package controller

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"strconv"
	"strings"
	"sync"
	"time"

	. "github.com/onsi/ginkgo/v2"
	. "github.com/onsi/gomega"
	appsv1 "k8s.io/api/apps/v1"
	corev1 "k8s.io/api/core/v1"
	policyv1 "k8s.io/api/policy/v1"
	apierrors "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/api/meta"
	"k8s.io/apimachinery/pkg/api/resource"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
	"k8s.io/apimachinery/pkg/types"
	"k8s.io/apimachinery/pkg/util/intstr"
	ctrl "sigs.k8s.io/controller-runtime"
	"sigs.k8s.io/controller-runtime/pkg/reconcile"

	terdutv1alpha1 "git.ryuvia.com/niklas/terdut-operator/api/v1alpha1"
	"git.ryuvia.com/niklas/terdut-operator/internal/tdclient"
)

// fakeVersionString/errJSONKey are shared by every response fakeTerdutServer
// writes -- goconst would otherwise flag "test" and "error" as repeated
// literals across its handlers.
const (
	fakeVersionString = "test"
	errJSONKey        = "error"
	// deadmanSwitchesPath is the literal path (not Printf'd like the others
	// below) shared by the exact-match collection route and the dispatcher
	// that routes into it -- goconst flags three occurrences of the same
	// string, so this is that string, once.
	deadmanSwitchesPath = "/deadman/switches"
)

// fakeTerdutServer reproduces the exact stateful semantics of
// /api/bootstrap, /api/service-accounts and /api/version that the
// bootstrap flow depends on (DESIGN.md §6, §11: "terdut-server's REST API
// is faked with a small httptest.Server per controller test ... matching
// the real handlers' request/response shapes"), including the 403-after-
// first-success and 409-on-name-conflict behavior the adopt-on-conflict
// recovery path exists for.
type fakeTerdutServer struct {
	mu           sync.Mutex
	bootstrapped bool
	bootstrap403 bool // force every /api/bootstrap call to 403, even the first
	nextID       int64
	accounts     map[string]int64 // name -> id
	keyMints     map[int64]int    // id -> number of keys minted so far

	nextTeamID int64
	teams      map[string]int64 // name -> id
	teamNames  map[int64]string // id -> current name (renames update this)
	teamOIDC   map[int64][2]string
	teamDelete map[int64]bool // id -> true once DELETEd, for 404-on-redelete

	// users backs GET /api/users for TerdutEscalationRule's username
	// resolution (DESIGN.md §4.3) -- a fixed, pre-seeded directory, since
	// nothing in this controller's own flow ever creates a user.
	users map[string]int64 // username -> id

	// escalation backs PUT /api/teams/{id}/escalation -- an upsert
	// server-side (confirmed against source), so this is just "the last
	// body PUT for this team", keyed by teamID, with no separate create
	// step to model.
	escalation map[int64]tdclient.SetEscalationRequest

	// switches/nextSwitchID/switchDelete back the dead man's switch
	// endpoints -- no unique-name constraint server-side (DESIGN.md §4.4),
	// so switches is keyed by id, not name, same as the real API's own
	// GET-list-and-match-by-name idempotent-create shape requires.
	nextSwitchID int64
	switches     map[int64]map[int64]tdclient.DeadmanSwitch // teamID -> switchID -> switch
	switchDelete map[int64]bool                             // switchID -> true once DELETEd, for 404-on-redelete

	// integrations/nextIntegrationID/integrationDelete back the alert
	// source endpoints -- no unique-name constraint server-side either
	// (DESIGN.md §4.5), same shape as switches, keyed by id.
	nextIntegrationID int64
	integrations      map[int64]map[int64]tdclient.Integration // teamID -> integrationID -> integration
	integrationDelete map[int64]bool                           // integrationID -> true once DELETEd, for 404-on-redelete

	// invites/nextInviteID/inviteDelete back TerdutTeam's own invite-minting
	// feature -- no unique constraint on an invite server-side either (every
	// POST mints a brand new row, confirmed against source), same keyed-by-id
	// shape as switches/integrations.
	nextInviteID int64
	invites      map[int64]map[int64]tdclient.Invite // teamID -> inviteID -> invite
	inviteDelete map[int64]bool                      // inviteID -> true once DELETEd, for 404-on-redelete
}

func newFakeTerdutServer() (*fakeTerdutServer, *httptest.Server) {
	f := &fakeTerdutServer{
		accounts:     map[string]int64{},
		keyMints:     map[int64]int{},
		teams:        map[string]int64{},
		teamNames:    map[int64]string{},
		teamOIDC:     map[int64][2]string{},
		teamDelete:   map[int64]bool{},
		users:        map[string]int64{},
		escalation:   map[int64]tdclient.SetEscalationRequest{},
		switches:     map[int64]map[int64]tdclient.DeadmanSwitch{},
		switchDelete: map[int64]bool{},

		integrations:      map[int64]map[int64]tdclient.Integration{},
		integrationDelete: map[int64]bool{},

		invites:      map[int64]map[int64]tdclient.Invite{},
		inviteDelete: map[int64]bool{},
	}
	return f, httptest.NewServer(f)
}

