package controller

import (
	"context"
	"net/http/httptest"

	. "github.com/onsi/ginkgo/v2"
	. "github.com/onsi/gomega"
	"k8s.io/apimachinery/pkg/api/meta"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/types"
	"sigs.k8s.io/controller-runtime/pkg/reconcile"

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

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

	var (
		reconciler *TerdutDeadmanSwitchReconciler
		fake       *fakeTerdutServer
		fakeSrv    *httptest.Server
		srv        *terdutv1alpha1.TerdutServer
		team       *terdutv1alpha1.TerdutTeam
		swName     string
		swKey      types.NamespacedName
	)

	BeforeEach(func(ctx SpecContext) {
		fake, fakeSrv = newFakeTerdutServer()
		DeferCleanup(fakeSrv.Close)

		srv = bootstrapReadyTerdutServer(ctx, uniqueName("dmserver"), fakeSrv.URL)
		team = readyTerdutTeam(ctx, operatorNamespace, uniqueName("dmteam"), srv, fakeSrv.URL)

		reconciler = &TerdutDeadmanSwitchReconciler{
			Client:            k8sClient,
			Scheme:            k8sClient.Scheme(),
			OperatorNamespace: operatorNamespace,
			NewClient:         func(string) *tdclient.Client { return tdclient.New(fakeSrv.URL) },
		}
		swName = uniqueName("switch")
		swKey = types.NamespacedName{Name: swName, Namespace: operatorNamespace}
	})

	AfterEach(func(ctx SpecContext) {
		sw := &terdutv1alpha1.TerdutDeadmanSwitch{}
		if err := k8sClient.Get(ctx, swKey, sw); err == nil {
			sw.Finalizers = nil
			_ = k8sClient.Update(ctx, sw)
			_ = k8sClient.Delete(ctx, sw)
		}

		teamKey := types.NamespacedName{Name: team.Name, Namespace: operatorNamespace}
		if err := k8sClient.Get(ctx, teamKey, team); err == nil {
			team.Finalizers = nil
			_ = k8sClient.Update(ctx, team)
			_ = k8sClient.Delete(ctx, team)
		}

		srvKey := types.NamespacedName{Name: srv.Name, Namespace: operatorNamespace}
		if err := k8sClient.Get(ctx, srvKey, srv); err == nil {
			srv.Finalizers = nil
			_ = k8sClient.Update(ctx, srv)
			_ = k8sClient.Delete(ctx, srv)
		}
	})

	createSwitch := func(ctx context.Context, teamRef terdutv1alpha1.TerdutTeamRef, name, matcher, timeout string) {
		sw := &terdutv1alpha1.TerdutDeadmanSwitch{
			ObjectMeta: metav1.ObjectMeta{Name: swName, Namespace: operatorNamespace},
			Spec: terdutv1alpha1.TerdutDeadmanSwitchSpec{
				TeamRef: teamRef,
				Name:    name,
				Matcher: matcher,
				Timeout: timeout,
			},
		}
		Expect(k8sClient.Create(ctx, sw)).To(Succeed())
	}

	reconcileOnce := func(ctx context.Context) {
		_, err := reconciler.Reconcile(ctx, reconcile.Request{NamespacedName: swKey})
		Expect(err).NotTo(HaveOccurred())
	}

	readyCondition := func(ctx context.Context) metav1.Condition {
		sw := &terdutv1alpha1.TerdutDeadmanSwitch{}
		Expect(k8sClient.Get(ctx, swKey, sw)).To(Succeed())
		c := meta.FindStatusCondition(sw.Status.Conditions, terdutv1alpha1.ConditionReady)
		Expect(c).NotTo(BeNil())
		return *c
	}

	sameTeamRef := func() terdutv1alpha1.TerdutTeamRef {
		return terdutv1alpha1.TerdutTeamRef{Name: team.Name}
	}

	Describe("the happy path", func() {
		It("creates the switch server-side", func(ctx SpecContext) {
			createSwitch(ctx, sameTeamRef(), "heartbeat", "alertname=Watchdog", "15m")
			reconcileOnce(ctx) // finalizer
			reconcileOnce(ctx) // create

			cond := readyCondition(ctx)
			Expect(cond.Status).To(Equal(metav1.ConditionTrue))
			Expect(cond.Reason).To(Equal(terdutv1alpha1.ReasonChildAdopted))

			sw := &terdutv1alpha1.TerdutDeadmanSwitch{}
			Expect(k8sClient.Get(ctx, swKey, sw)).To(Succeed())
			Expect(sw.Status.SwitchID).NotTo(BeZero())

			created, ok := fake.switches[team.Status.TeamID][sw.Status.SwitchID]
			Expect(ok).To(BeTrue())
			Expect(created.Matcher).To(Equal("alertname=Watchdog"))
			Expect(created.TimeoutSeconds).To(Equal(int64(900)))
			Expect(created.Severity).To(Equal("critical")) // kubebuilder default
		})
	})

