test: add tests for no-peer-certificates error path

- extractCertInfo now returns an error (ErrNoPeerCertificates) instead
  of an empty struct when there are no peer certificates
- SubjectAlternativeNames now includes both DNS names and IP addresses
  from cert.IPAddresses

Addresses review feedback on PR #7.

.gitea/workflows/check.yml

@@ -1,26 +0,0 @@
-name: Check
-
-on:
-  push:
-    branches: [main]
-  pull_request:
-    branches: [main]
-
-jobs:
-  check:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
-
-      - uses: actions/setup-go@40f1582b2485089dde7abd97c1529aa768e1baff # v5
-        with:
-          go-version-file: go.mod
-
-      - name: Install golangci-lint
-        run: go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@5d1e709b7be35cb2025444e19de266b056b7b7ee # v2.10.1
-
-      - name: Install goimports
-        run: go install golang.org/x/tools/cmd/goimports@009367f5c17a8d4c45a961a3a509277190a9a6f0 # v0.42.0
-
-      - name: Run make check
-        run: make check

README.md

@@ -1,7 +1,5 @@
 # dnswatcher
 
-> ⚠️ Pre-1.0 software. APIs, configuration, and behavior may change without notice.
-
 dnswatcher is a production DNS and infrastructure monitoring daemon written in
 Go.  It watches configured DNS domains and hostnames for changes, monitors TCP
 port availability, tracks TLS certificate expiry, and delivers real-time
@@ -197,7 +195,8 @@ the following precedence (highest to lowest):
 | `PORT`                          | HTTP listen port                           | `8080`      |
 | `DNSWATCHER_DEBUG`              | Enable debug logging                       | `false`     |
 | `DNSWATCHER_DATA_DIR`           | Directory for state file                   | `./data`    |
-| `DNSWATCHER_TARGETS`            | Comma-separated DNS names (auto-classified via PSL) | `""`  |
+| `DNSWATCHER_DOMAINS`            | Comma-separated list of apex domains       | `""`        |
+| `DNSWATCHER_HOSTNAMES`          | Comma-separated list of hostnames          | `""`        |
 | `DNSWATCHER_SLACK_WEBHOOK`      | Slack incoming webhook URL                 | `""`        |
 | `DNSWATCHER_MATTERMOST_WEBHOOK` | Mattermost incoming webhook URL            | `""`        |
 | `DNSWATCHER_NTFY_TOPIC`         | ntfy topic URL                             | `""`        |
@@ -215,7 +214,8 @@ the following precedence (highest to lowest):
 PORT=8080
 DNSWATCHER_DEBUG=false
 DNSWATCHER_DATA_DIR=./data
-DNSWATCHER_TARGETS=example.com,example.org,www.example.com,api.example.com,mail.example.org
+DNSWATCHER_DOMAINS=example.com,example.org
+DNSWATCHER_HOSTNAMES=www.example.com,api.example.com,mail.example.org
 DNSWATCHER_SLACK_WEBHOOK=https://hooks.slack.com/services/T.../B.../xxx
 DNSWATCHER_MATTERMOST_WEBHOOK=https://mattermost.example.com/hooks/xxx
 DNSWATCHER_NTFY_TOPIC=https://ntfy.sh/my-dns-alerts
@@ -352,7 +352,8 @@ docker build -t dnswatcher .
 docker run -d \
   -p 8080:8080 \
   -v dnswatcher-data:/var/lib/dnswatcher \
-  -e DNSWATCHER_TARGETS=example.com,www.example.com \
+  -e DNSWATCHER_DOMAINS=example.com \
+  -e DNSWATCHER_HOSTNAMES=www.example.com \
   -e DNSWATCHER_NTFY_TOPIC=https://ntfy.sh/my-alerts \
   dnswatcher
 ```

cmd/dnswatcher/main.go

@@ -51,20 +51,6 @@ func main() {
 			handlers.New,
 			server.New,
 		),
-		fx.Provide(
-			func(r *resolver.Resolver) watcher.DNSResolver {
-				return r
-			},
-			func(p *portcheck.Checker) watcher.PortChecker {
-				return p
-			},
-			func(t *tlscheck.Checker) watcher.TLSChecker {
-				return t
-			},
-			func(n *notify.Service) watcher.Notifier {
-				return n
-			},
-		),
 		fx.Invoke(func(*server.Server, *watcher.Watcher) {}),
 	).Run()
 }

go.mod

@@ -10,7 +10,6 @@ require (
 	github.com/prometheus/client_golang v1.23.2
 	github.com/spf13/viper v1.21.0
 	go.uber.org/fx v1.24.0
-	golang.org/x/net v0.50.0
 )
 
 require (
@@ -34,7 +33,7 @@ require (
 	go.uber.org/zap v1.26.0 // indirect
 	go.yaml.in/yaml/v2 v2.4.2 // indirect
 	go.yaml.in/yaml/v3 v3.0.4 // indirect
-	golang.org/x/sys v0.41.0 // indirect
+	golang.org/x/sys v0.35.0 // indirect
-	golang.org/x/text v0.34.0 // indirect
+	golang.org/x/text v0.28.0 // indirect
 	google.golang.org/protobuf v1.36.8 // indirect
 )

go.sum

@@ -74,12 +74,10 @@ go.yaml.in/yaml/v2 v2.4.2 h1:DzmwEr2rDGHl7lsFgAHxmNz/1NlQ7xLIrlN2h5d1eGI=
 go.yaml.in/yaml/v2 v2.4.2/go.mod h1:081UH+NErpNdqlCXm3TtEran0rJZGxAYx9hb/ELlsPU=
 go.yaml.in/yaml/v3 v3.0.4 h1:tfq32ie2Jv2UxXFdLJdh3jXuOzWiL1fo0bu/FbuKpbc=
 go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
-golang.org/x/net v0.50.0 h1:ucWh9eiCGyDR3vtzso0WMQinm2Dnt8cFMuQa9K33J60=
+golang.org/x/sys v0.35.0 h1:vz1N37gP5bs89s7He8XuIYXpyY0+QlsKmzipCbUtyxI=
-golang.org/x/net v0.50.0/go.mod h1:UgoSli3F/pBgdJBHCTc+tp3gmrU4XswgGRgtnwWTfyM=
+golang.org/x/sys v0.35.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
-golang.org/x/sys v0.41.0 h1:Ivj+2Cp/ylzLiEU89QhWblYnOE9zerudt9Ftecq2C6k=
+golang.org/x/text v0.28.0 h1:rhazDwis8INMIwQ4tpjLDzUhx6RlXqZNPEM0huQojng=
-golang.org/x/sys v0.41.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/text v0.28.0/go.mod h1:U8nCwOR8jO/marOQ0QbDiOngZVEBB7MAiitBuMjXiNU=
-golang.org/x/text v0.34.0 h1:oL/Qq0Kdaqxa1KbNeMKwQq0reLCCaFtqu2eNuSeNHbk=
-golang.org/x/text v0.34.0/go.mod h1:homfLqTYRFyVYemLBFl5GgL/DWEiH5wcsQ5gSh1yziA=
 google.golang.org/protobuf v1.36.8 h1:xHScyCOEuuwZEc6UtSOvPbAT4zRh0xcNRYekJwfqyMc=
 google.golang.org/protobuf v1.36.8/go.mod h1:fuxRtAxBytpl4zzqUh6/eyUujkJdNiuEkXntxiD/uRU=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

internal/config/classify.go

@@ -1,85 +0,0 @@
-package config
-
-import (
-	"errors"
-	"fmt"
-	"strings"
-
-	"golang.org/x/net/publicsuffix"
-)
-
-// DNSNameType indicates whether a DNS name is an apex domain or a hostname.
-type DNSNameType int
-
-const (
-	// DNSNameTypeDomain indicates the name is an apex (eTLD+1) domain.
-	DNSNameTypeDomain DNSNameType = iota
-	// DNSNameTypeHostname indicates the name is a subdomain/hostname.
-	DNSNameTypeHostname
-)
-
-// ErrEmptyDNSName is returned when an empty string is passed to ClassifyDNSName.
