/*
Copyright 2014 The Kubernetes Authors All rights reserved.

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 cmd

import (
	"fmt"
	"io"

	"github.com/spf13/cobra"

	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubectl"
	cmdutil "github.com/GoogleCloudPlatform/kubernetes/pkg/kubectl/cmd/util"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubectl/resource"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
	"github.com/golang/glog"
)

const (
	update_long = `Update a resource by filename or stdin.

JSON and YAML formats are accepted.`
	update_example = `// Update a pod using the data in pod.json.
$ kubectl update -f pod.json

// Update a pod based on the JSON passed into stdin.
$ cat pod.json | kubectl update -f -

// Partially update a node using strategic merge patch
kubectl --api-version=v1 update node k8s-node-1 --patch='{"spec":{"unschedulable":true}}'

// Force update, delete and then re-create the resource
kubectl update --force -f pod.json`
)

func NewCmdUpdate(f *cmdutil.Factory, out io.Writer) *cobra.Command {
	var filenames util.StringList
	cmd := &cobra.Command{
		Use:     "update -f FILENAME",
		Short:   "Update a resource by filename or stdin.",
		Long:    update_long,
		Example: update_example,
		Run: func(cmd *cobra.Command, args []string) {
			err := RunUpdate(f, out, cmd, args, filenames)
			cmdutil.CheckCustomErr("Update failed", err)
		},
	}
	usage := "Filename, directory, or URL to file to use to update the resource."
	kubectl.AddJsonFilenameFlag(cmd, &filenames, usage)
	cmd.MarkFlagRequired("filename")
	cmd.Flags().String("patch", "", "A JSON document to override the existing resource. The resource is downloaded, patched with the JSON, then updated.")
	cmd.MarkFlagRequired("patch")
	cmd.Flags().Bool("force", false, "Delete and re-create the specified resource")
	cmd.Flags().Bool("cascade", false, "Only relevant during a force update. If true, cascade the deletion of the resources managed by this resource (e.g. Pods created by a ReplicationController).  Default true.")
	cmd.Flags().Int("grace-period", -1, "Only relevant during a force update. Period of time in seconds given to the old resource to terminate gracefully. Ignored if negative.")
	cmd.Flags().Duration("timeout", 0, "Only relevant during a force update. The length of time to wait before giving up on a delete of the old resource, zero means determine a timeout from the size of the object")
	return cmd
}

func RunUpdate(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []string, filenames util.StringList) error {
	schema, err := f.Validator()
	if err != nil {
		return err
	}

	cmdNamespace, err := f.DefaultNamespace()
	if err != nil {
		return err
	}

	force := cmdutil.GetFlagBool(cmd, "force")
	patch := cmdutil.GetFlagString(cmd, "patch")
	if len(filenames) == 0 && len(patch) == 0 {
		return cmdutil.UsageError(cmd, "Must specify --filename or --patch to update")
	}
	if len(filenames) != 0 && len(patch) != 0 {
		return cmdutil.UsageError(cmd, "Can not specify both --filename and --patch")
	}
	if len(filenames) == 0 && force {
		return cmdutil.UsageError(cmd, "--force can only be used with --filename")
	}

	// TODO: Make patching work with -f, updating with patched JSON input files
	if len(filenames) == 0 {
		name, err := updateWithPatch(cmd, args, f, patch)
		if err != nil {
			return err
		}
		fmt.Fprintf(out, "%s\n", name)
		return nil
	}
	if len(filenames) == 0 {
		return cmdutil.UsageError(cmd, "Must specify --filename to update")
	}

	if force {
		return forceUpdate(f, out, cmd, args, filenames)
	}

	mapper, typer := f.Object()
	r := resource.NewBuilder(mapper, typer, f.ClientMapperForCommand()).
		Schema(schema).
		ContinueOnError().
		NamespaceParam(cmdNamespace).RequireNamespace().
		FilenameParam(filenames...).
		Flatten().
		Do()
	err = r.Err()
	if err != nil {
		return err
	}