// seedUser registers a username the fake GET /api/users will return --
// called from test setup, before the controller under test ever runs.
// Callers read the assigned id back from f.users themselves, so this has
// nothing left to return.
func (f *fakeTerdutServer) seedUser(username string) {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.nextID++
	f.users[username] = f.nextID
}

func (f *fakeTerdutServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	f.mu.Lock()
	defer f.mu.Unlock()

	switch {
	case r.URL.Path == "/api/version":
		writeJSON(w, http.StatusOK, map[string]string{"version": fakeVersionString})

	case r.URL.Path == "/api/bootstrap" && r.Method == http.MethodPost:
		if f.bootstrapped || f.bootstrap403 {
			writeJSON(w, http.StatusForbidden, map[string]string{errJSONKey: "bootstrap already completed"})
			return
		}
		f.bootstrapped = true
		writeJSON(w, http.StatusCreated, tdclient.BootstrapResult{
			APIKey: tdclient.APIKey{ID: 1, Name: "bootstrap", Key: "admin-key-raw"},
		})

	case r.URL.Path == "/api/service-accounts" && r.Method == http.MethodPost:
		var req struct {
			Name  string `json:"name"`
			Scope string `json:"scope"`
		}
		_ = json.NewDecoder(r.Body).Decode(&req)
		if _, exists := f.accounts[req.Name]; exists {
			writeJSON(w, http.StatusConflict, map[string]string{errJSONKey: "a service account with that name already exists"})
			return
		}
		f.nextID++
		id := f.nextID
		f.accounts[req.Name] = id
		f.keyMints[id] = 1
		writeJSON(w, http.StatusCreated, tdclient.CreateServiceAccountResult{
			ServiceAccount: tdclient.ServiceAccount{ID: id, Name: req.Name, Scope: req.Scope},
			Key:            tdclient.APIKey{ID: 1, Name: "initial", Key: fmt.Sprintf("instance-key-%d-initial", id)},
		})

	case r.URL.Path == "/api/service-accounts" && r.Method == http.MethodGet:
		name := r.URL.Query().Get("name")
		id, exists := f.accounts[name]
		if !exists {
			writeJSON(w, http.StatusOK, []tdclient.ServiceAccount{})
			return
		}
		writeJSON(w, http.StatusOK, []tdclient.ServiceAccount{{ID: id, Name: name, Scope: "instance"}})

	case r.URL.Path == "/api/teams" && r.Method == http.MethodPost:
		var req struct {
			Name string `json:"name"`
		}
		_ = json.NewDecoder(r.Body).Decode(&req)
		if _, exists := f.teams[req.Name]; exists {
			writeJSON(w, http.StatusConflict, map[string]string{errJSONKey: "a team with that name already exists"})
			return
		}
		f.nextTeamID++
		id := f.nextTeamID
		f.teams[req.Name] = id
		f.teamNames[id] = req.Name
		writeJSON(w, http.StatusCreated, tdclient.Team{ID: id, Name: req.Name})

	case r.URL.Path == "/api/teams" && r.Method == http.MethodGet:
		// The controller never calls this without ?name= (TEAM-LOOKUP.md's
		// own lookup shape) -- the fake only needs to answer that form.
		name := r.URL.Query().Get("name")
		id, exists := f.teams[name]
		if !exists {
			writeJSON(w, http.StatusOK, []tdclient.Team{})
			return
		}
		writeJSON(w, http.StatusOK, []tdclient.Team{{ID: id, Name: f.teamNames[id]}})

	case r.URL.Path == "/api/users" && r.Method == http.MethodGet:
		// No query filter -- GetUserByUsername fetches the whole list and
		// matches client-side (confirmed against source: no server-side
		// filter either), so the fake does the same.
		users := make([]tdclient.User, 0, len(f.users))
		for name, id := range f.users {
			users = append(users, tdclient.User{ID: id, Username: name})
		}
		writeJSON(w, http.StatusOK, users)

	default:
		if id, name, ok := parseKeysPath(r.URL.Path); ok && r.Method == http.MethodPost {
			f.keyMints[id]++
			writeJSON(w, http.StatusCreated, tdclient.APIKey{
				ID: int64(f.keyMints[id]), Name: name,
				Key: fmt.Sprintf("instance-key-%d-mint%d", id, f.keyMints[id]),
			})
			return
		}
		if id, rest, ok := parseTeamSubPath(r.URL.Path); ok {
			f.handleTeamSubPath(w, r, id, rest)
			return
		}
		w.WriteHeader(http.StatusNotFound)
	}
}

// handleTeamSubPath answers everything under /api/teams/{id}: PUT (rename),
// DELETE, PUT .../oidc-groups, PUT .../escalation, and the dead man's
// switch collection/item endpoints. rest is whatever parseTeamSubPath found
// after "/api/teams/{id}" -- "" for the bare resource.
func (f *fakeTerdutServer) handleTeamSubPath(w http.ResponseWriter, r *http.Request, id int64, rest string) {
	switch {
	case rest == "" && r.Method == http.MethodPut:
		var req struct {
			Name string `json:"name"`
		}
		_ = json.NewDecoder(r.Body).Decode(&req)
		oldName, exists := f.teamNames[id]
		if !exists {
			w.WriteHeader(http.StatusNotFound)
			return
		}
		delete(f.teams, oldName)
		f.teamNames[id] = req.Name
		f.teams[req.Name] = id
		w.WriteHeader(http.StatusNoContent)

