package engine

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"log/slog"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"testing"
	"time"

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

func TestImportAndAdopt(t *testing.T) {
	bins := testutil.FindBind()
	if bins == nil || bins.Named == "" || bins.RNDC == "" || bins.Dig == "" {
		t.Skip("named, rndc and dig are needed")
	}
	dir := t.TempDir()
	legacy := filepath.Join(dir, "legacy")
	run := filepath.Join(dir, "run")
	os.MkdirAll(legacy, 0o755)
	os.MkdirAll(run, 0o755)
	keyOut, err := runEnv(bins.Env, bins.TSIGKeygen, "-a", "hmac-sha256", "rndc-key")
	if err != nil {
		t.Fatal(err)
	}
	keyFile := filepath.Join(legacy, "rndc.key")
	os.WriteFile(keyFile, []byte(keyOut), 0o600)
	dnsPort, ctlPort := freePort(t), freePort(t)
	files := map[string]string{
		"named.conf": fmt.Sprintf(`include "%[1]s/named.conf.options";
include "%[1]s/named.conf.local";
include "%[1]s/rndc.key";
controls { inet 127.0.0.1 port %[2]d allow { 127.0.0.1; } keys { "rndc-key"; }; };
`, legacy, ctlPort),
		"named.conf.options": fmt.Sprintf(`acl homelab { 127.0.0.0/8; 192.168.1.0/24; };
options {
	directory "%[1]s";
	pid-file "%[1]s/named.pid";
	session-keyfile "%[1]s/session.key";
	listen-on port %[2]d { 127.0.0.1; };
	listen-on-v6 { none; };
	recursion no;
	allow-query { any; };
};
`, run, dnsPort),
		"named.conf.local": fmt.Sprintf(`zone "adbraun.test" { type master; file "%[1]s/db.adbraun.test"; };
zone "1.168.192.in-addr.arpa" { type master; file "%[1]s/db.192.168.1"; };
`, legacy),
		"db.adbraun.test": `$TTL 3600
@	IN	SOA	ns1.adbraun.test. admin.adbraun.test. ( 2024051201 3600 900 1209600 300 )
	IN	NS	ns1
ns1	IN	A	127.0.0.1
nas	IN	A	192.168.1.20	; synology
www	300	IN	CNAME	nas
`,
		"db.192.168.1": `$TTL 86400
@	IN	SOA	ns1.adbraun.test. admin.adbraun.test. ( 2024051201 3600 900 1209600 300 )
@	IN	NS	ns1.adbraun.test.
20	IN	PTR	nas.adbraun.test.
`,
	}
	for name, content := range files {
		os.WriteFile(filepath.Join(legacy, name), []byte(content), 0o644)
	}
	mainConf := filepath.Join(legacy, "named.conf")
	var namedLog bytes.Buffer
	cmd := exec.Command(bins.Named, "-c", mainConf, "-g", "-n", "1")
	cmd.Env = append(os.Environ(), bins.Env...)
	cmd.Stdout, cmd.Stderr = &namedLog, &namedLog
	if err := cmd.Start(); err != nil {
		t.Fatal(err)
	}
	defer func() {
		cmd.Process.Kill()
		cmd.Wait()
		if t.Failed() {
			t.Logf("named log:\n%s", namedLog.String())
		}
	}()
	tools := &bind.Tools{NamedCheckConf: bins.CheckConf, NamedCheckZone: bins.CheckZone, RNDC: bins.RNDC, Env: bins.Env,
		RNDCArgs: []string{"-k", keyFile, "-s", "127.0.0.1", "-p", fmt.Sprint(ctlPort)}}
	for i := 0; ; i++ {
		if _, err := tools.Status(context.Background()); err == nil {
			break
		}
		if i > 100 {
			t.Fatalf("named did not start:\n%s", namedLog.String())
		}
		time.Sleep(100 * time.Millisecond)
	}
	dig := func(name, typ string) string {
		out, _ := runEnv(bins.Env, bins.Dig, "+short", "+norec", "-p", fmt.Sprint(dnsPort), "@127.0.0.1", name, typ)
		return strings.TrimSpace(out)
	}
	if got := dig("nas.adbraun.test", "A"); got != "192.168.1.20" {
		t.Fatalf("legacy setup broken: %q", got)
	}

	st, err := store.Open(filepath.Join(dir, "jarl.db"))
	if err != nil {
		t.Fatal(err)
	}
	defer st.Close()
	cfg := Config{
		Paths:         render.Paths{ConfigDir: filepath.Join(dir, "jarl/etc"), ZoneDir: filepath.Join(dir, "jarl/zones"), CacheDir: filepath.Join(dir, "jarl/cache")},
		MainConfig:    mainConf,
		StagingDir:    filepath.Join(dir, "staging"),
		ReloadTimeout: 10 * time.Second,
	}
	e := New(st, tools, cfg, slog.New(slog.NewTextHandler(io.Discard, nil)))
	admin := &model.User{Username: "admin", Admin: true}
	st.CreateUser(context.Background(), admin)
	p := &auth.Principal{User: admin, Method: "local"}
	ctx := context.Background()

	imp, err := e.Import(ctx, mainConf, p, false)
	if err != nil {
		t.Fatal(err)
	}
	if !imp.Applied {
		t.Fatalf("import not applied: %+v %+v", imp.Result.Error, imp.Result.Problems)
	}
	if ok, _ := e.Adopted(); ok {
		t.Fatal("adopted before adopt")
	}
	ad, err := e.Adopt(ctx, p)
	if err != nil {
		t.Fatalf("adopt: %v", err)
	}
	if len(ad.Serials) != 2 || ad.Serials[0].New <= ad.Serials[0].Old {
		t.Errorf("serials = %+v", ad.Serials)
	}
	if b, _ := os.ReadFile(ad.Backup); !strings.Contains(string(b), "named.conf.options") {
		t.Error("backup missing")
	}
	if ok, _ := e.Adopted(); !ok {
		t.Error("not adopted after adopt")
	}
	// Same answers, now from Jarl's files.
	if got := dig("www.adbraun.test", "A"); !strings.Contains(got, "192.168.1.20") {
		t.Errorf("www after adopt = %q", got)
	}
	zs, err := tools.ZoneStatus(ctx, "adbraun.test", "")
	if err != nil || !strings.Contains(zs.Files, cfg.Paths.ZoneDir) {
		t.Errorf("zone not loaded from Jarl's file: %+v %v", zs, err)
	}
	// And Jarl manages the server from now on.
	if _, err := e.Submit(ctx, []Request{rec("adbraun.test", "printer", "A", "192.168.1.30")}, p, "test", "", ApplyOptions{}); err != nil {
		t.Fatal(err)
	}
	if got := dig("printer.adbraun.test", "A"); got != "192.168.1.30" {
		t.Errorf("printer = %q", got)
	}
	if got := dig("20.1.168.192.in-addr.arpa", "PTR"); got != "nas.adbraun.test." {
		t.Errorf("PTR = %q", got)
	}
}