package docker
 
 import (
 	"bufio"
 	"encoding/json"
 	"fmt"
 	"github.com/dotcloud/docker/utils"
 	"io"

 	"io/ioutil"

 	"os"

 	"path"

 	"reflect"
 	"strings"
 )
 
 type BuildFile interface {
 	Build(io.Reader, io.Reader) (string, error)
 	CmdFrom(string) error
 	CmdRun(string) error
 }
 
 type buildFile struct {
 	runtime *Runtime
 	builder *Builder
 	srv     *Server
 
 	image      string
 	maintainer string
 	config     *Config

 	context    string

 
 	tmpContainers map[string]struct{}
 	tmpImages     map[string]struct{}
 
 	out io.Writer
 }
 
 func (b *buildFile) clearTmp(containers, images map[string]struct{}) {
 	for c := range containers {
 		tmp := b.runtime.Get(c)
 		b.runtime.Destroy(tmp)
 		utils.Debugf("Removing container %s", c)
 	}
 	for i := range images {
 		b.runtime.graph.Delete(i)
 		utils.Debugf("Removing image %s", i)
 	}
 }
 
 func (b *buildFile) CmdFrom(name string) error {
 	image, err := b.runtime.repositories.LookupImage(name)
 	if err != nil {
 		if b.runtime.graph.IsNotExist(err) {
 
 			var tag, remote string
 			if strings.Contains(name, ":") {
 				remoteParts := strings.Split(name, ":")
 				tag = remoteParts[1]
 				remote = remoteParts[0]
 			} else {
 				remote = name
 			}
 

 			if err := b.srv.ImagePull(remote, tag, "", b.out, utils.NewStreamFormatter(false), nil); err != nil {

 				return err
 			}
 
 			image, err = b.runtime.repositories.LookupImage(name)
 			if err != nil {
 				return err
 			}
 		} else {
 			return err
 		}
 	}

 	b.image = image.ID

 	b.config = &Config{}
 	return nil
 }
 
 func (b *buildFile) CmdMaintainer(name string) error {
 	b.maintainer = name

 	return b.commit("", b.config.Cmd, fmt.Sprintf("MAINTAINER %s", name))

 }
 
 func (b *buildFile) CmdRun(args string) error {
 	if b.image == "" {
 		return fmt.Errorf("Please provide a source image with `from` prior to run")
 	}
 	config, _, err := ParseRun([]string{b.image, "/bin/sh", "-c", args}, nil)
 	if err != nil {
 		return err
 	}
 

 	cmd := b.config.Cmd

 	b.config.Cmd = nil
 	MergeConfig(b.config, config)
 

 	utils.Debugf("Command to be executed: %v", b.config.Cmd)

 	if cache, err := b.srv.ImageGetCached(b.image, b.config); err != nil {

 		return err
 	} else if cache != nil {

 		fmt.Fprintf(b.out, " ---> Using cache\n")

 		utils.Debugf("[BUILDER] Use cached version")

 		b.image = cache.ID

 		return nil

 	} else {
 		utils.Debugf("[BUILDER] Cache miss")

 	}
 
 	cid, err := b.run()
 	if err != nil {
 		return err
 	}

 	if err := b.commit(cid, cmd, "run"); err != nil {

 		return err
 	}
 	b.config.Cmd = cmd
 	return nil

 }
 
 func (b *buildFile) CmdEnv(args string) error {
 	tmp := strings.SplitN(args, " ", 2)
 	if len(tmp) != 2 {
 		return fmt.Errorf("Invalid ENV format")
 	}
 	key := strings.Trim(tmp[0], " ")
 	value := strings.Trim(tmp[1], " ")
 
 	for i, elem := range b.config.Env {
 		if strings.HasPrefix(elem, key+"=") {
 			b.config.Env[i] = key + "=" + value
 			return nil
 		}
 	}
 	b.config.Env = append(b.config.Env, key+"="+value)

 	return b.commit("", b.config.Cmd, fmt.Sprintf("ENV %s=%s", key, value))