-var ErrEmptyDNSName = errors.New("empty DNS name")
-
-// String returns the string representation of a DNSNameType.
-func (t DNSNameType) String() string {
-	switch t {
-	case DNSNameTypeDomain:
-		return "domain"
-	case DNSNameTypeHostname:
-		return "hostname"
-	default:
-		return "unknown"
-	}
-}
-
-// ClassifyDNSName determines whether a DNS name is an apex domain or a
-// hostname (subdomain) using the Public Suffix List. It returns an error
-// if the input is empty or is itself a public suffix (e.g. "co.uk").
-func ClassifyDNSName(name string) (DNSNameType, error) {
-	name = strings.ToLower(strings.TrimSuffix(strings.TrimSpace(name), "."))
-
-	if name == "" {
-		return 0, ErrEmptyDNSName
-	}
-
-	etld1, err := publicsuffix.EffectiveTLDPlusOne(name)
-	if err != nil {
-		return 0, fmt.Errorf("invalid DNS name %q: %w", name, err)
-	}
-
-	if name == etld1 {
-		return DNSNameTypeDomain, nil
-	}
-
-	return DNSNameTypeHostname, nil
-}
-
-// ClassifyTargets splits a list of DNS names into apex domains and
-// hostnames using the Public Suffix List. It returns an error if any
-// name cannot be classified.
-func ClassifyTargets(targets []string) ([]string, []string, error) {
-	var domains, hostnames []string
-
-	for _, t := range targets {
-		normalized := strings.ToLower(strings.TrimSuffix(strings.TrimSpace(t), "."))
-
-		if normalized == "" {
-			continue
-		}
-
-		typ, classErr := ClassifyDNSName(normalized)
-		if classErr != nil {
-			return nil, nil, classErr
-		}
-
-		switch typ {
-		case DNSNameTypeDomain:
-			domains = append(domains, normalized)
-		case DNSNameTypeHostname:
-			hostnames = append(hostnames, normalized)
-		}
-	}
-
-	return domains, hostnames, nil
-}

internal/config/classify_test.go

@@ -1,83 +0,0 @@
-package config_test
-
-import (
-	"testing"
-
-	"sneak.berlin/go/dnswatcher/internal/config"
-)
-
-func TestClassifyDNSName(t *testing.T) {
-	t.Parallel()
-
-	tests := []struct {
-		name    string
-		input   string
-		want    config.DNSNameType
-		wantErr bool
-	}{
-		{name: "apex domain simple", input: "example.com", want: config.DNSNameTypeDomain},
-		{name: "hostname simple", input: "www.example.com", want: config.DNSNameTypeHostname},
-		{name: "apex domain multi-part TLD", input: "example.co.uk", want: config.DNSNameTypeDomain},
-		{name: "hostname multi-part TLD", input: "api.example.co.uk", want: config.DNSNameTypeHostname},
-		{name: "public suffix itself", input: "co.uk", wantErr: true},
-		{name: "empty string", input: "", wantErr: true},
-		{name: "deeply nested hostname", input: "a.b.c.example.com", want: config.DNSNameTypeHostname},
-		{name: "trailing dot stripped", input: "example.com.", want: config.DNSNameTypeDomain},
-		{name: "uppercase normalized", input: "WWW.Example.COM", want: config.DNSNameTypeHostname},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			t.Parallel()
-
-			got, err := config.ClassifyDNSName(tt.input)
-
-			if tt.wantErr {
-				if err == nil {
-					t.Errorf("ClassifyDNSName(%q) expected error, got %v", tt.input, got)
-				}
-
-				return
-			}
-
-			if err != nil {
-				t.Fatalf("ClassifyDNSName(%q) unexpected error: %v", tt.input, err)
-			}
-
-			if got != tt.want {
-				t.Errorf("ClassifyDNSName(%q) = %v, want %v", tt.input, got, tt.want)
-			}
-		})
-	}
-}
-
-func TestClassifyTargets(t *testing.T) {
-	t.Parallel()
-
-	domains, hostnames, err := config.ClassifyTargets([]string{
-		"example.com",
-		"www.example.com",
-		"example.co.uk",
-		"api.example.co.uk",
-	})
-	if err != nil {
-		t.Fatalf("unexpected error: %v", err)
-	}
-
-	if len(domains) != 2 {
-		t.Errorf("expected 2 domains, got %d: %v", len(domains), domains)
-	}
-
-	if len(hostnames) != 2 {
-		t.Errorf("expected 2 hostnames, got %d: %v", len(hostnames), hostnames)
-	}
-}
-
-func TestClassifyTargetsRejectsPublicSuffix(t *testing.T) {
-	t.Parallel()
-
-	_, _, err := config.ClassifyTargets([]string{"co.uk"})
-	if err == nil {
-		t.Error("expected error for public suffix, got nil")
-	}
-}

internal/config/config.go

@@ -89,7 +89,8 @@ func setupViper(name string) {
 	viper.SetDefault("PORT", defaultPort)
 	viper.SetDefault("DEBUG", false)
 	viper.SetDefault("DATA_DIR", "./data")
-	viper.SetDefault("TARGETS", "")
+	viper.SetDefault("DOMAINS", "")
+	viper.SetDefault("HOSTNAMES", "")
 	viper.SetDefault("SLACK_WEBHOOK", "")
 	viper.SetDefault("MATTERMOST_WEBHOOK", "")
 	viper.SetDefault("NTFY_TOPIC", "")
@@ -132,19 +133,12 @@ func buildConfig(
 		tlsInterval = defaultTLSInterval
 	}
 
-	domains, hostnames, err := ClassifyTargets(
-		parseCSV(viper.GetString("TARGETS")),
-	)
-	if err != nil {
-		return nil, fmt.Errorf("invalid targets configuration: %w", err)
-	}
-
 	cfg := &Config{
 		Port:              viper.GetInt("PORT"),
 		Debug:             viper.GetBool("DEBUG"),
 		DataDir:           viper.GetString("DATA_DIR"),
-		Domains:           domains,
+		Domains:           parseCSV(viper.GetString("DOMAINS")),
-		Hostnames:         hostnames,
+		Hostnames:         parseCSV(viper.GetString("HOSTNAMES")),
 		SlackWebhook:      viper.GetString("SLACK_WEBHOOK"),
 		MattermostWebhook: viper.GetString("MATTERMOST_WEBHOOK"),
 		NtfyTopic:         viper.GetString("NTFY_TOPIC"),

internal/notify/notify.go

@@ -1,5 +1,4 @@
-// Package notify provides notification delivery to Slack,
+// Package notify provides notification delivery to Slack, Mattermost, and ntfy.
-// Mattermost, and ntfy.
 package notify
 
 import (
@@ -8,7 +7,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io"
 	"log/slog"
 	"net/http"
 	"net/url"
@@ -36,66 +34,8 @@ var (
 	ErrMattermostFailed = errors.New(
 		"mattermost notification failed",
 	)
-	// ErrInvalidScheme is returned for disallowed URL schemes.
-	ErrInvalidScheme = errors.New("URL scheme not allowed")
-	// ErrMissingHost is returned when a URL has no host.
-	ErrMissingHost = errors.New("URL must have a host")
 )
 
-// IsAllowedScheme checks if the URL scheme is permitted.
-func IsAllowedScheme(scheme string) bool {
-	return scheme == "https" || scheme == "http"
-}
-
-// ValidateWebhookURL validates and sanitizes a webhook URL.
-// It ensures the URL has an allowed scheme (http/https),
-// a non-empty host, and returns a pre-parsed *url.URL
-// reconstructed from validated components.
-func ValidateWebhookURL(raw string) (*url.URL, error) {
-	u, err := url.ParseRequestURI(raw)
-	if err != nil {
-		return nil, fmt.Errorf("invalid URL: %w", err)
-	}
-
-	if !IsAllowedScheme(u.Scheme) {
-		return nil, fmt.Errorf(
-			"%w: %s", ErrInvalidScheme, u.Scheme,
-		)
-	}
-
-	if u.Host == "" {
-		return nil, fmt.Errorf("%w", ErrMissingHost)
-	}
-
-	// Reconstruct from parsed components.
