package image

import (
	"archive/tar"
	"bufio"
	"bytes"
	"fmt"
	"io"
	"io/ioutil"
	"os"
	"path/filepath"
	"regexp"
	"runtime"
	"time"

	"github.com/docker/distribution/reference"
	"github.com/docker/docker/api"
	"github.com/docker/docker/api/types"
	"github.com/docker/docker/api/types/container"
	"github.com/docker/docker/builder/dockerignore"
	"github.com/docker/docker/cli"
	"github.com/docker/docker/cli/command"
	"github.com/docker/docker/cli/command/image/build"
	"github.com/docker/docker/opts"
	"github.com/docker/docker/pkg/archive"
	"github.com/docker/docker/pkg/fileutils"
	"github.com/docker/docker/pkg/jsonmessage"
	"github.com/docker/docker/pkg/progress"
	"github.com/docker/docker/pkg/streamformatter"
	"github.com/docker/docker/pkg/stringid"
	"github.com/docker/docker/pkg/urlutil"
	runconfigopts "github.com/docker/docker/runconfig/opts"
	units "github.com/docker/go-units"
	"github.com/pkg/errors"
	"github.com/spf13/cobra"
	"golang.org/x/net/context"
)

type buildOptions struct {
	context        string
	dockerfileName string
	tags           opts.ListOpts
	labels         opts.ListOpts
	buildArgs      opts.ListOpts
	extraHosts     opts.ListOpts
	ulimits        *opts.UlimitOpt
	memory         opts.MemBytes
	memorySwap     opts.MemSwapBytes
	shmSize        opts.MemBytes
	cpuShares      int64
	cpuPeriod      int64
	cpuQuota       int64
	cpuSetCpus     string
	cpuSetMems     string
	cgroupParent   string
	isolation      string
	quiet          bool
	noCache        bool
	rm             bool
	forceRm        bool
	pull           bool
	cacheFrom      []string
	compress       bool
	securityOpt    []string
	networkMode    string
	squash         bool
	target         string
}

// NewBuildCommand creates a new `docker build` command
func NewBuildCommand(dockerCli *command.DockerCli) *cobra.Command {
	ulimits := make(map[string]*units.Ulimit)
	options := buildOptions{
		tags:       opts.NewListOpts(validateTag),
		buildArgs:  opts.NewListOpts(opts.ValidateEnv),
		ulimits:    opts.NewUlimitOpt(&ulimits),
		labels:     opts.NewListOpts(opts.ValidateEnv),
		extraHosts: opts.NewListOpts(opts.ValidateExtraHost),
	}

	cmd := &cobra.Command{
		Use:   "build [OPTIONS] PATH | URL | -",
		Short: "Build an image from a Dockerfile",
		Args:  cli.ExactArgs(1),
		RunE: func(cmd *cobra.Command, args []string) error {
			options.context = args[0]
			return runBuild(dockerCli, options)
		},
	}

	flags := cmd.Flags()