	return r.Visit(func(info *resource.Info) error {
		data, err := info.Mapping.Codec.Encode(info.Object)
		if err != nil {
			return cmdutil.AddSourceToErr("updating", info.Source, err)
		}
		obj, err := resource.NewHelper(info.Client, info.Mapping).Update(info.Namespace, info.Name, true, data)
		if err != nil {
			return cmdutil.AddSourceToErr("updating", info.Source, err)
		}
		info.Refresh(obj, true)
		printObjectSpecificMessage(obj, out)
		fmt.Fprintf(out, "%s/%s\n", info.Mapping.Resource, info.Name)
		return nil
	})
}

func updateWithPatch(cmd *cobra.Command, args []string, f *cmdutil.Factory, patch string) (string, error) {
	cmdNamespace, err := f.DefaultNamespace()
	if err != nil {
		return "", err
	}

	mapper, typer := f.Object()
	r := resource.NewBuilder(mapper, typer, f.ClientMapperForCommand()).
		ContinueOnError().
		NamespaceParam(cmdNamespace).DefaultNamespace().
		ResourceTypeOrNameArgs(false, args...).
		Flatten().
		Do()
	err = r.Err()
	if err != nil {
		return "", err
	}
	mapping, err := r.ResourceMapping()
	if err != nil {
		return "", err
	}
	client, err := f.RESTClient(mapping)
	if err != nil {
		return "", err
	}

	infos, err := r.Infos()
	if err != nil {
		return "", err
	}
	name, namespace := infos[0].Name, infos[0].Namespace

	helper := resource.NewHelper(client, mapping)
	_, err = helper.Patch(namespace, name, api.StrategicMergePatchType, []byte(patch))
	return name, err
}

func forceUpdate(f *cmdutil.Factory, out io.Writer, cmd *cobra.Command, args []string, filenames util.StringList) error {
	schema, err := f.Validator()
	if err != nil {
		return err
	}

	cmdNamespace, err := f.DefaultNamespace()
	if err != nil {
		return err
	}

	mapper, typer := f.Object()
	r := resource.NewBuilder(mapper, typer, f.ClientMapperForCommand()).
		ContinueOnError().
		NamespaceParam(cmdNamespace).DefaultNamespace().
		FilenameParam(filenames...).
		ResourceTypeOrNameArgs(false, args...).RequireObject(false).
		Flatten().
		Do()
	err = r.Err()
	if err != nil {
		return err
	}
	//Update will create a resource if it doesn't exist already, so ignore not found error
	ignoreNotFound := true
	// By default use a reaper to delete all related resources.
	if cmdutil.GetFlagBool(cmd, "cascade") {
		glog.Warningf("\"cascade\" is set, kubectl will delete and re-create all resources managed by this resource (e.g. Pods created by a ReplicationController). Consider using \"kubectl rolling-update\" if you want to update a ReplicationController together with its Pods.")
		err = ReapResult(r, f, out, cmdutil.GetFlagBool(cmd, "cascade"), ignoreNotFound, cmdutil.GetFlagDuration(cmd, "timeout"), cmdutil.GetFlagInt(cmd, "grace-period"))
	} else {
		err = DeleteResult(r, out, ignoreNotFound)
	}
	if err != nil {
		return err
	}

	r = resource.NewBuilder(mapper, typer, f.ClientMapperForCommand()).
		Schema(schema).
		ContinueOnError().
		NamespaceParam(cmdNamespace).RequireNamespace().
		FilenameParam(filenames...).
		Flatten().
		Do()
	err = r.Err()
	if err != nil {
		return err
	}

	count := 0
	err = r.Visit(func(info *resource.Info) error {
		data, err := info.Mapping.Codec.Encode(info.Object)
		if err != nil {
			return err
		}
		obj, err := resource.NewHelper(info.Client, info.Mapping).Create(info.Namespace, true, data)
		if err != nil {
			return err
		}
		count++
		info.Refresh(obj, true)
		printObjectSpecificMessage(obj, out)
		fmt.Fprintf(out, "%s/%s\n", info.Mapping.Resource, info.Name)
		return nil
	})
	if err != nil {
		return err
	}
	if count == 0 {
		return fmt.Errorf("no objects passed to update")
	}
	return nil
}