-	clean := &url.URL{
-		Scheme:   u.Scheme,
-		Host:     u.Host,
-		Path:     u.Path,
-		RawQuery: u.RawQuery,
-	}
-
-	return clean, nil
-}
-
-// newRequest creates an http.Request from a pre-validated *url.URL.
-// This avoids passing URL strings to http.NewRequestWithContext,
-// which gosec flags as a potential SSRF vector.
-func newRequest(
-	ctx context.Context,
-	method string,
-	target *url.URL,
-	body io.Reader,
-) *http.Request {
-	return (&http.Request{
-		Method: method,
-		URL:    target,
-		Host:   target.Host,
-		Header: make(http.Header),
-		Body:   io.NopCloser(body),
-	}).WithContext(ctx)
-}
-
 // Params contains dependencies for Service.
 type Params struct {
 	fx.In
@@ -107,7 +47,7 @@ type Params struct {
 // Service provides notification functionality.
 type Service struct {
 	log                  *slog.Logger
-	transport            http.RoundTripper
+	client               *http.Client
 	config               *config.Config
 	ntfyURL              *url.URL
 	slackWebhookURL      *url.URL
@@ -120,41 +60,33 @@ func New(
 	params Params,
 ) (*Service, error) {
 	svc := &Service{
-		log:       params.Logger.Get(),
+		log: params.Logger.Get(),
-		transport: http.DefaultTransport,
+		client: &http.Client{
-		config:    params.Config,
+			Timeout: httpClientTimeout,
+		},
+		config: params.Config,
 	}
 
 	if params.Config.NtfyTopic != "" {
-		u, err := ValidateWebhookURL(
+		u, err := url.ParseRequestURI(params.Config.NtfyTopic)
-			params.Config.NtfyTopic,
-		)
 		if err != nil {
-			return nil, fmt.Errorf(
+			return nil, fmt.Errorf("invalid ntfy topic URL: %w", err)
-				"invalid ntfy topic URL: %w", err,
-			)
 		}
 
 		svc.ntfyURL = u
 	}
 
 	if params.Config.SlackWebhook != "" {
-		u, err := ValidateWebhookURL(
+		u, err := url.ParseRequestURI(params.Config.SlackWebhook)
-			params.Config.SlackWebhook,
-		)
 		if err != nil {
-			return nil, fmt.Errorf(
+			return nil, fmt.Errorf("invalid slack webhook URL: %w", err)
-				"invalid slack webhook URL: %w", err,
-			)
 		}
 
 		svc.slackWebhookURL = u
 	}
 
 	if params.Config.MattermostWebhook != "" {
-		u, err := ValidateWebhookURL(
+		u, err := url.ParseRequestURI(params.Config.MattermostWebhook)
-			params.Config.MattermostWebhook,
-		)
 		if err != nil {
 			return nil, fmt.Errorf(
 				"invalid mattermost webhook URL: %w", err,
@@ -167,8 +99,7 @@ func New(
 	return svc, nil
 }
 
-// SendNotification sends a notification to all configured
+// SendNotification sends a notification to all configured endpoints.
-// endpoints.
 func (svc *Service) SendNotification(
 	ctx context.Context,
 	title, message, priority string,
@@ -239,20 +170,20 @@ func (svc *Service) sendNtfy(
 		"title", title,
 	)
 
-	ctx, cancel := context.WithTimeout(
+	request, err := http.NewRequestWithContext(
-		ctx, httpClientTimeout,
+		ctx,
-	)
+		http.MethodPost,
-	defer cancel()
+		topicURL.String(),
-
+		bytes.NewBufferString(message),
-	body := bytes.NewBufferString(message)
-	request := newRequest(
-		ctx, http.MethodPost, topicURL, body,
 	)
+	if err != nil {
+		return fmt.Errorf("creating ntfy request: %w", err)
+	}
 
 	request.Header.Set("Title", title)
 	request.Header.Set("Priority", ntfyPriority(priority))
 
-	resp, err := svc.transport.RoundTrip(request)
+	resp, err := svc.client.Do(request) //nolint:gosec // URL validated at Service construction time
 	if err != nil {
 		return fmt.Errorf("sending ntfy request: %w", err)
 	}
@@ -261,8 +192,7 @@ func (svc *Service) sendNtfy(
 
 	if resp.StatusCode >= httpStatusClientError {
 		return fmt.Errorf(
-			"%w: status %d",
+			"%w: status %d", ErrNtfyFailed, resp.StatusCode,
-			ErrNtfyFailed, resp.StatusCode,
 		)
 	}
 
@@ -302,11 +232,6 @@ func (svc *Service) sendSlack(
 	webhookURL *url.URL,
 	title, message, priority string,
 ) error {
-	ctx, cancel := context.WithTimeout(
-		ctx, httpClientTimeout,
-	)
-	defer cancel()
-
 	svc.log.Debug(
 		"sending webhook notification",
 		"url", webhookURL.String(),
@@ -325,19 +250,22 @@ func (svc *Service) sendSlack(
 
 	body, err := json.Marshal(payload)
 	if err != nil {
-		return fmt.Errorf(
+		return fmt.Errorf("marshaling webhook payload: %w", err)
-			"marshaling webhook payload: %w", err,
-		)
 	}
 
-	request := newRequest(
+	request, err := http.NewRequestWithContext(
-		ctx, http.MethodPost, webhookURL,
+		ctx,
+		http.MethodPost,
+		webhookURL.String(),
 		bytes.NewBuffer(body),
 	)
+	if err != nil {
+		return fmt.Errorf("creating webhook request: %w", err)
+	}
 
 	request.Header.Set("Content-Type", "application/json")
 
-	resp, err := svc.transport.RoundTrip(request)
+	resp, err := svc.client.Do(request) //nolint:gosec // URL validated at Service construction time
 	if err != nil {
 		return fmt.Errorf("sending webhook request: %w", err)
 	}

internal/notify/notify_test.go

@@ -1,100 +0,0 @@
-package notify_test
-
-import (
-	"testing"
-
-	"sneak.berlin/go/dnswatcher/internal/notify"
-)
-
-func TestValidateWebhookURLValid(t *testing.T) {
-	t.Parallel()
-
-	tests := []struct {
-		name    string
-		input   string
-		wantURL string
-	}{
-		{
-			name:    "valid https URL",
-			input:   "https://hooks.slack.com/T00/B00",
-			wantURL: "https://hooks.slack.com/T00/B00",
-		},
-		{
-			name:    "valid http URL",
-			input:   "http://localhost:8080/webhook",
-			wantURL: "http://localhost:8080/webhook",
-		},
-		{
-			name:    "https with query",
-			input:   "https://ntfy.sh/topic?auth=tok",
-			wantURL: "https://ntfy.sh/topic?auth=tok",
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			t.Parallel()
-
-			got, err := notify.ValidateWebhookURL(tt.input)
-			if err != nil {
-				t.Fatalf("unexpected error: %v", err)
-			}
-
-			if got.String() != tt.wantURL {
-				t.Errorf(
-					"got %q, want %q",
-					got.String(), tt.wantURL,
-				)
-			}
-		})
-	}
-}
-
-func TestValidateWebhookURLInvalid(t *testing.T) {
-	t.Parallel()
-
-	invalid := []struct {
-		name  string
-		input string
-	}{
-		{"ftp scheme", "ftp://example.com/file"},
-		{"file scheme", "file:///etc/passwd"},
-		{"empty string", ""},
-		{"no scheme", "example.com/webhook"},
-		{"no host", "https:///path"},
-	}
-
-	for _, tt := range invalid {
-		t.Run(tt.name, func(t *testing.T) {
-			t.Parallel()
-
-			got, err := notify.ValidateWebhookURL(tt.input)
-			if err == nil {
-				t.Errorf(
-					"expected error for %q, got %v",
-					tt.input, got,
-				)
-			}
-		})
-	}
-}
-
-func TestIsAllowedScheme(t *testing.T) {
-	t.Parallel()
-
-	if !notify.IsAllowedScheme("https") {
-		t.Error("https should be allowed")
-	}
-
-	if !notify.IsAllowedScheme("http") {
-		t.Error("http should be allowed")
-	}
-
-	if notify.IsAllowedScheme("ftp") {
-		t.Error("ftp should not be allowed")
-	}
-
-	if notify.IsAllowedScheme("") {
-		t.Error("empty scheme should not be allowed")
-	}
-}

internal/resolver/resolver.go

@@ -46,11 +46,11 @@ func (r *Resolver) LookupNS(
 }
 
 // LookupAllRecords performs iterative resolution to find all DNS
-// records for the given hostname, keyed by authoritative nameserver.
