/*
Copyright The Helm Authors.

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 registry

import (
	"bytes"
	"context"
	"crypto/tls"
	"fmt"
	"io"
	"net"
	"net/http"
	"net/http/httptest"
	"net/url"
	"os"
	"path/filepath"
	"strings"
	"time"

	"github.com/distribution/distribution/v3/configuration"
	"github.com/distribution/distribution/v3/registry"
	_ "github.com/distribution/distribution/v3/registry/auth/htpasswd"
	_ "github.com/distribution/distribution/v3/registry/storage/driver/inmemory"
	"github.com/foxcpp/go-mockdns"
	"github.com/phayes/freeport"
	"github.com/stretchr/testify/suite"
	"golang.org/x/crypto/bcrypt"

	"helm.sh/helm/v3/internal/tlsutil"
)

const (
	tlsServerKey  = "./testdata/tls/server-key.pem"
	tlsServerCert = "./testdata/tls/server-cert.pem"
	tlsCA         = "./testdata/tls/ca-cert.pem"
	tlsKey        = "./testdata/tls/client-key.pem"
	tlsCert       = "./testdata/tls/client-cert.pem"
)

var (
	testWorkspaceDir         = "helm-registry-test"
	testHtpasswdFileBasename = "authtest.htpasswd"
	testUsername             = "myuser"
	testPassword             = "mypass"
)

type TestSuite struct {
	suite.Suite
	Out                     io.Writer
	DockerRegistryHost      string
	CompromisedRegistryHost string
	WorkspaceDir            string
	RegistryClient          *Client

	// A mock DNS server needed for TLS connection testing.
	srv *mockdns.Server
}

func setup(suite *TestSuite, tlsEnabled bool, insecure bool) *registry.Registry {
	suite.WorkspaceDir = testWorkspaceDir
	os.RemoveAll(suite.WorkspaceDir)
	os.Mkdir(suite.WorkspaceDir, 0700)

	var (
		out bytes.Buffer
		err error
	)
	suite.Out = &out
	credentialsFile := filepath.Join(suite.WorkspaceDir, CredentialsFileBasename)

	// init test client
	if tlsEnabled {
		var tlsConf *tls.Config
		tlsConf, err = tlsutil.NewClientTLS(tlsCert, tlsKey, tlsCA, insecure)
		httpClient := &http.Client{
			Transport: &http.Transport{
				TLSClientConfig: tlsConf,
			},
		}
		suite.Nil(err, "no error loading tlsconfog")
		suite.RegistryClient, err = NewClient(
			ClientOptDebug(true),
			ClientOptEnableCache(true),
			ClientOptWriter(suite.Out),
			ClientOptCredentialsFile(credentialsFile),
			ClientOptHTTPClient(httpClient),
		)
	} else {
		suite.RegistryClient, err = NewClient(
			ClientOptDebug(true),
			ClientOptEnableCache(true),
			ClientOptWriter(suite.Out),
			ClientOptCredentialsFile(credentialsFile),
		)
	}

	suite.Nil(err, "no error creating registry client")

	// create htpasswd file (w BCrypt, which is required)
	pwBytes, err := bcrypt.GenerateFromPassword([]byte(testPassword), bcrypt.DefaultCost)
	suite.Nil(err, "no error generating bcrypt password for test htpasswd file")
	htpasswdPath := filepath.Join(suite.WorkspaceDir, testHtpasswdFileBasename)
	err = os.WriteFile(htpasswdPath, []byte(fmt.Sprintf("%s:%s\n", testUsername, string(pwBytes))), 0644)
	suite.Nil(err, "no error creating test htpasswd file")

	// Registry config
	config := &configuration.Configuration{}
	port, err := freeport.GetFreePort()
	suite.Nil(err, "no error finding free port for test registry")
	if tlsEnabled {
		// docker has  "MatchLocalhost is a host match function which returns true for
		// localhost, and is used to enforce http for localhost requests."
		// That function does not handle matching of ip addresses in octal,
		// decimal or hex form.
		suite.DockerRegistryHost = fmt.Sprintf("0x7f000001:%d", port)

