package engine

import (
	"context"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"jarl/internal/auth"
	"jarl/internal/model"
	"jarl/internal/render"
	"jarl/internal/store"
)

type testEnv struct {
	t     *testing.T
	ctx   context.Context
	e     *Engine
	st    *store.Store
	admin *auth.Principal
	dir   string
}

func newEnv(t *testing.T) *testEnv {
	t.Helper()
	dir := t.TempDir()
	st, err := store.Open(filepath.Join(dir, "jarl.db"))
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { st.Close() })
	cfg := Config{
		Paths:      render.Paths{ConfigDir: filepath.Join(dir, "etc"), ZoneDir: filepath.Join(dir, "zones"), CacheDir: filepath.Join(dir, "cache")},
		StagingDir: filepath.Join(dir, "staging"),
		NoReload:   true,
		SkipCheck:  true,
	}
	e := New(st, nil, cfg, nil)
	e.Now = func() time.Time { return time.Date(2026, 10, 7, 12, 0, 0, 0, time.UTC) }
	admin := &model.User{Username: "admin", Admin: true}
	if err := st.CreateUser(context.Background(), admin); err != nil {
		t.Fatal(err)
	}
	env := &testEnv{t: t, ctx: context.Background(), e: e, st: st, admin: &auth.Principal{User: admin, Method: "local"}, dir: dir}
	// Defaults for new zones.
	env.submit(env.admin, NewRequest(OpSettingsUpdate, 0, SettingsInput{Nameservers: &[]string{"ns1.example.com."}, RName: model.Ptr("hostmaster@example.com")}))
	return env
}

func (env *testEnv) submit(p *auth.Principal, reqs ...Request) *Result {
	env.t.Helper()
	res, err := env.e.Submit(env.ctx, reqs, p, "test", "", ApplyOptions{})
	if err != nil {
		env.t.Fatalf("submit %v: %v (%+v)", reqs[0].Op, err, res)
	}
	return res
}

func (env *testEnv) submitErr(p *auth.Principal, reqs ...Request) *Error {
	env.t.Helper()
	_, err := env.e.Submit(env.ctx, reqs, p, "test", "", ApplyOptions{})
	if err == nil {
		env.t.Fatalf("submit %v succeeded, want error", reqs[0].Op)
	}
	ee, ok := AsError(err)
	if !ok {
		env.t.Fatalf("unexpected error type %T: %v", err, err)
	}
	return ee
}

func (env *testEnv) state() *model.State {
	s, err := env.st.LoadState(env.ctx)
	if err != nil {
		env.t.Fatal(err)
	}
	return s
}

func rec(zone, name, typ, data string) Request {
	return NewRequest(OpRecordCreate, 0, RecordInput{Zone: zone, Name: &name, Type: &typ, Data: &data})
}

func (env *testEnv) records(zone string) []string {
	s := env.state()
	zs := s.ZonesNamed(zone)
	var out []string
	for _, r := range s.ZoneRecords(zs[0].ID) {
		out = append(out, r.Name+" "+r.Type+" "+r.Data)
	}
	return out
}