	Describe("list-and-match-by-name adoption", func() {
		It("adopts an already-created switch instead of creating a duplicate", func(ctx SpecContext) {
			// Simulates a prior, interrupted reconcile that got as far as
			// POSTing the switch -- no 409 signal exists for this resource
			// (DESIGN.md §4.4), so the recovery path is GET-list-and-match,
			// not adopt-on-409.
			fake.nextSwitchID = 1
			fake.switches[team.Status.TeamID] = map[int64]tdclient.DeadmanSwitch{
				1: {ID: 1, Name: "heartbeat", Matcher: "alertname=Watchdog", TimeoutSeconds: 900, Severity: "critical"},
			}

			createSwitch(ctx, sameTeamRef(), "heartbeat", "alertname=Watchdog", "15m")
			reconcileOnce(ctx) // finalizer
			reconcileOnce(ctx)

			sw := &terdutv1alpha1.TerdutDeadmanSwitch{}
			Expect(k8sClient.Get(ctx, swKey, sw)).To(Succeed())
			Expect(sw.Status.SwitchID).To(Equal(int64(1)))
			Expect(fake.switches[team.Status.TeamID]).To(HaveLen(1), "should not have created a second switch")
		})
	})

	Describe("update-in-place on spec drift", func() {
		It("PUTs the new spec rather than creating a second switch", func(ctx SpecContext) {
			createSwitch(ctx, sameTeamRef(), "heartbeat", "alertname=Watchdog", "15m")
			reconcileOnce(ctx) // finalizer
			reconcileOnce(ctx)
			Expect(readyCondition(ctx).Status).To(Equal(metav1.ConditionTrue))

			sw := &terdutv1alpha1.TerdutDeadmanSwitch{}
			Expect(k8sClient.Get(ctx, swKey, sw)).To(Succeed())
			switchID := sw.Status.SwitchID

			sw.Spec.Timeout = "30m"
			Expect(k8sClient.Update(ctx, sw)).To(Succeed())
			reconcileOnce(ctx)

			Expect(fake.switches[team.Status.TeamID]).To(HaveLen(1), "update-in-place, not a second switch")
			Expect(fake.switches[team.Status.TeamID][switchID].TimeoutSeconds).To(Equal(int64(1800)))
		})
	})

	Describe("waiting on the referenced TerdutTeam", func() {
		It("reports TeamRefNotFound when the TerdutTeam doesn't exist", func(ctx SpecContext) {
			createSwitch(ctx, terdutv1alpha1.TerdutTeamRef{Name: testRefNotFoundName}, "heartbeat", "alertname=Watchdog", "15m")
			reconcileOnce(ctx) // finalizer
			reconcileOnce(ctx)

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

		It("reports WaitingForTeam when the TerdutTeam exists but isn't Ready yet", func(ctx SpecContext) {
			unreadyName := uniqueName("dmteam-unready")
			unready := &terdutv1alpha1.TerdutTeam{
				ObjectMeta: metav1.ObjectMeta{Name: unreadyName, Namespace: operatorNamespace},
				Spec: terdutv1alpha1.TerdutTeamSpec{
					ServerRef:   terdutv1alpha1.TerdutServerRef{Name: srv.Name},
					DisplayName: testUnreadyDisplayName,
				},
			}
			Expect(k8sClient.Create(ctx, unready)).To(Succeed())
			DeferCleanup(func() { _ = k8sClient.Delete(ctx, unready) })

			createSwitch(ctx, terdutv1alpha1.TerdutTeamRef{Name: unreadyName}, "heartbeat", "alertname=Watchdog", "15m")
			reconcileOnce(ctx) // finalizer
			reconcileOnce(ctx)

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

	Describe("deletion", func() {
		It("deletes the switch server-side (the real DELETE this resource has) and removes the finalizer", func(ctx SpecContext) {
			createSwitch(ctx, sameTeamRef(), "heartbeat", "alertname=Watchdog", "15m")
			reconcileOnce(ctx)
			reconcileOnce(ctx)
			Expect(readyCondition(ctx).Status).To(Equal(metav1.ConditionTrue))

			sw := &terdutv1alpha1.TerdutDeadmanSwitch{}
			Expect(k8sClient.Get(ctx, swKey, sw)).To(Succeed())
			switchID := sw.Status.SwitchID

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

			Expect(fake.switchDelete[switchID]).To(BeTrue())
			err := k8sClient.Get(ctx, swKey, sw)
			Expect(err).To(HaveOccurred(), "the TerdutDeadmanSwitch itself should be gone once the finalizer clears")
		})
	})
})