/*
Copyright (c) 2018 VMware, Inc. 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 cluster

import (
	"context"
	"flag"
	"fmt"
	"io"
	"os"
	"text/tabwriter"

	"github.com/vmware/govmomi/govc/cli"
	"github.com/vmware/govmomi/govc/flags"
	"github.com/vmware/govmomi/object"
	"github.com/vmware/govmomi/property"
	"github.com/vmware/govmomi/vim25/mo"
	"github.com/vmware/govmomi/vim25/types"
)

type info struct {
	*flags.DatacenterFlag
}

func init() {
	cli.Register("datastore.cluster.info", &info{})
}

func (cmd *info) Register(ctx context.Context, f *flag.FlagSet) {
	cmd.DatacenterFlag, ctx = flags.NewDatacenterFlag(ctx)
	cmd.DatacenterFlag.Register(ctx, f)
}

func (cmd *info) Usage() string {
	return "[PATH]..."
}

func (cmd *info) Description() string {
	return `Display datastore cluster info.

Examples:
  govc datastore.cluster.info
  govc datastore.cluster.info MyDatastoreCluster`
}

func (cmd *info) Run(ctx context.Context, f *flag.FlagSet) error {
	c, err := cmd.Client()
	if err != nil {
		return err
	}

	finder, err := cmd.Finder()
	if err != nil {
		return err
	}

	args := f.Args()
	if len(args) == 0 {
		args = []string{"*"}
	}

	var res infoResult
	var props []string

	if cmd.OutputFlag.All() {
		props = nil // Load everything
	} else {
		props = []string{"podStorageDrsEntry", "summary"} // Load summary
	}

	for _, arg := range args {
		objects, err := finder.DatastoreClusterList(ctx, arg)
		if err != nil {
			return err
		}
		res.objects = append(res.objects, objects...)
	}

	if len(res.objects) != 0 {
		refs := make([]types.ManagedObjectReference, 0, len(res.objects))
		for _, o := range res.objects {
			refs = append(refs, o.Reference())
		}

		pc := property.DefaultCollector(c)
		err = pc.Retrieve(ctx, refs, props, &res.Clusters)
		if err != nil {
			return err
		}
	}

	return cmd.WriteResult(&res)
}

type infoResult struct {
	Clusters []mo.StoragePod
	objects  []*object.StoragePod
}

func (r *infoResult) Write(w io.Writer) error {
	// Maintain order via r.objects as Property collector does not always return results in order.
	objects := make(map[types.ManagedObjectReference]mo.StoragePod, len(r.Clusters))
	for _, o := range r.Clusters {
		objects[o.Reference()] = o
	}

	tw := tabwriter.NewWriter(os.Stdout, 2, 0, 2, ' ', 0)

	for _, o := range r.objects {
		ds := objects[o.Reference()]
		s := ds.Summary
		c := ds.PodStorageDrsEntry.StorageDrsConfig
		fmt.Fprintf(tw, "Name:\t%s\n", s.Name)
		fmt.Fprintf(tw, "  Path:\t%s\n", o.InventoryPath)
		fmt.Fprintf(tw, "  Capacity:\t%.1f GB\n", float64(s.Capacity)/(1<<30))
		fmt.Fprintf(tw, "  Free:\t%.1f GB\n", float64(s.FreeSpace)/(1<<30))
		fmt.Fprintf(tw, "  SDRS Enabled:\t%t\n", c.PodConfig.Enabled)
		fmt.Fprintf(tw, "  SDRS Mode:\t%s\n", c.PodConfig.DefaultVmBehavior)
	}

	return tw.Flush()
}