func TestZoneLifecycle(t *testing.T) {
	env := newEnv(t)
	res := env.submit(env.admin,
		NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("example.com")}),
		rec("example.com", "ns1", "A", "192.0.2.1"),
		rec("example.com", "www", "A", "192.0.2.10"),
	)
	if !res.Applied || len(res.Files) != 2 || !strings.HasSuffix(res.Files[0], "etc/named.conf") || !strings.HasSuffix(res.Files[1], "example.com.zone") {
		t.Fatalf("result = %+v", res)
	}
	s := env.state()
	z := s.ZonesNamed("example.com")[0]
	if z.SOA.Serial != 2026100700 || z.SOA.MName != "ns1.example.com." || z.SOA.RName != "hostmaster.example.com." || z.DefaultTTL != 3600 {
		t.Errorf("zone defaults = %+v", z.SOA)
	}
	got := strings.Join(env.records("example.com"), "|")
	if got != "example.com. NS ns1.example.com.|ns1.example.com. A 192.0.2.1|www.example.com. A 192.0.2.10" {
		t.Errorf("records = %s", got)
	}
	zf, err := os.ReadFile(filepath.Join(env.dir, "zones/_default/example.com.zone"))
	if err != nil || !strings.Contains(string(zf), "www\t\tIN\tA\t192.0.2.10") {
		t.Errorf("zone file: %v\n%s", err, zf)
	}
	// A change bumps the serial once.
	env.submit(env.admin, rec("example.com", "mail", "A", "192.0.2.25"), rec("example.com", "@", "MX", "10 mail"))
	if s := env.state().ZonesNamed("example.com")[0].SOA.Serial; s != 2026100701 {
		t.Errorf("serial after change = %d", s)
	}
	// Comment-only changes don't.
	r := findRec(env.state(), "www.example.com.", "A")
	env.submit(env.admin, NewRequest(OpRecordUpdate, r.ID, RecordInput{Comment: model.Ptr("web server")}))
	if s := env.state().ZonesNamed("example.com")[0].SOA.Serial; s != 2026100701 {
		t.Errorf("serial after comment change = %d", s)
	}
}

func findRec(s *model.State, name, typ string) *model.Record {
	for _, r := range s.Records {
		if r.Name == name && r.Type == typ {
			return r
		}
	}
	return nil
}

func setupZone(env *testEnv) {
	env.submit(env.admin,
		NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("example.com")}),
		rec("example.com", "ns1", "A", "192.0.2.1"),
	)
}

func TestConflictsRejected(t *testing.T) {
	env := newEnv(t)
	setupZone(env)
	env.submit(env.admin, rec("example.com", "www", "CNAME", "ns1"))
	// The headline rule: no A record next to a CNAME.
	e := env.submitErr(env.admin, rec("example.com", "www", "A", "192.0.2.10"))
	if e.Kind != KindValidation || !strings.Contains(e.Message, "CNAME") {
		t.Errorf("error = %+v", e)
	}
	// Bad data is rejected before validation.
	e = env.submitErr(env.admin, rec("example.com", "bad", "A", "300.1.1.1"))
	if e.Kind != KindBadRequest {
		t.Errorf("bad data error = %+v", e)
	}
	// Swapping CNAME for A works when both happen in one changeset.
	r := findRec(env.state(), "www.example.com.", "CNAME")
	env.submit(env.admin, NewRequest(OpRecordDelete, r.ID, nil), rec("example.com", "www", "A", "192.0.2.10"))
	if findRec(env.state(), "www.example.com.", "A") == nil {
		t.Error("swap failed")
	}
	// Nothing is stored when a submit fails.
	cs, _ := env.st.ListChangesets(env.ctx, store.ChangesetFilter{})
	for _, c := range cs {
		if c.Status != model.ChangesetApplied {
			t.Errorf("unexpected changeset %+v", c)
		}
	}
}

