/*
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 client

import (
	"encoding/json"
	"fmt"
	"syscall"

	"strconv"

	"regexp"

	"github.com/pkg/errors"
	"github.com/rook/rook/pkg/clusterd"
	"github.com/rook/rook/pkg/util/display"
	"github.com/rook/rook/pkg/util/exec"
)

const (
	ImageMinSize = uint64(1048576) // 1 MB
)

type CephBlockImage struct {
	Name     string `json:"image"`
	Size     uint64 `json:"size"`
	Format   int    `json:"format"`
	InfoName string `json:"name"`
}

func ListImages(context *clusterd.Context, clusterName, poolName string) ([]CephBlockImage, error) {
	args := []string{"ls", "-l", poolName}
	cmd := NewRBDCommand(context, clusterName, args)
	cmd.JsonOutput = true
	buf, err := cmd.Run()
	if err != nil {
		return nil, errors.Wrapf(err, "failed to list images for pool %s", poolName)
	}

	//The regex expression captures the json result at the end buf
	//When logLevel is DEBUG buf contains log statements of librados (see tests for examples)
	//It can happen that the end of the "real" output doesn't not contain a new line
	//that's why looking for the end isn't an option here (anymore?)
	res := regexp.MustCompile(`(?m)^\[(.*)\]`).FindStringSubmatch(string(buf))
	if len(res) == 0 {
		return []CephBlockImage{}, nil
	}
	buf = []byte(res[0])

	var images []CephBlockImage
	if err = json.Unmarshal(buf, &images); err != nil {
		return nil, errors.Wrapf(err, "unmarshal failed, raw buffer response: %s", string(buf))
	}

	return images, nil
}

// CreateImage creates a block storage image.
// If dataPoolName is not empty, the image will use poolName as the metadata pool and the dataPoolname for data.
// If size is zero an empty image will be created. Otherwise, an image will be
// created with a size rounded up to the nearest Mi. The adjusted image size is
// placed in return value CephBlockImage.Size.
func CreateImage(context *clusterd.Context, clusterName, name, poolName, dataPoolName string, size uint64) (*CephBlockImage, error) {
	if size > 0 && size < ImageMinSize {
		// rbd tool uses MB as the smallest unit for size input.  0 is OK but anything else smaller
		// than 1 MB should just be rounded up to 1 MB.
		logger.Warningf("requested image size %d is less than the minimum size of %d, using the minimum.", size, ImageMinSize)
		size = ImageMinSize
	}

	// Roundup the size of the volume image since we only create images on 1MB bundaries and we should never create an image
	// size that's smaller than the requested one, e.g, requested 1048698 bytes should be 2MB while not be truncated to 1MB
	sizeMB := int((size + ImageMinSize - 1) / ImageMinSize)

	imageSpec := getImageSpec(name, poolName)

	args := []string{"create", imageSpec, "--size", strconv.Itoa(sizeMB)}

	if dataPoolName != "" {
		args = append(args, fmt.Sprintf("--data-pool=%s", dataPoolName))
	}

	buf, err := NewRBDCommand(context, clusterName, args).Run()
	if err != nil {
		cmdErr, ok := err.(*exec.CommandError)
		if ok && cmdErr.ExitStatus() == int(syscall.EEXIST) {
			// Image with the same name already exists in the given rbd pool. Continuing with the link to PV.
			logger.Warningf("Requested image %s exists in pool %s. Continuing", name, poolName)
		} else {
			return nil, errors.Wrapf(err, "failed to create image %s in pool %s of size %d, output: %s",
				name, poolName, size, string(buf))
		}
	}

	// report the adjusted size which will always be >= to the requested size
	var newSizeBytes uint64
	if sizeMB > 0 {
		newSizeBytes = display.MbTob(uint64(sizeMB))
	} else {
		newSizeBytes = 0
	}

	return &CephBlockImage{Name: name, Size: newSizeBytes}, nil
}

func DeleteImage(context *clusterd.Context, clusterName, name, poolName string) error {
	imageSpec := getImageSpec(name, poolName)
	args := []string{"rm", imageSpec}
	buf, err := NewRBDCommand(context, clusterName, args).Run()
	if err != nil {
		return errors.Wrapf(err, "failed to delete image %s in pool %s, output: %s",
			name, poolName, string(buf))
	}

	return nil
}

func ExpandImage(context *clusterd.Context, clusterName, name, poolName, monitors, keyring string, size uint64) error {
	imageSpec := getImageSpec(name, poolName)
	args := []string{
		"resize",
		imageSpec,
		fmt.Sprintf("--size=%s", strconv.FormatUint(size, 10)),
		fmt.Sprintf("--cluster=%s", clusterName),
		fmt.Sprintf("--keyring=%s", keyring),
		"-m", monitors,
	}
	output, err := ExecuteRBDCommandWithTimeout(context, clusterName, args)
	if err != nil {
		return errors.Wrapf(err, "failed to resize image %s in pool %s, output: %s", name, poolName, string(output))
	}
	return nil
}

// MapImage maps an RBD image using admin cephfx and returns the device path
func MapImage(context *clusterd.Context, imageName, poolName, id, keyring, clusterName, monitors string) error {
	imageSpec := getImageSpec(imageName, poolName)
	args := []string{
		"map",
		imageSpec,
		fmt.Sprintf("--id=%s", id),
		fmt.Sprintf("--cluster=%s", clusterName),
		fmt.Sprintf("--keyring=%s", keyring),
		"-m", monitors,
		"--conf=/dev/null", // no config file needed because we are passing all required config as arguments
	}

	output, err := ExecuteRBDCommandWithTimeout(context, clusterName, args)
	if err != nil {
		return errors.Wrapf(err, "failed to map image %s, output: %s", imageSpec, output)
	}

	return nil
}

// UnMapImage unmap an RBD image from the node
func UnMapImage(context *clusterd.Context, imageName, poolName, id, keyring, clusterName, monitors string, force bool) error {
	deviceImage := getImageSpec(imageName, poolName)
	args := []string{
		"unmap",
		deviceImage,
		fmt.Sprintf("--id=%s", id),
		fmt.Sprintf("--cluster=%s", clusterName),
		fmt.Sprintf("--keyring=%s", keyring),
		"-m", monitors,
		"--conf=/dev/null", // no config file needed because we are passing all required config as arguments
	}

	if force {
		args = append(args, "-o", "force")
	}

	output, err := ExecuteRBDCommandWithTimeout(context, clusterName, args)
	if err != nil {
		return errors.Wrapf(err, "failed to unmap image %s, output: %s", deviceImage, output)
	}

	return nil
}

func getImageSpec(name, poolName string) string {
	return fmt.Sprintf("%s/%s", poolName, name)
}