	case rest == "" && r.Method == http.MethodDelete:
		name, exists := f.teamNames[id]
		if !exists {
			w.WriteHeader(http.StatusNotFound)
			return
		}
		delete(f.teams, name)
		delete(f.teamNames, id)
		f.teamDelete[id] = true
		w.WriteHeader(http.StatusNoContent)

	case rest == "/oidc-groups" && r.Method == http.MethodPut:
		var req struct {
			MemberGroup string `json:"member_group"`
			OwnerGroup  string `json:"owner_group"`
		}
		_ = json.NewDecoder(r.Body).Decode(&req)
		if _, exists := f.teamNames[id]; !exists {
			w.WriteHeader(http.StatusNotFound)
			return
		}
		f.teamOIDC[id] = [2]string{req.MemberGroup, req.OwnerGroup}
		w.WriteHeader(http.StatusNoContent)

	case rest == "/escalation" && r.Method == http.MethodPut:
		var req tdclient.SetEscalationRequest
		_ = json.NewDecoder(r.Body).Decode(&req)
		f.escalation[id] = req
		w.WriteHeader(http.StatusNoContent)

	case rest == deadmanSwitchesPath || strings.HasPrefix(rest, deadmanSwitchesPath+"/"):
		f.handleDeadmanSubPath(w, r, id, rest)

	case rest == "/integrations" || strings.HasPrefix(rest, "/integrations/"):
		f.handleIntegrationSubPath(w, r, id, rest)

	case rest == "/invites" || strings.HasPrefix(rest, "/invites/"):
		f.handleInviteSubPath(w, r, id, rest)

	default:
		w.WriteHeader(http.StatusNotFound)
	}
}

// handleDeadmanSubPath answers GET/POST /api/teams/{id}/deadman/switches and
// PUT/DELETE .../deadman/switches/{switchID} -- split out of
// handleTeamSubPath for the same gocyclo reason as handleIntegrationSubPath.
func (f *fakeTerdutServer) handleDeadmanSubPath(w http.ResponseWriter, r *http.Request, id int64, rest string) {
	switch {
	case rest == deadmanSwitchesPath && r.Method == http.MethodGet:
		existing := f.switches[id]
		out := make([]tdclient.DeadmanSwitch, 0, len(existing))
		for _, s := range existing {
			out = append(out, s)
		}
		writeJSON(w, http.StatusOK, out)

	case rest == deadmanSwitchesPath && r.Method == http.MethodPost:
		var req deadmanSwitchFakeRequest
		_ = json.NewDecoder(r.Body).Decode(&req)
		f.nextSwitchID++
		switchID := f.nextSwitchID
		name := req.Name
		if name == "" {
			name = "derived-" + req.Matcher
		}
		sw := tdclient.DeadmanSwitch{
			ID: switchID, Name: name, Matcher: req.Matcher,
			TimeoutSeconds: req.TimeoutSeconds, Severity: req.Severity,
		}
		if f.switches[id] == nil {
			f.switches[id] = map[int64]tdclient.DeadmanSwitch{}
		}
		f.switches[id][switchID] = sw
		writeJSON(w, http.StatusCreated, sw)

	case strings.HasPrefix(rest, "/deadman/switches/") && r.Method == http.MethodPut:
		switchID, ok := parseTrailingID(rest, "/deadman/switches/")
		if !ok {
			w.WriteHeader(http.StatusNotFound)
			return
		}
		if _, exists := f.switches[id][switchID]; !exists {
			w.WriteHeader(http.StatusNotFound)
			return
		}
		var req deadmanSwitchFakeRequest
		_ = json.NewDecoder(r.Body).Decode(&req)
		name := req.Name
		if name == "" {
			name = f.switches[id][switchID].Name
		}
		f.switches[id][switchID] = tdclient.DeadmanSwitch{
			ID: switchID, Name: name, Matcher: req.Matcher,
			TimeoutSeconds: req.TimeoutSeconds, Severity: req.Severity,
		}
		w.WriteHeader(http.StatusNoContent)

	case strings.HasPrefix(rest, "/deadman/switches/") && r.Method == http.MethodDelete:
		switchID, ok := parseTrailingID(rest, "/deadman/switches/")
		if !ok {
			w.WriteHeader(http.StatusNotFound)
			return
		}
		if _, exists := f.switches[id][switchID]; !exists {
			w.WriteHeader(http.StatusNotFound)
			return
		}
		delete(f.switches[id], switchID)
		f.switchDelete[switchID] = true
		w.WriteHeader(http.StatusNoContent)

	default:
		w.WriteHeader(http.StatusNotFound)
	}
}

// handleInviteSubPath answers POST /api/teams/{id}/invites and
// DELETE .../invites/{inviteID} -- split out for the same gocyclo reason as
// handleIntegrationSubPath.
func (f *fakeTerdutServer) handleInviteSubPath(w http.ResponseWriter, r *http.Request, id int64, rest string) {
	switch {
	case rest == "/invites" && r.Method == http.MethodPost:
		var req struct {
			Role    string `json:"role"`
			MaxUses int64  `json:"max_uses"`
		}
		_ = json.NewDecoder(r.Body).Decode(&req)
		f.nextInviteID++
		inviteID := f.nextInviteID
		inv := tdclient.Invite{
			ID: inviteID, TeamID: id, Role: req.Role, MaxUses: req.MaxUses,
			ExpiresAt: time.Now().Add(7 * 24 * time.Hour),
			URL:       fmt.Sprintf("https://terdut.example.invalid/signup?invite=invite-token-%d", inviteID),
		}
		if f.invites[id] == nil {
			f.invites[id] = map[int64]tdclient.Invite{}
		}
		f.invites[id][inviteID] = inv
		writeJSON(w, http.StatusCreated, inv)