func TestStagedChangeset(t *testing.T) {
	env := newEnv(t)
	setupZone(env)
	cs, err := env.e.CreateChangeset(env.ctx, env.admin, "web", "add web")
	if err != nil {
		t.Fatal(err)
	}
	if _, err := env.e.Stage(env.ctx, cs.ID, []Request{rec("example.com", "www", "CNAME", "ns1")}, env.admin); err != nil {
		t.Fatal(err)
	}
	// Staging a conflicting record is rejected right away.
	if _, err := env.e.Stage(env.ctx, cs.ID, []Request{rec("example.com", "www", "TXT", "hello")}, env.admin); err == nil {
		t.Error("conflicting record staged")
	}
	prev, err := env.e.Preview(env.ctx, cs.ID, env.admin)
	if err != nil || !prev.Valid || !strings.Contains(prev.Diff, "+www\t\tIN\tCNAME\tns1.example.com.") {
		t.Fatalf("preview = %+v %v", prev, err)
	}
	if findRec(env.state(), "www.example.com.", "CNAME") != nil {
		t.Error("preview changed the state")
	}
	// Someone else changes the configuration meanwhile.
	env.submit(env.admin, rec("example.com", "www", "A", "192.0.2.10"))
	if _, err := env.e.Apply(env.ctx, cs.ID, env.admin, ApplyOptions{}); err == nil {
		t.Fatal("stale changeset applied")
	}
	// Staging the delete of the conflicting A record fixes the
	// changeset (it removes an error rather than adding one).
	a := findRec(env.state(), "www.example.com.", "A")
	if _, err := env.e.Stage(env.ctx, cs.ID, []Request{NewRequest(OpRecordDelete, a.ID, nil)}, env.admin); err != nil {
		t.Fatal(err)
	}
	res, err := env.e.Apply(env.ctx, cs.ID, env.admin, ApplyOptions{})
	if err != nil || !res.Applied {
		t.Fatalf("apply: %v %+v", err, res)
	}
	got, _ := env.st.GetChangeset(env.ctx, cs.ID)
	if got.Status != model.ChangesetApplied || got.Diff == "" {
		t.Errorf("changeset = %+v", got)
	}
	if _, err := env.e.Stage(env.ctx, cs.ID, []Request{rec("example.com", "x", "A", "192.0.2.3")}, env.admin); err == nil {
		t.Error("staged into applied changeset")
	}
}

func TestVersionConflict(t *testing.T) {
	env := newEnv(t)
	setupZone(env)
	env.submit(env.admin, rec("example.com", "www", "A", "192.0.2.10"))
	r := findRec(env.state(), "www.example.com.", "A")
	cs, _ := env.e.CreateChangeset(env.ctx, env.admin, "web", "")
	if _, err := env.e.Stage(env.ctx, cs.ID, []Request{NewRequest(OpRecordUpdate, r.ID, RecordInput{Data: model.Ptr("192.0.2.11")})}, env.admin); err != nil {
		t.Fatal(err)
	}
	env.submit(env.admin, NewRequest(OpRecordUpdate, r.ID, RecordInput{Data: model.Ptr("192.0.2.12")}))
	_, err := env.e.Apply(env.ctx, cs.ID, env.admin, ApplyOptions{})
	if ee, ok := AsError(err); !ok || ee.Kind != KindConflict {
		t.Errorf("expected version conflict, got %v", err)
	}
}

func TestPermissions(t *testing.T) {
	env := newEnv(t)
	setupZone(env)
	g, _ := auth.ParseGrant("records:write zones=example.com names=_acme-challenge.* types=TXT")
	u := &model.User{Username: "acme", Grants: []model.Grant{g}}
	env.st.CreateUser(env.ctx, u)
	p := &auth.Principal{User: u, Method: "token"}
	env.submit(p, rec("example.com", "_acme-challenge.www", "TXT", "token123"))
	if e := env.submitErr(p, rec("example.com", "www", "A", "192.0.2.66")); e.Kind != KindForbidden {
		t.Errorf("A record allowed: %+v", e)
	}
	if e := env.submitErr(p, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("evil.com")})); e.Kind != KindForbidden {
		t.Errorf("zone create allowed: %+v", e)
	}
	// ACME cleanup: delete by match, idempotent.
	del := NewRequest(OpRecordDelete, 0, RecordInput{Zone: "example.com", Name: model.Ptr("_acme-challenge.www"), Type: model.Ptr("TXT"), Data: model.Ptr("token123")})
	env.submit(p, del)
	if findRec(env.state(), "_acme-challenge.www.example.com.", "TXT") != nil {
		t.Error("challenge not deleted")
	}
	e := env.submitErr(p, del)
	if e.Kind != KindNotFound {
		t.Errorf("second delete = %+v", e)
	}
	env.submit(p, NewRequest(OpRecordDelete, 0, RecordInput{Zone: "example.com", Name: model.Ptr("_acme-challenge.www"), Type: model.Ptr("TXT"), Data: model.Ptr("token123"), MissingOK: true}))
}

