: &[]string{"any"}}))
	env.submit(env.admin, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("example.com"), View: model.Ptr("internal")}))
	env.submit(env.admin,
		recIn("internal", "www", "A", "192.0.2.10"),
		recIn("internal", "mail", "A", "192.0.2.25"),
		recIn("internal", "@", "MX", "10 mail"))
	return env
}

func recIn(view, name, typ, data string) Request {
	return NewRequest(OpRecordCreate, 0, RecordInput{Zone: "example.com", View: view, Name: &name, Type: &typ, Data: &data})
}

// view returns a view's records of example.com as "name type data S|L",
// S for shared, L for local.
func (env *testEnv) view(name string) []string {
	env.t.Helper()
	s := env.state()
	v := s.ViewByName(name)
	z := s.FindZone("example.com.", v.ID)
	var out []string
	for _, r := range s.ZoneRecords(z.ID) {
		if r.Type == "NS" {
			continue
		}
		mark := "L"
		if r.SharedID != 0 {
			mark = "S"
		}
		if r.Disabled {
			mark += " disabled"
		}
		out = append(out, strings.TrimSuffix(r.Name, ".example.com.")+" "+r.Type+" "+r.Data+" "+mark)
	}
	return out
}

func (env *testEnv) recordID(view, name, typ string) int64 {
	env.t.Helper()
	s := env.state()
	z := s.FindZone("example.com.", s.ViewByName(view).ID)
	for _, r := range s.ZoneRecords(z.ID) {
		if r.Name == name+".example.com." && r.Type == typ {
			return r.ID
		}
	}
	env.t.Fatalf("no %s %s in %s", name, typ, view)
	return 0
}

func want(t *testing.T, what string, got []string, w ...string) {
	t.Helper()
	if !slices.Equal(got, w) {
		t.Errorf("%s:\n got  %q\n want %q", what, got, w)
	}
}

func TestLinkedZones(t *testing.T) {
	env := linkedEnv(t)
	// A zone created linked copies everything; both are linked and shared.
	env.submit(env.admin, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("example.com"), View: model.Ptr("external"), LinkWith: "internal"}))
	all := []string{"mail A 192.0.2.25 S", "www A 192.0.2.10 S", "example.com. MX 10 mail.example.com. S"}
	slices.Sort(all)
	got := env.view("external")
	slices.Sort(got)
	want(t, "linked copy", got, all...)
	s := env.state()
	if zs := s.ZonesNamed("example.com."); zs[0].LinkGroup == 0 || zs[0].LinkGroup != zs[1].LinkGroup {
		t.Fatalf("not linked: %+v %+v", zs[0], zs[1])
	}

	// Adding, changing, disabling and deleting a shared record reaches the other view.
	env.submit(env.admin, recIn("external", "ftp", "CNAME", "www"))
	if !slices.Contains(env.view("internal"), "ftp CNAME www.example.com. S") {
		t.Errorf("shared add didn't reach internal: %q", env.view("internal"))
	}
	env.submit(env.admin, NewRequest(OpRecordUpdate, env.recordID("internal", "mail", "A"), RecordInput{Data: model.Ptr("192.0.2.26")}))
	if !slices.Contains(env.view("external"), "mail A 192.0.2.26 S") {
		t.Errorf("shared change didn't reach external: %q", env.view("external"))
	}
	env.submit(env.admin, NewRequest(OpRecordDisable, 0, RecordInput{Zone: "example.com", View: "external", Name: model.Ptr("ftp"), Type: model.Ptr("CNAME")}))
	if !slices.Contains(env.view("internal"), "ftp CNAME www.example.com. S disabled") {
		t.Errorf("disable didn't reach internal: %q", env.view("internal"))
	}
	env.submit(env.admin, NewRequest(OpRecordDelete, 0, RecordInput{Zone: "example.com", View: "internal", Name: model.Ptr("ftp"), Type: model.Ptr("CNAME")}))
	for _, v := range []string{"internal", "external"} {
		for _, r := range env.view(v) {
			if strings.HasPrefix(r, "ftp ") {
				t.Errorf("delete by match left %s in %s", r, v)
			}
		}
	}

