// GetSize, return real size, virtual size
func (container *Container) GetSize() (int64, int64) {
	var (
		sizeRw, sizeRootfs int64
		err                error
		driver             = container.daemon.driver
	)

	if err := container.Mount(); err != nil {
		log.Errorf("Warning: failed to compute size of container rootfs %s: %s", container.ID, err)
		return sizeRw, sizeRootfs
	}
	defer container.Unmount()

	initID := fmt.Sprintf("%s-init", container.ID)
	sizeRw, err = driver.DiffSize(container.ID, initID)
	if err != nil {
		log.Errorf("Warning: driver %s couldn't return diff size of container %s: %s", driver, container.ID, err)
		// FIXME: GetSize should return an error. Not changing it now in case
		// there is a side-effect.
		sizeRw = -1
	}

	if _, err = os.Stat(container.basefs); err != nil {
		if sizeRootfs, err = utils.TreeSize(container.basefs); err != nil {
			sizeRootfs = -1
		}
	}
	return sizeRw, sizeRootfs
}

// ApplyDiff extracts the changeset from the given diff into the
// layer with the specified id and parent, returning the size of the
// new layer in bytes.
func (gdw *naiveDiffDriver) ApplyDiff(id, parent string, diff archive.ArchiveReader) (bytes int64, err error) {
	driver := gdw.ProtoDriver

	// Mount the root filesystem so we can apply the diff/layer.
	layerFs, err := driver.Get(id, "")
	if err != nil {
		return
	}
	defer driver.Put(id)

	start := time.Now().UTC()
	log.Debugf("Start untar layer")
	if err = archive.ApplyLayer(layerFs, diff); err != nil {
		return
	}
	log.Debugf("Untar time: %vs", time.Now().UTC().Sub(start).Seconds())

	if parent == "" {
		return utils.TreeSize(layerFs)
	}

	parentFs, err := driver.Get(parent, "")
	if err != nil {
		err = fmt.Errorf("Driver %s failed to get image parent %s: %s", driver, parent, err)
		return
	}
	defer driver.Put(parent)

	changes, err := archive.ChangesDirs(layerFs, parentFs)
	if err != nil {
		return
	}

	return archive.ChangesSize(layerFs, changes), nil
}

// Get returns the image with the given id, or an error if the image doesn't exist.
func (graph *Graph) Get(name string) (*image.Image, error) {
	id, err := graph.idIndex.Get(name)
	if err != nil {
		return nil, err
	}
	// FIXME: return nil when the image doesn't exist, instead of an error
	img, err := image.LoadImage(graph.ImageRoot(id))
	if err != nil {
		return nil, err
	}
	if img.ID != id {
		return nil, fmt.Errorf("Image stored at '%s' has wrong id '%s'", id, img.ID)
	}
	img.SetGraph(graph)

	if img.Size < 0 {
		rootfs, err := graph.driver.Get(img.ID, "")
		if err != nil {
			return nil, fmt.Errorf("Driver %s failed to get image rootfs %s: %s", graph.driver, img.ID, err)
		}
		defer graph.driver.Put(img.ID)

		var size int64
		if img.Parent == "" {
			if size, err = utils.TreeSize(rootfs); err != nil {
				return nil, err
			}
		} else {
			parentFs, err := graph.driver.Get(img.Parent, "")
			if err != nil {
				return nil, err
			}
			changes, err := archive.ChangesDirs(rootfs, parentFs)
			if err != nil {
				return nil, err
			}
			size = archive.ChangesSize(rootfs, changes)
		}

		img.Size = size
		if err := img.SaveSize(graph.ImageRoot(id)); err != nil {
			return nil, err
		}
	}
	return img, nil
}

// GetSize, return real size, virtual size
func (container *Container) GetSize() (int64, int64) {
	var (
		sizeRw, sizeRootfs int64
		err                error
		driver             = container.daemon.driver
	)

	if err := container.Mount(); err != nil {
		utils.Errorf("Warning: failed to compute size of container rootfs %s: %s", container.ID, err)
		return sizeRw, sizeRootfs
	}
	defer container.Unmount()

	if differ, ok := container.daemon.driver.(graphdriver.Differ); ok {
		sizeRw, err = differ.DiffSize(container.ID)
		if err != nil {
			utils.Errorf("Warning: driver %s couldn't return diff size of container %s: %s", driver, container.ID, err)
			// FIXME: GetSize should return an error. Not changing it now in case
			// there is a side-effect.
			sizeRw = -1
		}
	} else {
		changes, _ := container.Changes()
		if changes != nil {
			sizeRw = archive.ChangesSize(container.basefs, changes)
		} else {
			sizeRw = -1
		}
	}

	if _, err = os.Stat(container.basefs); err != nil {
		if sizeRootfs, err = utils.TreeSize(container.basefs); err != nil {
			sizeRootfs = -1
		}
	}
	return sizeRw, sizeRootfs
}

// DiffSize calculates the changes between the specified id
// and its parent and returns the size in bytes of the changes
// relative to its base filesystem directory.
func (a *Driver) DiffSize(id, parent string) (size int64, err error) {
	// AUFS doesn't need the parent layer to calculate the diff size.
	return utils.TreeSize(path.Join(a.rootPath(), "diff", id))
}

func StoreImage(img *Image, jsonData []byte, layerData archive.ArchiveReader, root, layer string) error {
	// Store the layer
	var (
		size   int64
		err    error
		driver = img.graph.Driver()
	)
	if err := os.MkdirAll(layer, 0755); err != nil {
		return err
	}

	// If layerData is not nil, unpack it into the new layer
	if layerData != nil {
		if differ, ok := driver.(graphdriver.Differ); ok {
			if err := differ.ApplyDiff(img.ID, layerData); err != nil {
				return err
			}

			if size, err = differ.DiffSize(img.ID); err != nil {
				return err
			}
		} else {
			start := time.Now().UTC()
			log.Debugf("Start untar layer")
			if err := archive.ApplyLayer(layer, layerData); err != nil {
				return err
			}
			log.Debugf("Untar time: %vs", time.Now().UTC().Sub(start).Seconds())

			if img.Parent == "" {
				if size, err = utils.TreeSize(layer); err != nil {
					return err
				}
			} else {
				parent, err := driver.Get(img.Parent, "")
				if err != nil {
					return err
				}
				defer driver.Put(img.Parent)
				changes, err := archive.ChangesDirs(layer, parent)
				if err != nil {
					return err
				}
				size = archive.ChangesSize(layer, changes)
			}
		}
	}

	img.Size = size
	if err := img.SaveSize(root); err != nil {
		return err
	}

	// If raw json is provided, then use it
	if jsonData != nil {
		if err := ioutil.WriteFile(jsonPath(root), jsonData, 0600); err != nil {
			return err
		}
	} else {
		if jsonData, err = json.Marshal(img); err != nil {
			return err
		}
		if err := ioutil.WriteFile(jsonPath(root), jsonData, 0600); err != nil {
			return err
		}
	}
	return nil
}

// Returns the size of the contents for the id
func (a *Driver) DiffSize(id string) (int64, error) {
	return utils.TreeSize(path.Join(a.rootPath(), "diff", id))
}