func TestPTRAndRRSet(t *testing.T) {
	env := newEnv(t)
	setupZone(env)
	env.submit(env.admin, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("192.0.2.0/24")}))
	in := RecordInput{Zone: "example.com", Name: model.Ptr("nas"), Type: model.Ptr("A"), Data: model.Ptr("192.0.2.20"), PTR: true}
	res := env.submit(env.admin, NewRequest(OpRecordCreate, 0, in))
	if len(res.Ops) != 2 || res.Ops[1].Summary != "add 20.2.0.192.in-addr.arpa. IN PTR nas.example.com." {
		t.Fatalf("ops = %+v", res.Ops)
	}
	ptr := findRec(env.state(), "20.2.0.192.in-addr.arpa.", "PTR")
	if ptr == nil || ptr.Data != "nas.example.com." {
		t.Fatalf("PTR = %+v", ptr)
	}
	// Changing the address moves the PTR.
	a := findRec(env.state(), "nas.example.com.", "A")
	env.submit(env.admin, NewRequest(OpRecordUpdate, a.ID, RecordInput{Data: model.Ptr("192.0.2.21"), PTR: true}))
	if findRec(env.state(), "20.2.0.192.in-addr.arpa.", "PTR") != nil || findRec(env.state(), "21.2.0.192.in-addr.arpa.", "PTR") == nil {
		t.Error("PTR not moved")
	}
	// RRset replace keeps matching records and sets the TTL on all.
	env.submit(env.admin, NewRequest(OpRRSetReplace, 0, RRSetInput{Zone: "example.com", Name: "api", Type: "A", TTL: model.Some(uint32(60)), Data: []string{"192.0.2.30", "192.0.2.31"}}))
	keep := findRecData(env.state(), "api.example.com.", "192.0.2.30")
	env.submit(env.admin, NewRequest(OpRRSetReplace, 0, RRSetInput{Zone: "example.com", Name: "api", Type: "A", Data: []string{"192.0.2.30", "192.0.2.32"}}))
	s := env.state()
	if findRecData(s, "api.example.com.", "192.0.2.31") != nil || findRecData(s, "api.example.com.", "192.0.2.32") == nil {
		t.Error("rrset replace wrong")
	}
	if k := findRecData(s, "api.example.com.", "192.0.2.30"); k == nil || k.ID != keep.ID || *k.TTL != 60 || *findRecData(s, "api.example.com.", "192.0.2.32").TTL != 60 {
		t.Error("rrset replace did not keep record or TTL")
	}
	// A new record joining an RRset inherits its TTL.
	env.submit(env.admin, rec("example.com", "api", "A", "192.0.2.33"))
	if r := findRecData(env.state(), "api.example.com.", "192.0.2.33"); r.TTL == nil || *r.TTL != 60 {
		t.Error("TTL not inherited")
	}
	// A conflicting TTL is rejected.
	ttl := RecordInput{Zone: "example.com", Name: model.Ptr("api"), Type: model.Ptr("A"), Data: model.Ptr("192.0.2.34"), TTL: model.Some(uint32(300))}
	if e := env.submitErr(env.admin, NewRequest(OpRecordCreate, 0, ttl)); !strings.Contains(e.Message, "same TTL") {
		t.Errorf("TTL mismatch error = %+v", e)
	}
}

func findRecData(s *model.State, name, data string) *model.Record {
	for _, r := range s.Records {
		if r.Name == name && r.Data == data {
			return r
		}
	}
	return nil
}

