// Copyright (c) 2022 Alibaba Group Holding Ltd.
//
// 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 kubernetes

import (
	"bytes"
	"context"
	"errors"
	"fmt"
	"io"
	"net/http"
	"strings"
	"testing"

	ingress "github.com/alibaba/higress/test/ingress/conformance"
	"github.com/stretchr/testify/require"
	apierrors "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
	"k8s.io/apimachinery/pkg/types"
	"k8s.io/apimachinery/pkg/util/yaml"
	"sigs.k8s.io/controller-runtime/pkg/client"

	"github.com/alibaba/higress/test/ingress/conformance/utils/config"
)

// Applier prepares manifests depending on the available options and applies
// them to the Kubernetes cluster.
type Applier struct {
	NamespaceLabels map[string]string

	// IngressClass will be used as the spec.ingressClassName when applying Ingress resources
	IngressClass string
}

// prepareNamespace adjusts the Namespace labels.
func prepareNamespace(t *testing.T, uObj *unstructured.Unstructured, namespaceLabels map[string]string) {
	labels, _, err := unstructured.NestedStringMap(uObj.Object, "metadata", "labels")
	require.NoErrorf(t, err, "error getting labels on Namespace %s", uObj.GetName())

	for k, v := range namespaceLabels {
		if labels == nil {
			labels = map[string]string{}
		}

		labels[k] = v
	}

	// SetNestedStringMap converts nil to an empty map
	if labels != nil {
		err = unstructured.SetNestedStringMap(uObj.Object, labels, "metadata", "labels")
	}
	require.NoErrorf(t, err, "error setting labels on Namespace %s", uObj.GetName())
}

// prepareResources uses the options from an Applier to tweak resources given by
// a set of manifests.
func (a Applier) prepareResources(t *testing.T, decoder *yaml.YAMLOrJSONDecoder) ([]unstructured.Unstructured, error) {
	var resources []unstructured.Unstructured

	for {
		uObj := unstructured.Unstructured{}
		if err := decoder.Decode(&uObj); err != nil {
			if errors.Is(err, io.EOF) {
				break
			}
			return nil, err
		}
		if len(uObj.Object) == 0 {
			continue
		}

		if uObj.GetKind() == "Namespace" && uObj.GetObjectKind().GroupVersionKind().Group == "" {
			prepareNamespace(t, &uObj, a.NamespaceLabels)
		}

		resources = append(resources, uObj)
	}

	return resources, nil
}

func (a Applier) MustApplyObjectsWithCleanup(t *testing.T, c client.Client, timeoutConfig config.TimeoutConfig, resources []client.Object, cleanup bool) {
	for _, resource := range resources {
		resource := resource

		ctx, cancel := context.WithTimeout(context.Background(), timeoutConfig.CreateTimeout)
		defer cancel()

		t.Logf("Creating %s %s", resource.GetName(), resource.GetObjectKind().GroupVersionKind().Kind)

		err := c.Create(ctx, resource)
		if err != nil {
			if !apierrors.IsAlreadyExists(err) {
				require.NoError(t, err, "error creating resource")
			}
		}

		if cleanup {
			t.Cleanup(func() {
				ctx, cancel = context.WithTimeout(context.Background(), timeoutConfig.DeleteTimeout)
				defer cancel()
				t.Logf("Deleting %s %s", resource.GetName(), resource.GetObjectKind().GroupVersionKind().Kind)
				err = c.Delete(ctx, resource)
				require.NoErrorf(t, err, "error deleting resource")
			})
		}
	}
}

// MustApplyWithCleanup creates or updates Kubernetes resources defined with the
// provided YAML file and registers a cleanup function for resources it created.
// Note that this does not remove resources that already existed in the cluster.
func (a Applier) MustApplyWithCleanup(t *testing.T, c client.Client, timeoutConfig config.TimeoutConfig, location string, cleanup bool) {
	data, err := getContentsFromPathOrURL(location, timeoutConfig)
	require.NoError(t, err)

	decoder := yaml.NewYAMLOrJSONDecoder(data, 4096)

	resources, err := a.prepareResources(t, decoder)
	if err != nil {
		t.Logf("manifest: %s", data.String())
		require.NoErrorf(t, err, "error parsing manifest")
	}

	for i := range resources {
		uObj := &resources[i]

		ctx, cancel := context.WithTimeout(context.Background(), timeoutConfig.CreateTimeout)
		defer cancel()

		namespacedName := types.NamespacedName{Namespace: uObj.GetNamespace(), Name: uObj.GetName()}
		fetchedObj := uObj.DeepCopy()
		err := c.Get(ctx, namespacedName, fetchedObj)
		if err != nil {
			if !apierrors.IsNotFound(err) {
				require.NoErrorf(t, err, "error getting resource")
			}
			t.Logf("Creating %s %s", uObj.GetName(), uObj.GetKind())
			err = c.Create(ctx, uObj)
			require.NoErrorf(t, err, "error creating resource")

			if cleanup {
				t.Cleanup(func() {
					ctx, cancel = context.WithTimeout(context.Background(), timeoutConfig.DeleteTimeout)
					defer cancel()
					t.Logf("Deleting %s %s", uObj.GetName(), uObj.GetKind())
					err = c.Delete(ctx, uObj)
					require.NoErrorf(t, err, "error deleting resource")
				})
			}
			continue
		}

		uObj.SetResourceVersion(fetchedObj.GetResourceVersion())
		t.Logf("Updating %s %s", uObj.GetName(), uObj.GetKind())
		err = c.Update(ctx, uObj)

		if cleanup {
			t.Cleanup(func() {
				ctx, cancel = context.WithTimeout(context.Background(), timeoutConfig.DeleteTimeout)
				defer cancel()
				t.Logf("Deleting %s %s", uObj.GetName(), uObj.GetKind())
				err = c.Delete(ctx, uObj)
				require.NoErrorf(t, err, "error deleting resource")
			})
		}
		require.NoErrorf(t, err, "error updating resource")
	}
}

// getContentsFromPathOrURL takes a string that can either be a local file
// path or an https:// URL to YAML manifests and provides the contents.
func getContentsFromPathOrURL(location string, timeoutConfig config.TimeoutConfig) (*bytes.Buffer, error) {
	if strings.HasPrefix(location, "http://") {
		return nil, fmt.Errorf("data can't be retrieved from %s: http is not supported, use https", location)
	} else if strings.HasPrefix(location, "https://") {
		ctx, cancel := context.WithTimeout(context.Background(), timeoutConfig.ManifestFetchTimeout)
		defer cancel()

		req, err := http.NewRequestWithContext(ctx, http.MethodGet, location, nil)
		if err != nil {
			return nil, err
		}

		resp, err := http.DefaultClient.Do(req)
		if err != nil {
			return nil, err
		}
		defer resp.Body.Close()

		manifests := new(bytes.Buffer)
		count, err := manifests.ReadFrom(resp.Body)
		if err != nil {
			return nil, err
		}

		if resp.ContentLength != -1 && count != resp.ContentLength {
			return nil, fmt.Errorf("received %d bytes from %s, expected %d", count, location, resp.ContentLength)
		}
		return manifests, nil
	}
	b, err := ingress.Manifests.ReadFile(location)
	if err != nil {
		return nil, err
	}
	return bytes.NewBuffer(b), nil
}