// Copyright 2020-2021 the Pinniped contributors. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
package integration

import (
	"bufio"
	"bytes"
	"context"
	"encoding/base64"
	"errors"
	"fmt"
	"io"
	"io/ioutil"
	"net/url"
	"os"
	"os/exec"
	"path/filepath"
	"regexp"
	"sort"
	"strings"
	"testing"
	"time"

	coreosoidc "github.com/coreos/go-oidc/v3/oidc"
	"github.com/creack/pty"
	"github.com/stretchr/testify/require"
	authorizationv1 "k8s.io/api/authorization/v1"
	corev1 "k8s.io/api/core/v1"
	rbacv1 "k8s.io/api/rbac/v1"

	authv1alpha "go.pinniped.dev/generated/latest/apis/concierge/authentication/v1alpha1"
	configv1alpha1 "go.pinniped.dev/generated/latest/apis/supervisor/config/v1alpha1"
	idpv1alpha1 "go.pinniped.dev/generated/latest/apis/supervisor/idp/v1alpha1"
	"go.pinniped.dev/internal/certauthority"
	"go.pinniped.dev/internal/here"
	"go.pinniped.dev/internal/oidc"
	"go.pinniped.dev/internal/testutil"
	"go.pinniped.dev/pkg/oidcclient"
	"go.pinniped.dev/pkg/oidcclient/filesession"
	"go.pinniped.dev/test/library"
	"go.pinniped.dev/test/library/browsertest"
)

// TestE2EFullIntegration tests a full integration scenario that combines the supervisor, concierge, and CLI.
func TestE2EFullIntegration(t *testing.T) {
	env := library.IntegrationEnv(t)

	ctx, cancelFunc := context.WithTimeout(context.Background(), 5*time.Minute)
	defer cancelFunc()

	// Build pinniped CLI.
	pinnipedExe := library.PinnipedCLIPath(t)
	tempDir := testutil.TempDir(t)

	// Start the browser driver.
	page := browsertest.Open(t)

	// Infer the downstream issuer URL from the callback associated with the upstream test client registration.
	issuerURL, err := url.Parse(env.SupervisorUpstreamOIDC.CallbackURL)
	require.NoError(t, err)
	require.True(t, strings.HasSuffix(issuerURL.Path, "/callback"))
	issuerURL.Path = strings.TrimSuffix(issuerURL.Path, "/callback")
	t.Logf("testing with downstream issuer URL %s", issuerURL.String())

	// Generate a CA bundle with which to serve this provider.
	t.Logf("generating test CA")
	ca, err := certauthority.New("Downstream Test CA", 1*time.Hour)
	require.NoError(t, err)

	// Save that bundle plus the one that signs the upstream issuer, for test purposes.
	testCABundlePath := filepath.Join(tempDir, "test-ca.pem")
	testCABundlePEM := []byte(string(ca.Bundle()) + "\n" + env.SupervisorUpstreamOIDC.CABundle)
	testCABundleBase64 := base64.StdEncoding.EncodeToString(testCABundlePEM)
	require.NoError(t, ioutil.WriteFile(testCABundlePath, testCABundlePEM, 0600))

	// Use the CA to issue a TLS server cert.
	t.Logf("issuing test certificate")
	tlsCert, err := ca.IssueServerCert([]string{issuerURL.Hostname()}, nil, 1*time.Hour)
	require.NoError(t, err)
	certPEM, keyPEM, err := certauthority.ToPEM(tlsCert)
	require.NoError(t, err)

	// Write the serving cert to a secret.
	certSecret := library.CreateTestSecret(t,
		env.SupervisorNamespace,
		"oidc-provider-tls",
		corev1.SecretTypeTLS,
		map[string]string{"tls.crt": string(certPEM), "tls.key": string(keyPEM)},
	)

	// Create the downstream FederationDomain and expect it to go into the success status condition.
	downstream := library.CreateTestFederationDomain(ctx, t,
		issuerURL.String(),
		certSecret.Name,
		configv1alpha1.SuccessFederationDomainStatusCondition,
	)

	// Create a JWTAuthenticator that will validate the tokens from the downstream issuer.
	clusterAudience := "test-cluster-" + library.RandHex(t, 8)
	authenticator := library.CreateTestJWTAuthenticator(ctx, t, authv1alpha.JWTAuthenticatorSpec{
		Issuer:   downstream.Spec.Issuer,
		Audience: clusterAudience,
		TLS:      &authv1alpha.TLSSpec{CertificateAuthorityData: testCABundleBase64},
	})

