//go:build e2e
// +build e2e

/*
Copyright 2026.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package e2e

import (
	"context"
	"crypto/tls"
	"encoding/json"
	"fmt"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"time"

	. "github.com/onsi/ginkgo/v2"
	. "github.com/onsi/gomega"

	"github.com/LMCache/LMCache/test/utils"
)

// namespace where the project is deployed in
const namespace = "lmcache-operator-system"

// serviceAccountName created for the project
const serviceAccountName = "lmcache-operator-controller-manager"

// metricsServiceName is the name of the metrics service of the project
const metricsServiceName = "lmcache-operator-controller-manager-metrics-service"

// metricsRoleBindingName is the name of the RBAC that will be created to allow get the metrics data
const metricsRoleBindingName = "operator-metrics-binding"

var _ = Describe("Manager", Ordered, func() {
	var controllerPodName string

	// Suite-level BeforeSuite (in integration_suite_test.go) handles building/loading
	// the manager image, installing CRDs, deploying the controller, and
	// labeling the operator namespace. This Describe block focuses on the
	// metrics-endpoint contract; per-test setup runs in AfterEach.

	// After each test, check for failures and collect logs, events,
	// and pod descriptions for debugging.
	AfterEach(func() {
		specReport := CurrentSpecReport()
		if specReport.Failed() {
			By("Fetching controller manager pod logs")
			cmd := exec.Command("kubectl", "logs", controllerPodName, "-n", namespace)
			controllerLogs, err := utils.Run(cmd)
			if err == nil {
				_, _ = fmt.Fprintf(GinkgoWriter, "Controller logs:\n %s", controllerLogs)
			} else {
				_, _ = fmt.Fprintf(GinkgoWriter, "Failed to get Controller logs: %s", err)
			}

			By("Fetching Kubernetes events")
			cmd = exec.Command("kubectl", "get", "events", "-n", namespace, "--sort-by=.lastTimestamp")
			eventsOutput, err := utils.Run(cmd)
			if err == nil {
				_, _ = fmt.Fprintf(GinkgoWriter, "Kubernetes events:\n%s", eventsOutput)
			} else {
				_, _ = fmt.Fprintf(GinkgoWriter, "Failed to get Kubernetes events: %s", err)
			}

			By("Fetching controller manager pod description")
			cmd = exec.Command("kubectl", "describe", "pod", controllerPodName, "-n", namespace)
			podDescription, err := utils.Run(cmd)
			if err == nil {
				fmt.Println("Pod description:\n", podDescription)
			} else {
				fmt.Println("Failed to describe controller pod")
			}
		}
	})

	SetDefaultEventuallyTimeout(2 * time.Minute)
	SetDefaultEventuallyPollingInterval(time.Second)

	Context("Manager", func() {
		It("should run successfully", func() {
			By("validating that the controller-manager pod is running as expected")
			verifyControllerUp := func(g Gomega) {
				// Get the name of the controller-manager pod
				cmd := exec.Command("kubectl", "get",
					"pods", "-l", "control-plane=controller-manager",
					"-o", "go-template={{ range .items }}"+
						"{{ if not .metadata.deletionTimestamp }}"+
						"{{ .metadata.name }}"+
						"{{ \"\\n\" }}{{ end }}{{ end }}",
					"-n", namespace,
				)

				podOutput, err := utils.Run(cmd)
				g.Expect(err).NotTo(HaveOccurred(), "Failed to retrieve controller-manager pod information")
				podNames := utils.GetNonEmptyLines(podOutput)
				g.Expect(podNames).To(HaveLen(1), "expected 1 controller pod running")
				controllerPodName = podNames[0]
				g.Expect(controllerPodName).To(ContainSubstring("controller-manager"))

				// Validate the pod's status
				cmd = exec.Command("kubectl", "get",
					"pods", controllerPodName, "-o", "jsonpath={.status.phase}",
					"-n", namespace,
				)
				output, err := utils.Run(cmd)
				g.Expect(err).NotTo(HaveOccurred())
				g.Expect(output).To(Equal("Running"), "Incorrect controller-manager pod status")
			}
			Eventually(verifyControllerUp).Should(Succeed())
		})

		It("should ensure the metrics endpoint is serving metrics", func() {
			By("creating a ClusterRoleBinding for the service account to allow access to metrics")
			cmd := exec.Command("kubectl", "create", "clusterrolebinding", metricsRoleBindingName,
				"--clusterrole=lmcache-operator-metrics-reader",
				fmt.Sprintf("--serviceaccount=%s:%s", namespace, serviceAccountName),
			)
			_, err := utils.Run(cmd)
			Expect(err).NotTo(HaveOccurred(), "Failed to create ClusterRoleBinding")

			By("validating that the metrics service is available")
			cmd = exec.Command("kubectl", "get", "service", metricsServiceName, "-n", namespace)
			_, err = utils.Run(cmd)
			Expect(err).NotTo(HaveOccurred(), "Metrics service should exist")

			By("getting the service account token")
			token, err := serviceAccountToken()
			Expect(err).NotTo(HaveOccurred())
			Expect(token).NotTo(BeEmpty())

