/*
Copyright 2020 The Flux 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 main

import (
	"context"
	"fmt"
	"strings"
	"time"

	"github.com/spf13/cobra"
	"k8s.io/apimachinery/pkg/api/errors"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/types"
	"k8s.io/apimachinery/pkg/util/wait"
	"sigs.k8s.io/controller-runtime/pkg/client"

	helmv2 "github.com/fluxcd/helm-controller/api/v2"
	kustomizev1 "github.com/fluxcd/kustomize-controller/api/v1"
	"github.com/fluxcd/pkg/apis/meta"

	"github.com/fluxcd/flux2/v2/internal/flags"
	"github.com/fluxcd/flux2/v2/internal/utils"
)

var createKsCmd = &cobra.Command{
	Use:     "kustomization [name]",
	Aliases: []string{"ks"},
	Short:   "Create or update a Kustomization resource",
	Long:    `The create command generates a Kustomization resource for a given source.`,
	Example: `  # Create a Kustomization resource from a source at a given path
  flux create kustomization kyverno \
    --source=GitRepository/kyverno \
    --path="./config/release" \
    --prune=true \
    --interval=60m \
    --wait=true \
    --health-check-timeout=3m

  # Create a Kustomization resource that depends on the previous one
  flux create kustomization kyverno-policies \
    --depends-on=kyverno \
    --source=GitRepository/kyverno-policies \
    --path="./policies/flux" \
    --prune=true \
    --interval=5m

  # Create a Kustomization using a source from a different namespace
  flux create kustomization podinfo \
    --namespace=default \
    --source=GitRepository/podinfo.flux-system \
    --path="./kustomize" \
    --prune=true \
    --interval=5m

  # Create a Kustomization resource that references an OCIRepository
  flux create kustomization podinfo \
    --source=OCIRepository/podinfo \
    --target-namespace=default \
    --prune=true \
    --interval=5m

  # Create a Kustomization resource that references a Bucket
  flux create kustomization secrets \
    --source=Bucket/secrets \
    --prune=true \
    --interval=5m`,
	RunE: createKsCmdRun,
}

type kustomizationFlags struct {
	source              flags.KustomizationSource
	path                flags.SafeRelativePath
	prune               bool
	dependsOn           []string
	validation          string
	healthCheck         []string
	healthTimeout       time.Duration
	saName              string
	decryptionProvider  flags.DecryptionProvider
	decryptionSecret    string
	targetNamespace     string
	wait                bool
	kubeConfigSecretRef string
	retryInterval       time.Duration
}

var kustomizationArgs = NewKustomizationFlags()

func init() {
	createKsCmd.Flags().Var(&kustomizationArgs.source, "source", kustomizationArgs.source.Description())
	createKsCmd.Flags().Var(&kustomizationArgs.path, "path", "path to the directory containing a kustomization.yaml file")
	createKsCmd.Flags().BoolVar(&kustomizationArgs.prune, "prune", false, "enable garbage collection")
	createKsCmd.Flags().BoolVar(&kustomizationArgs.wait, "wait", false, "enable health checking of all the applied resources")
	createKsCmd.Flags().StringSliceVar(&kustomizationArgs.healthCheck, "health-check", nil, "workload to be included in the health assessment, in the format '<kind>/<name>.<namespace>'")
	createKsCmd.Flags().DurationVar(&kustomizationArgs.healthTimeout, "health-check-timeout", 2*time.Minute, "timeout of health checking operations")
	createKsCmd.Flags().StringVar(&kustomizationArgs.validation, "validation", "", "validate the manifests before applying them on the cluster, can be 'client' or 'server'")
	createKsCmd.Flags().StringSliceVar(&kustomizationArgs.dependsOn, "depends-on", nil, "Kustomization that must be ready before this Kustomization can be applied, supported formats '<name>' and '<namespace>/<name>', also accepts comma-separated values")
	createKsCmd.Flags().StringVar(&kustomizationArgs.saName, "service-account", "", "the name of the service account to impersonate when reconciling this Kustomization")
	createKsCmd.Flags().Var(&kustomizationArgs.decryptionProvider, "decryption-provider", kustomizationArgs.decryptionProvider.Description())
	createKsCmd.Flags().StringVar(&kustomizationArgs.decryptionSecret, "decryption-secret", "", "set the Kubernetes secret name that contains the OpenPGP private keys used for sops decryption")
	createKsCmd.Flags().StringVar(&kustomizationArgs.targetNamespace, "target-namespace", "", "overrides the namespace of all Kustomization objects reconciled by this Kustomization")
	createKsCmd.Flags().StringVar(&kustomizationArgs.kubeConfigSecretRef, "kubeconfig-secret-ref", "", "the name of the Kubernetes Secret that contains a key with the kubeconfig file for connecting to a remote cluster")
	createKsCmd.Flags().MarkDeprecated("validation", "this arg is no longer used, all resources are validated using server-side apply dry-run")
	createKsCmd.Flags().DurationVar(&kustomizationArgs.retryInterval, "retry-interval", 0, "the interval at which to retry a previously failed reconciliation")