 }
 
 func (b *buildFile) CmdCmd(args string) error {
 	var cmd []string
 	if err := json.Unmarshal([]byte(args), &cmd); err != nil {
 		utils.Debugf("Error unmarshalling: %s, using /bin/sh -c", err)

 		cmd = []string{"/bin/sh", "-c", args}

 	}

 	if err := b.commit("", cmd, fmt.Sprintf("CMD %v", cmd)); err != nil {
 		return err

 	}

 	b.config.Cmd = cmd

 	return nil
 }
 
 func (b *buildFile) CmdExpose(args string) error {
 	ports := strings.Split(args, " ")
 	b.config.PortSpecs = append(ports, b.config.PortSpecs...)

 	return b.commit("", b.config.Cmd, fmt.Sprintf("EXPOSE %v", ports))

 }
 
 func (b *buildFile) CmdInsert(args string) error {

 	return fmt.Errorf("INSERT has been deprecated. Please use ADD instead")
 }

 func (b *buildFile) CmdCopy(args string) error {
 	return fmt.Errorf("COPY has been deprecated. Please use ADD instead")

 }
 

 func (b *buildFile) CmdAdd(args string) error {

 	if b.context == "" {
 		return fmt.Errorf("No context given. Impossible to use ADD")
 	}

 	tmp := strings.SplitN(args, " ", 2)
 	if len(tmp) != 2 {

 		return fmt.Errorf("Invalid ADD format")

 	}
 	orig := strings.Trim(tmp[0], " ")
 	dest := strings.Trim(tmp[1], " ")
 

 	cmd := b.config.Cmd

 
 	// Create the container and start it

 	b.config.Cmd = []string{"/bin/sh", "-c", fmt.Sprintf("#(nop) ADD %s in %s", orig, dest)}
 	b.config.Image = b.image

 	container, err := b.builder.Create(b.config)

 	if err != nil {
 		return err
 	}

 	b.tmpContainers[container.ID] = struct{}{}

 	fmt.Fprintf(b.out, " ---> Running in %s\n", utils.TruncateID(container.ID))

 	if err := container.EnsureMounted(); err != nil {

 		return err
 	}

 	defer container.Unmount()

 	origPath := path.Join(b.context, orig)

 	destPath := path.Join(container.RootfsPath(), dest)

 	// Preserve the trailing '/'
 	if dest[len(dest)-1] == '/' {
 		destPath = destPath + "/"
 	}

 	fi, err := os.Stat(origPath)
 	if err != nil {

 		return err
 	}

 	if fi.IsDir() {

 		if err := CopyWithTar(origPath, destPath); err != nil {

 			return err
 		}

 		// First try to unpack the source as an archive
 	} else if err := UntarPath(origPath, destPath); err != nil {
 		utils.Debugf("Couldn't untar %s to %s: %s", origPath, destPath, err)
 		// If that fails, just copy it as a regular file

 		if err := os.MkdirAll(path.Dir(destPath), 0700); err != nil {
 			return err
 		}

 		if err := CopyWithTar(origPath, destPath); err != nil {

 			return err
 		}
 	}

 	if err := b.commit(container.ID, cmd, fmt.Sprintf("ADD %s in %s", orig, dest)); err != nil {

 		return err
 	}
 	b.config.Cmd = cmd
 	return nil

 }
 

 func (b *buildFile) run() (string, error) {
 	if b.image == "" {
 		return "", fmt.Errorf("Please provide a source image with `from` prior to run")
 	}
 	b.config.Image = b.image
 
 	// Create the container and start it
 	c, err := b.builder.Create(b.config)
 	if err != nil {
 		return "", err
 	}

 	b.tmpContainers[c.ID] = struct{}{}

 	fmt.Fprintf(b.out, " ---> Running in %s\n", utils.TruncateID(c.ID))