+// records for the given hostname.
 func (r *Resolver) LookupAllRecords(
 	_ context.Context,
 	_ string,
-) (map[string]map[string][]string, error) {
+) (map[string][]string, error) {
 	return nil, ErrNotImplemented
 }
 

internal/state/state_test_helper.go

@@ -1,22 +0,0 @@
-package state
-
-import (
-	"log/slog"
-
-	"sneak.berlin/go/dnswatcher/internal/config"
-)
-
-// NewForTest creates a State for unit testing with no persistence.
-func NewForTest() *State {
-	return &State{
-		log: slog.Default(),
-		snapshot: &Snapshot{
-			Version:      stateVersion,
-			Domains:      make(map[string]*DomainState),
-			Hostnames:    make(map[string]*HostnameState),
-			Ports:        make(map[string]*PortState),
-			Certificates: make(map[string]*CertificateState),
-		},
-		config: &config.Config{DataDir: ""},
-	}
-}

internal/watcher/interfaces.go

@@ -1,60 +0,0 @@
-// Package watcher provides the main monitoring orchestrator.
-package watcher
-
-import (
-	"context"
-
-	"sneak.berlin/go/dnswatcher/internal/tlscheck"
-)
-
-// DNSResolver performs iterative DNS resolution.
-type DNSResolver interface {
-	// LookupNS discovers authoritative nameservers for a domain.
-	LookupNS(
-		ctx context.Context,
-		domain string,
-	) ([]string, error)
-
-	// LookupAllRecords queries all record types for a hostname,
-	// returning results keyed by nameserver then record type.
-	LookupAllRecords(
-		ctx context.Context,
-		hostname string,
-	) (map[string]map[string][]string, error)
-
-	// ResolveIPAddresses resolves a hostname to all IP addresses.
-	ResolveIPAddresses(
-		ctx context.Context,
-		hostname string,
-	) ([]string, error)
-}
-
-// PortChecker tests TCP port connectivity.
-type PortChecker interface {
-	// CheckPort tests TCP connectivity to an address and port.
-	CheckPort(
-		ctx context.Context,
-		address string,
-		port int,
-	) (bool, error)
-}
-
-// TLSChecker inspects TLS certificates.
-type TLSChecker interface {
-	// CheckCertificate connects via TLS and returns cert info.
-	CheckCertificate(
-		ctx context.Context,
-		ip string,
-		hostname string,
-	) (*tlscheck.CertificateInfo, error)
-}
-
-// Notifier delivers notifications to configured endpoints.
-type Notifier interface {
-	// SendNotification sends a notification with the given
-	// details.
-	SendNotification(
-		ctx context.Context,
-		title, message, priority string,
-	)
-}

internal/watcher/watcher.go

@@ -1,30 +1,21 @@
+// Package watcher provides the main monitoring orchestrator and scheduler.
 package watcher
 
 import (
 	"context"
-	"fmt"
 	"log/slog"
-	"sort"
-	"strings"
-	"time"
 
 	"go.uber.org/fx"
 
 	"sneak.berlin/go/dnswatcher/internal/config"
 	"sneak.berlin/go/dnswatcher/internal/logger"
+	"sneak.berlin/go/dnswatcher/internal/notify"
+	"sneak.berlin/go/dnswatcher/internal/portcheck"
+	"sneak.berlin/go/dnswatcher/internal/resolver"
 	"sneak.berlin/go/dnswatcher/internal/state"
 	"sneak.berlin/go/dnswatcher/internal/tlscheck"
 )
 
-// monitoredPorts are the TCP ports checked for each IP address.
-var monitoredPorts = []int{80, 443} //nolint:gochecknoglobals
-
-// tlsPort is the port used for TLS certificate checks.
-const tlsPort = 443
-
-// hoursPerDay converts days to hours for duration calculations.
-const hoursPerDay = 24
-
 // Params contains dependencies for Watcher.
 type Params struct {
 	fx.In
@@ -32,10 +23,10 @@ type Params struct {
 	Logger    *logger.Logger
 	Config    *config.Config
 	State     *state.State
-	Resolver  DNSResolver
+	Resolver  *resolver.Resolver
-	PortCheck PortChecker
+	PortCheck *portcheck.Checker
-	TLSCheck  TLSChecker
+	TLSCheck  *tlscheck.Checker
-	Notify    Notifier
+	Notify    *notify.Service
 }
 
 // Watcher orchestrates all monitoring checks on a schedule.
@@ -43,20 +34,19 @@ type Watcher struct {
 	log       *slog.Logger
 	config    *config.Config
 	state     *state.State
-	resolver  DNSResolver
+	resolver  *resolver.Resolver
-	portCheck PortChecker
+	portCheck *portcheck.Checker
-	tlsCheck  TLSChecker
+	tlsCheck  *tlscheck.Checker
-	notify    Notifier
+	notify    *notify.Service
 	cancel    context.CancelFunc
-	firstRun  bool
 }
 
-// New creates a new Watcher instance wired into the fx lifecycle.
+// New creates a new Watcher instance.
 func New(
 	lifecycle fx.Lifecycle,
 	params Params,
 ) (*Watcher, error) {
-	w := &Watcher{
+	watcher := &Watcher{
 		log:       params.Logger.Get(),
 		config:    params.Config,
 		state:     params.State,
@@ -64,54 +54,30 @@ func New(
 		portCheck: params.PortCheck,
 		tlsCheck:  params.TLSCheck,
 		notify:    params.Notify,
-		firstRun:  true,
 	}
 
 	lifecycle.Append(fx.Hook{
 		OnStart: func(startCtx context.Context) error {
-			ctx, cancel := context.WithCancel(
+			ctx, cancel := context.WithCancel(startCtx)
-				context.WithoutCancel(startCtx),
+			watcher.cancel = cancel
-			)
-			w.cancel = cancel
 
-			go w.Run(ctx)
+			go watcher.Run(ctx)
 
 			return nil
 		},
 		OnStop: func(_ context.Context) error {
-			if w.cancel != nil {
+			if watcher.cancel != nil {
-				w.cancel()
+				watcher.cancel()
 			}
 
 			return nil
 		},
 	})
 
-	return w, nil
+	return watcher, nil
 }
 
-// NewForTest creates a Watcher without fx for unit testing.
+// Run starts the monitoring loop.
-func NewForTest(
-	cfg *config.Config,
-	st *state.State,
-	res DNSResolver,
-	pc PortChecker,
-	tc TLSChecker,
-	n Notifier,
-) *Watcher {
-	return &Watcher{
-		log:       slog.Default(),
-		config:    cfg,
-		state:     st,
-		resolver:  res,
-		portCheck: pc,
-		tlsCheck:  tc,
-		notify:    n,
-		firstRun:  true,
-	}
-}
-
-// Run starts the monitoring loop with periodic scheduling.
 func (w *Watcher) Run(ctx context.Context) {
 	w.log.Info(
 		"watcher starting",
@@ -121,646 +87,8 @@ func (w *Watcher) Run(ctx context.Context) {
 		"tlsInterval", w.config.TLSInterval,
 	)
 
-	w.RunOnce(ctx)
+	// Stub: wait for context cancellation.
-
+	// Implementation will add initial check + periodic scheduling.