func TestRevert(t *testing.T) {
	env := newEnv(t)
	setupZone(env)
	env.submit(env.admin, rec("example.com", "www", "A", "192.0.2.10"))
	before := env.records("example.com")
	r := findRec(env.state(), "www.example.com.", "A")
	res := env.submit(env.admin, NewRequest(OpRecordDelete, r.ID, nil), rec("example.com", "web", "A", "192.0.2.11"))
	rev, err := env.e.Revert(env.ctx, res.ChangesetID, env.admin)
	if err != nil {
		t.Fatal(err)
	}
	if _, err := env.e.Apply(env.ctx, rev.ID, env.admin, ApplyOptions{}); err != nil {
		t.Fatal(err)
	}
	if got := strings.Join(env.records("example.com"), "|"); got != strings.Join(before, "|") {
		t.Errorf("after revert %s, want %s", got, strings.Join(before, "|"))
	}
	// Reverting a zone deletion restores records and options.
	z := env.state().ZonesNamed("example.com")[0]
	env.submit(env.admin, NewRequest(OpOptionCreate, 0, OptionInput{Scope: model.Ptr(model.ScopeZone), ScopeID: &z.ID, Name: model.Ptr("notify"), Value: model.Ptr("no")}))
	del := env.submit(env.admin, NewRequest(OpZoneDelete, z.ID, nil))
	if len(env.state().Zones) != 0 {
		t.Fatal("zone not deleted")
	}
	rev, _ = env.e.Revert(env.ctx, del.ChangesetID, env.admin)
	if _, err := env.e.Apply(env.ctx, rev.ID, env.admin, ApplyOptions{}); err != nil {
		t.Fatal(err)
	}
	s := env.state()
	if len(s.Zones) != 1 || len(s.Records) != 3 || s.FindOption(model.ScopeZone, z.ID, "notify") == nil {
		t.Errorf("zone not restored: %d zones, %d records", len(s.Zones), len(s.Records))
	}
}

func TestViewsAndACLs(t *testing.T) {
	env := newEnv(t)
	setupZone(env)
	env.submit(env.admin, NewRequest(OpACLCreate, 0, ACLInput{Name: model.Ptr("lan"), Elements: &[]string{"192.168.0.0/16", "10/8"}}))
	a := env.state().ACLByName("lan")
	if strings.Join(a.Elements, ",") != "192.168.0.0/16,10.0.0.0/8" {
		t.Errorf("elements = %v", a.Elements)
	}
	// Creating a view moves existing zones into it.
	env.submit(env.admin, NewRequest(OpViewCreate, 0, ViewInput{Name: model.Ptr("internal"), MatchClients: &[]string{"lan", "localhost"}, AdoptZones: true}))
	s := env.state()
	v := s.ViewByName("internal")
	if s.ZonesNamed("example.com")[0].ViewID != v.ID {
		t.Error("zone not adopted into view")
	}
	// A view without adopt_zones and zones outside views is rejected.
	env.submit(env.admin, NewRequest(OpViewCreate, 0, ViewInput{Name: model.Ptr("external"), MatchClients: &[]string{"any"}}))
	// Clone the zone into the external view.
	z := env.state().ZonesNamed("example.com")[0]
	env.submit(env.admin, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("example.com"), View: model.Ptr("external"), CloneFrom: z.ID}))
	if zs := env.state().ZonesNamed("example.com"); len(zs) != 2 {
		t.Fatalf("clone failed: %d zones", len(zs))
	}
	// Records now need a view to say which zone.
	if e := env.submitErr(env.admin, rec("example.com", "x", "A", "192.0.2.5")); !strings.Contains(e.Message, "several views") {
		t.Errorf("ambiguous zone error = %+v", e)
	}
	// Renaming an ACL rewrites references.
	env.submit(env.admin, NewRequest(OpOptionCreate, 0, OptionInput{Scope: model.Ptr(model.ScopeView), ScopeID: &v.ID, Name: model.Ptr("allow-recursion"), Value: model.Ptr("{ lan; }")}))
	env.submit(env.admin, NewRequest(OpACLUpdate, a.ID, ACLInput{Name: model.Ptr("home")}))
	s = env.state()
	if strings.Join(s.ViewByName("internal").MatchClients, ",") != "home,localhost" || s.FindOption(model.ScopeView, v.ID, "allow-recursion").Value != "{ home; }" {
		t.Errorf("references not renamed: %v %q", s.ViewByName("internal").MatchClients, s.FindOption(model.ScopeView, v.ID, "allow-recursion").Value)
	}
	// Deleting an ACL in use is refused with the users listed.
	e := env.submitErr(env.admin, NewRequest(OpACLDelete, a.ID, nil))
	if !strings.Contains(e.Message, "view internal") || !strings.Contains(e.Message, "allow-recursion") {
		t.Errorf("delete in-use ACL error = %+v", e)
	}
	// Invalid options are rejected with the catalog's help.
	e = env.submitErr(env.admin, NewRequest(OpOptionCreate, 0, OptionInput{Scope: model.Ptr(model.ScopeOptions), Name: model.Ptr("recursion"), Value: model.Ptr("maybe")}))
	if !strings.Contains(e.Message, "boolean") {
		t.Errorf("bad option error = %+v", e)
	}
	e = env.submitErr(env.admin, NewRequest(OpOptionCreate, 0, OptionInput{Scope: model.Ptr(model.ScopeOptions), Name: model.Ptr("match-clients"), Value: model.Ptr("{ any; }")}))
	if e.Kind != KindBadRequest {
		t.Errorf("option in wrong scope = %+v", e)
	}
	// String options get quoted automatically.
	env.submit(env.admin, NewRequest(OpOptionCreate, 0, OptionInput{Scope: model.Ptr(model.ScopeOptions), Name: model.Ptr("directory"), Value: model.Ptr("/var/cache/bind")}))
	if o := env.state().FindOption(model.ScopeOptions, 0, "directory"); o.Value != `"/var/cache/bind"` {
		t.Errorf("directory = %q", o.Value)
	}
}

