/*
Copyright 2019 The Kubernetes 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 external

import (
	"context"
	"flag"
	"io/ioutil"

	"github.com/pkg/errors"

	storagev1 "k8s.io/api/storage/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/runtime/schema"
	"k8s.io/apimachinery/pkg/util/sets"
	"k8s.io/client-go/kubernetes/scheme"
	"k8s.io/kubernetes/test/e2e/framework"
	"k8s.io/kubernetes/test/e2e/framework/config"
	e2epod "k8s.io/kubernetes/test/e2e/framework/pod"
	e2eskipper "k8s.io/kubernetes/test/e2e/framework/skipper"
	"k8s.io/kubernetes/test/e2e/framework/volume"
	"k8s.io/kubernetes/test/e2e/storage/testpatterns"
	"k8s.io/kubernetes/test/e2e/storage/testsuites"
	"k8s.io/kubernetes/test/e2e/storage/utils"

	"github.com/onsi/ginkgo"
)

// DriverDefinition needs to be filled in via a .yaml or .json
// file. Its methods then implement the TestDriver interface, using
// nothing but the information in this struct.
type driverDefinition struct {
	// DriverInfo is the static information that the storage testsuite
	// expects from a test driver. See test/e2e/storage/testsuites/testdriver.go
	// for details. The only field with a non-zero default is the list of
	// supported file systems (SupportedFsType): it is set so that tests using
	// the default file system are enabled.
	DriverInfo testsuites.DriverInfo

	// StorageClass must be set to enable dynamic provisioning tests.
	// The default is to not run those tests.
	StorageClass struct {
		// FromName set to true enables the usage of a storage
		// class with DriverInfo.Name as provisioner and no
		// parameters.
		FromName bool

		// FromFile is used only when FromName is false.  It
		// loads a storage class from the given .yaml or .json
		// file. File names are resolved by the
		// framework.testfiles package, which typically means
		// that they can be absolute or relative to the test
		// suite's --repo-root parameter.
		//
		// This can be used when the storage class is meant to have
		// additional parameters.
		FromFile string

		// FromExistingClassName specifies the name of a pre-installed
		// StorageClass that will be copied and used for the tests.
		FromExistingClassName string
	}

	// SnapshotClass must be set to enable snapshotting tests.
	// The default is to not run those tests.
	SnapshotClass struct {
		// FromName set to true enables the usage of a
		// snapshotter class with DriverInfo.Name as provisioner.
		FromName bool

		// TODO (?): load from file
	}

	// InlineVolumes defines one or more volumes for use as inline
	// ephemeral volumes. At least one such volume has to be
	// defined to enable testing of inline ephemeral volumes.  If
	// a test needs more volumes than defined, some of the defined
	// volumes will be used multiple times.
	//
	// DriverInfo.Name is used as name of the driver in the inline volume.
	InlineVolumes []struct {
		// Attributes are passed as NodePublishVolumeReq.volume_context.
		// Can be empty.
		Attributes map[string]string
		// Shared defines whether the resulting volume is
		// shared between different pods (i.e.  changes made
		// in one pod are visible in another)
		Shared bool
		// ReadOnly must be set to true if the driver does not
		// support mounting as read/write.
		ReadOnly bool
	}

	// SupportedSizeRange defines the desired size of dynamically
	// provisioned volumes.
	SupportedSizeRange volume.SizeRange

	// ClientNodeName selects a specific node for scheduling test pods.
	// Can be left empty. Most drivers should not need this and instead
	// use topology to ensure that pods land on the right node(s).
	ClientNodeName string
}