	case strings.HasPrefix(rest, "/invites/") && r.Method == http.MethodDelete:
		inviteID, ok := parseTrailingID(rest, "/invites/")
		if !ok {
			w.WriteHeader(http.StatusNotFound)
			return
		}
		if _, exists := f.invites[id][inviteID]; !exists {
			w.WriteHeader(http.StatusNotFound)
			return
		}
		delete(f.invites[id], inviteID)
		f.inviteDelete[inviteID] = true
		w.WriteHeader(http.StatusNoContent)

	default:
		w.WriteHeader(http.StatusNotFound)
	}
}

// handleIntegrationSubPath answers POST /api/teams/{id}/integrations,
// PATCH .../integrations/{integrationID} and DELETE .../integrations/{integrationID}
// -- split out of handleTeamSubPath so that switch's own cyclomatic
// complexity stays under golangci-lint's gocyclo threshold.
func (f *fakeTerdutServer) handleIntegrationSubPath(w http.ResponseWriter, r *http.Request, id int64, rest string) {
	switch {
	case rest == "/integrations" && r.Method == http.MethodPost:
		var req struct {
			Name string `json:"name"`
			Kind string `json:"kind"`
		}
		_ = json.NewDecoder(r.Body).Decode(&req)
		f.nextIntegrationID++
		integID := f.nextIntegrationID
		integ := tdclient.Integration{
			ID: integID, TeamID: id, Kind: req.Kind, Name: req.Name,
			// Key/URL are only ever in *this* response -- never again,
			// matching terdut-server's own one-time-show semantics
			// (DESIGN.md §4.5) -- so what's stored for later GET/PATCH
			// calls in this fake deliberately omits them too.
			Key: fmt.Sprintf("webhook-key-%d", integID),
			URL: fmt.Sprintf("https://terdut.example.invalid/api/integrations/webhook-key-%d/%s", integID, req.Kind),
		}
		if f.integrations[id] == nil {
			f.integrations[id] = map[int64]tdclient.Integration{}
		}
		f.integrations[id][integID] = tdclient.Integration{ID: integID, TeamID: id, Kind: req.Kind, Name: req.Name}
		writeJSON(w, http.StatusCreated, integ)

	case strings.HasPrefix(rest, "/integrations/") && r.Method == http.MethodPatch:
		integID, ok := parseTrailingID(rest, "/integrations/")
		if !ok {
			w.WriteHeader(http.StatusNotFound)
			return
		}
		existing, exists := f.integrations[id][integID]
		if !exists {
			w.WriteHeader(http.StatusNotFound)
			return
		}
		var req struct {
			Name string `json:"name"`
		}
		_ = json.NewDecoder(r.Body).Decode(&req)
		existing.Name = req.Name
		f.integrations[id][integID] = existing
		w.WriteHeader(http.StatusNoContent)

	case strings.HasPrefix(rest, "/integrations/") && r.Method == http.MethodDelete:
		integID, ok := parseTrailingID(rest, "/integrations/")
		if !ok {
			w.WriteHeader(http.StatusNotFound)
			return
		}
		if _, exists := f.integrations[id][integID]; !exists {
			w.WriteHeader(http.StatusNotFound)
			return
		}
		delete(f.integrations[id], integID)
		f.integrationDelete[integID] = true
		w.WriteHeader(http.StatusNoContent)

	default:
		w.WriteHeader(http.StatusNotFound)
	}
}

// deadmanSwitchFakeRequest mirrors tdclient's own (unexported)
// deadmanSwitchRequest -- the fake needs its own copy to decode the same
// wire shape without reaching across package boundaries for an internal type.
type deadmanSwitchFakeRequest struct {
	Name           string `json:"name,omitempty"`
	Matcher        string `json:"matcher"`
	TimeoutSeconds int64  `json:"timeout_seconds"`
	Severity       string `json:"severity"`
}

// parseTeamSubPath splits "/api/teams/{id}" from anything after it --
// "" for an exact match, "/oidc-groups", "/escalation", "/deadman/switches"
// or "/deadman/switches/{switchID}" otherwise. Doesn't itself validate the
// suffix; handleTeamSubPath's own switch does that.
func parseTeamSubPath(path string) (id int64, rest string, ok bool) {
	const prefix = "/api/teams/"
	if !strings.HasPrefix(path, prefix) {
		return 0, "", false
	}
	trimmed := path[len(prefix):]
	parts := strings.SplitN(trimmed, "/", 2)
	parsedID, err := strconv.ParseInt(parts[0], 10, 64)
	if err != nil {
		return 0, "", false
	}
	if len(parts) == 1 {
		return parsedID, "", true
	}
	return parsedID, "/" + parts[1], true
}