	flags.VarP(&options.tags, "tag", "t", "Name and optionally a tag in the 'name:tag' format")
	flags.Var(&options.buildArgs, "build-arg", "Set build-time variables")
	flags.Var(options.ulimits, "ulimit", "Ulimit options")
	flags.StringVarP(&options.dockerfileName, "file", "f", "", "Name of the Dockerfile (Default is 'PATH/Dockerfile')")
	flags.VarP(&options.memory, "memory", "m", "Memory limit")
	flags.Var(&options.memorySwap, "memory-swap", "Swap limit equal to memory plus swap: '-1' to enable unlimited swap")
	flags.Var(&options.shmSize, "shm-size", "Size of /dev/shm")
	flags.Int64VarP(&options.cpuShares, "cpu-shares", "c", 0, "CPU shares (relative weight)")
	flags.Int64Var(&options.cpuPeriod, "cpu-period", 0, "Limit the CPU CFS (Completely Fair Scheduler) period")
	flags.Int64Var(&options.cpuQuota, "cpu-quota", 0, "Limit the CPU CFS (Completely Fair Scheduler) quota")
	flags.StringVar(&options.cpuSetCpus, "cpuset-cpus", "", "CPUs in which to allow execution (0-3, 0,1)")
	flags.StringVar(&options.cpuSetMems, "cpuset-mems", "", "MEMs in which to allow execution (0-3, 0,1)")
	flags.StringVar(&options.cgroupParent, "cgroup-parent", "", "Optional parent cgroup for the container")
	flags.StringVar(&options.isolation, "isolation", "", "Container isolation technology")
	flags.Var(&options.labels, "label", "Set metadata for an image")
	flags.BoolVar(&options.noCache, "no-cache", false, "Do not use cache when building the image")
	flags.BoolVar(&options.rm, "rm", true, "Remove intermediate containers after a successful build")
	flags.BoolVar(&options.forceRm, "force-rm", false, "Always remove intermediate containers")
	flags.BoolVarP(&options.quiet, "quiet", "q", false, "Suppress the build output and print image ID on success")
	flags.BoolVar(&options.pull, "pull", false, "Always attempt to pull a newer version of the image")
	flags.StringSliceVar(&options.cacheFrom, "cache-from", []string{}, "Images to consider as cache sources")
	flags.BoolVar(&options.compress, "compress", false, "Compress the build context using gzip")
	flags.StringSliceVar(&options.securityOpt, "security-opt", []string{}, "Security options")
	flags.StringVar(&options.networkMode, "network", "default", "Set the networking mode for the RUN instructions during build")
	flags.SetAnnotation("network", "version", []string{"1.25"})
	flags.Var(&options.extraHosts, "add-host", "Add a custom host-to-IP mapping (host:ip)")
	flags.StringVar(&options.target, "target", "", "Set the target build stage to build.")

	command.AddTrustVerificationFlags(flags)

	flags.BoolVar(&options.squash, "squash", false, "Squash newly built layers into a single new layer")
	flags.SetAnnotation("squash", "experimental", nil)
	flags.SetAnnotation("squash", "version", []string{"1.25"})

	return cmd
}

// lastProgressOutput is the same as progress.Output except
// that it only output with the last update. It is used in
// non terminal scenarios to suppress verbose messages
type lastProgressOutput struct {
	output progress.Output
}

// WriteProgress formats progress information from a ProgressReader.
func (out *lastProgressOutput) WriteProgress(prog progress.Progress) error {
	if !prog.LastUpdate {
		return nil
	}

	return out.output.WriteProgress(prog)
}

func runBuild(dockerCli *command.DockerCli, options buildOptions) error {
	var (
		buildCtx      io.ReadCloser
		dockerfileCtx io.ReadCloser
		err           error
		contextDir    string
		tempDir       string
		relDockerfile string
		progBuff      io.Writer
		buildBuff     io.Writer
	)

	specifiedContext := options.context
	progBuff = dockerCli.Out()
	buildBuff = dockerCli.Out()
	if options.quiet {
		progBuff = bytes.NewBuffer(nil)
		buildBuff = bytes.NewBuffer(nil)
	}

	if options.dockerfileName == "-" {
		if specifiedContext == "-" {
			return errors.New("invalid argument: can't use stdin for both build context and dockerfile")
		}
		dockerfileCtx = dockerCli.In()
	}

	switch {
	case specifiedContext == "-":
		buildCtx, relDockerfile, err = build.GetContextFromReader(dockerCli.In(), options.dockerfileName)
	case isLocalDir(specifiedContext):
		contextDir, relDockerfile, err = build.GetContextFromLocalDir(specifiedContext, options.dockerfileName)
	case urlutil.IsGitURL(specifiedContext):
		tempDir, relDockerfile, err = build.GetContextFromGitURL(specifiedContext, options.dockerfileName)
	case urlutil.IsURL(specifiedContext):
		buildCtx, relDockerfile, err = build.GetContextFromURL(progBuff, specifiedContext, options.dockerfileName)
	default:
		return errors.Errorf("unable to prepare context: path %q not found", specifiedContext)
	}

	if err != nil {
		if options.quiet && urlutil.IsURL(specifiedContext) {
			fmt.Fprintln(dockerCli.Err(), progBuff)
		}
		return errors.Errorf("unable to prepare context: %s", err)
	}