	// Add an OIDC upstream IDP and try using it to authenticate during kubectl commands.
	t.Run("with Supervisor OIDC upstream IDP", func(t *testing.T) {
		expectedUsername := env.SupervisorUpstreamOIDC.Username
		expectedGroups := env.SupervisorUpstreamOIDC.ExpectedGroups

		// Create a ClusterRoleBinding to give our test user from the upstream read-only access to the cluster.
		library.CreateTestClusterRoleBinding(t,
			rbacv1.Subject{Kind: rbacv1.UserKind, APIGroup: rbacv1.GroupName, Name: expectedUsername},
			rbacv1.RoleRef{Kind: "ClusterRole", APIGroup: rbacv1.GroupName, Name: "view"},
		)
		library.WaitForUserToHaveAccess(t, expectedUsername, []string{}, &authorizationv1.ResourceAttributes{
			Verb:     "get",
			Group:    "",
			Version:  "v1",
			Resource: "namespaces",
		})

		// Create upstream OIDC provider and wait for it to become ready.
		library.CreateTestOIDCIdentityProvider(t, idpv1alpha1.OIDCIdentityProviderSpec{
			Issuer: env.SupervisorUpstreamOIDC.Issuer,
			TLS: &idpv1alpha1.TLSSpec{
				CertificateAuthorityData: base64.StdEncoding.EncodeToString([]byte(env.SupervisorUpstreamOIDC.CABundle)),
			},
			AuthorizationConfig: idpv1alpha1.OIDCAuthorizationConfig{
				AdditionalScopes: env.SupervisorUpstreamOIDC.AdditionalScopes,
			},
			Claims: idpv1alpha1.OIDCClaims{
				Username: env.SupervisorUpstreamOIDC.UsernameClaim,
				Groups:   env.SupervisorUpstreamOIDC.GroupsClaim,
			},
			Client: idpv1alpha1.OIDCClient{
				SecretName: library.CreateClientCredsSecret(t, env.SupervisorUpstreamOIDC.ClientID, env.SupervisorUpstreamOIDC.ClientSecret).Name,
			},
		}, idpv1alpha1.PhaseReady)

		// Use a specific session cache for this test.
		sessionCachePath := tempDir + "/oidc-test-sessions.yaml"

		kubeconfigPath := runPinnipedGetKubeconfig(t, env, pinnipedExe, tempDir, []string{
			"get", "kubeconfig",
			"--concierge-api-group-suffix", env.APIGroupSuffix,
			"--concierge-authenticator-type", "jwt",
			"--concierge-authenticator-name", authenticator.Name,
			"--oidc-skip-browser",
			"--oidc-ca-bundle", testCABundlePath,
			"--oidc-session-cache", sessionCachePath,
		})

		// Run "kubectl get namespaces" which should trigger a browser login via the plugin.
		start := time.Now()
		kubectlCmd := exec.CommandContext(ctx, "kubectl", "get", "namespace", "--kubeconfig", kubeconfigPath)
		kubectlCmd.Env = append(os.Environ(), env.ProxyEnv()...)
		stderrPipe, err := kubectlCmd.StderrPipe()
		require.NoError(t, err)
		stdoutPipe, err := kubectlCmd.StdoutPipe()
		require.NoError(t, err)

		t.Logf("starting kubectl subprocess")
		require.NoError(t, kubectlCmd.Start())
		t.Cleanup(func() {
			err := kubectlCmd.Wait()
			t.Logf("kubectl subprocess exited with code %d", kubectlCmd.ProcessState.ExitCode())
			stdout, stdoutErr := ioutil.ReadAll(stdoutPipe)
			if stdoutErr != nil {
				stdout = []byte("<error reading stdout: " + stdoutErr.Error() + ">")
			}
			stderr, stderrErr := ioutil.ReadAll(stderrPipe)
			if stderrErr != nil {
				stderr = []byte("<error reading stderr: " + stderrErr.Error() + ">")
			}
			require.NoErrorf(t, err, "kubectl process did not exit cleanly, stdout/stderr: %q/%q", string(stdout), string(stderr))
		})

		// Start a background goroutine to read stderr from the CLI and parse out the login URL.
		loginURLChan := make(chan string)
		spawnTestGoroutine(t, func() (err error) {
			defer func() {
				closeErr := stderrPipe.Close()
				if closeErr == nil || errors.Is(closeErr, os.ErrClosed) {
					return
				}
				if err == nil {
					err = fmt.Errorf("stderr stream closed with error: %w", closeErr)
				}
			}()

			reader := bufio.NewReader(library.NewLoggerReader(t, "stderr", stderrPipe))
			line, err := reader.ReadString('\n')
			if err != nil {
				return fmt.Errorf("could not read login URL line from stderr: %w", err)
			}
			const prompt = "Please log in: "
			if !strings.HasPrefix(line, prompt) {
				return fmt.Errorf("expected %q to have prefix %q", line, prompt)
			}
			loginURLChan <- strings.TrimPrefix(line, prompt)
			return readAndExpectEmpty(reader)
		})