// parseTrailingID parses the numeric id after prefix within rest, e.g.
// parseTrailingID("/deadman/switches/7", "/deadman/switches/") -> 7, true.
func parseTrailingID(rest, prefix string) (id int64, ok bool) {
	parsedID, err := strconv.ParseInt(strings.TrimPrefix(rest, prefix), 10, 64)
	if err != nil {
		return 0, false
	}
	return parsedID, true
}

func parseKeysPath(path string) (id int64, mintName string, ok bool) {
	var parsedID int64
	n, err := fmt.Sscanf(path, "/api/service-accounts/%d/keys", &parsedID)
	if err != nil || n != 1 {
		return 0, "", false
	}
	return parsedID, "minted", true
}

func writeJSON(w http.ResponseWriter, status int, v any) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	_ = json.NewEncoder(w).Encode(v)
}

var _ = Describe("TerdutServer Controller", func() {
	const operatorNamespace = "default"

	var (
		reconciler *TerdutServerReconciler
		name       string
		objKey     types.NamespacedName
	)

	BeforeEach(func() {
		reconciler = &TerdutServerReconciler{
			Client:            k8sClient,
			Scheme:            k8sClient.Scheme(),
			OperatorNamespace: operatorNamespace,
		}
		name = fmt.Sprintf("test-server-%d-%d", GinkgoRandomSeed(), GinkgoParallelProcess())
		objKey = types.NamespacedName{Name: name, Namespace: operatorNamespace}
	})

	AfterEach(func(ctx SpecContext) {
		srv := &terdutv1alpha1.TerdutServer{}
		if err := k8sClient.Get(ctx, objKey, srv); err == nil {
			srv.Finalizers = nil
			_ = k8sClient.Update(ctx, srv)
			_ = k8sClient.Delete(ctx, srv)
		}
		for _, n := range []string{checkpointSecretNameFor(name), credentialsSecretNameFor(name)} {
			_ = k8sClient.Delete(ctx, &corev1.Secret{ObjectMeta: metav1.ObjectMeta{Name: n, Namespace: operatorNamespace}})
		}
	})

	dsnSpec := func() terdutv1alpha1.TerdutServerSpec {
		return terdutv1alpha1.TerdutServerSpec{
			Image:      terdutv1alpha1.ImageSpec{Repository: testImageRepo, Tag: testImageTag},
			Networking: terdutv1alpha1.NetworkingSpec{Hostname: "terdut.example.invalid", ServicePort: 8080},
			Database:   terdutv1alpha1.DatabaseSpec{DSN: testDSN},
		}
	}

	createServer := func(ctx context.Context, spec terdutv1alpha1.TerdutServerSpec) {
		srv := &terdutv1alpha1.TerdutServer{
			ObjectMeta: metav1.ObjectMeta{Name: name, Namespace: operatorNamespace},
			Spec:       spec,
		}
		Expect(k8sClient.Create(ctx, srv)).To(Succeed())
	}

	reconcileOnce := func(ctx context.Context) ctrl.Result {
		res, err := reconciler.Reconcile(ctx, reconcile.Request{NamespacedName: objKey})
		Expect(err).NotTo(HaveOccurred())
		return res
	}

	markDeploymentReady := func(ctx context.Context) {
		var deploy appsv1.Deployment
		Expect(k8sClient.Get(ctx, objKey, &deploy)).To(Succeed())
		deploy.Status.ReadyReplicas = 1
		deploy.Status.Replicas = 1
		Expect(k8sClient.Status().Update(ctx, &deploy)).To(Succeed())
	}

	readyCondition := func(ctx context.Context) metav1.Condition {
		srv := &terdutv1alpha1.TerdutServer{}
		Expect(k8sClient.Get(ctx, objKey, srv)).To(Succeed())
		c := meta.FindStatusCondition(srv.Status.Conditions, terdutv1alpha1.ConditionReady)
		Expect(c).NotTo(BeNil(), "Ready condition should always be set after a reconcile past the finalizer-add pass")
		return *c
	}

	Describe("bring-your-own DSN path", func() {
		It("reaches Ready through the full lifecycle: finalizer, Deployment/Service, wait, bootstrap", func(ctx SpecContext) {
			fake, fakeSrv := newFakeTerdutServer()
			DeferCleanup(fakeSrv.Close)
			reconciler.NewClient = func(string) *tdclient.Client { return tdclient.New(fakeSrv.URL) }

			createServer(ctx, dsnSpec())

			// Pass 1: adds the finalizer and returns early.
			reconcileOnce(ctx)
			srv := &terdutv1alpha1.TerdutServer{}
			Expect(k8sClient.Get(ctx, objKey, srv)).To(Succeed())
			Expect(srv.Finalizers).To(ContainElement(finalizerName))

			// Pass 2: creates Deployment + Service, waits for readiness.
			reconcileOnce(ctx)
			Expect(readyCondition(ctx).Reason).To(Equal(terdutv1alpha1.ReasonWaitingForDeployment))

			var deploy appsv1.Deployment
			Expect(k8sClient.Get(ctx, objKey, &deploy)).To(Succeed())
			Expect(deploy.Spec.Template.Spec.Containers[0].Image).To(Equal("example.invalid/terdut-server:test"))
			envNames := map[string]string{}
			for _, e := range deploy.Spec.Template.Spec.Containers[0].Env {
				envNames[e.Name] = e.Value
			}
			Expect(envNames).To(HaveKeyWithValue("TERDUT_DB_DSN", testDSN))
			Expect(envNames).To(HaveKeyWithValue("TERDUT_OPERATOR_MODE", "true"))

			var svc corev1.Service
			Expect(k8sClient.Get(ctx, objKey, &svc)).To(Succeed())
			Expect(svc.Spec.Ports[0].Port).To(Equal(int32(8080)))