	// A local override: www in internal points elsewhere; external keeps
	// the shared one.
	res := env.submit(env.admin, NewRequest(OpRecordCreate, 0, RecordInput{Zone: "example.com", View: "internal", Name: model.Ptr("www"), Type: model.Ptr("A"), Data: model.Ptr("10.0.0.10"), Local: model.Ptr(true)}))
	if !slices.Contains(env.view("internal"), "www A 10.0.0.10 L") || slices.Contains(env.view("internal"), "www A 192.0.2.10 S") {
		t.Errorf("override: internal %q", env.view("internal"))
	}
	if !slices.Contains(env.view("external"), "www A 192.0.2.10 S") {
		t.Errorf("override changed external: %q", env.view("external"))
	}
	_ = res
	// A new record of an overridden set joins it as local.
	env.submit(env.admin, recIn("internal", "www", "A", "10.0.0.11"))
	if !slices.Contains(env.view("internal"), "www A 10.0.0.11 L") || len(env.view("external")) != 3 {
		t.Errorf("join override: internal %q external %q", env.view("internal"), env.view("external"))
	}
	// Changing the shared www in external doesn't touch internal's override.
	env.submit(env.admin, NewRequest(OpRRSetReplace, 0, RRSetInput{Zone: "example.com", View: "external", Name: "www", Type: "A", Data: []string{"192.0.2.11"}}))
	if !slices.Contains(env.view("external"), "www A 192.0.2.11 S") || slices.Contains(env.view("internal"), "www A 192.0.2.11 S") {
		t.Errorf("shared set with an override elsewhere: internal %q external %q", env.view("internal"), env.view("external"))
	}
	// Removing the override brings the shared records back.
	env.submit(env.admin, NewRequest(OpRRSetReplace, 0, RRSetInput{Zone: "example.com", View: "internal", Name: "www", Type: "A", Data: []string{}}))
	if !slices.Contains(env.view("internal"), "www A 192.0.2.11 S") {
		t.Errorf("override removed: internal %q", env.view("internal"))
	}

	// Make a shared set local, then share another view's version.
	env.submit(env.admin, NewRequest(OpRecordUpdate, env.recordID("external", "mail", "A"), RecordInput{Local: model.Ptr(true)}))
	env.submit(env.admin, NewRequest(OpRecordUpdate, env.recordID("external", "mail", "A"), RecordInput{Data: model.Ptr("198.51.100.25")}))
	if !slices.Contains(env.view("external"), "mail A 198.51.100.25 L") || !slices.Contains(env.view("internal"), "mail A 192.0.2.26 S") {
		t.Errorf("local edit: internal %q external %q", env.view("internal"), env.view("external"))
	}
	env.submit(env.admin, NewRequest(OpRecordUpdate, env.recordID("external", "mail", "A"), RecordInput{Local: model.Ptr(false)}))
	if !slices.Contains(env.view("internal"), "mail A 198.51.100.25 S") || slices.Contains(env.view("internal"), "mail A 192.0.2.26 S") {
		t.Errorf("share external's version: internal %q", env.view("internal"))
	}
	if probs := env.e.Validate(env.state()); hasCode(probs, "linked_out_of_sync") || hasCode(probs, "linked_mixed") {
		t.Errorf("validation: %+v", probs)
	}

	// Undoing a changeset undoes it in both views.
	r := env.submit(env.admin, NewRequest(OpRecordUpdate, env.recordID("internal", "mail", "A"), RecordInput{Data: model.Ptr("198.51.100.99")}))
	cs, err := env.e.Revert(env.ctx, r.ChangesetID, env.admin)
	if err != nil {
		t.Fatal(err)
	}
	if _, err := env.e.Apply(env.ctx, cs.ID, env.admin, ApplyOptions{}); err != nil {
		t.Fatal(err)
	}
	for _, v := range []string{"internal", "external"} {
		if !slices.Contains(env.view(v), "mail A 198.51.100.25 S") {
			t.Errorf("revert in %s: %q", v, env.view(v))
		}
	}

	// Unlinking keeps every record, all local.
	env.submit(env.admin, NewRequest(OpZoneUnlink, 0, LinkInput{Zone: "example.com", View: "external"}))
	for _, z := range env.state().ZonesNamed("example.com.") {
		if z.LinkGroup != 0 {
			t.Errorf("still linked: %s", zoneDesc(env.state(), z))
		}
	}
	for _, v := range []string{"internal", "external"} {
		for _, r := range env.view(v) {
			if strings.HasSuffix(r, " S") {
				t.Errorf("still shared after unlink in %s: %s", v, r)
			}
		}
	}
	env.submit(env.admin, recIn("internal", "solo", "A", "10.0.0.5"))
	if slices.Contains(env.view("external"), "solo A 10.0.0.5 L") {
		t.Error("an unlinked zone was changed")
	}

	// Linking again works out what is shared: same in both, or not.
	env.submit(env.admin, NewRequest(OpZoneLink, 0, LinkInput{Zone: "example.com", View: "internal"}))
	in, ex := env.view("internal"), env.view("external")
	if !slices.Contains(in, "mail A 198.51.100.25 S") || !slices.Contains(ex, "mail A 198.51.100.25 S") {
		t.Errorf("relink: same records not shared: internal %q external %q", in, ex)
	}
	if !slices.Contains(in, "solo A 10.0.0.5 L") {
		t.Errorf("relink: internal-only record should be local: %q", in)
	}
	if probs := env.e.Validate(env.state()); hasCode(probs, "linked_out_of_sync") || hasCode(probs, "linked_mixed") {
		t.Errorf("validation after relink: %+v", probs)
	}