 
 	//start the container
 	if err := c.Start(); err != nil {
 		return "", err
 	}
 
 	// Wait for it to finish
 	if ret := c.Wait(); ret != 0 {
 		return "", fmt.Errorf("The command %v returned a non-zero code: %d", b.config.Cmd, ret)
 	}
 

 	return c.ID, nil

 }
 

 // Commit the container <id> with the autorun command <autoCmd>

 func (b *buildFile) commit(id string, autoCmd []string, comment string) error {

 	if b.image == "" {
 		return fmt.Errorf("Please provide a source image with `from` prior to commit")
 	}
 	b.config.Image = b.image
 	if id == "" {

 		b.config.Cmd = []string{"/bin/sh", "-c", "#(nop) " + comment}

 
 		if cache, err := b.srv.ImageGetCached(b.image, b.config); err != nil {
 			return err
 		} else if cache != nil {

 			fmt.Fprintf(b.out, " ---> Using cache\n")

 			utils.Debugf("[BUILDER] Use cached version")

 			b.image = cache.ID

 			return nil
 		} else {
 			utils.Debugf("[BUILDER] Cache miss")
 		}
 

 		// Create the container and start it
 		container, err := b.builder.Create(b.config)

 		if err != nil {

 			return err
 		}

 		b.tmpContainers[container.ID] = struct{}{}

 		fmt.Fprintf(b.out, " ---> Running in %s\n", utils.TruncateID(container.ID))

 
 		if err := container.EnsureMounted(); err != nil {
 			return err
 		}
 		defer container.Unmount()
 
 		id = container.ID

 	}
 
 	container := b.runtime.Get(id)
 	if container == nil {
 		return fmt.Errorf("An error occured while creating the container")
 	}
 

 	// Note: Actually copy the struct
 	autoConfig := *b.config
 	autoConfig.Cmd = autoCmd

 	// Commit the container

 	image, err := b.builder.Commit(container, "", "", "", b.maintainer, &autoConfig)

 	if err != nil {
 		return err
 	}

 	b.tmpImages[image.ID] = struct{}{}
 	b.image = image.ID

 	return nil
 }
 
 func (b *buildFile) Build(dockerfile, context io.Reader) (string, error) {

 	if context != nil {
 		name, err := ioutil.TempDir("/tmp", "docker-build")
 		if err != nil {
 			return "", err
 		}
 		if err := Untar(context, name); err != nil {
 			return "", err
 		}
 		defer os.RemoveAll(name)
 		b.context = name
 	}

 	file := bufio.NewReader(dockerfile)

 	stepN := 0

 	for {
 		line, err := file.ReadString('\n')
 		if err != nil {

 			if err == io.EOF && line == "" {

 				break

 			} else if err != io.EOF {
 				return "", err

 			}
 		}
 		line = strings.Replace(strings.TrimSpace(line), "	", " ", 1)
 		// Skip comments and empty line
 		if len(line) == 0 || line[0] == '#' {
 			continue
 		}
 		tmp := strings.SplitN(line, " ", 2)
 		if len(tmp) != 2 {
 			return "", fmt.Errorf("Invalid Dockerfile format")
 		}
 		instruction := strings.ToLower(strings.Trim(tmp[0], " "))
 		arguments := strings.Trim(tmp[1], " ")

 		stepN += 1
 		// FIXME: only count known instructions as build steps
 		fmt.Fprintf(b.out, "Step %d : %s %s\n", stepN, strings.ToUpper(instruction), arguments)

 
 		method, exists := reflect.TypeOf(b).MethodByName("Cmd" + strings.ToUpper(instruction[:1]) + strings.ToLower(instruction[1:]))
 		if !exists {

 			fmt.Fprintf(b.out, "# Skipping unknown instruction %s\n", strings.ToUpper(instruction))

 			continue

 		}
 		ret := method.Func.Call([]reflect.Value{reflect.ValueOf(b), reflect.ValueOf(arguments)})[0].Interface()
 		if ret != nil {
 			return "", ret.(error)
 		}
 

 		fmt.Fprintf(b.out, " ---> %v\n", utils.TruncateID(b.image))

 	}
 	if b.image != "" {

 		fmt.Fprintf(b.out, "Successfully built %s\n", utils.TruncateID(b.image))

 		return b.image, nil
 	}
 	return "", fmt.Errorf("An error occured during the build\n")
 }
 
 func NewBuildFile(srv *Server, out io.Writer) BuildFile {
 	return &buildFile{
 		builder:       NewBuilder(srv.runtime),
 		runtime:       srv.runtime,
 		srv:           srv,
 		config:        &Config{},

 		out:           out,

 		tmpContainers: make(map[string]struct{}),
 		tmpImages:     make(map[string]struct{}),
 	}
 }