			By("ensuring the controller pod is ready")
			verifyControllerPodReady := func(g Gomega) {
				cmd := exec.Command("kubectl", "get", "pod", controllerPodName, "-n", namespace,
					"-o", "jsonpath={.status.conditions[?(@.type=='Ready')].status}")
				output, err := utils.Run(cmd)
				g.Expect(err).NotTo(HaveOccurred())
				g.Expect(output).To(Equal("True"), "Controller pod not ready")
			}
			Eventually(verifyControllerPodReady, 3*time.Minute, time.Second).Should(Succeed())

			By("verifying that the controller manager is serving the metrics server")
			verifyMetricsServerStarted := func(g Gomega) {
				cmd := exec.Command("kubectl", "logs", controllerPodName, "-n", namespace)
				output, err := utils.Run(cmd)
				g.Expect(err).NotTo(HaveOccurred())
				g.Expect(output).To(ContainSubstring("Serving metrics server"),
					"Metrics server not yet started")
			}
			Eventually(verifyMetricsServerStarted, 3*time.Minute, time.Second).Should(Succeed())

			// +kubebuilder:scaffold:e2e-metrics-webhooks-readiness

			By("waiting for metrics service to have endpoints")
			verifyEndpoints := func(g Gomega) {
				cmd := exec.Command("kubectl", "get", "endpoints", metricsServiceName, "-n", namespace,
					"-o", "jsonpath={.subsets[0].addresses[0].ip}")
				output, err := utils.Run(cmd)
				g.Expect(err).NotTo(HaveOccurred())
				g.Expect(output).NotTo(BeEmpty(), "metrics service has no endpoints")
			}
			Eventually(verifyEndpoints, 5*time.Minute, time.Second).Should(Succeed())

			By("port-forwarding the metrics service to localhost")
			portForwardCmd := exec.Command("kubectl", "port-forward",
				fmt.Sprintf("svc/%s", metricsServiceName),
				"8443:8443", "-n", namespace)
			portForwardCmd.Dir, _ = utils.GetProjectDir()
			Expect(portForwardCmd.Start()).To(Succeed(), "Failed to start port-forward")
			defer func() { _ = portForwardCmd.Process.Kill() }()

			By("verifying metrics endpoint returns 200 via port-forward")
			verifyMetrics := func(g Gomega) {
				client := &http.Client{
					Transport: &http.Transport{
						TLSClientConfig: &tls.Config{InsecureSkipVerify: true}, // #nosec G402
					},
				}
				req, err := http.NewRequestWithContext(context.Background(),
					http.MethodGet, "https://localhost:8443/metrics", nil)
				g.Expect(err).NotTo(HaveOccurred())
				req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))

				resp, err := client.Do(req)
				g.Expect(err).NotTo(HaveOccurred())
				defer resp.Body.Close()
				g.Expect(resp.StatusCode).To(Equal(http.StatusOK), "metrics endpoint returned non-200 status")
			}
			Eventually(verifyMetrics, 5*time.Minute, time.Second).Should(Succeed())
		})

		// +kubebuilder:scaffold:e2e-webhooks-checks

		// TODO: Customize the e2e test suite with scenarios specific to your project.
		// Consider applying sample/CR(s) and check their status and/or verifying
		// the reconciliation by using the metrics, i.e.:
		// metricsOutput, err := getMetricsOutput()
		// Expect(err).NotTo(HaveOccurred(), "Failed to retrieve logs from curl pod")
		// Expect(metricsOutput).To(ContainSubstring(
		//    fmt.Sprintf(`controller_runtime_reconcile_total{controller="%s",result="success"} 1`,
		//    strings.ToLower(<Kind>),
		// ))
	})
})

// serviceAccountToken returns a token for the specified service account in the given namespace.
// It uses the Kubernetes TokenRequest API to generate a token by directly sending a request
// and parsing the resulting token from the API response.
func serviceAccountToken() (string, error) {
	const tokenRequestRawString = `{
		"apiVersion": "authentication.k8s.io/v1",
		"kind": "TokenRequest"
	}`

	// Temporary file to store the token request
	secretName := fmt.Sprintf("%s-token-request", serviceAccountName)
	tokenRequestFile := filepath.Join("/tmp", secretName)
	err := os.WriteFile(tokenRequestFile, []byte(tokenRequestRawString), os.FileMode(0o644))
	if err != nil {
		return "", err
	}

	var out string
	verifyTokenCreation := func(g Gomega) {
		// Execute kubectl command to create the token
		cmd := exec.Command("kubectl", "create", "--raw", fmt.Sprintf(
			"/api/v1/namespaces/%s/serviceaccounts/%s/token",
			namespace,
			serviceAccountName,
		), "-f", tokenRequestFile)

		output, err := cmd.CombinedOutput()
		g.Expect(err).NotTo(HaveOccurred())

		// Parse the JSON output to extract the token
		var token tokenRequest
		err = json.Unmarshal(output, &token)
		g.Expect(err).NotTo(HaveOccurred())

		out = token.Status.Token
	}
	Eventually(verifyTokenCreation).Should(Succeed())

	return out, err
}

// tokenRequest is a simplified representation of the Kubernetes TokenRequest API response,
// containing only the token field that we need to extract.
type tokenRequest struct {
	Status struct {
		Token string `json:"token"`
	} `json:"status"`
}