		// Start a background goroutine to read stdout from kubectl and return the result as a string.
		kubectlOutputChan := make(chan string)
		spawnTestGoroutine(t, func() (err error) {
			defer func() {
				closeErr := stdoutPipe.Close()
				if closeErr == nil || errors.Is(closeErr, os.ErrClosed) {
					return
				}
				if err == nil {
					err = fmt.Errorf("stdout stream closed with error: %w", closeErr)
				}
			}()
			output, err := ioutil.ReadAll(stdoutPipe)
			if err != nil {
				return err
			}
			t.Logf("kubectl output:\n%s\n", output)
			kubectlOutputChan <- string(output)
			return nil
		})

		// Wait for the CLI to print out the login URL and open the browser to it.
		t.Logf("waiting for CLI to output login URL")
		var loginURL string
		select {
		case <-time.After(1 * time.Minute):
			require.Fail(t, "timed out waiting for login URL")
		case loginURL = <-loginURLChan:
		}
		t.Logf("navigating to login page")
		require.NoError(t, page.Navigate(loginURL))

		// Expect to be redirected to the upstream provider and log in.
		browsertest.LoginToUpstream(t, page, env.SupervisorUpstreamOIDC)

		// Expect to be redirected to the localhost callback.
		t.Logf("waiting for redirect to callback")
		browsertest.WaitForURL(t, page, regexp.MustCompile(`\Ahttp://127\.0\.0\.1:[0-9]+/callback\?.+\z`))

		// Wait for the "pre" element that gets rendered for a `text/plain` page, and
		// assert that it contains the success message.
		t.Logf("verifying success page")
		browsertest.WaitForVisibleElements(t, page, "pre")
		msg, err := page.First("pre").Text()
		require.NoError(t, err)
		require.Equal(t, "you have been logged in and may now close this tab", msg)

		// Expect the CLI to output a list of namespaces in JSON format.
		t.Logf("waiting for kubectl to output namespace list JSON")
		var kubectlOutput string
		select {
		case <-time.After(10 * time.Second):
			require.Fail(t, "timed out waiting for kubectl output")
		case kubectlOutput = <-kubectlOutputChan:
		}
		require.Greaterf(t, len(strings.Split(kubectlOutput, "\n")), 2, "expected some namespaces to be returned, got %q", kubectlOutput)
		t.Logf("first kubectl command took %s", time.Since(start).String())

		requireUserCanUseKubectlWithoutAuthenticatingAgain(ctx, t, env,
			downstream,
			kubeconfigPath,
			sessionCachePath,
			pinnipedExe,
			expectedUsername,
			expectedGroups,
		)
	})

	// Add an LDAP upstream IDP and try using it to authenticate during kubectl commands.
	t.Run("with Supervisor LDAP upstream IDP", func(t *testing.T) {
		expectedUsername := env.SupervisorUpstreamLDAP.TestUserMailAttributeValue
		expectedGroups := []string{} // LDAP groups are not implemented yet

		// Create a ClusterRoleBinding to give our test user from the upstream read-only access to the cluster.
		library.CreateTestClusterRoleBinding(t,
			rbacv1.Subject{Kind: rbacv1.UserKind, APIGroup: rbacv1.GroupName, Name: expectedUsername},
			rbacv1.RoleRef{Kind: "ClusterRole", APIGroup: rbacv1.GroupName, Name: "view"},
		)
		library.WaitForUserToHaveAccess(t, expectedUsername, []string{}, &authorizationv1.ResourceAttributes{
			Verb:     "get",
			Group:    "",
			Version:  "v1",
			Resource: "namespaces",
		})

		// Put the bind service account's info into a Secret.
		bindSecret := library.CreateTestSecret(t, env.SupervisorNamespace, "ldap-service-account", corev1.SecretTypeBasicAuth,
			map[string]string{
				corev1.BasicAuthUsernameKey: env.SupervisorUpstreamLDAP.BindUsername,
				corev1.BasicAuthPasswordKey: env.SupervisorUpstreamLDAP.BindPassword,
			},
		)