			// Simulate the Deployment becoming ready (envtest has no
			// kubelet/deployment-controller to do this for real).
			markDeploymentReady(ctx)

			// Pass 3: bootstraps for real against the fake server.
			reconcileOnce(ctx)

			Expect(fake.bootstrapped).To(BeTrue())

			Expect(k8sClient.Get(ctx, objKey, srv)).To(Succeed())
			ready := meta.FindStatusCondition(srv.Status.Conditions, terdutv1alpha1.ConditionReady)
			Expect(ready.Status).To(Equal(metav1.ConditionTrue))
			Expect(ready.Reason).To(Equal(terdutv1alpha1.ReasonAdopted))
			Expect(srv.Status.CredentialsSecretRef).NotTo(BeNil())
			Expect(srv.Status.CredentialsSecretRef.Key).To(Equal(credentialsSecretDataKey))

			var credsSecret corev1.Secret
			Expect(k8sClient.Get(ctx, types.NamespacedName{
				Name: srv.Status.CredentialsSecretRef.Name, Namespace: operatorNamespace,
			}, &credsSecret)).To(Succeed())
			Expect(string(credsSecret.Data[credentialsSecretDataKey])).To(Equal("instance-key-1-initial"))

			// The checkpoint is cleaned up once the lasting credential is
			// written (DESIGN.md §6 point 2).
			var checkpoint corev1.Secret
			err := k8sClient.Get(ctx, types.NamespacedName{Name: checkpointSecretName(srv), Namespace: operatorNamespace}, &checkpoint)
			Expect(err).To(HaveOccurred())
		})
	})

	Describe("the adopt-on-409 recovery path", func() {
		It("mints a fresh key instead of erroring when the service account already exists", func(ctx SpecContext) {
			fake, fakeSrv := newFakeTerdutServer()
			DeferCleanup(fakeSrv.Close)
			fake.bootstrapped = true // an earlier attempt already bootstrapped...
			fake.nextID = 1
			fake.accounts[serviceAccountName] = 1 // ...and already created the service account.
			fake.keyMints[1] = 1
			reconciler.NewClient = func(string) *tdclient.Client { return tdclient.New(fakeSrv.URL) }

			createServer(ctx, dsnSpec())
			reconcileOnce(ctx) // finalizer
			reconcileOnce(ctx) // Deployment/Service, WaitingForDeployment
			markDeploymentReady(ctx)

			// The earlier attempt's checkpoint survived (that's how this
			// reconcile can authenticate at all to recover).
			Expect(writeOperatorSecret(ctx, k8sClient, operatorNamespace, checkpointSecretName(&terdutv1alpha1.TerdutServer{
				ObjectMeta: metav1.ObjectMeta{Name: name, Namespace: operatorNamespace},
			}), "admin-key-raw")).To(Succeed())

			reconcileOnce(ctx)

			srv := &terdutv1alpha1.TerdutServer{}
			Expect(k8sClient.Get(ctx, objKey, srv)).To(Succeed())
			Expect(meta.FindStatusCondition(srv.Status.Conditions, terdutv1alpha1.ConditionReady).Status).To(Equal(metav1.ConditionTrue))

			var credsSecret corev1.Secret
			Expect(k8sClient.Get(ctx, types.NamespacedName{
				Name: srv.Status.CredentialsSecretRef.Name, Namespace: operatorNamespace,
			}, &credsSecret)).To(Succeed())
			// Minted fresh, not the (never-seen-by-this-reconcile) "initial"
			// key from the account's original creation.
			Expect(string(credsSecret.Data[credentialsSecretDataKey])).To(Equal("instance-key-1-mint2"))
		})
	})

	Describe("the BootstrapStateLost path", func() {
		It("fails closed when the server reports already-bootstrapped with no checkpoint to recover from", func(ctx SpecContext) {
			fake, fakeSrv := newFakeTerdutServer()
			_ = fake
			DeferCleanup(fakeSrv.Close)
			fake.bootstrap403 = true
			reconciler.NewClient = func(string) *tdclient.Client { return tdclient.New(fakeSrv.URL) }

			createServer(ctx, dsnSpec())
			reconcileOnce(ctx) // finalizer
			reconcileOnce(ctx) // Deployment/Service
			markDeploymentReady(ctx)

			reconcileOnce(ctx)

			cond := readyCondition(ctx)
			Expect(cond.Status).To(Equal(metav1.ConditionFalse))
			Expect(cond.Reason).To(Equal(terdutv1alpha1.ReasonBootstrapStateLost))
		})
	})

	Describe("the Zalando postgresClusterRef path", func() {
		zalandoSpec := func(clusterName string) terdutv1alpha1.TerdutServerSpec {
			s := dsnSpec()
			s.Database = terdutv1alpha1.DatabaseSpec{
				PostgresClusterRef: &terdutv1alpha1.PostgresClusterRef{Name: clusterName},
			}
			return s
		}