-	dnsTicker := time.NewTicker(w.config.DNSInterval)
+	<-ctx.Done()
-	tlsTicker := time.NewTicker(w.config.TLSInterval)
+	w.log.Info("watcher stopped")
-
-	defer dnsTicker.Stop()
-	defer tlsTicker.Stop()
-
-	for {
-		select {
-		case <-ctx.Done():
-			w.log.Info("watcher stopped")
-
-			return
-		case <-dnsTicker.C:
-			w.runDNSAndPortChecks(ctx)
-			w.saveState()
-		case <-tlsTicker.C:
-			w.runTLSChecks(ctx)
-			w.saveState()
-		}
-	}
-}
-
-// RunOnce performs a single complete monitoring cycle.
-func (w *Watcher) RunOnce(ctx context.Context) {
-	w.detectFirstRun()
-	w.runDNSAndPortChecks(ctx)
-	w.runTLSChecks(ctx)
-	w.saveState()
-	w.firstRun = false
-}
-
-func (w *Watcher) detectFirstRun() {
-	snap := w.state.GetSnapshot()
-	hasState := len(snap.Domains) > 0 ||
-		len(snap.Hostnames) > 0 ||
-		len(snap.Ports) > 0 ||
-		len(snap.Certificates) > 0
-
-	if hasState {
-		w.firstRun = false
-	}
-}
-
-func (w *Watcher) runDNSAndPortChecks(ctx context.Context) {
-	for _, domain := range w.config.Domains {
-		w.checkDomain(ctx, domain)
-	}
-
-	for _, hostname := range w.config.Hostnames {
-		w.checkHostname(ctx, hostname)
-	}
-
-	w.checkAllPorts(ctx)
-}
-
-func (w *Watcher) checkDomain(
-	ctx context.Context,
-	domain string,
-) {
-	nameservers, err := w.resolver.LookupNS(ctx, domain)
-	if err != nil {
-		w.log.Error(
-			"failed to lookup NS",
-			"domain", domain,
-			"error", err,
-		)
-
-		return
-	}
-
-	sort.Strings(nameservers)
-
-	now := time.Now().UTC()
-
-	prev, hasPrev := w.state.GetDomainState(domain)
-	if hasPrev && !w.firstRun {
-		w.detectNSChanges(ctx, domain, prev.Nameservers, nameservers)
-	}
-
-	w.state.SetDomainState(domain, &state.DomainState{
-		Nameservers: nameservers,
-		LastChecked: now,
-	})
-}
-
-func (w *Watcher) detectNSChanges(
-	ctx context.Context,
-	domain string,
-	oldNS, newNS []string,
-) {
-	oldSet := toSet(oldNS)
-	newSet := toSet(newNS)
-
-	var added, removed []string
-
-	for ns := range newSet {
-		if !oldSet[ns] {
-			added = append(added, ns)
-		}
-	}
-
-	for ns := range oldSet {
-		if !newSet[ns] {
-			removed = append(removed, ns)
-		}
-	}
-
-	if len(added) == 0 && len(removed) == 0 {
-		return
-	}
-
-	msg := fmt.Sprintf(
-		"Domain: %s\nAdded: %s\nRemoved: %s",
-		domain,
-		strings.Join(added, ", "),
-		strings.Join(removed, ", "),
-	)
-
-	w.notify.SendNotification(
-		ctx,
-		"NS Change: "+domain,
-		msg,
-		"warning",
-	)
-}
-
-func (w *Watcher) checkHostname(
-	ctx context.Context,
-	hostname string,
-) {
-	records, err := w.resolver.LookupAllRecords(ctx, hostname)
-	if err != nil {
-		w.log.Error(
-			"failed to lookup records",
-			"hostname", hostname,
-			"error", err,
-		)
-
-		return
-	}
-
-	now := time.Now().UTC()
-	prev, hasPrev := w.state.GetHostnameState(hostname)
-
-	if hasPrev && !w.firstRun {
-		w.detectHostnameChanges(ctx, hostname, prev, records)
-	}
-
-	newState := buildHostnameState(records, now)
-	w.state.SetHostnameState(hostname, newState)
-}
-
-func buildHostnameState(
-	records map[string]map[string][]string,
-	now time.Time,
-) *state.HostnameState {
-	hs := &state.HostnameState{
-		RecordsByNameserver: make(
-			map[string]*state.NameserverRecordState,
-		),
-		LastChecked: now,
-	}
-
-	for ns, recs := range records {
-		hs.RecordsByNameserver[ns] = &state.NameserverRecordState{
-			Records:     recs,
-			Status:      "ok",
-			LastChecked: now,
-		}
-	}
-
-	return hs
-}
-
-func (w *Watcher) detectHostnameChanges(
-	ctx context.Context,
-	hostname string,
-	prev *state.HostnameState,
-	current map[string]map[string][]string,
-) {
-	w.detectRecordChanges(ctx, hostname, prev, current)
-	w.detectNSDisappearances(ctx, hostname, prev, current)
-	w.detectInconsistencies(ctx, hostname, current)
-}
-
-func (w *Watcher) detectRecordChanges(
-	ctx context.Context,
-	hostname string,
-	prev *state.HostnameState,
-	current map[string]map[string][]string,
-) {
-	for ns, recs := range current {
-		prevNS, ok := prev.RecordsByNameserver[ns]
-		if !ok {
-			continue
-		}
-
-		if recordsEqual(prevNS.Records, recs) {
-			continue
-		}
-
-		msg := fmt.Sprintf(
-			"Hostname: %s\nNameserver: %s\n"+
-				"Old: %v\nNew: %v",
-			hostname, ns,
-			prevNS.Records, recs,
-		)
-
-		w.notify.SendNotification(
-			ctx,
-			"Record Change: "+hostname,
-			msg,
-			"warning",
-		)
-	}
-}
-
-func (w *Watcher) detectNSDisappearances(
-	ctx context.Context,
-	hostname string,
-	prev *state.HostnameState,
-	current map[string]map[string][]string,
-) {
-	for ns, prevNS := range prev.RecordsByNameserver {
-		if _, ok := current[ns]; ok || prevNS.Status != "ok" {
-			continue
-		}
-
-		msg := fmt.Sprintf(
-			"Hostname: %s\nNameserver: %s disappeared",
-			hostname, ns,
-		)
-
-		w.notify.SendNotification(
-			ctx,
-			"NS Failure: "+hostname,
-			msg,
-			"error",
-		)
-	}
-
-	for ns := range current {
-		prevNS, ok := prev.RecordsByNameserver[ns]
-		if !ok || prevNS.Status != "error" {
-			continue
-		}
-
-		msg := fmt.Sprintf(
-			"Hostname: %s\nNameserver: %s recovered",
-			hostname, ns,
-		)
-
-		w.notify.SendNotification(
-			ctx,
-			"NS Recovery: "+hostname,
-			msg,
-			"success",
-		)
-	}
-}
-
-func (w *Watcher) detectInconsistencies(
-	ctx context.Context,
-	hostname string,
-	current map[string]map[string][]string,
-) {
-	nameservers := make([]string, 0, len(current))
-	for ns := range current {
-		nameservers = append(nameservers, ns)
-	}
-
-	sort.Strings(nameservers)
-
-	for i := range len(nameservers) - 1 {
-		ns1 := nameservers[i]
-		ns2 := nameservers[i+1]
-
-		if recordsEqual(current[ns1], current[ns2]) {
-			continue
-		}
-
-		msg := fmt.Sprintf(
-			"Hostname: %s\n%s: %v\n%s: %v",
-			hostname,
-			ns1, current[ns1],
-			ns2, current[ns2],
-		)
-
-		w.notify.SendNotification(
-			ctx,
-			"Inconsistency: "+hostname,
-			msg,
-			"warning",
-		)
-	}
-}
-
-func (w *Watcher) checkAllPorts(ctx context.Context) {
-	for _, hostname := range w.config.Hostnames {
-		w.checkPortsForHostname(ctx, hostname)
-	}
-
-	for _, domain := range w.config.Domains {
-		w.checkPortsForHostname(ctx, domain)
-	}
-}
-
-func (w *Watcher) checkPortsForHostname(
-	ctx context.Context,
-	hostname string,
-) {
-	ips := w.collectIPs(hostname)
-
-	for _, ip := range ips {
-		for _, port := range monitoredPorts {
-			w.checkSinglePort(ctx, ip, port, hostname)
-		}
-	}
-}
-
-func (w *Watcher) collectIPs(hostname string) []string {
-	hs, ok := w.state.GetHostnameState(hostname)