		// As of Go 1.20, Go may lookup "0x7f000001" as a DNS entry and fail.
		// Using a mock DNS server to handle the address.
		suite.srv, _ = mockdns.NewServer(map[string]mockdns.Zone{
			"0x7f000001.": {
				A: []string{"127.0.0.1"},
			},
		}, false)
		suite.srv.PatchNet(net.DefaultResolver)
	} else {
		suite.DockerRegistryHost = fmt.Sprintf("localhost:%d", port)
	}
	config.HTTP.Addr = fmt.Sprintf(":%d", port)
	// config.HTTP.Addr = fmt.Sprintf("127.0.0.1:%d", port)
	config.HTTP.DrainTimeout = time.Duration(10) * time.Second
	config.Storage = map[string]configuration.Parameters{"inmemory": map[string]interface{}{}}
	config.Auth = configuration.Auth{
		"htpasswd": configuration.Parameters{
			"realm": "localhost",
			"path":  htpasswdPath,
		},
	}

	// config tls
	if tlsEnabled {
		// TLS config
		// this set tlsConf.ClientAuth = tls.RequireAndVerifyClientCert in the
		// server tls config
		config.HTTP.TLS.Certificate = tlsServerCert
		config.HTTP.TLS.Key = tlsServerKey
		config.HTTP.TLS.ClientCAs = []string{tlsCA}
	}
	dockerRegistry, err := registry.NewRegistry(context.Background(), config)
	suite.Nil(err, "no error creating test registry")

	suite.CompromisedRegistryHost = initCompromisedRegistryTestServer()
	return dockerRegistry
}

func teardown(suite *TestSuite) {
	if suite.srv != nil {
		mockdns.UnpatchNet(net.DefaultResolver)
		suite.srv.Close()
	}
}

func initCompromisedRegistryTestServer() string {
	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if strings.Contains(r.URL.Path, "manifests") {
			w.Header().Set("Content-Type", "application/vnd.oci.image.manifest.v1+json")
			w.WriteHeader(200)

			// layers[0] is the blob []byte("a")
			w.Write([]byte(
				fmt.Sprintf(`{ "schemaVersion": 2, "config": {
    "mediaType": "%s",
    "digest": "sha256:a705ee2789ab50a5ba20930f246dbd5cc01ff9712825bb98f57ee8414377f133",
    "size": 181
  },
  "layers": [
    {
      "mediaType": "%s",
      "digest": "sha256:ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb",
      "size": 1
    }
  ]
}`, ConfigMediaType, ChartLayerMediaType)))
		} else if r.URL.Path == "/v2/testrepo/supposedlysafechart/blobs/sha256:a705ee2789ab50a5ba20930f246dbd5cc01ff9712825bb98f57ee8414377f133" {
			w.Header().Set("Content-Type", "application/json")
			w.WriteHeader(200)
			w.Write([]byte("{\"name\":\"mychart\",\"version\":\"0.1.0\",\"description\":\"A Helm chart for Kubernetes\\n" +
				"an 'application' or a 'library' chart.\",\"apiVersion\":\"v2\",\"appVersion\":\"1.16.0\",\"type\":" +
				"\"application\"}"))
		} else if r.URL.Path == "/v2/testrepo/supposedlysafechart/blobs/sha256:ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb" {
			w.Header().Set("Content-Type", ChartLayerMediaType)
			w.WriteHeader(200)
			w.Write([]byte("b"))
		} else {
			w.WriteHeader(500)
		}
	}))

	u, _ := url.Parse(s.URL)
	return fmt.Sprintf("localhost:%s", u.Port())
}

func testPush(suite *TestSuite) {
	// Bad bytes
	ref := fmt.Sprintf("%s/testrepo/testchart:1.2.3", suite.DockerRegistryHost)
	_, err := suite.RegistryClient.Push([]byte("hello"), ref, PushOptTest(true))
	suite.NotNil(err, "error pushing non-chart bytes")

	// Load a test chart
	chartData, err := os.ReadFile("../repo/repotest/testdata/examplechart-0.1.0.tgz")
	suite.Nil(err, "no error loading test chart")
	meta, err := extractChartMeta(chartData)
	suite.Nil(err, "no error extracting chart meta")

	// non-strict ref (chart name)
	ref = fmt.Sprintf("%s/testrepo/boop:%s", suite.DockerRegistryHost, meta.Version)
	_, err = suite.RegistryClient.Push(chartData, ref, PushOptTest(true))
	suite.NotNil(err, "error pushing non-strict ref (bad basename)")

	// non-strict ref (chart name), with strict mode disabled
	_, err = suite.RegistryClient.Push(chartData, ref, PushOptStrictMode(false), PushOptTest(true))
	suite.Nil(err, "no error pushing non-strict ref (bad basename), with strict mode disabled")