		It("waits with reason PostgresClusterNotFound when the postgresql CR doesn't exist yet", func(ctx SpecContext) {
			createServer(ctx, zalandoSpec("missing-cluster"))
			reconcileOnce(ctx) // finalizer
			reconcileOnce(ctx)

			Expect(readyCondition(ctx).Reason).To(Equal(terdutv1alpha1.ReasonPostgresClusterNotFound))
		})

		It("resolves a real DSN and reaches Ready once the CR and its generated Secret both exist", func(ctx SpecContext) {
			clusterName := "pg-" + name
			cluster := &unstructured.Unstructured{}
			cluster.SetGroupVersionKind(postgresqlGVK)
			cluster.SetName(clusterName)
			cluster.SetNamespace(operatorNamespace)
			Expect(unstructured.SetNestedField(cluster.Object, map[string]any{}, "spec")).To(Succeed())
			Expect(k8sClient.Create(ctx, cluster)).To(Succeed())
			DeferCleanup(func() { _ = k8sClient.Delete(ctx, cluster) })

			credsSecretName := fmt.Sprintf("terdut.%s.credentials.postgresql.acid.zalan.do", clusterName)
			zalandoSecret := &corev1.Secret{
				ObjectMeta: metav1.ObjectMeta{Name: credsSecretName, Namespace: operatorNamespace},
				Data:       map[string][]byte{"password": []byte("whatever")},
			}
			Expect(k8sClient.Create(ctx, zalandoSecret)).To(Succeed())
			DeferCleanup(func() { _ = k8sClient.Delete(ctx, zalandoSecret) })

			fake, fakeSrv := newFakeTerdutServer()
			_ = fake
			DeferCleanup(fakeSrv.Close)
			reconciler.NewClient = func(string) *tdclient.Client { return tdclient.New(fakeSrv.URL) }

			createServer(ctx, zalandoSpec(clusterName))
			reconcileOnce(ctx) // finalizer
			reconcileOnce(ctx) // Deployment/Service created with resolved DB env

			var deploy appsv1.Deployment
			Expect(k8sClient.Get(ctx, objKey, &deploy)).To(Succeed())
			var dsn string
			for _, e := range deploy.Spec.Template.Spec.Containers[0].Env {
				if e.Name == "TERDUT_DB_DSN" {
					dsn = e.Value
				}
			}
			Expect(dsn).To(Equal(fmt.Sprintf("postgres://terdut@%s.%s.svc:5432/terdut?sslmode=require", clusterName, operatorNamespace)))

			markDeploymentReady(ctx)
			reconcileOnce(ctx)

			Expect(readyCondition(ctx).Status).To(Equal(metav1.ConditionTrue))
		})
	})

	Describe("spec.pod", func() {
		It("wires pod-level customization onto the right spot on the Deployment", func(ctx SpecContext) {
			fake, fakeSrv := newFakeTerdutServer()
			_ = fake
			DeferCleanup(fakeSrv.Close)
			reconciler.NewClient = func(string) *tdclient.Client { return tdclient.New(fakeSrv.URL) }

			spec := dsnSpec()
			qty := resource.MustParse("250m")
			spec.Pod = terdutv1alpha1.PodSpec{
				Resources:          corev1.ResourceRequirements{Requests: corev1.ResourceList{corev1.ResourceCPU: qty}},
				Tolerations:        []corev1.Toleration{{Key: "dedicated", Operator: corev1.TolerationOpEqual, Value: "terdut", Effect: corev1.TaintEffectNoSchedule}},
				ExtraEnv:           []corev1.EnvVar{{Name: "EXTRA_FLAG", Value: "on"}},
				ServiceAccountName: "terdut-server-custom",
				ExtraVolumes:       []corev1.Volume{{Name: "extra-ca", VolumeSource: corev1.VolumeSource{EmptyDir: &corev1.EmptyDirVolumeSource{}}}},
				ExtraVolumeMounts:  []corev1.VolumeMount{{Name: "extra-ca", MountPath: "/etc/extra-ca"}},
			}
			createServer(ctx, spec)
			reconcileOnce(ctx) // finalizer
			reconcileOnce(ctx) // Deployment/Service/PDB

			var deploy appsv1.Deployment
			Expect(k8sClient.Get(ctx, objKey, &deploy)).To(Succeed())

			podSpec := deploy.Spec.Template.Spec
			Expect(podSpec.Tolerations).To(ConsistOf(spec.Pod.Tolerations))
			Expect(podSpec.ServiceAccountName).To(Equal("terdut-server-custom"))
			Expect(podSpec.Volumes).To(ConsistOf(spec.Pod.ExtraVolumes))

			main := podSpec.Containers[0]
			Expect(main.Name).To(Equal("terdut-server"))
			Expect(main.Resources).To(Equal(spec.Pod.Resources))
			Expect(main.VolumeMounts).To(ConsistOf(spec.Pod.ExtraVolumeMounts))
			Expect(main.Env).To(ContainElement(corev1.EnvVar{Name: "EXTRA_FLAG", Value: "on"}))

			initContainer := podSpec.InitContainers[0]
			Expect(initContainer.Name).To(Equal("wait-for-postgres"))
			Expect(initContainer.VolumeMounts).To(BeEmpty(), "extraVolumeMounts must not leak onto wait-for-postgres")
		})
	})