// List of testSuites to be executed for each external driver.
var csiTestSuites = []func() testsuites.TestSuite{
	testsuites.InitEphemeralTestSuite,
	testsuites.InitMultiVolumeTestSuite,
	testsuites.InitProvisioningTestSuite,
	testsuites.InitSnapshottableTestSuite,
	testsuites.InitSubPathTestSuite,
	testsuites.InitVolumeIOTestSuite,
	testsuites.InitVolumeModeTestSuite,
	testsuites.InitVolumesTestSuite,
	testsuites.InitVolumeExpandTestSuite,
	testsuites.InitDisruptiveTestSuite,
	testsuites.InitVolumeLimitsTestSuite,
}

func init() {
	config.Flags.Var(testDriverParameter{}, "storage.testdriver", "name of a .yaml or .json file that defines a driver for storage testing, can be used more than once")
}

// testDriverParameter is used to hook loading of the driver
// definition file and test instantiation into argument parsing: for
// each of potentially many parameters, Set is called and then does
// both immediately. There is no other code location between argument
// parsing and starting of the test suite where those test could be
// defined.
type testDriverParameter struct {
}

var _ flag.Value = testDriverParameter{}

func (t testDriverParameter) String() string {
	return "<.yaml or .json file>"
}

func (t testDriverParameter) Set(filename string) error {
	return AddDriverDefinition(filename)
}

// AddDriverDefinition defines ginkgo tests for CSI driver definition file.
// Either --storage.testdriver cmdline argument or AddDriverDefinition can be used
// to define the tests.
func AddDriverDefinition(filename string) error {
	driver, err := loadDriverDefinition(filename)
	if err != nil {
		return err
	}
	if driver.DriverInfo.Name == "" {
		return errors.Errorf("%q: DriverInfo.Name not set", filename)
	}

	description := "External Storage " + testsuites.GetDriverNameWithFeatureTags(driver)
	ginkgo.Describe(description, func() {
		testsuites.DefineTestSuite(driver, csiTestSuites)
	})

	return nil
}

func loadDriverDefinition(filename string) (*driverDefinition, error) {
	if filename == "" {
		return nil, errors.New("missing file name")
	}
	data, err := ioutil.ReadFile(filename)
	if err != nil {
		return nil, err
	}
	// Some reasonable defaults follow.
	driver := &driverDefinition{
		DriverInfo: testsuites.DriverInfo{
			SupportedFsType: sets.NewString(
				"", // Default fsType
			),
		},
		SupportedSizeRange: volume.SizeRange{
			Min: "5Gi",
		},
	}
	// TODO: strict checking of the file content once https://github.com/kubernetes/kubernetes/pull/71589
	// or something similar is merged.
	if err := runtime.DecodeInto(scheme.Codecs.UniversalDecoder(), data, driver); err != nil {
		return nil, errors.Wrap(err, filename)
	}
	return driver, nil
}

var _ testsuites.TestDriver = &driverDefinition{}

// We have to implement the interface because dynamic PV may or may
// not be supported. driverDefinition.SkipUnsupportedTest checks that
// based on the actual driver definition.
var _ testsuites.DynamicPVTestDriver = &driverDefinition{}

// Same for snapshotting.
var _ testsuites.SnapshottableTestDriver = &driverDefinition{}

// And for ephemeral volumes.
var _ testsuites.EphemeralTestDriver = &driverDefinition{}

// runtime.DecodeInto needs a runtime.Object but doesn't do any
// deserialization of it and therefore none of the methods below need
// an implementation.
var _ runtime.Object = &driverDefinition{}

func (d *driverDefinition) DeepCopyObject() runtime.Object {
	return nil
}

func (d *driverDefinition) GetObjectKind() schema.ObjectKind {
	return nil
}

func (d *driverDefinition) GetDriverInfo() *testsuites.DriverInfo {
	return &d.DriverInfo
}

func (d *driverDefinition) SkipUnsupportedTest(pattern testpatterns.TestPattern) {
	supported := false
	// TODO (?): add support for more volume types
	switch pattern.VolType {
	case "":
		supported = true
	case testpatterns.DynamicPV:
		if d.StorageClass.FromName || d.StorageClass.FromFile != "" || d.StorageClass.FromExistingClassName != "" {
			supported = true
		}
	case testpatterns.CSIInlineVolume:
		supported = len(d.InlineVolumes) != 0
	}
	if !supported {
		e2eskipper.Skipf("Driver %q does not support volume type %q - skipping", d.DriverInfo.Name, pattern.VolType)
	}