	// Deleting one zone of two dissolves the link.
	z := env.state().FindZone("example.com.", env.state().ViewByName("external").ID)
	env.submit(env.admin, NewRequest(OpZoneDelete, z.ID, nil))
	if zs := env.state().ZonesNamed("example.com."); len(zs) != 1 || zs[0].LinkGroup != 0 {
		t.Errorf("after deleting external: %+v", zs)
	}
	for _, r := range env.view("internal") {
		if strings.HasSuffix(r, " S") {
			t.Errorf("shared record left in an unlinked zone: %s", r)
		}
	}
}

func hasCode(probs []validate.Problem, code string) bool {
	for _, p := range probs {
		if p.Code == code {
			return true
		}
	}
	return false
}

func TestLinkedPermissions(t *testing.T) {
	env := linkedEnv(t)
	env.submit(env.admin, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("example.com"), View: model.Ptr("external"), LinkWith: "internal"}))
	u := &model.User{Username: "lan", Grants: []model.Grant{{Resource: auth.ResRecords, Access: "write", Views: []string{"internal"}}, {Resource: auth.ResZones, Access: "read"}}}
	if err := env.st.CreateUser(env.ctx, u); err != nil {
		t.Fatal(err)
	}
	lan := &auth.Principal{User: u, Method: "token"}
	// A shared change would reach external, which this user may not change.
	e := env.submitErr(lan, NewRequest(OpRecordUpdate, env.recordID("internal", "www", "A"), RecordInput{Data: model.Ptr("10.9.9.9")}))
	if e.Kind != KindForbidden || !strings.Contains(e.Message, "shared with example.com [external]") || !strings.Contains(e.Message, "local") {
		t.Errorf("shared change: %v", e)
	}
	// A local override is theirs to make.
	env.submit(lan, NewRequest(OpRecordCreate, 0, RecordInput{Zone: "example.com", View: "internal", Name: model.Ptr("www"), Type: model.Ptr("A"), Data: model.Ptr("10.9.9.9"), Local: model.Ptr(true)}))
	if !slices.Contains(env.view("internal"), "www A 10.9.9.9 L") || !slices.Contains(env.view("external"), "www A 192.0.2.10 S") {
		t.Errorf("override by a view-restricted user: internal %q external %q", env.view("internal"), env.view("external"))
	}
	// Records of a zone that isn't linked can't be "local".
	e = env.submitErr(env.admin, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("example.org"), View: model.Ptr("internal"), LinkWith: "external"}))
	if e.Kind != KindNotFound {
		t.Errorf("link_with a view without the zone: %v", e)
	}
}

func TestLinkExisting(t *testing.T) {
	env := linkedEnv(t)
	// external was made by hand: the same apart from www.
	env.submit(env.admin, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("example.com"), View: model.Ptr("external")}))
	env.submit(env.admin,
		recIn("external", "www", "A", "203.0.113.10"),
		recIn("external", "mail", "A", "192.0.2.25"),
		recIn("external", "@", "MX", "10 mail"))
	before := []string{}
	for _, v := range []string{"internal", "external"} {
		before = append(before, strings.Join(env.view(v), ";"))
	}
	res := env.submit(env.admin, NewRequest(OpZoneLink, 0, LinkInput{Zone: "example.com", View: "external", With: []string{"internal"}}))
	in, ex := env.view("internal"), env.view("external")
	if !slices.Contains(in, "www A 192.0.2.10 L") || !slices.Contains(ex, "www A 203.0.113.10 L") {
		t.Errorf("different www should stay local: internal %q external %q", in, ex)
	}
	if !slices.Contains(in, "mail A 192.0.2.25 S") || !slices.Contains(ex, "mail A 192.0.2.25 S") {
		t.Errorf("same mail should be shared: internal %q external %q", in, ex)
	}
	if !strings.Contains(strings.Join(res.Warnings, " "), "www.example.com A (internal, external)") {
		t.Errorf("warnings: %q", res.Warnings)
	}
	// Linking never changes what named answers: the same data as before.
	for i, v := range []string{"internal", "external"} {
		var data []string
		for _, r := range env.view(v) {
			data = append(data, strings.TrimSuffix(strings.TrimSuffix(r, " S"), " L"))
		}
		var was []string
		for _, r := range strings.Split(before[i], ";") {
			was = append(was, strings.TrimSuffix(strings.TrimSuffix(r, " S"), " L"))
		}
		want(t, "answers in "+v, data, was...)
	}
	// Sharing internal's www replaces external's.
	env.submit(env.admin, NewRequest(OpRecordUpdate, env.recordID("internal", "www", "A"), RecordInput{Local: model.Ptr(false)}))
	if !slices.Contains(env.view("external"), "www A 192.0.2.10 S") {
		t.Errorf("shared from internal: external %q", env.view("external"))
	}
}