	if tempDir != "" {
		defer os.RemoveAll(tempDir)
		contextDir = tempDir
	}

	if buildCtx == nil {
		// And canonicalize dockerfile name to a platform-independent one
		relDockerfile, err = archive.CanonicalTarNameForPath(relDockerfile)
		if err != nil {
			return errors.Errorf("cannot canonicalize dockerfile path %s: %v", relDockerfile, err)
		}

		f, err := os.Open(filepath.Join(contextDir, ".dockerignore"))
		if err != nil && !os.IsNotExist(err) {
			return err
		}
		defer f.Close()

		var excludes []string
		if err == nil {
			excludes, err = dockerignore.ReadAll(f)
			if err != nil {
				return err
			}
		}

		if err := build.ValidateContextDirectory(contextDir, excludes); err != nil {
			return errors.Errorf("Error checking context: '%s'.", err)
		}

		// If .dockerignore mentions .dockerignore or the Dockerfile then make
		// sure we send both files over to the daemon because Dockerfile is,
		// obviously, needed no matter what, and .dockerignore is needed to know
		// if either one needs to be removed. The daemon will remove them
		// if necessary, after it parses the Dockerfile. Ignore errors here, as
		// they will have been caught by validateContextDirectory above.
		// Excludes are used instead of includes to maintain the order of files
		// in the archive.
		if keep, _ := fileutils.Matches(".dockerignore", excludes); keep {
			excludes = append(excludes, "!.dockerignore")
		}
		if keep, _ := fileutils.Matches(relDockerfile, excludes); keep && dockerfileCtx == nil {
			excludes = append(excludes, "!"+relDockerfile)
		}

		compression := archive.Uncompressed
		if options.compress {
			compression = archive.Gzip
		}
		buildCtx, err = archive.TarWithOptions(contextDir, &archive.TarOptions{
			Compression:     compression,
			ExcludePatterns: excludes,
		})
		if err != nil {
			return err
		}
	}

	// replace Dockerfile if added dynamically
	if dockerfileCtx != nil {
		buildCtx, relDockerfile, err = addDockerfileToBuildContext(dockerfileCtx, buildCtx)
		if err != nil {
			return err
		}
	}

	ctx := context.Background()

	var resolvedTags []*resolvedTag
	if command.IsTrusted() {
		translator := func(ctx context.Context, ref reference.NamedTagged) (reference.Canonical, error) {
			return TrustedReference(ctx, dockerCli, ref, nil)
		}
		// Wrap the tar archive to replace the Dockerfile entry with the rewritten
		// Dockerfile which uses trusted pulls.
		buildCtx = replaceDockerfileTarWrapper(ctx, buildCtx, relDockerfile, translator, &resolvedTags)
	}

	// Setup an upload progress bar
	progressOutput := streamformatter.NewStreamFormatter().NewProgressOutput(progBuff, true)
	if !dockerCli.Out().IsTerminal() {
		progressOutput = &lastProgressOutput{output: progressOutput}
	}

	var body io.Reader = progress.NewProgressReader(buildCtx, progressOutput, 0, "", "Sending build context to Docker daemon")

	authConfigs, _ := dockerCli.GetAllCredentials()
	buildOptions := types.ImageBuildOptions{
		Memory:         options.memory.Value(),
		MemorySwap:     options.memorySwap.Value(),
		Tags:           options.tags.GetAll(),
		SuppressOutput: options.quiet,
		NoCache:        options.noCache,
		Remove:         options.rm,
		ForceRemove:    options.forceRm,
		PullParent:     options.pull,
		Isolation:      container.Isolation(options.isolation),
		CPUSetCPUs:     options.cpuSetCpus,
		CPUSetMems:     options.cpuSetMems,
		CPUShares:      options.cpuShares,
		CPUQuota:       options.cpuQuota,
		CPUPeriod:      options.cpuPeriod,
		CgroupParent:   options.cgroupParent,
		Dockerfile:     relDockerfile,
		ShmSize:        options.shmSize.Value(),
		Ulimits:        options.ulimits.GetList(),
		BuildArgs:      runconfigopts.ConvertKVStringsToMapWithNil(options.buildArgs.GetAll()),
		AuthConfigs:    authConfigs,
		Labels:         runconfigopts.ConvertKVStringsToMap(options.labels.GetAll()),
		CacheFrom:      options.cacheFrom,
		SecurityOpt:    options.securityOpt,
		NetworkMode:    options.networkMode,
		Squash:         options.squash,
		ExtraHosts:     options.extraHosts.GetAll(),
		Target:         options.target,
	}

