/*
Copyright (c) 2015 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 storage

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

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

type partition struct {
	*flags.HostSystemFlag
	*flags.OutputFlag
}

func init() {
	cli.Register("host.storage.partition", &partition{})
}

func (cmd *partition) Register(ctx context.Context, f *flag.FlagSet) {
	cmd.HostSystemFlag, ctx = flags.NewHostSystemFlag(ctx)
	cmd.HostSystemFlag.Register(ctx, f)
	cmd.OutputFlag, ctx = flags.NewOutputFlag(ctx)
	cmd.OutputFlag.Register(ctx, f)
}

func (cmd *partition) Process(ctx context.Context) error {
	if err := cmd.HostSystemFlag.Process(ctx); err != nil {
		return err
	}
	if err := cmd.OutputFlag.Process(ctx); err != nil {
		return err
	}
	return nil
}

func (cmd *partition) Usage() string {
	return "DEVICE_PATH"
}

func (cmd *partition) Description() string {
	return `Show partition table for device at DEVICE_PATH.`
}

func (cmd *partition) Run(ctx context.Context, f *flag.FlagSet) error {
	if f.NArg() != 1 {
		return fmt.Errorf("specify device path")
	}

	path := f.Args()[0]

	host, err := cmd.HostSystem()
	if err != nil {
		return err
	}

	ss, err := host.ConfigManager().StorageSystem(ctx)
	if err != nil {
		return err
	}

	var hss mo.HostStorageSystem
	err = ss.Properties(ctx, ss.Reference(), nil, &hss)
	if err != nil {
		return nil
	}

	info, err := ss.RetrieveDiskPartitionInfo(ctx, path)
	if err != nil {
		return err
	}

	return cmd.WriteResult(partitionInfo(*info))
}

type partitionInfo types.HostDiskPartitionInfo

func (p partitionInfo) Write(w io.Writer) error {
	tw := tabwriter.NewWriter(w, 2, 0, 2, ' ', 0)

	fmt.Fprintf(tw, "Table format: %s\n", p.Spec.PartitionFormat)
	fmt.Fprintf(tw, "Number of sectors: %d\n", p.Spec.TotalSectors)
	fmt.Fprintf(tw, "\n")

	fmt.Fprintf(tw, "Number\t")
	fmt.Fprintf(tw, "Start\t")
	fmt.Fprintf(tw, "End\t")
	fmt.Fprintf(tw, "Size\t")
	fmt.Fprintf(tw, "Type\t")
	fmt.Fprintf(tw, "\n")

	for _, e := range p.Spec.Partition {
		sectors := e.EndSector - e.StartSector

		fmt.Fprintf(tw, "%d\t", e.Partition)
		fmt.Fprintf(tw, "%d\t", e.StartSector)
		fmt.Fprintf(tw, "%d\t", e.EndSector)
		fmt.Fprintf(tw, "%s\t", units.ByteSize(sectors*512))
		fmt.Fprintf(tw, "%s\t", e.Type)
		fmt.Fprintf(tw, "\n")
	}

	return tw.Flush()
}