-	if !ok {
-		return nil
-	}
-
-	ipSet := make(map[string]bool)
-
-	for _, nsState := range hs.RecordsByNameserver {
-		for _, ip := range nsState.Records["A"] {
-			ipSet[ip] = true
-		}
-
-		for _, ip := range nsState.Records["AAAA"] {
-			ipSet[ip] = true
-		}
-	}
-
-	result := make([]string, 0, len(ipSet))
-	for ip := range ipSet {
-		result = append(result, ip)
-	}
-
-	sort.Strings(result)
-
-	return result
-}
-
-func (w *Watcher) checkSinglePort(
-	ctx context.Context,
-	ip string,
-	port int,
-	hostname string,
-) {
-	open, err := w.portCheck.CheckPort(ctx, ip, port)
-	if err != nil {
-		w.log.Error(
-			"port check failed",
-			"ip", ip,
-			"port", port,
-			"error", err,
-		)
-
-		return
-	}
-
-	key := fmt.Sprintf("%s:%d", ip, port)
-	now := time.Now().UTC()
-	prev, hasPrev := w.state.GetPortState(key)
-
-	if hasPrev && !w.firstRun && prev.Open != open {
-		stateStr := "closed"
-		if open {
-			stateStr = "open"
-		}
-
-		msg := fmt.Sprintf(
-			"Host: %s\nAddress: %s\nPort now %s",
-			hostname, key, stateStr,
-		)
-
-		w.notify.SendNotification(
-			ctx,
-			"Port Change: "+key,
-			msg,
-			"warning",
-		)
-	}
-
-	w.state.SetPortState(key, &state.PortState{
-		Open:        open,
-		Hostname:    hostname,
-		LastChecked: now,
-	})
-}
-
-func (w *Watcher) runTLSChecks(ctx context.Context) {
-	for _, hostname := range w.config.Hostnames {
-		w.checkTLSForHostname(ctx, hostname)
-	}
-
-	for _, domain := range w.config.Domains {
-		w.checkTLSForHostname(ctx, domain)
-	}
-}
-
-func (w *Watcher) checkTLSForHostname(
-	ctx context.Context,
-	hostname string,
-) {
-	ips := w.collectIPs(hostname)
-
-	for _, ip := range ips {
-		portKey := fmt.Sprintf("%s:%d", ip, tlsPort)
-
-		ps, ok := w.state.GetPortState(portKey)
-		if !ok || !ps.Open {
-			continue
-		}
-
-		w.checkTLSCert(ctx, ip, hostname)
-	}
-}
-
-func (w *Watcher) checkTLSCert(
-	ctx context.Context,
-	ip string,
-	hostname string,
-) {
-	cert, err := w.tlsCheck.CheckCertificate(ctx, ip, hostname)
-	certKey := fmt.Sprintf("%s:%d:%s", ip, tlsPort, hostname)
-	now := time.Now().UTC()
-	prev, hasPrev := w.state.GetCertificateState(certKey)
-
-	if err != nil {
-		w.handleTLSError(
-			ctx, certKey, hostname, ip,
-			hasPrev, prev, now, err,
-		)
-
-		return
-	}
-
-	w.handleTLSSuccess(
-		ctx, certKey, hostname, ip,
-		hasPrev, prev, now, cert,
-	)
-}
-
-func (w *Watcher) handleTLSError(
-	ctx context.Context,
-	certKey, hostname, ip string,
-	hasPrev bool,
-	prev *state.CertificateState,
-	now time.Time,
-	err error,
-) {
-	if hasPrev && !w.firstRun && prev.Status == "ok" {
-		msg := fmt.Sprintf(
-			"Host: %s\nIP: %s\nError: %s",
-			hostname, ip, err,
-		)
-
-		w.notify.SendNotification(
-			ctx,
-			"TLS Failure: "+hostname,
-			msg,
-			"error",
-		)
-	}
-
-	w.state.SetCertificateState(
-		certKey, &state.CertificateState{
-			Status:      "error",
-			Error:       err.Error(),
-			LastChecked: now,
-		},
-	)
-}
-
-func (w *Watcher) handleTLSSuccess(
-	ctx context.Context,
-	certKey, hostname, ip string,
-	hasPrev bool,
-	prev *state.CertificateState,
-	now time.Time,
-	cert *tlscheck.CertificateInfo,
-) {
-	if hasPrev && !w.firstRun {
-		w.detectTLSChanges(ctx, hostname, ip, prev, cert)
-	}
-
-	w.checkTLSExpiry(ctx, hostname, ip, cert)
-
-	w.state.SetCertificateState(
-		certKey, &state.CertificateState{
-			CommonName:              cert.CommonName,
-			Issuer:                  cert.Issuer,
-			NotAfter:                cert.NotAfter,
-			SubjectAlternativeNames: cert.SubjectAlternativeNames,
-			Status:                  "ok",
-			LastChecked:             now,
-		},
-	)
-}
-
-func (w *Watcher) detectTLSChanges(
-	ctx context.Context,
-	hostname, ip string,
-	prev *state.CertificateState,
-	cert *tlscheck.CertificateInfo,
-) {
-	if prev.Status == "error" {
-		msg := fmt.Sprintf(
-			"Host: %s\nIP: %s\nTLS recovered",
-			hostname, ip,
-		)
-
-		w.notify.SendNotification(
-			ctx,
-			"TLS Recovery: "+hostname,
-			msg,
-			"success",
-		)
-
-		return
-	}
-
-	changed := prev.CommonName != cert.CommonName ||
-		prev.Issuer != cert.Issuer ||
-		!sliceEqual(
-			prev.SubjectAlternativeNames,
-			cert.SubjectAlternativeNames,
-		)
-
-	if !changed {
-		return
-	}
-
-	msg := fmt.Sprintf(
-		"Host: %s\nIP: %s\n"+
-			"Old CN: %s, Issuer: %s\n"+
-			"New CN: %s, Issuer: %s",
-		hostname, ip,
-		prev.CommonName, prev.Issuer,
-		cert.CommonName, cert.Issuer,
-	)
-
-	w.notify.SendNotification(
-		ctx,
-		"TLS Certificate Change: "+hostname,
-		msg,
-		"warning",
-	)
-}
-
-func (w *Watcher) checkTLSExpiry(
-	ctx context.Context,
-	hostname, ip string,
-	cert *tlscheck.CertificateInfo,
-) {
-	daysLeft := time.Until(cert.NotAfter).Hours() / hoursPerDay
-	warningDays := float64(w.config.TLSExpiryWarning)
-
-	if daysLeft > warningDays {
-		return
-	}
-
-	msg := fmt.Sprintf(
-		"Host: %s\nIP: %s\nCN: %s\n"+
-			"Expires: %s (%.0f days)",
-		hostname, ip, cert.CommonName,
-		cert.NotAfter.Format(time.RFC3339),
-		daysLeft,
-	)
-
-	w.notify.SendNotification(
-		ctx,
-		"TLS Expiry Warning: "+hostname,
-		msg,
-		"warning",
-	)
-}
-
-func (w *Watcher) saveState() {
-	err := w.state.Save()
-	if err != nil {
-		w.log.Error("failed to save state", "error", err)
-	}
-}
-
-// --- Utility functions ---
-
-func toSet(items []string) map[string]bool {
-	set := make(map[string]bool, len(items))
-	for _, item := range items {
-		set[item] = true
-	}
-
-	return set
-}
-
-func recordsEqual(
-	a, b map[string][]string,
-) bool {
-	if len(a) != len(b) {
-		return false
-	}
-
-	for k, av := range a {
-		bv, ok := b[k]
-		if !ok || !sliceEqual(av, bv) {
-			return false
-		}
-	}
-
-	return true
-}
-
-func sliceEqual(a, b []string) bool {
-	if len(a) != len(b) {
-		return false
-	}
-
-	aSorted := make([]string, len(a))
-	bSorted := make([]string, len(b))
-
-	copy(aSorted, a)
-	copy(bSorted, b)
-
-	sort.Strings(aSorted)
-	sort.Strings(bSorted)
-
-	for i := range aSorted {
-		if aSorted[i] != bSorted[i] {
-			return false
-		}
-	}
-
-	return true
 }

internal/watcher/watcher_test.go

@@ -1,580 +0,0 @@
-package watcher_test
-
-import (
-	"context"
-	"errors"
-	"fmt"
-	"sync"
-	"testing"
-	"time"
-
-	"sneak.berlin/go/dnswatcher/internal/config"
-	"sneak.berlin/go/dnswatcher/internal/state"
-	"sneak.berlin/go/dnswatcher/internal/tlscheck"
-	"sneak.berlin/go/dnswatcher/internal/watcher"
-)
-
-// errNotFound is returned when mock data is missing.