	createCmd.AddCommand(createKsCmd)
}

func NewKustomizationFlags() kustomizationFlags {
	return kustomizationFlags{
		path: "./",
	}
}

func createKsCmdRun(cmd *cobra.Command, args []string) error {
	name := args[0]

	if kustomizationArgs.path == "" {
		return fmt.Errorf("path is required")
	}
	if !strings.HasPrefix(kustomizationArgs.path.String(), "./") {
		return fmt.Errorf("path must begin with ./")
	}
	if kustomizationArgs.source.Name == "" {
		return fmt.Errorf("source is required")
	}

	if !createArgs.export {
		logger.Generatef("generating Kustomization")
	}

	kslabels, err := parseLabels()
	if err != nil {
		return err
	}

	kustomization := kustomizev1.Kustomization{
		ObjectMeta: metav1.ObjectMeta{
			Name:      name,
			Namespace: *kubeconfigArgs.Namespace,
			Labels:    kslabels,
		},
		Spec: kustomizev1.KustomizationSpec{
			Interval: metav1.Duration{
				Duration: createArgs.interval,
			},
			Path:  kustomizationArgs.path.ToSlash(),
			Prune: kustomizationArgs.prune,
			SourceRef: kustomizev1.CrossNamespaceSourceReference{
				Kind:      kustomizationArgs.source.Kind,
				Name:      kustomizationArgs.source.Name,
				Namespace: kustomizationArgs.source.Namespace,
			},
			Suspend:         false,
			TargetNamespace: kustomizationArgs.targetNamespace,
		},
	}

	if len(kustomizationArgs.dependsOn) > 0 {
		ls := meta.MakeDependsOn(kustomizationArgs.dependsOn)
		ksDependsOn := make([]kustomizev1.DependencyReference, 0, len(ls))
		for _, d := range ls {
			ksDependsOn = append(ksDependsOn, kustomizev1.DependencyReference{
				Name:      d.Name,
				Namespace: d.Namespace,
			})
		}
		kustomization.Spec.DependsOn = ksDependsOn
	}

	if kustomizationArgs.kubeConfigSecretRef != "" {
		kustomization.Spec.KubeConfig = &meta.KubeConfigReference{
			SecretRef: &meta.SecretKeyReference{
				Name: kustomizationArgs.kubeConfigSecretRef,
			},
		}
	}

	if len(kustomizationArgs.healthCheck) > 0 && !kustomizationArgs.wait {
		healthChecks := make([]meta.NamespacedObjectKindReference, 0)
		for _, w := range kustomizationArgs.healthCheck {
			kindObj := strings.Split(w, "/")
			if len(kindObj) != 2 {
				return fmt.Errorf("invalid health check '%s' must be in the format 'kind/name.namespace' %v", w, kindObj)
			}
			kind := kindObj[0]

