package render

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

	"jarl/internal/dnsname"
	"jarl/internal/model"
	"jarl/internal/rr"
	"jarl/internal/testutil"
	"jarl/internal/validate"
)

// sampleState builds a split-horizon configuration exercising most
// features.
func sampleState(t *testing.T) *model.State {
	t.Helper()
	s := model.NewState()
	id := int64(0)
	next := func() int64 { id++; return id }
	s.ACLs[next()] = &model.ACL{ID: id, Name: "lan", Elements: []string{"192.168.1.0/24", "10/8"}, Comment: "home networks"}
	s.Keys[next()] = &model.TSIGKey{ID: id, Name: "xfer-key", Algorithm: "hmac-sha256", Secret: "s0cvDUATzPDPntCVDfO3S9JjT8+51cRZSuWTNM9Eosc="}
	internal := &model.View{ID: next(), Name: "internal", Position: 0, MatchClients: []string{"lan", "localhost"}}
	external := &model.View{ID: next(), Name: "external", Position: 1, MatchClients: []string{"any"}}
	s.Views[internal.ID], s.Views[external.ID] = internal, external
	opt := func(scope string, scopeID int64, name, value string) {
		o := &model.Option{ID: next(), Scope: scope, ScopeID: scopeID, Name: name, Value: value, Position: int(id)}
		s.Options[o.ID] = o
	}
	opt(model.ScopeOptions, 0, "directory", `"/var/cache/bind"`)
	opt(model.ScopeOptions, 0, "dnssec-validation", "auto")
	opt(model.ScopeOptions, 0, "listen-on-v6", "{ any; }")
	opt(model.ScopeView, internal.ID, "recursion", "yes")
	opt(model.ScopeView, internal.ID, "allow-recursion", "{ lan; localhost; }")
	opt(model.ScopeView, external.ID, "recursion", "no")
	opt(model.ScopeTopLevel, 0, "logging", `{ channel default_log { stderr; severity info; }; category default { default_log; }; }`)

	zone := func(name string, v *model.View, typ string) *model.Zone {
		z := &model.Zone{ID: next(), Name: dnsname.Fqdn(name), ViewID: v.ID, Type: typ, DefaultTTL: 3600,
			SOA: model.SOA{MName: "ns1.example.com.", RName: "hostmaster.example.com.", Serial: 2026100700, Refresh: 3600, Retry: 900, Expire: 1209600, Minimum: 300}}
		s.Zones[z.ID] = z
		return z
	}
	rec := func(z *model.Zone, name, typ, data string) *model.Record {
		owner, _ := dnsname.Owner(name, z.Name)
		p, err := rr.Parse(z.Name, owner, typ, data)
		if err != nil {
			t.Fatalf("%s %s %s: %v", name, typ, data, err)
		}
		r := &model.Record{ID: next(), ZoneID: z.ID, Name: owner, Type: p.Type, Data: p.Data}
		s.Records[r.ID] = r
		return r
	}
	in := zone("example.com", internal, model.ZonePrimary)
	in.Comment = "internal version"
	rec(in, "@", "NS", "ns1")
	rec(in, "ns1", "A", "192.168.1.2")
	r := rec(in, "nas", "A", "192.168.1.20")
	r.Comment = "storage box"
	r.TTL = model.Ptr(uint32(300))
	rec(in, "www", "CNAME", "nas")
	rec(in, "@", "TXT", "v=spf1 -all")
	rec(in, "@", "CAA", `0 issue "letsencrypt.org"`)
	rec(in, "_acme-challenge", "TXT", "abc123")
	ext := zone("example.com", external, model.ZonePrimary)
	rec(ext, "@", "NS", "ns1")
	rec(ext, "ns1", "A", "203.0.113.2")
	rec(ext, "www", "A", "203.0.113.10")
	opt(model.ScopeZone, ext.ID, "allow-transfer", "{ key xfer-key; }")
	rev := zone("1.168.192.in-addr.arpa", internal, model.ZonePrimary)
	rec(rev, "@", "NS", "ns1.example.com.")
	rec(rev, "20", "PTR", "nas.example.com.")
	fwd := zone("consul", internal, model.ZoneForward)
	opt(model.ScopeZone, fwd.ID, "forwarders", "{ 127.0.0.1 port 8600; }")
	opt(model.ScopeZone, fwd.ID, "forward", "only")
	sec := zone("partner.example", external, model.ZoneSecondary)
	opt(model.ScopeZone, sec.ID, "primaries", "{ 198.51.100.1 key xfer-key; }")
	hint := zone(".", internal, model.ZoneHint)
	hint.File = "/usr/share/dns/root.hints"
	return s
}

