package daemon
 
 import (

 	"fmt"

 	"io"

 	"time"

 	"github.com/Sirupsen/logrus"

 	"github.com/docker/docker/api/types/backend"

 	"github.com/docker/docker/container"

 	"github.com/docker/docker/daemon/logger"

 	"github.com/docker/docker/errors"

 	"github.com/docker/docker/pkg/stdcopy"

 )
 

 // ContainerAttach attaches to logs according to the config passed in. See ContainerAttachConfig.
 func (daemon *Daemon) ContainerAttach(prefixOrName string, c *backend.ContainerAttachConfig) error {

 	container, err := daemon.GetContainer(prefixOrName)

 	if err != nil {

 		return err

 	}
 	if container.IsPaused() {

 		err := fmt.Errorf("Container %s is paused. Unpause the container before attach", prefixOrName)
 		return errors.NewRequestConflictError(err)

 	}
 

 	inStream, outStream, errStream, err := c.GetStreams()

 	if err != nil {

 		return err
 	}

 	defer inStream.Close()

 	if !container.Config.Tty && c.MuxStreams {
 		errStream = stdcopy.NewStdWriter(errStream, stdcopy.Stderr)

 		outStream = stdcopy.NewStdWriter(outStream, stdcopy.Stdout)

 	}
 

 	var stdin io.ReadCloser
 	var stdout, stderr io.Writer

 	if c.UseStdin {

 		stdin = inStream

 	}
 	if c.UseStdout {

 		stdout = outStream

 	}
 	if c.UseStderr {
 		stderr = errStream

 	}
 

 	if err := daemon.containerAttach(container, stdin, stdout, stderr, c.Logs, c.Stream, c.DetachKeys); err != nil {

 		fmt.Fprintf(outStream, "Error attaching: %s\n", err)
 	}
 	return nil

 }

 // ContainerAttachRaw attaches the provided streams to the container's stdio
 func (daemon *Daemon) ContainerAttachRaw(prefixOrName string, stdin io.ReadCloser, stdout, stderr io.Writer, stream bool) error {

 	container, err := daemon.GetContainer(prefixOrName)

 	if err != nil {
 		return err
 	}

 	return daemon.containerAttach(container, stdin, stdout, stderr, false, stream, nil)

 }
 

 func (daemon *Daemon) containerAttach(container *container.Container, stdin io.ReadCloser, stdout, stderr io.Writer, logs, stream bool, keys []byte) error {

 	if logs {

 		logDriver, err := daemon.getLogger(container)

 		if err != nil {
 			return err
 		}
 		cLog, ok := logDriver.(logger.LogReader)
 		if !ok {
 			return logger.ErrReadLogsNotSupported
 		}
 		logs := cLog.ReadLogs(logger.ReadConfig{Tail: -1})
 
 	LogLoop:
 		for {
 			select {
 			case msg, ok := <-logs.Msg:
 				if !ok {
 					break LogLoop
 				}
 				if msg.Source == "stdout" && stdout != nil {
 					stdout.Write(msg.Line)
 				}
 				if msg.Source == "stderr" && stderr != nil {
 					stderr.Write(msg.Line)
 				}
 			case err := <-logs.Err:
 				logrus.Errorf("Error streaming logs: %v", err)
 				break LogLoop
 			}
 		}
 	}
 
 	daemon.LogContainerEvent(container, "attach")
 
 	//stream
 	if stream {
 		var stdinPipe io.ReadCloser
 		if stdin != nil {
 			r, w := io.Pipe()
 			go func() {
 				defer w.Close()
 				defer logrus.Debugf("Closing buffered stdin pipe")
 				io.Copy(w, stdin)
 			}()
 			stdinPipe = r
 		}

 		<-container.Attach(stdinPipe, stdout, stderr, keys)

 		// If we are in stdinonce mode, wait for the process to end
 		// otherwise, simply return
 		if container.Config.StdinOnce && !container.Config.Tty {
 			container.WaitStop(-1 * time.Second)
 		}
 	}
 	return nil

 }