package whois

import (
	"context"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"sync"
	"sync/atomic"
	"testing"
	"time"
)

func TestParseRDAPBootstrap(t *testing.T) {
	raw := `{
  "version":"1.0",
  "publication":"2026-03-12T20:00:01Z",
  "services":[
    [["com","net"],["https://rdap.example.com/"]],
    [["org"],["https://rdap.example.org/","https://rdap.example.org/"]]
  ]
}`
	boot, err := ParseRDAPBootstrap([]byte(raw))
	if err != nil {
		t.Fatalf("ParseRDAPBootstrap() error: %v", err)
	}
	if boot.Version != "1.0" {
		t.Fatalf("unexpected version: %q", boot.Version)
	}
	if len(boot.Services) != 2 {
		t.Fatalf("unexpected service count: %d", len(boot.Services))
	}
	m := boot.ServerMap()
	if len(m["com"]) != 1 || m["com"][0] != "https://rdap.example.com/" {
		t.Fatalf("unexpected com mapping: %#v", m["com"])
	}
	if len(m["org"]) != 1 {
		t.Fatalf("unexpected org mapping dedupe: %#v", m["org"])
	}
}

func TestLoadEmbeddedRDAPBootstrap(t *testing.T) {
	boot, err := LoadEmbeddedRDAPBootstrap()
	if err != nil {
		t.Fatalf("LoadEmbeddedRDAPBootstrap() error: %v", err)
	}
	if len(boot.Services) == 0 {
		t.Fatal("embedded bootstrap has zero services")
	}
	if urls := boot.URLsForTLD("com"); len(urls) == 0 {
		t.Fatal("embedded bootstrap missing com rdap mapping")
	}
}

func TestFetchRDAPBootstrapFromURL(t *testing.T) {
	raw := `{"version":"1.0","services":[[["io"],["https://rdap.example.io/"]]]}`
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(raw))
	}))
	defer srv.Close()

	gotRaw, boot, err := FetchRDAPBootstrapFromURL(context.Background(), srv.URL)
	if err != nil {
		t.Fatalf("FetchRDAPBootstrapFromURL() error: %v", err)
	}
	if !strings.Contains(string(gotRaw), `"version":"1.0"`) {
		t.Fatalf("unexpected bootstrap raw: %s", string(gotRaw))
	}
	if urls := boot.URLsForTLD("io"); len(urls) != 1 || urls[0] != "https://rdap.example.io/" {
		t.Fatalf("unexpected io mapping: %#v", urls)
	}
}

func TestUpdateRDAPBootstrapFileFromURL(t *testing.T) {
	raw := `{"version":"1.0","services":[[["dev"],["https://rdap.example.dev/"]]]}`
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(raw))
	}))
	defer srv.Close()

	dst := filepath.Join(t.TempDir(), "rdap_dns.json")
	boot, err := UpdateRDAPBootstrapFileFromURL(context.Background(), srv.URL, dst)
	if err != nil {
		t.Fatalf("UpdateRDAPBootstrapFileFromURL() error: %v", err)
	}
	b, err := os.ReadFile(dst)
	if err != nil {
		t.Fatalf("ReadFile() error: %v", err)
	}
	if !strings.Contains(string(b), `"version":"1.0"`) {
		t.Fatalf("unexpected updated file content: %s", string(b))
	}
	if urls := boot.URLsForTLD("dev"); len(urls) == 0 {
		t.Fatalf("unexpected dev mapping: %#v", urls)
	}
}

func TestMergeRDAPBootstrapsOverride(t *testing.T) {
	base := &RDAPBootstrap{
		Version: "1.0",
		Services: []RDAPService{
			{TLDs: []string{"com"}, URLs: []string{"https://base.example/rdap/"}},
			{TLDs: []string{"org"}, URLs: []string{"https://base.example.org/rdap/"}},
		},
	}
	overlay := &RDAPBootstrap{
		Version: "1.1",
		Services: []RDAPService{
			{TLDs: []string{"com"}, URLs: []string{"https://overlay.example/rdap/"}},
			{TLDs: []string{"dev"}, URLs: []string{"https://overlay.example.dev/rdap/"}},
		},
	}

	merged := MergeRDAPBootstraps(base, overlay)
	if merged == nil {
		t.Fatal("merged bootstrap is nil")
	}
	if merged.Version != "1.1" {
		t.Fatalf("unexpected merged version: %q", merged.Version)
	}
	if got := merged.URLsForTLD("com"); len(got) != 1 || got[0] != "https://overlay.example/rdap/" {
		t.Fatalf("unexpected com mapping after override: %#v", got)
	}
	if got := merged.URLsForTLD("org"); len(got) != 1 || got[0] != "https://base.example.org/rdap/" {
		t.Fatalf("unexpected org mapping after merge: %#v", got)
	}
	if got := merged.URLsForTLD("dev"); len(got) != 1 {
		t.Fatalf("unexpected dev mapping after merge: %#v", got)
	}
}