	supported = false
	switch pattern.SnapshotType {
	case "":
		supported = true
	case testpatterns.DynamicCreatedSnapshot:
		if d.SnapshotClass.FromName {
			supported = true
		}
	}
	if !supported {
		e2eskipper.Skipf("Driver %q does not support snapshot type %q - skipping", d.DriverInfo.Name, pattern.SnapshotType)
	}
}

func (d *driverDefinition) GetDynamicProvisionStorageClass(config *testsuites.PerTestConfig, fsType string) *storagev1.StorageClass {
	var (
		sc  *storagev1.StorageClass
		err error
	)

	f := config.Framework

	switch {
	case d.StorageClass.FromName:
		sc = &storagev1.StorageClass{Provisioner: d.DriverInfo.Name}
	case d.StorageClass.FromExistingClassName != "":
		sc, err = f.ClientSet.StorageV1().StorageClasses().Get(context.TODO(), d.StorageClass.FromExistingClassName, metav1.GetOptions{})
		framework.ExpectNoError(err, "getting storage class %s", d.StorageClass.FromExistingClassName)
	case d.StorageClass.FromFile != "":
		var ok bool

		items, err := utils.LoadFromManifests(d.StorageClass.FromFile)
		framework.ExpectNoError(err, "load storage class from %s", d.StorageClass.FromFile)
		framework.ExpectEqual(len(items), 1, "exactly one item from %s", d.StorageClass.FromFile)

		err = utils.PatchItems(f, items...)
		framework.ExpectNoError(err, "patch items")

		sc, ok = items[0].(*storagev1.StorageClass)
		framework.ExpectEqual(ok, true, "storage class from %s", d.StorageClass.FromFile)
	}

	framework.ExpectNotEqual(sc, nil, "storage class is unexpectantly nil")

	if fsType != "" {
		if sc.Parameters == nil {
			sc.Parameters = map[string]string{}
		}
		// This limits the external storage test suite to only CSI drivers, which may need to be
		// reconsidered if we eventually need to move in-tree storage tests out.
		sc.Parameters["csi.storage.k8s.io/fstype"] = fsType
	}
	return testsuites.GetStorageClass(sc.Provisioner, sc.Parameters, sc.VolumeBindingMode, f.Namespace.Name, "e2e-sc")
}

func (d *driverDefinition) GetSnapshotClass(config *testsuites.PerTestConfig) *unstructured.Unstructured {
	if !d.SnapshotClass.FromName {
		e2eskipper.Skipf("Driver %q does not support snapshotting - skipping", d.DriverInfo.Name)
	}

	snapshotter := d.DriverInfo.Name
	parameters := map[string]string{}
	ns := config.Framework.Namespace.Name
	suffix := snapshotter + "-vsc"

	return testsuites.GetSnapshotClass(snapshotter, parameters, ns, suffix)
}

func (d *driverDefinition) GetVolume(config *testsuites.PerTestConfig, volumeNumber int) (map[string]string, bool, bool) {
	if len(d.InlineVolumes) == 0 {
		e2eskipper.Skipf("%s does not have any InlineVolumeAttributes defined", d.DriverInfo.Name)
	}
	volume := d.InlineVolumes[volumeNumber%len(d.InlineVolumes)]
	return volume.Attributes, volume.Shared, volume.ReadOnly
}

func (d *driverDefinition) GetCSIDriverName(config *testsuites.PerTestConfig) string {
	return d.DriverInfo.Name
}

func (d *driverDefinition) PrepareTest(f *framework.Framework) (*testsuites.PerTestConfig, func()) {
	config := &testsuites.PerTestConfig{
		Driver:              d,
		Prefix:              "external",
		Framework:           f,
		ClientNodeSelection: e2epod.NodeSelection{Name: d.ClientNodeName},
	}
	return config, func() {}
}