	// non-strict ref (chart version)
	ref = fmt.Sprintf("%s/testrepo/%s:latest", suite.DockerRegistryHost, meta.Name)
	_, err = suite.RegistryClient.Push(chartData, ref, PushOptTest(true))
	suite.NotNil(err, "error pushing non-strict ref (bad tag)")

	// non-strict ref (chart version), with strict mode disabled
	_, err = suite.RegistryClient.Push(chartData, ref, PushOptStrictMode(false), PushOptTest(true))
	suite.Nil(err, "no error pushing non-strict ref (bad tag), with strict mode disabled")

	// basic push, good ref
	chartData, err = os.ReadFile("../downloader/testdata/local-subchart-0.1.0.tgz")
	suite.Nil(err, "no error loading test chart")
	meta, err = extractChartMeta(chartData)
	suite.Nil(err, "no error extracting chart meta")
	ref = fmt.Sprintf("%s/testrepo/%s:%s", suite.DockerRegistryHost, meta.Name, meta.Version)
	_, err = suite.RegistryClient.Push(chartData, ref, PushOptTest(true))
	suite.Nil(err, "no error pushing good ref")

	_, err = suite.RegistryClient.Pull(ref)
	suite.Nil(err, "no error pulling a simple chart")

	// Load another test chart
	chartData, err = os.ReadFile("../downloader/testdata/signtest-0.1.0.tgz")
	suite.Nil(err, "no error loading test chart")
	meta, err = extractChartMeta(chartData)
	suite.Nil(err, "no error extracting chart meta")

	// Load prov file
	provData, err := os.ReadFile("../downloader/testdata/signtest-0.1.0.tgz.prov")
	suite.Nil(err, "no error loading test prov")

	// push with prov
	ref = fmt.Sprintf("%s/testrepo/%s:%s", suite.DockerRegistryHost, meta.Name, meta.Version)
	result, err := suite.RegistryClient.Push(chartData, ref, PushOptProvData(provData), PushOptTest(true))
	suite.Nil(err, "no error pushing good ref with prov")

	_, err = suite.RegistryClient.Pull(ref)
	suite.Nil(err, "no error pulling a simple chart")

	// Validate the output
	// Note: these digests/sizes etc may change if the test chart/prov files are modified,
	// or if the format of the OCI manifest changes
	suite.Equal(ref, result.Ref)
	suite.Equal(meta.Name, result.Chart.Meta.Name)
	suite.Equal(meta.Version, result.Chart.Meta.Version)
	suite.Equal(int64(684), result.Manifest.Size)
	suite.Equal(int64(99), result.Config.Size)
	suite.Equal(int64(973), result.Chart.Size)
	suite.Equal(int64(695), result.Prov.Size)
	suite.Equal(
		"sha256:b57e8ffd938c43253f30afedb3c209136288e6b3af3b33473e95ea3b805888e6",
		result.Manifest.Digest)
	suite.Equal(
		"sha256:8d17cb6bf6ccd8c29aace9a658495cbd5e2e87fc267876e86117c7db681c9580",
		result.Config.Digest)
	suite.Equal(
		"sha256:e5ef611620fb97704d8751c16bab17fedb68883bfb0edc76f78a70e9173f9b55",
		result.Chart.Digest)
	suite.Equal(
		"sha256:b0a02b7412f78ae93324d48df8fcc316d8482e5ad7827b5b238657a29a22f256",
		result.Prov.Digest)
}

func testPull(suite *TestSuite) {
	// bad/missing ref
	ref := fmt.Sprintf("%s/testrepo/no-existy:1.2.3", suite.DockerRegistryHost)
	_, err := suite.RegistryClient.Pull(ref)
	suite.NotNil(err, "error on bad/missing ref")

	// Load test chart (to build ref pushed in previous test)
	chartData, err := os.ReadFile("../downloader/testdata/local-subchart-0.1.0.tgz")
	suite.Nil(err, "no error loading test chart")
	meta, err := extractChartMeta(chartData)
	suite.Nil(err, "no error extracting chart meta")
	ref = fmt.Sprintf("%s/testrepo/%s:%s", suite.DockerRegistryHost, meta.Name, meta.Version)

	// Simple pull, chart only
	_, err = suite.RegistryClient.Pull(ref)
	suite.Nil(err, "no error pulling a simple chart")

	// Simple pull with prov (no prov uploaded)
	_, err = suite.RegistryClient.Pull(ref, PullOptWithProv(true))
	suite.NotNil(err, "error pulling a chart with prov when no prov exists")