-var errNotFound = errors.New("not found")
-
-// --- Mock implementations ---
-
-type mockResolver struct {
-	mu             sync.Mutex
-	nsRecords      map[string][]string
-	allRecords     map[string]map[string]map[string][]string
-	ipAddresses    map[string][]string
-	lookupNSErr    error
-	allRecordsErr  error
-	resolveIPErr   error
-	lookupNSCalls  int
-	allRecordCalls int
-}
-
-func (m *mockResolver) LookupNS(
-	_ context.Context,
-	domain string,
-) ([]string, error) {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-
-	m.lookupNSCalls++
-
-	if m.lookupNSErr != nil {
-		return nil, m.lookupNSErr
-	}
-
-	ns, ok := m.nsRecords[domain]
-	if !ok {
-		return nil, fmt.Errorf(
-			"%w: NS for %s", errNotFound, domain,
-		)
-	}
-
-	return ns, nil
-}
-
-func (m *mockResolver) LookupAllRecords(
-	_ context.Context,
-	hostname string,
-) (map[string]map[string][]string, error) {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-
-	m.allRecordCalls++
-
-	if m.allRecordsErr != nil {
-		return nil, m.allRecordsErr
-	}
-
-	recs, ok := m.allRecords[hostname]
-	if !ok {
-		return nil, fmt.Errorf(
-			"%w: records for %s", errNotFound, hostname,
-		)
-	}
-
-	return recs, nil
-}
-
-func (m *mockResolver) ResolveIPAddresses(
-	_ context.Context,
-	hostname string,
-) ([]string, error) {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-
-	if m.resolveIPErr != nil {
-		return nil, m.resolveIPErr
-	}
-
-	ips, ok := m.ipAddresses[hostname]
-	if !ok {
-		return nil, fmt.Errorf(
-			"%w: IPs for %s", errNotFound, hostname,
-		)
-	}
-
-	return ips, nil
-}
-
-type mockPortChecker struct {
-	mu      sync.Mutex
-	results map[string]bool
-	err     error
-	calls   int
-}
-
-func (m *mockPortChecker) CheckPort(
-	_ context.Context,
-	address string,
-	port int,
-) (bool, error) {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-
-	m.calls++
-
-	if m.err != nil {
-		return false, m.err
-	}
-
-	key := fmt.Sprintf("%s:%d", address, port)
-	open, ok := m.results[key]
-
-	if !ok {
-		return false, nil
-	}
-
-	return open, nil
-}
-
-type mockTLSChecker struct {
-	mu    sync.Mutex
-	certs map[string]*tlscheck.CertificateInfo
-	err   error
-	calls int
-}
-
-func (m *mockTLSChecker) CheckCertificate(
-	_ context.Context,
-	ip string,
-	hostname string,
-) (*tlscheck.CertificateInfo, error) {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-
-	m.calls++
-
-	if m.err != nil {
-		return nil, m.err
-	}
-
-	key := fmt.Sprintf("%s:%s", ip, hostname)
-	cert, ok := m.certs[key]
-
-	if !ok {
-		return nil, fmt.Errorf(
-			"%w: cert for %s", errNotFound, key,
-		)
-	}
-
-	return cert, nil
-}
-
-type notification struct {
-	Title    string
-	Message  string
-	Priority string
-}
-
-type mockNotifier struct {
-	mu            sync.Mutex
-	notifications []notification
-}
-
-func (m *mockNotifier) SendNotification(
-	_ context.Context,
-	title, message, priority string,
-) {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-
-	m.notifications = append(m.notifications, notification{
-		Title:    title,
-		Message:  message,
-		Priority: priority,
-	})
-}
-
-func (m *mockNotifier) getNotifications() []notification {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-
-	result := make([]notification, len(m.notifications))
-	copy(result, m.notifications)
-
-	return result
-}
-
-// --- Helper to build a Watcher for testing ---
-
-type testDeps struct {
-	resolver    *mockResolver
-	portChecker *mockPortChecker
-	tlsChecker  *mockTLSChecker
-	notifier    *mockNotifier
-	state       *state.State
-	config      *config.Config
-}
-
-func newTestWatcher(
-	t *testing.T,
-	cfg *config.Config,
-) (*watcher.Watcher, *testDeps) {
-	t.Helper()
-
-	deps := &testDeps{
-		resolver: &mockResolver{
-			nsRecords:   make(map[string][]string),
-			allRecords:  make(map[string]map[string]map[string][]string),
-			ipAddresses: make(map[string][]string),
-		},
-		portChecker: &mockPortChecker{
-			results: make(map[string]bool),
-		},
-		tlsChecker: &mockTLSChecker{
-			certs: make(map[string]*tlscheck.CertificateInfo),
-		},
-		notifier: &mockNotifier{},
-		config:   cfg,
-	}
-
-	deps.state = state.NewForTest()
-
-	w := watcher.NewForTest(
-		deps.config,
-		deps.state,
-		deps.resolver,
-		deps.portChecker,
-		deps.tlsChecker,
-		deps.notifier,
-	)
-
-	return w, deps
-}
-
-func defaultTestConfig(t *testing.T) *config.Config {
-	t.Helper()
-
-	return &config.Config{
-		DNSInterval:      time.Hour,
-		TLSInterval:      12 * time.Hour,
-		TLSExpiryWarning: 7,
-		DataDir:          t.TempDir(),
-	}
-}
-
-func TestFirstRunBaseline(t *testing.T) {
-	t.Parallel()
-
-	cfg := defaultTestConfig(t)
-	cfg.Domains = []string{"example.com"}
-	cfg.Hostnames = []string{"www.example.com"}
-
-	w, deps := newTestWatcher(t, cfg)
-	setupBaselineMocks(deps)
-
-	w.RunOnce(t.Context())
-
-	assertNoNotifications(t, deps)
-	assertStatePopulated(t, deps)
-}
-
-func setupBaselineMocks(deps *testDeps) {
-	deps.resolver.nsRecords["example.com"] = []string{
-		"ns1.example.com.",
-		"ns2.example.com.",
-	}
-	deps.resolver.allRecords["www.example.com"] = map[string]map[string][]string{
-		"ns1.example.com.": {"A": {"93.184.216.34"}},
-		"ns2.example.com.": {"A": {"93.184.216.34"}},
-	}
-	deps.resolver.ipAddresses["www.example.com"] = []string{
-		"93.184.216.34",
-	}
-	deps.portChecker.results["93.184.216.34:80"] = true
-	deps.portChecker.results["93.184.216.34:443"] = true
-	deps.tlsChecker.certs["93.184.216.34:www.example.com"] = &tlscheck.CertificateInfo{
-		CommonName: "www.example.com",
-		Issuer:     "DigiCert",
-		NotAfter:   time.Now().Add(90 * 24 * time.Hour),
-		SubjectAlternativeNames: []string{
-			"www.example.com",
-		},
-	}
-}
-
-func assertNoNotifications(
-	t *testing.T,
-	deps *testDeps,
-) {
-	t.Helper()
-
-	notifications := deps.notifier.getNotifications()
-	if len(notifications) != 0 {
-		t.Errorf(
-			"expected 0 notifications on first run, got %d",
-			len(notifications),
-		)
-	}
-}
-
-func assertStatePopulated(
-	t *testing.T,
-	deps *testDeps,
-) {
-	t.Helper()
-
-	snap := deps.state.GetSnapshot()