	Describe("spec.pod.disruptionBudget", func() {
		It("creates an owned PodDisruptionBudget when set, and deletes it once cleared", func(ctx SpecContext) {
			fake, fakeSrv := newFakeTerdutServer()
			_ = fake
			DeferCleanup(fakeSrv.Close)
			reconciler.NewClient = func(string) *tdclient.Client { return tdclient.New(fakeSrv.URL) }

			spec := dsnSpec()
			minAvail := intstr.FromInt32(1)
			spec.Pod.DisruptionBudget = &terdutv1alpha1.PodDisruptionBudgetSpec{MinAvailable: &minAvail}
			createServer(ctx, spec)
			reconcileOnce(ctx) // finalizer
			reconcileOnce(ctx) // Deployment/Service/PDB

			var pdb policyv1.PodDisruptionBudget
			Expect(k8sClient.Get(ctx, objKey, &pdb)).To(Succeed())
			Expect(pdb.Spec.Selector.MatchLabels).To(Equal(labelsFor(&terdutv1alpha1.TerdutServer{ObjectMeta: metav1.ObjectMeta{Name: name}})))
			Expect(pdb.Spec.MinAvailable).To(Equal(&minAvail))
			Expect(pdb.OwnerReferences).To(ContainElement(HaveField("Name", name)))

			srv := &terdutv1alpha1.TerdutServer{}
			Expect(k8sClient.Get(ctx, objKey, srv)).To(Succeed())
			srv.Spec.Pod.DisruptionBudget = nil
			Expect(k8sClient.Update(ctx, srv)).To(Succeed())
			reconcileOnce(ctx)

			err := k8sClient.Get(ctx, objKey, &policyv1.PodDisruptionBudget{})
			Expect(apierrors.IsNotFound(err)).To(BeTrue(), "PodDisruptionBudget should be deleted once spec.pod.disruptionBudget is cleared")
		})

		It("rejects both minAvailable and maxUnavailable set together, and neither set", func(ctx SpecContext) {
			bothSet := dsnSpec()
			minAvail, maxUnavail := intstr.FromInt32(1), intstr.FromInt32(1)
			bothSet.Pod.DisruptionBudget = &terdutv1alpha1.PodDisruptionBudgetSpec{MinAvailable: &minAvail, MaxUnavailable: &maxUnavail}
			Expect(k8sClient.Create(ctx, &terdutv1alpha1.TerdutServer{
				ObjectMeta: metav1.ObjectMeta{Name: name + "-both", Namespace: operatorNamespace},
				Spec:       bothSet,
			})).To(HaveOccurred())

			neitherSet := dsnSpec()
			neitherSet.Pod.DisruptionBudget = &terdutv1alpha1.PodDisruptionBudgetSpec{}
			Expect(k8sClient.Create(ctx, &terdutv1alpha1.TerdutServer{
				ObjectMeta: metav1.ObjectMeta{Name: name + "-neither", Namespace: operatorNamespace},
				Spec:       neitherSet,
			})).To(HaveOccurred())
		})
	})

	Describe("deletion", func() {
		It("removes the credentials and checkpoint Secrets and the finalizer", func(ctx SpecContext) {
			fake, fakeSrv := newFakeTerdutServer()
			_ = fake
			DeferCleanup(fakeSrv.Close)
			reconciler.NewClient = func(string) *tdclient.Client { return tdclient.New(fakeSrv.URL) }

			createServer(ctx, dsnSpec())
			reconcileOnce(ctx)
			reconcileOnce(ctx)
			markDeploymentReady(ctx)
			reconcileOnce(ctx)

			srv := &terdutv1alpha1.TerdutServer{}
			Expect(k8sClient.Get(ctx, objKey, srv)).To(Succeed())
			credsName := srv.Status.CredentialsSecretRef.Name

			Expect(k8sClient.Delete(ctx, srv)).To(Succeed())
			reconcileOnce(ctx) // runs the finalizer

			err := k8sClient.Get(ctx, objKey, srv)
			Expect(err).To(HaveOccurred(), "the TerdutServer itself should be gone once the finalizer clears")

			var leftover corev1.Secret
			err = k8sClient.Get(ctx, types.NamespacedName{Name: credsName, Namespace: operatorNamespace}, &leftover)
			Expect(err).To(HaveOccurred(), "the credentials Secret should have been cleaned up by the finalizer")
		})
	})

	When("the TerdutServer object no longer exists", func() {
		It("returns no error (deleted between enqueue and reconcile)", func(ctx SpecContext) {
			_, err := reconciler.Reconcile(ctx, reconcile.Request{
				NamespacedName: types.NamespacedName{Name: "never-created", Namespace: operatorNamespace},
			})
			Expect(err).NotTo(HaveOccurred())
		})
	})
})

// checkpointSecretNameFor/credentialsSecretNameFor let AfterEach clean up
// without needing a live TerdutServer object (it may already be gone by
// then in the deletion test).
func checkpointSecretNameFor(name string) string {
	return fmt.Sprintf("default.%s-bootstrap-admin", name)
}
func credentialsSecretNameFor(name string) string {
	return fmt.Sprintf("default.%s-instance-credentials", name)
}