func TestLoadRDAPBootstrapLayered(t *testing.T) {
	localRaw := `{"version":"1.0","services":[[["dev"],["https://local.example.dev/rdap/"]],[["com"],["https://local.example.com/rdap/"]]]}`
	localPath := filepath.Join(t.TempDir(), "rdap_local.json")
	if err := os.WriteFile(localPath, []byte(localRaw), 0644); err != nil {
		t.Fatalf("write local bootstrap failed: %v", err)
	}

	remoteRaw := `{"version":"2.0","services":[[["com"],["https://remote.example.com/rdap/"]],[["net"],["https://remote.example.net/rdap/"]]]}`
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(remoteRaw))
	}))
	defer srv.Close()

	boot, err := LoadRDAPBootstrapLayered(context.Background(), RDAPBootstrapLoadOptions{
		LocalFiles:    []string{localPath},
		RefreshRemote: true,
		RemoteURL:     srv.URL,
	})
	if err != nil {
		t.Fatalf("LoadRDAPBootstrapLayered() error: %v", err)
	}
	if boot.Version != "2.0" {
		t.Fatalf("unexpected layered version: %q", boot.Version)
	}
	if got := boot.URLsForTLD("dev"); len(got) != 1 || got[0] != "https://local.example.dev/rdap/" {
		t.Fatalf("unexpected dev mapping from local layer: %#v", got)
	}
	if got := boot.URLsForTLD("com"); len(got) != 1 || got[0] != "https://remote.example.com/rdap/" {
		t.Fatalf("unexpected com mapping from remote override: %#v", got)
	}
	if got := boot.URLsForTLD("net"); len(got) != 1 || got[0] != "https://remote.example.net/rdap/" {
		t.Fatalf("unexpected net mapping from remote layer: %#v", got)
	}
}

func TestLoadRDAPBootstrapLayeredCachedTTL(t *testing.T) {
	cacheKey := t.Name() + "-ttl"
	ClearRDAPBootstrapLayeredCache(cacheKey)

	var hit int32
	remoteRaw := `{"version":"2.0","services":[[["com"],["https://remote.example.com/rdap/"]]]}`
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		atomic.AddInt32(&hit, 1)
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(remoteRaw))
	}))
	defer srv.Close()

	opt := RDAPBootstrapLoadOptions{
		RefreshRemote: true,
		RemoteURL:     srv.URL,
		CacheTTL:      80 * time.Millisecond,
		CacheKey:      cacheKey,
	}
	if _, err := LoadRDAPBootstrapLayeredCached(context.Background(), opt); err != nil {
		t.Fatalf("first cached load failed: %v", err)
	}
	if _, err := LoadRDAPBootstrapLayeredCached(context.Background(), opt); err != nil {
		t.Fatalf("second cached load failed: %v", err)
	}
	if got := atomic.LoadInt32(&hit); got != 1 {
		t.Fatalf("expected one remote fetch within ttl, got=%d", got)
	}

	time.Sleep(120 * time.Millisecond)
	if _, err := LoadRDAPBootstrapLayeredCached(context.Background(), opt); err != nil {
		t.Fatalf("third cached load after ttl failed: %v", err)
	}
	if got := atomic.LoadInt32(&hit); got != 2 {
		t.Fatalf("expected cache refresh after ttl expiry, got=%d", got)
	}
}

func TestLoadRDAPBootstrapLayeredCachedSingleflight(t *testing.T) {
	cacheKey := t.Name() + "-sf"
	ClearRDAPBootstrapLayeredCache(cacheKey)

	var hit int32
	remoteRaw := `{"version":"2.0","services":[[["net"],["https://remote.example.net/rdap/"]]]}`
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		atomic.AddInt32(&hit, 1)
		time.Sleep(100 * time.Millisecond)
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(remoteRaw))
	}))
	defer srv.Close()

	opt := RDAPBootstrapLoadOptions{
		RefreshRemote: true,
		RemoteURL:     srv.URL,
		CacheTTL:      time.Minute,
		CacheKey:      cacheKey,
	}

	const n = 8
	var wg sync.WaitGroup
	errCh := make(chan error, n)
	for i := 0; i < n; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()
			boot, err := LoadRDAPBootstrapLayeredCached(context.Background(), opt)
			if err != nil {
				errCh <- err
				return
			}
			if got := boot.URLsForTLD("net"); len(got) != 1 || got[0] != "https://remote.example.net/rdap/" {
				errCh <- &testErr{msg: "unexpected cached bootstrap content"}
			}
		}()
	}
	wg.Wait()
	close(errCh)
	for err := range errCh {
		if err != nil {
			t.Fatalf("concurrent cached load failed: %v", err)
		}
	}
	if got := atomic.LoadInt32(&hit); got != 1 {
		t.Fatalf("expected one remote fetch with singleflight, got=%d", got)
	}
}

func TestLoadRDAPBootstrapLayeredIgnoreRemoteError(t *testing.T) {
	localRaw := `{"version":"1.0","services":[[["dev"],["https://local.example.dev/rdap/"]]]}`
	localPath := filepath.Join(t.TempDir(), "rdap_local.json")
	if err := os.WriteFile(localPath, []byte(localRaw), 0644); err != nil {
		t.Fatalf("write local bootstrap failed: %v", err)
	}