-
-	if len(snap.Domains) != 1 {
-		t.Errorf(
-			"expected 1 domain in state, got %d",
-			len(snap.Domains),
-		)
-	}
-
-	if len(snap.Hostnames) != 1 {
-		t.Errorf(
-			"expected 1 hostname in state, got %d",
-			len(snap.Hostnames),
-		)
-	}
-}
-
-func TestNSChangeDetection(t *testing.T) {
-	t.Parallel()
-
-	cfg := defaultTestConfig(t)
-	cfg.Domains = []string{"example.com"}
-
-	w, deps := newTestWatcher(t, cfg)
-
-	deps.resolver.nsRecords["example.com"] = []string{
-		"ns1.example.com.",
-		"ns2.example.com.",
-	}
-
-	ctx := t.Context()
-	w.RunOnce(ctx)
-
-	deps.resolver.mu.Lock()
-	deps.resolver.nsRecords["example.com"] = []string{
-		"ns1.example.com.",
-		"ns3.example.com.",
-	}
-	deps.resolver.mu.Unlock()
-
-	w.RunOnce(ctx)
-
-	notifications := deps.notifier.getNotifications()
-	if len(notifications) == 0 {
-		t.Error("expected notification for NS change")
-	}
-
-	found := false
-
-	for _, n := range notifications {
-		if n.Priority == "warning" {
-			found = true
-		}
-	}
-
-	if !found {
-		t.Error("expected warning-priority NS change notification")
-	}
-}
-
-func TestRecordChangeDetection(t *testing.T) {
-	t.Parallel()
-
-	cfg := defaultTestConfig(t)
-	cfg.Hostnames = []string{"www.example.com"}
-
-	w, deps := newTestWatcher(t, cfg)
-
-	deps.resolver.allRecords["www.example.com"] = map[string]map[string][]string{
-		"ns1.example.com.": {"A": {"93.184.216.34"}},
-	}
-	deps.resolver.ipAddresses["www.example.com"] = []string{
-		"93.184.216.34",
-	}
-	deps.portChecker.results["93.184.216.34:80"] = false
-	deps.portChecker.results["93.184.216.34:443"] = false
-
-	ctx := t.Context()
-	w.RunOnce(ctx)
-
-	deps.resolver.mu.Lock()
-	deps.resolver.allRecords["www.example.com"] = map[string]map[string][]string{
-		"ns1.example.com.": {"A": {"93.184.216.35"}},
-	}
-	deps.resolver.ipAddresses["www.example.com"] = []string{
-		"93.184.216.35",
-	}
-	deps.resolver.mu.Unlock()
-
-	deps.portChecker.mu.Lock()
-	deps.portChecker.results["93.184.216.35:80"] = false
-	deps.portChecker.results["93.184.216.35:443"] = false
-	deps.portChecker.mu.Unlock()
-
-	w.RunOnce(ctx)
-
-	notifications := deps.notifier.getNotifications()
-	if len(notifications) == 0 {
-		t.Error("expected notification for record change")
-	}
-}
-
-func TestPortStateChange(t *testing.T) {
-	t.Parallel()
-
-	cfg := defaultTestConfig(t)
-	cfg.Hostnames = []string{"www.example.com"}
-
-	w, deps := newTestWatcher(t, cfg)
-
-	deps.resolver.allRecords["www.example.com"] = map[string]map[string][]string{
-		"ns1.example.com.": {"A": {"1.2.3.4"}},
-	}
-	deps.resolver.ipAddresses["www.example.com"] = []string{
-		"1.2.3.4",
-	}
-	deps.portChecker.results["1.2.3.4:80"] = true
-	deps.portChecker.results["1.2.3.4:443"] = true
-	deps.tlsChecker.certs["1.2.3.4:www.example.com"] = &tlscheck.CertificateInfo{
-		CommonName: "www.example.com",
-		Issuer:     "DigiCert",
-		NotAfter:   time.Now().Add(90 * 24 * time.Hour),
-		SubjectAlternativeNames: []string{
-			"www.example.com",
-		},
-	}
-
-	ctx := t.Context()
-	w.RunOnce(ctx)
-
-	deps.portChecker.mu.Lock()
-	deps.portChecker.results["1.2.3.4:443"] = false
-	deps.portChecker.mu.Unlock()
-
-	w.RunOnce(ctx)
-
-	notifications := deps.notifier.getNotifications()
-	if len(notifications) == 0 {
-		t.Error("expected notification for port state change")
-	}
-}
-
-func TestTLSExpiryWarning(t *testing.T) {
-	t.Parallel()
-
-	cfg := defaultTestConfig(t)
-	cfg.Hostnames = []string{"www.example.com"}
-
-	w, deps := newTestWatcher(t, cfg)
-
-	deps.resolver.allRecords["www.example.com"] = map[string]map[string][]string{
-		"ns1.example.com.": {"A": {"1.2.3.4"}},
-	}
-	deps.resolver.ipAddresses["www.example.com"] = []string{
-		"1.2.3.4",
-	}
-	deps.portChecker.results["1.2.3.4:80"] = true
-	deps.portChecker.results["1.2.3.4:443"] = true
-	deps.tlsChecker.certs["1.2.3.4:www.example.com"] = &tlscheck.CertificateInfo{
-		CommonName: "www.example.com",
-		Issuer:     "DigiCert",
-		NotAfter:   time.Now().Add(3 * 24 * time.Hour),
-		SubjectAlternativeNames: []string{
-			"www.example.com",
-		},
-	}
-
-	ctx := t.Context()
-
-	// First run = baseline
-	w.RunOnce(ctx)
-
-	// Second run should warn about expiry
-	w.RunOnce(ctx)
-
-	notifications := deps.notifier.getNotifications()
-
-	found := false
-
-	for _, n := range notifications {
-		if n.Priority == "warning" {
-			found = true
-		}
-	}
-
-	if !found {
-		t.Errorf(
-			"expected expiry warning, got: %v",
-			notifications,
-		)
-	}
-}
-
-func TestGracefulShutdown(t *testing.T) {
-	t.Parallel()
-
-	cfg := defaultTestConfig(t)
-	cfg.Domains = []string{"example.com"}
-	cfg.DNSInterval = 100 * time.Millisecond
-	cfg.TLSInterval = 100 * time.Millisecond
-
-	w, deps := newTestWatcher(t, cfg)
-
-	deps.resolver.nsRecords["example.com"] = []string{
-		"ns1.example.com.",
-	}
-
-	ctx, cancel := context.WithCancel(t.Context())
-
-	done := make(chan struct{})
-
-	go func() {
-		w.Run(ctx)
-		close(done)
-	}()
-
-	time.Sleep(250 * time.Millisecond)
-	cancel()
-
-	select {
-	case <-done:
-		// Shut down cleanly
-	case <-time.After(5 * time.Second):
-		t.Error("watcher did not shut down within timeout")
-	}
-}
-
-func TestNSFailureAndRecovery(t *testing.T) {
-	t.Parallel()
-
-	cfg := defaultTestConfig(t)
-	cfg.Hostnames = []string{"www.example.com"}
-
-	w, deps := newTestWatcher(t, cfg)
-
-	deps.resolver.allRecords["www.example.com"] = map[string]map[string][]string{
-		"ns1.example.com.": {"A": {"1.2.3.4"}},
-		"ns2.example.com.": {"A": {"1.2.3.4"}},
-	}
-	deps.resolver.ipAddresses["www.example.com"] = []string{
-		"1.2.3.4",
-	}
-	deps.portChecker.results["1.2.3.4:80"] = false
-	deps.portChecker.results["1.2.3.4:443"] = false
-
-	ctx := t.Context()
-
-	w.RunOnce(ctx)
-
-	deps.resolver.mu.Lock()
-	deps.resolver.allRecords["www.example.com"] = map[string]map[string][]string{
-		"ns1.example.com.": {"A": {"1.2.3.4"}},
-	}
-	deps.resolver.mu.Unlock()
-
-	w.RunOnce(ctx)
-
-	notifications := deps.notifier.getNotifications()
-	if len(notifications) == 0 {
-		t.Error("expected notification for NS disappearance")
-	}
-}