			//TODO: (stefan) extend this list with all the kstatus builtin kinds
			kinds := map[string]bool{
				"Deployment":           true,
				"DaemonSet":            true,
				"StatefulSet":          true,
				helmv2.HelmReleaseKind: true,
			}
			if !kinds[kind] {
				return fmt.Errorf("invalid health check kind '%s' can be HelmRelease, Deployment, DaemonSet or StatefulSet", kind)
			}
			nameNs := strings.Split(kindObj[1], ".")
			if len(nameNs) != 2 {
				return fmt.Errorf("invalid health check '%s' must be in the format 'kind/name.namespace'", w)
			}

			check := meta.NamespacedObjectKindReference{
				Kind:      kind,
				Name:      nameNs[0],
				Namespace: nameNs[1],
			}

			if kind == helmv2.HelmReleaseKind {
				check.APIVersion = helmv2.GroupVersion.String()
			}
			healthChecks = append(healthChecks, check)
		}
		kustomization.Spec.HealthChecks = healthChecks
		kustomization.Spec.Timeout = &metav1.Duration{
			Duration: kustomizationArgs.healthTimeout,
		}
	}

	if kustomizationArgs.wait {
		kustomization.Spec.Wait = true
		kustomization.Spec.Timeout = &metav1.Duration{
			Duration: kustomizationArgs.healthTimeout,
		}
	}

	if kustomizationArgs.saName != "" {
		kustomization.Spec.ServiceAccountName = kustomizationArgs.saName
	}

	if kustomizationArgs.decryptionProvider != "" {
		kustomization.Spec.Decryption = &kustomizev1.Decryption{
			Provider: kustomizationArgs.decryptionProvider.String(),
		}

		if kustomizationArgs.decryptionSecret != "" {
			kustomization.Spec.Decryption.SecretRef = &meta.LocalObjectReference{Name: kustomizationArgs.decryptionSecret}
		}
	}

	if kustomizationArgs.retryInterval > 0 {
		kustomization.Spec.RetryInterval = &metav1.Duration{Duration: kustomizationArgs.retryInterval}
	}

	if createArgs.export {
		return printExport(exportKs(&kustomization))
	}

	ctx, cancel := context.WithTimeout(context.Background(), rootArgs.timeout)
	defer cancel()

	kubeClient, err := utils.KubeClient(kubeconfigArgs, kubeclientOptions)
	if err != nil {
		return err
	}

	logger.Actionf("applying Kustomization")
	namespacedName, err := upsertKustomization(ctx, kubeClient, &kustomization)
	if err != nil {
		return err
	}

	logger.Waitingf("waiting for Kustomization reconciliation")
	if err := wait.PollUntilContextTimeout(ctx, rootArgs.pollInterval, rootArgs.timeout, true,
		isObjectReadyConditionFunc(kubeClient, namespacedName, &kustomization)); err != nil {
		return err
	}
	logger.Successf("Kustomization %s is ready", name)

	logger.Successf("applied revision %s", kustomization.Status.LastAppliedRevision)
	return nil
}

func upsertKustomization(ctx context.Context, kubeClient client.Client,
	kustomization *kustomizev1.Kustomization) (types.NamespacedName, error) {
	namespacedName := types.NamespacedName{
		Namespace: kustomization.GetNamespace(),
		Name:      kustomization.GetName(),
	}

	var existing kustomizev1.Kustomization
	err := kubeClient.Get(ctx, namespacedName, &existing)
	if err != nil {
		if errors.IsNotFound(err) {
			if err := kubeClient.Create(ctx, kustomization); err != nil {
				return namespacedName, err
			} else {
				logger.Successf("Kustomization created")
				return namespacedName, nil
			}
		}
		return namespacedName, err
	}

	existing.Labels = kustomization.Labels
	existing.Spec = kustomization.Spec
	if err := kubeClient.Update(ctx, &existing); err != nil {
		return namespacedName, err
	}
	kustomization = &existing
	logger.Successf("Kustomization updated")
	return namespacedName, nil
}