func TestRenderDeterministicAndValid(t *testing.T) {
	s := sampleState(t)
	if ps := validate.Errors(validate.State(s, validate.Options{})); len(ps) > 0 {
		t.Fatalf("sample state has errors: %v", ps)
	}
	dir := t.TempDir()
	p := Paths{ConfigDir: filepath.Join(dir, "etc"), ZoneDir: filepath.Join(dir, "zones"), CacheDir: filepath.Join(dir, "cache")}
	out1 := Render(s, p)
	out2 := Render(s.Clone(), p)
	if len(out1.Files) != len(out2.Files) {
		t.Fatal("file count differs")
	}
	for i := range out1.Files {
		if string(out1.Files[i].Content) != string(out2.Files[i].Content) {
			t.Errorf("rendering of %s is not deterministic", out1.Files[i].Path)
		}
	}
	conf := string(out1.File(p.MainConfig()).Content)
	for _, want := range []string{
		`include "` + p.KeysConfig() + `";`,
		"acl \"lan\" { 192.168.1.0/24; 10.0.0.0/8; };",
		"view \"internal\" {\n\tmatch-clients { lan; localhost; };",
		"\tzone \"example.com\" {\n\t\ttype primary;",
		"zone \"consul\" {\n\t\ttype forward;",
		"\t\tforwarders { 127.0.0.1 port 8600; };",
		`file "/usr/share/dns/root.hints";`,
	} {
		if !strings.Contains(conf, want) {
			t.Errorf("named.conf missing %q:\n%s", want, conf)
		}
	}
	if strings.Contains(conf, "s0cvDUAT") {
		t.Error("secret leaked into named.conf")
	}
	keys := out1.File(p.KeysConfig())
	if !keys.Secret || !strings.Contains(string(keys.Content), `secret "s0cvDUAT`) {
		t.Error("keys.conf wrong")
	}
	if len(out1.Dirs) != 1 || !strings.HasSuffix(out1.Dirs[0], "cache/external") {
		t.Errorf("dirs = %v", out1.Dirs)
	}
	// Source map: the line with the internal zone maps to that zone.
	lines := strings.Split(conf, "\n")
	for i, l := range lines {
		if strings.Contains(l, "forwarders { 127.0.0.1 port 8600; }") {
			span, ok := out1.Lookup(p.MainConfig(), i+1)
			if !ok || span.ObjectType != "option" || !strings.Contains(span.Label, "consul") {
				t.Errorf("span for line %d = %+v %v", i+1, span, ok)
			}
		}
	}
	zf := ZoneFile(s, s.FindZone("example.com", s.ViewByName("internal").ID))
	for _, want := range []string{"$ORIGIN example.com.", "$TTL 3600", "nas\t300\tIN\tA\t192.168.1.20\t; storage box", "www\t\tIN\tCNAME\tnas.example.com.", "@\t\tIN\tNS\tns1.example.com.", "2026100700\t; serial"} {
		if !strings.Contains(zf, want) {
			t.Errorf("zone file missing %q:\n%s", want, zf)
		}
	}
}

func TestRenderWithNamedCheckconf(t *testing.T) {
	tools := testutil.BindTools(t)
	s := sampleState(t)
	dir := t.TempDir()
	p := Paths{ConfigDir: filepath.Join(dir, "etc"), ZoneDir: filepath.Join(dir, "zones"), CacheDir: filepath.Join(dir, "cache")}
	// named-checkconf changes into the directory option, so it must exist.
	s.FindOption(model.ScopeOptions, 0, "directory").Value = `"` + dir + `"`
	// The hint zone's file must exist too.
	hints := filepath.Join(dir, "root.hints")
	if err := os.WriteFile(hints, []byte(".\t3600000\tNS\tA.ROOT-SERVERS.NET.\nA.ROOT-SERVERS.NET.\t3600000\tA\t198.41.0.4\n"), 0o644); err != nil {
		t.Fatal(err)
	}
	for _, z := range s.Zones {
		if z.Type == model.ZoneHint {
			z.File = hints
		}
	}
	out := Render(s, p)
	for _, f := range out.Files {
		if err := os.MkdirAll(filepath.Dir(f.Path), 0o755); err != nil {
			t.Fatal(err)
		}
		if err := os.WriteFile(f.Path, f.Content, 0o644); err != nil {
			t.Fatal(err)
		}
	}
	res, err := tools.CheckConfig(context.Background(), p.MainConfig(), true)
	if err != nil {
		t.Fatal(err)
	}
	if !res.OK {
		t.Fatalf("named-checkconf failed:\n%s\n--- named.conf:\n%s", res.Output, out.File(p.MainConfig()).Content)
	}
	for _, f := range out.Files {
		if f.Kind != KindZone {
			continue
		}
		z := s.Zones[f.ZoneID]
		r, err := tools.CheckZone(context.Background(), z.Name, f.Path)
		if err != nil || !r.OK {
			t.Errorf("named-checkzone %s: %v\n%s", z.Name, err, r.Output)
		}
	}
}

func TestZoneContentHash(t *testing.T) {
	s := sampleState(t)
	z := s.FindZone("example.com", s.ViewByName("internal").ID)
	h1 := ZoneContentHash(s, z)
	z.SOA.Serial++
	for _, r := range s.ZoneRecords(z.ID) {
		r.Comment = "changed comment"
	}
	if ZoneContentHash(s, z) != h1 {
		t.Error("serial or comments changed the content hash")
	}
	z.DefaultTTL = 7200
	if ZoneContentHash(s, z) == h1 {
		t.Error("default TTL change not reflected")
	}
}