/*
Copyright 2016 The Rook 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 clusterd

import (
	"regexp"
	"strconv"

	"github.com/coreos/pkg/capnslog"

	"github.com/rook/rook/pkg/util/exec"
	"github.com/rook/rook/pkg/util/sys"
)

var (
	logger = capnslog.NewPackageLogger("github.com/rook/rook", "inventory")
	isRBD  = regexp.MustCompile("^rbd[0-9]+p?[0-9]{0,}$")
)

type LocalDisk struct {
	Name        string `json:"name"`
	ID          string `json:"id"`
	UUID        string `json:"uuid"`
	Size        uint64 `json:"size"`
	Rotational  bool   `json:"rotational"`
	Readonly    bool   `json:"readonly"`
	FileSystem  string `json:"fileSystem"`
	MountPoint  string `json:"mountPoint"`
	Type        string `json:"type"`
	Parent      string `json:"parent"`
	HasChildren bool   `json:"hasChildren"`
	Empty       bool   `json:"empty"`
}

func GetAvailableDevices(devices []*LocalDisk) []string {

	var available []string
	for _, device := range devices {
		logger.Debugf("Evaluating device %+v", device)
		if getDeviceEmpty(device) {
			logger.Debugf("Available device: %s", device.Name)
			available = append(available, device.Name)
		}
	}

	return available
}

// check whether a device is completely empty
func getDeviceEmpty(device *LocalDisk) bool {
	return device.Parent == "" && device.Type == sys.DiskType && device.FileSystem == ""
}

func ignoreDevice(d string) bool {
	return isRBD.MatchString(d)
}

// Discover all the details of devices available on the local node
func DiscoverDevices(executor exec.Executor) ([]*LocalDisk, error) {

	var disks []*LocalDisk
	devices, err := sys.ListDevices(executor)
	if err != nil {
		return nil, err
	}

	for _, d := range devices {

		if ignoreDevice(d) {
			// skip device
			continue
		}

		diskProps, err := sys.GetDeviceProperties(d, executor)
		if err != nil {
			logger.Warningf("skipping device %s: %+v", d, err)
			continue
		}

		diskType, ok := diskProps["TYPE"]
		if !ok || (diskType != sys.SSDType && diskType != sys.DiskType && diskType != sys.PartType) {
			// unsupported disk type, just continue
			continue
		}

		// get the UUID for disks
		var diskUUID string
		if diskType != sys.PartType {
			diskUUID, err = sys.GetDiskUUID(d, executor)
			if err != nil {
				logger.Warningf("skipping device %s with an unknown uuid. %+v", d, err)
				continue
			}
		}

		fs, err := sys.GetDeviceFilesystems(d, executor)
		if err != nil {
			return nil, err
		}

		disk := &LocalDisk{Name: d, UUID: diskUUID, FileSystem: fs}

		if val, ok := diskProps["TYPE"]; ok {
			disk.Type = val
		}
		if val, ok := diskProps["SIZE"]; ok {
			if size, err := strconv.ParseUint(val, 10, 64); err == nil {
				disk.Size = size
			}
		}
		if val, ok := diskProps["ROTA"]; ok {
			if rotates, err := strconv.ParseBool(val); err == nil {
				disk.Rotational = rotates
			}
		}
		if val, ok := diskProps["RO"]; ok {
			if ro, err := strconv.ParseBool(val); err == nil {
				disk.Readonly = ro
			}
		}
		if val, ok := diskProps["PKNAME"]; ok {
			disk.Parent = val
		}

		disk.Empty = getDeviceEmpty(disk)

		disks = append(disks, disk)
	}

	return disks, nil
}