		// Create upstream LDAP provider and wait for it to become ready.
		library.CreateTestLDAPIdentityProvider(t, idpv1alpha1.LDAPIdentityProviderSpec{
			Host: env.SupervisorUpstreamLDAP.Host,
			TLS: &idpv1alpha1.TLSSpec{
				CertificateAuthorityData: base64.StdEncoding.EncodeToString([]byte(env.SupervisorUpstreamLDAP.CABundle)),
			},
			Bind: idpv1alpha1.LDAPIdentityProviderBind{
				SecretName: bindSecret.Name,
			},
			UserSearch: idpv1alpha1.LDAPIdentityProviderUserSearch{
				Base:   env.SupervisorUpstreamLDAP.UserSearchBase,
				Filter: "",
				Attributes: idpv1alpha1.LDAPIdentityProviderUserSearchAttributes{
					Username: env.SupervisorUpstreamLDAP.TestUserMailAttributeName,
					UID:      env.SupervisorUpstreamLDAP.TestUserUniqueIDAttributeName,
				},
			},
		}, idpv1alpha1.LDAPPhaseReady)

		// Use a specific session cache for this test.
		sessionCachePath := tempDir + "/ldap-test-sessions.yaml"

		kubeconfigPath := runPinnipedGetKubeconfig(t, env, pinnipedExe, tempDir, []string{
			"get", "kubeconfig",
			"--concierge-api-group-suffix", env.APIGroupSuffix,
			"--concierge-authenticator-type", "jwt",
			"--concierge-authenticator-name", authenticator.Name,
			"--oidc-session-cache", sessionCachePath,
		})

		// Run "kubectl get namespaces" which should trigger an LDAP-style login CLI prompt via the plugin.
		start := time.Now()
		kubectlCmd := exec.CommandContext(ctx, "kubectl", "get", "namespace", "--kubeconfig", kubeconfigPath)
		kubectlCmd.Env = append(os.Environ(), env.ProxyEnv()...)
		ptyFile, err := pty.Start(kubectlCmd)
		require.NoError(t, err)

		// Wait for the subprocess to print the username prompt, then type the user's username.
		readFromFileUntilStringIsSeen(t, ptyFile, "Username: ")
		_, err = ptyFile.WriteString(expectedUsername + "\n")
		require.NoError(t, err)

		// Wait for the subprocess to print the password prompt, then type the user's password.
		readFromFileUntilStringIsSeen(t, ptyFile, "Password: ")
		_, err = ptyFile.WriteString(env.SupervisorUpstreamLDAP.TestUserPassword + "\n")
		require.NoError(t, err)

		// Read all of the remaining output from the subprocess until EOF.
		remainingOutput, err := ioutil.ReadAll(ptyFile)
		require.NoError(t, err)
		require.Greaterf(t, len(strings.Split(string(remainingOutput), "\n")), 2, "expected some namespaces to be returned, got %q", string(remainingOutput))
		t.Logf("first kubectl command took %s", time.Since(start).String())

		requireUserCanUseKubectlWithoutAuthenticatingAgain(ctx, t, env,
			downstream,
			kubeconfigPath,
			sessionCachePath,
			pinnipedExe,
			expectedUsername,
			expectedGroups,
		)
	})
}

func readFromFileUntilStringIsSeen(t *testing.T, f *os.File, until string) {
	readFromFile := ""

	library.RequireEventuallyWithoutError(t, func() (bool, error) {
		someOutput, foundEOF := readAvailableOutput(t, f)
		readFromFile += someOutput
		if strings.Contains(readFromFile, until) {
			return true, nil // found it! finished.
		}
		if foundEOF {
			return false, fmt.Errorf("reached EOF of subcommand's output without seeing expected string %q", until)
		}
		return false, nil // keep waiting and reading
	}, 1*time.Minute, 1*time.Second)
}

func readAvailableOutput(t *testing.T, r io.Reader) (string, bool) {
	buf := make([]byte, 1024)
	n, err := r.Read(buf)
	if err != nil {
		if err == io.EOF {
			return string(buf[:n]), true
		}
		require.NoError(t, err)
	}
	return string(buf[:n]), false
}

func requireUserCanUseKubectlWithoutAuthenticatingAgain(
	ctx context.Context,
	t *testing.T,
	env *library.TestEnv,
	downstream *configv1alpha1.FederationDomain,
	kubeconfigPath string,
	sessionCachePath string,
	pinnipedExe string,
	expectedUsername string,
	expectedGroups []string,
) {
	// 	Run kubectl, which should work without any prompting for authentication.
	kubectlCmd := exec.CommandContext(ctx, "kubectl", "get", "namespace", "--kubeconfig", kubeconfigPath)
	kubectlCmd.Env = append(os.Environ(), env.ProxyEnv()...)
	startTime := time.Now()
	kubectlOutput2, err := kubectlCmd.CombinedOutput()
	require.NoError(t, err)
	require.Greaterf(t, len(bytes.Split(kubectlOutput2, []byte("\n"))), 2, "expected some namespaces to be returned again")
	t.Logf("second kubectl command took %s", time.Since(startTime).String())