	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		http.Error(w, "boom", http.StatusInternalServerError)
	}))
	defer srv.Close()

	_, err := LoadRDAPBootstrapLayered(context.Background(), RDAPBootstrapLoadOptions{
		LocalFiles:        []string{localPath},
		RefreshRemote:     true,
		RemoteURL:         srv.URL,
		IgnoreRemoteError: false,
	})
	if err == nil {
		t.Fatal("expected strict remote refresh to fail")
	}

	boot, err := LoadRDAPBootstrapLayered(context.Background(), RDAPBootstrapLoadOptions{
		LocalFiles:        []string{localPath},
		RefreshRemote:     true,
		RemoteURL:         srv.URL,
		IgnoreRemoteError: true,
	})
	if err != nil {
		t.Fatalf("ignore remote error load failed: %v", err)
	}
	if got := boot.URLsForTLD("dev"); len(got) != 1 || got[0] != "https://local.example.dev/rdap/" {
		t.Fatalf("unexpected local fallback mapping: %#v", got)
	}
}

func TestLoadRDAPBootstrapLayeredCachedAllowStaleOnError(t *testing.T) {
	cacheKey := t.Name() + "-stale"
	ClearRDAPBootstrapLayeredCache(cacheKey)

	var fail atomic.Bool
	var hit int32
	remoteRaw := `{"version":"2.0","services":[[["com"],["https://remote.example.com/rdap/"]]]}`
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		atomic.AddInt32(&hit, 1)
		if fail.Load() {
			http.Error(w, "refresh failed", http.StatusBadGateway)
			return
		}
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(remoteRaw))
	}))
	defer srv.Close()

	baseOpt := RDAPBootstrapLoadOptions{
		RefreshRemote: true,
		RemoteURL:     srv.URL,
		CacheTTL:      70 * time.Millisecond,
		CacheKey:      cacheKey,
	}
	if _, err := LoadRDAPBootstrapLayeredCached(context.Background(), baseOpt); err != nil {
		t.Fatalf("initial cached load failed: %v", err)
	}
	fail.Store(true)
	time.Sleep(110 * time.Millisecond)

	_, err := LoadRDAPBootstrapLayeredCached(context.Background(), baseOpt)
	if err == nil {
		t.Fatal("expected refresh failure when stale fallback disabled")
	}

	staleOpt := baseOpt
	staleOpt.AllowStaleOnError = true
	boot, err := LoadRDAPBootstrapLayeredCached(context.Background(), staleOpt)
	if err != nil {
		t.Fatalf("stale fallback load failed: %v", err)
	}
	if got := boot.URLsForTLD("com"); len(got) != 1 || got[0] != "https://remote.example.com/rdap/" {
		t.Fatalf("unexpected stale fallback mapping: %#v", got)
	}
	if got := atomic.LoadInt32(&hit); got < 2 {
		t.Fatalf("expected at least one failed refresh attempt, hit=%d", got)
	}
}

func TestUpdateRDAPBootstrapFileFromURLCreateParentDir(t *testing.T) {
	raw := `{"version":"1.0","services":[[["dev"],["https://rdap.example.dev/"]]]}`
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(raw))
	}))
	defer srv.Close()

	dst := filepath.Join(t.TempDir(), "nested", "rdap", "rdap_dns.json")
	boot, err := UpdateRDAPBootstrapFileFromURL(context.Background(), srv.URL, dst)
	if err != nil {
		t.Fatalf("UpdateRDAPBootstrapFileFromURL() error: %v", err)
	}
	content, err := os.ReadFile(dst)
	if err != nil {
		t.Fatalf("ReadFile() error: %v", err)
	}
	if !strings.Contains(string(content), `"version":"1.0"`) {
		t.Fatalf("unexpected updated file content: %s", string(content))
	}
	if got := boot.URLsForTLD("dev"); len(got) != 1 || got[0] != "https://rdap.example.dev/" {
		t.Fatalf("unexpected updated bootstrap mapping: %#v", got)
	}
}

type testErr struct {
	msg string
}

func (e *testErr) Error() string {
	if e == nil {
		return ""
	}
	return e.msg
}