	response, err := dockerCli.Client().ImageBuild(ctx, body, buildOptions)
	if err != nil {
		if options.quiet {
			fmt.Fprintf(dockerCli.Err(), "%s", progBuff)
		}
		return err
	}
	defer response.Body.Close()

	err = jsonmessage.DisplayJSONMessagesStream(response.Body, buildBuff, dockerCli.Out().FD(), dockerCli.Out().IsTerminal(), nil)
	if err != nil {
		if jerr, ok := err.(*jsonmessage.JSONError); ok {
			// If no error code is set, default to 1
			if jerr.Code == 0 {
				jerr.Code = 1
			}
			if options.quiet {
				fmt.Fprintf(dockerCli.Err(), "%s%s", progBuff, buildBuff)
			}
			return cli.StatusError{Status: jerr.Message, StatusCode: jerr.Code}
		}
		return err
	}

	// Windows: show error message about modified file permissions if the
	// daemon isn't running Windows.
	if response.OSType != "windows" && runtime.GOOS == "windows" && !options.quiet {
		fmt.Fprintln(dockerCli.Out(), "SECURITY WARNING: You are building a Docker "+
			"image from Windows against a non-Windows Docker host. All files and "+
			"directories added to build context will have '-rwxr-xr-x' permissions. "+
			"It is recommended to double check and reset permissions for sensitive "+
			"files and directories.")
	}

	// Everything worked so if -q was provided the output from the daemon
	// should be just the image ID and we'll print that to stdout.
	if options.quiet {
		fmt.Fprintf(dockerCli.Out(), "%s", buildBuff)
	}

	if command.IsTrusted() {
		// Since the build was successful, now we must tag any of the resolved
		// images from the above Dockerfile rewrite.
		for _, resolved := range resolvedTags {
			if err := TagTrusted(ctx, dockerCli, resolved.digestRef, resolved.tagRef); err != nil {
				return err
			}
		}
	}

	return nil
}

func addDockerfileToBuildContext(dockerfileCtx io.ReadCloser, buildCtx io.ReadCloser) (io.ReadCloser, string, error) {
	file, err := ioutil.ReadAll(dockerfileCtx)
	dockerfileCtx.Close()
	if err != nil {
		return nil, "", err
	}
	now := time.Now()
	hdrTmpl := &tar.Header{
		Mode:       0600,
		Uid:        0,
		Gid:        0,
		ModTime:    now,
		Typeflag:   tar.TypeReg,
		AccessTime: now,
		ChangeTime: now,
	}
	randomName := ".dockerfile." + stringid.GenerateRandomID()[:20]

	buildCtx = archive.ReplaceFileTarWrapper(buildCtx, map[string]archive.TarModifierFunc{
		// Add the dockerfile with a random filename
		randomName: func(_ string, h *tar.Header, content io.Reader) (*tar.Header, []byte, error) {
			return hdrTmpl, file, nil
		},
		// Update .dockerignore to include the random filename
		".dockerignore": func(_ string, h *tar.Header, content io.Reader) (*tar.Header, []byte, error) {
			if h == nil {
				h = hdrTmpl
			}

			b := &bytes.Buffer{}
			if content != nil {
				if _, err := b.ReadFrom(content); err != nil {
					return nil, nil, err
				}
			} else {
				b.WriteString(".dockerignore")
			}
			b.WriteString("\n" + randomName + "\n")
			return h, b.Bytes(), nil
		},
	})
	return buildCtx, randomName, nil
}

func isLocalDir(c string) bool {
	_, err := os.Stat(c)
	return err == nil
}

type translatorFunc func(context.Context, reference.NamedTagged) (reference.Canonical, error)

