package daemon
 
 import (

 	"encoding/json"

 	"fmt"
 	"runtime"

 	"strings"
 	"time"

 	"github.com/docker/docker/container"

 	"github.com/docker/docker/dockerversion"

 	"github.com/docker/docker/image"

 	"github.com/docker/docker/layer"

 	"github.com/docker/docker/pkg/archive"
 	"github.com/docker/docker/pkg/ioutils"

 	"github.com/docker/docker/reference"

 	"github.com/docker/engine-api/types"
 	containertypes "github.com/docker/engine-api/types/container"

 	"github.com/docker/go-connections/nat"

 )
 

 // merge merges two Config, the image container configuration (defaults values),
 // and the user container configuration, either passed by the API or generated
 // by the cli.
 // It will mutate the specified user configuration (userConf) with the image
 // configuration where the user configuration is incomplete.
 func merge(userConf, imageConf *containertypes.Config) error {
 	if userConf.User == "" {
 		userConf.User = imageConf.User
 	}
 	if len(userConf.ExposedPorts) == 0 {
 		userConf.ExposedPorts = imageConf.ExposedPorts
 	} else if imageConf.ExposedPorts != nil {
 		if userConf.ExposedPorts == nil {
 			userConf.ExposedPorts = make(nat.PortSet)
 		}
 		for port := range imageConf.ExposedPorts {
 			if _, exists := userConf.ExposedPorts[port]; !exists {
 				userConf.ExposedPorts[port] = struct{}{}
 			}
 		}
 	}
 
 	if len(userConf.Env) == 0 {
 		userConf.Env = imageConf.Env
 	} else {
 		for _, imageEnv := range imageConf.Env {
 			found := false
 			imageEnvKey := strings.Split(imageEnv, "=")[0]
 			for _, userEnv := range userConf.Env {
 				userEnvKey := strings.Split(userEnv, "=")[0]
 				if imageEnvKey == userEnvKey {
 					found = true
 					break
 				}
 			}
 			if !found {
 				userConf.Env = append(userConf.Env, imageEnv)
 			}
 		}
 	}
 
 	if userConf.Labels == nil {
 		userConf.Labels = map[string]string{}
 	}
 	if imageConf.Labels != nil {
 		for l := range userConf.Labels {
 			imageConf.Labels[l] = userConf.Labels[l]
 		}
 		userConf.Labels = imageConf.Labels
 	}
 

 	if len(userConf.Entrypoint) == 0 {
 		if len(userConf.Cmd) == 0 {

 			userConf.Cmd = imageConf.Cmd
 		}
 
 		if userConf.Entrypoint == nil {
 			userConf.Entrypoint = imageConf.Entrypoint
 		}
 	}
 	if userConf.WorkingDir == "" {
 		userConf.WorkingDir = imageConf.WorkingDir
 	}
 	if len(userConf.Volumes) == 0 {
 		userConf.Volumes = imageConf.Volumes
 	} else {
 		for k, v := range imageConf.Volumes {
 			userConf.Volumes[k] = v
 		}
 	}

 
 	if userConf.StopSignal == "" {
 		userConf.StopSignal = imageConf.StopSignal
 	}

 	return nil
 }
 

 // Commit creates a new filesystem image from the current state of a container.

 // The image can optionally be tagged into a repository.

 func (daemon *Daemon) Commit(name string, c *types.ContainerCommitConfig) (string, error) {

 	container, err := daemon.GetContainer(name)

 	if err != nil {

 		return "", err

 	}
 
 	// It is not possible to commit a running container on Windows
 	if runtime.GOOS == "windows" && container.IsRunning() {

 		return "", fmt.Errorf("Windows does not support commit of a running container")

 	}
 

 	if c.Pause && !container.IsPaused() {

 		daemon.containerPause(container)
 		defer daemon.containerUnpause(container)

 	}
 

 	if c.MergeConfigs {

 		if err := merge(c.Config, container.Config); err != nil {

 			return "", err

 		}
 	}
 

 	rwTar, err := daemon.exportContainerRw(container)

 	if err != nil {

 		return "", err

 	}

 	defer func() {
 		if rwTar != nil {
 			rwTar.Close()
 		}
 	}()

 	var history []image.History
 	rootFS := image.NewRootFS()
 
 	if container.ImageID != "" {
 		img, err := daemon.imageStore.Get(container.ImageID)
 		if err != nil {
 			return "", err
 		}
 		history = img.History
 		rootFS = img.RootFS
 	}
 
 	l, err := daemon.layerStore.Register(rwTar, rootFS.ChainID())

 	if err != nil {

 		return "", err
 	}
 	defer layer.ReleaseAndLog(daemon.layerStore, l)
 
 	h := image.History{
 		Author:     c.Author,
 		Created:    time.Now().UTC(),

 		CreatedBy:  strings.Join(container.Config.Cmd, " "),

 		Comment:    c.Comment,
 		EmptyLayer: true,
 	}
 
 	if diffID := l.DiffID(); layer.DigestSHA256EmptyTar != diffID {
 		h.EmptyLayer = false
 		rootFS.Append(diffID)
 	}
 
 	history = append(history, h)
 
 	config, err := json.Marshal(&image.Image{
 		V1Image: image.V1Image{
 			DockerVersion:   dockerversion.Version,
 			Config:          c.Config,
 			Architecture:    runtime.GOARCH,
 			OS:              runtime.GOOS,
 			Container:       container.ID,
 			ContainerConfig: *container.Config,
 			Author:          c.Author,
 			Created:         h.Created,
 		},
 		RootFS:  rootFS,
 		History: history,
 	})
 
 	if err != nil {
 		return "", err
 	}
 
 	id, err := daemon.imageStore.Create(config)
 	if err != nil {
 		return "", err
 	}
 
 	if container.ImageID != "" {
 		if err := daemon.imageStore.SetParent(id, container.ImageID); err != nil {
 			return "", err
 		}

 	}
 

 	if c.Repo != "" {

 		newTag, err := reference.WithName(c.Repo) // todo: should move this to API layer
 		if err != nil {
 			return "", err
 		}
 		if c.Tag != "" {
 			if newTag, err = reference.WithTag(newTag, c.Tag); err != nil {
 				return "", err
 			}
 		}

 		if err := daemon.TagImage(newTag, id.String()); err != nil {

 			return "", err

 		}
 	}

 	attributes := map[string]string{
 		"comment": c.Comment,
 	}
 	daemon.LogContainerEventWithAttributes(container, "commit", attributes)

 	return id.String(), nil

 }

 func (daemon *Daemon) exportContainerRw(container *container.Container) (archive.Archive, error) {

 	if err := daemon.Mount(container); err != nil {
 		return nil, err
 	}
 

 	archive, err := container.RWLayer.TarStream()

 	if err != nil {

 		daemon.Unmount(container) // logging is already handled in the `Unmount` function

 		return nil, err
 	}
 	return ioutils.NewReadCloserWrapper(archive, func() error {

 			archive.Close()

 			return container.RWLayer.Unmount()

 		}),
 		nil
 }