	// Probe our cache for the current ID token as a proxy for a whoami API.
	cache := filesession.New(sessionCachePath, filesession.WithErrorReporter(func(err error) {
		require.NoError(t, err)
	}))

	downstreamScopes := []string{coreosoidc.ScopeOfflineAccess, coreosoidc.ScopeOpenID, "pinniped:request-audience"}
	sort.Strings(downstreamScopes)
	token := cache.GetToken(oidcclient.SessionCacheKey{
		Issuer:      downstream.Spec.Issuer,
		ClientID:    "pinniped-cli",
		Scopes:      downstreamScopes,
		RedirectURI: "http://localhost:0/callback",
	})
	require.NotNil(t, token)

	idTokenClaims := token.IDToken.Claims
	require.Equal(t, expectedUsername, idTokenClaims[oidc.DownstreamUsernameClaim])

	// The groups claim in the file ends up as an []interface{}, so adjust our expectation to match.
	expectedGroupsAsEmptyInterfaces := make([]interface{}, 0, len(expectedGroups))
	for _, g := range expectedGroups {
		expectedGroupsAsEmptyInterfaces = append(expectedGroupsAsEmptyInterfaces, g)
	}
	require.Equal(t, expectedGroupsAsEmptyInterfaces, idTokenClaims[oidc.DownstreamGroupsClaim])

	expectedYAMLGroups := func() string {
		var b strings.Builder
		for _, g := range expectedGroups {
			b.WriteString("\n")
			b.WriteString(`      - `)
			b.WriteString(g)
		}
		return b.String()
	}()

	// Confirm we are the right user according to Kube by calling the whoami API.
	kubectlCmd3 := exec.CommandContext(ctx, "kubectl", "create", "-f", "-", "-o", "yaml", "--kubeconfig", kubeconfigPath)
	kubectlCmd3.Env = append(os.Environ(), env.ProxyEnv()...)
	kubectlCmd3.Stdin = strings.NewReader(here.Docf(`
			apiVersion: identity.concierge.%s/v1alpha1
			kind: WhoAmIRequest
		`, env.APIGroupSuffix))

	kubectlOutput3, err := kubectlCmd3.CombinedOutput()
	require.NoError(t, err)

	require.Equal(t, here.Docf(`
			apiVersion: identity.concierge.%s/v1alpha1
			kind: WhoAmIRequest
			metadata:
			  creationTimestamp: null
			spec: {}
			status:
			  kubernetesUserInfo:
				user:
				  groups:%s
				  - system:authenticated
				  username: %s
		`, env.APIGroupSuffix, expectedYAMLGroups, expectedUsername),
		string(kubectlOutput3))

	expectedGroupsPlusAuthenticated := append([]string{}, expectedGroups...)
	expectedGroupsPlusAuthenticated = append(expectedGroupsPlusAuthenticated, "system:authenticated")
	// Validate that `pinniped whoami` returns the correct identity.
	assertWhoami(
		ctx,
		t,
		true,
		pinnipedExe,
		kubeconfigPath,
		expectedUsername,
		expectedGroupsPlusAuthenticated,
	)
}

func runPinnipedGetKubeconfig(t *testing.T, env *library.TestEnv, pinnipedExe string, tempDir string, pinnipedCLICommand []string) string {
	// Run "pinniped get kubeconfig" to get a kubeconfig YAML.
	envVarsWithProxy := append(os.Environ(), env.ProxyEnv()...)
	kubeconfigYAML, stderr := runPinnipedCLI(t, envVarsWithProxy, pinnipedExe, pinnipedCLICommand...)
	t.Logf("stderr output from 'pinniped get kubeconfig':\n%s\n\n", stderr)
	t.Logf("test kubeconfig:\n%s\n\n", kubeconfigYAML)

	restConfig := library.NewRestConfigFromKubeconfig(t, kubeconfigYAML)
	require.NotNil(t, restConfig.ExecProvider)
	require.Equal(t, []string{"login", "oidc"}, restConfig.ExecProvider.Args[:2])

	kubeconfigPath := filepath.Join(tempDir, "kubeconfig.yaml")
	require.NoError(t, ioutil.WriteFile(kubeconfigPath, []byte(kubeconfigYAML), 0600))

	return kubeconfigPath
}