	// Simple pull with prov, ignoring missing prov
	_, err = suite.RegistryClient.Pull(ref,
		PullOptWithProv(true),
		PullOptIgnoreMissingProv(true))
	suite.Nil(err,
		"no error pulling a chart with prov when no prov exists, ignoring missing")

	// Load test chart (to build ref pushed in previous test)
	chartData, err = os.ReadFile("../downloader/testdata/signtest-0.1.0.tgz")
	suite.Nil(err, "no error loading test chart")
	meta, err = extractChartMeta(chartData)
	suite.Nil(err, "no error extracting chart meta")
	ref = fmt.Sprintf("%s/testrepo/%s:%s", suite.DockerRegistryHost, meta.Name, meta.Version)

	// Load prov file
	provData, err := os.ReadFile("../downloader/testdata/signtest-0.1.0.tgz.prov")
	suite.Nil(err, "no error loading test prov")

	// no chart and no prov causes error
	_, err = suite.RegistryClient.Pull(ref,
		PullOptWithChart(false),
		PullOptWithProv(false))
	suite.NotNil(err, "error on both no chart and no prov")

	// full pull with chart and prov
	result, err := suite.RegistryClient.Pull(ref, PullOptWithProv(true))
	suite.Nil(err, "no error pulling a chart with prov")

	// Validate the output
	// Note: these digests/sizes etc may change if the test chart/prov files are modified,
	// or if the format of the OCI manifest changes
	suite.Equal(ref, result.Ref)
	suite.Equal(meta.Name, result.Chart.Meta.Name)
	suite.Equal(meta.Version, result.Chart.Meta.Version)
	suite.Equal(int64(684), result.Manifest.Size)
	suite.Equal(int64(99), result.Config.Size)
	suite.Equal(int64(973), result.Chart.Size)
	suite.Equal(int64(695), result.Prov.Size)
	suite.Equal(
		"sha256:b57e8ffd938c43253f30afedb3c209136288e6b3af3b33473e95ea3b805888e6",
		result.Manifest.Digest)
	suite.Equal(
		"sha256:8d17cb6bf6ccd8c29aace9a658495cbd5e2e87fc267876e86117c7db681c9580",
		result.Config.Digest)
	suite.Equal(
		"sha256:e5ef611620fb97704d8751c16bab17fedb68883bfb0edc76f78a70e9173f9b55",
		result.Chart.Digest)
	suite.Equal(
		"sha256:b0a02b7412f78ae93324d48df8fcc316d8482e5ad7827b5b238657a29a22f256",
		result.Prov.Digest)
	suite.Equal("{\"schemaVersion\":2,\"config\":{\"mediaType\":\"application/vnd.cncf.helm.config.v1+json\",\"digest\":\"sha256:8d17cb6bf6ccd8c29aace9a658495cbd5e2e87fc267876e86117c7db681c9580\",\"size\":99},\"layers\":[{\"mediaType\":\"application/vnd.cncf.helm.chart.provenance.v1.prov\",\"digest\":\"sha256:b0a02b7412f78ae93324d48df8fcc316d8482e5ad7827b5b238657a29a22f256\",\"size\":695},{\"mediaType\":\"application/vnd.cncf.helm.chart.content.v1.tar+gzip\",\"digest\":\"sha256:e5ef611620fb97704d8751c16bab17fedb68883bfb0edc76f78a70e9173f9b55\",\"size\":973}],\"annotations\":{\"org.opencontainers.image.description\":\"A Helm chart for Kubernetes\",\"org.opencontainers.image.title\":\"signtest\",\"org.opencontainers.image.version\":\"0.1.0\"}}",
		string(result.Manifest.Data))
	suite.Equal("{\"name\":\"signtest\",\"version\":\"0.1.0\",\"description\":\"A Helm chart for Kubernetes\",\"apiVersion\":\"v1\"}",
		string(result.Config.Data))
	suite.Equal(chartData, result.Chart.Data)
	suite.Equal(provData, result.Prov.Data)
}

func testTags(suite *TestSuite) {
	// Load test chart (to build ref pushed in previous test)
	chartData, err := os.ReadFile("../downloader/testdata/local-subchart-0.1.0.tgz")
	suite.Nil(err, "no error loading test chart")
	meta, err := extractChartMeta(chartData)
	suite.Nil(err, "no error extracting chart meta")
	ref := fmt.Sprintf("%s/testrepo/%s", suite.DockerRegistryHost, meta.Name)

	// Query for tags and validate length
	tags, err := suite.RegistryClient.Tags(ref)
	suite.Nil(err, "no error retrieving tags")
	suite.Equal(1, len(tags))
}