func TestTSIGAndDrift(t *testing.T) {
	env := newEnv(t)
	setupZone(env)
	res := env.submit(env.admin, NewRequest(OpTSIGCreate, 0, TSIGInput{Name: model.Ptr("xfer")}))
	if strings.Contains(string(res.Ops[0].Data), `"secret":"`) && !strings.Contains(string(res.Ops[0].Data), "(hidden)") {
		t.Errorf("secret not redacted: %s", res.Ops[0].Data)
	}
	k := env.state().KeyByName("xfer")
	if k == nil || len(k.Secret) != 44 {
		t.Fatalf("key = %+v", k)
	}
	if !strings.Contains(res.Diff, "contents hidden") || strings.Contains(res.Diff, k.Secret) {
		t.Errorf("secret in diff:\n%s", res.Diff)
	}
	// Edit a managed file behind Jarl's back.
	zf := filepath.Join(env.dir, "zones/_default/example.com.zone")
	os.WriteFile(zf, []byte("hand edited\n"), 0o640)
	e := env.submitErr(env.admin, rec("example.com", "www", "A", "192.0.2.10"))
	if e.Kind != KindDrift {
		t.Errorf("drift not detected: %+v", e)
	}
	if _, err := env.e.Submit(env.ctx, []Request{rec("example.com", "www", "A", "192.0.2.10")}, env.admin, "test", "", ApplyOptions{Force: true}); err != nil {
		t.Errorf("forced apply: %v", err)
	}
	if b, _ := os.ReadFile(zf); strings.Contains(string(b), "hand edited") {
		t.Error("drifted file not overwritten")
	}
}

func TestZoneCreateWithOptions(t *testing.T) {
	env := newEnv(t)
	// A secondary zone is only valid together with its primaries option.
	e := env.submitErr(env.admin, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("partner.example"), Type: model.Ptr("slave")}))
	if e.Kind != KindValidation || !strings.Contains(e.Message, "primaries") {
		t.Errorf("secondary without primaries = %+v", e)
	}
	env.submit(env.admin, NewRequest(OpZoneCreate, 0, ZoneInput{Name: model.Ptr("partner.example"), Type: model.Ptr("slave"),
		Options: []ZoneOption{{Name: "masters", Value: "{ 192.0.2.53; }"}}}))
	s := env.state()
	z := s.ZonesNamed("partner.example")[0]
	if z.Type != model.ZoneSecondary {
		t.Errorf("type = %s", z.Type)
	}
	o := s.FindOption(model.ScopeZone, z.ID, "primaries")
	if o == nil || o.Value != "{ 192.0.2.53; }" {
		t.Errorf("primaries option = %+v (the masters synonym should be normalized)", o)
	}
}