// validateTag checks if the given image name can be resolved.
func validateTag(rawRepo string) (string, error) {
	_, err := reference.ParseNormalizedNamed(rawRepo)
	if err != nil {
		return "", err
	}

	return rawRepo, nil
}

var dockerfileFromLinePattern = regexp.MustCompile(`(?i)^[\s]*FROM[ \f\r\t\v]+(?P<image>[^ \f\r\t\v\n#]+)`)

// resolvedTag records the repository, tag, and resolved digest reference
// from a Dockerfile rewrite.
type resolvedTag struct {
	digestRef reference.Canonical
	tagRef    reference.NamedTagged
}

// rewriteDockerfileFrom rewrites the given Dockerfile by resolving images in
// "FROM <image>" instructions to a digest reference. `translator` is a
// function that takes a repository name and tag reference and returns a
// trusted digest reference.
func rewriteDockerfileFrom(ctx context.Context, dockerfile io.Reader, translator translatorFunc) (newDockerfile []byte, resolvedTags []*resolvedTag, err error) {
	scanner := bufio.NewScanner(dockerfile)
	buf := bytes.NewBuffer(nil)

	// Scan the lines of the Dockerfile, looking for a "FROM" line.
	for scanner.Scan() {
		line := scanner.Text()

		matches := dockerfileFromLinePattern.FindStringSubmatch(line)
		if matches != nil && matches[1] != api.NoBaseImageSpecifier {
			// Replace the line with a resolved "FROM repo@digest"
			var ref reference.Named
			ref, err = reference.ParseNormalizedNamed(matches[1])
			if err != nil {
				return nil, nil, err
			}
			ref = reference.TagNameOnly(ref)
			if ref, ok := ref.(reference.NamedTagged); ok && command.IsTrusted() {
				trustedRef, err := translator(ctx, ref)
				if err != nil {
					return nil, nil, err
				}

				line = dockerfileFromLinePattern.ReplaceAllLiteralString(line, fmt.Sprintf("FROM %s", reference.FamiliarString(trustedRef)))
				resolvedTags = append(resolvedTags, &resolvedTag{
					digestRef: trustedRef,
					tagRef:    ref,
				})
			}
		}

		_, err := fmt.Fprintln(buf, line)
		if err != nil {
			return nil, nil, err
		}
	}

	return buf.Bytes(), resolvedTags, scanner.Err()
}

// replaceDockerfileTarWrapper wraps the given input tar archive stream and
// replaces the entry with the given Dockerfile name with the contents of the
// new Dockerfile. Returns a new tar archive stream with the replaced
// Dockerfile.
func replaceDockerfileTarWrapper(ctx context.Context, inputTarStream io.ReadCloser, dockerfileName string, translator translatorFunc, resolvedTags *[]*resolvedTag) io.ReadCloser {
	pipeReader, pipeWriter := io.Pipe()
	go func() {
		tarReader := tar.NewReader(inputTarStream)
		tarWriter := tar.NewWriter(pipeWriter)

		defer inputTarStream.Close()

		for {
			hdr, err := tarReader.Next()
			if err == io.EOF {
				// Signals end of archive.
				tarWriter.Close()
				pipeWriter.Close()
				return
			}
			if err != nil {
				pipeWriter.CloseWithError(err)
				return
			}

			content := io.Reader(tarReader)
			if hdr.Name == dockerfileName {
				// This entry is the Dockerfile. Since the tar archive was
				// generated from a directory on the local filesystem, the
				// Dockerfile will only appear once in the archive.
				var newDockerfile []byte
				newDockerfile, *resolvedTags, err = rewriteDockerfileFrom(ctx, content, translator)
				if err != nil {
					pipeWriter.CloseWithError(err)
					return
				}
				hdr.Size = int64(len(newDockerfile))
				content = bytes.NewBuffer(newDockerfile)
			}

			if err := tarWriter.WriteHeader(hdr); err != nil {
				pipeWriter.CloseWithError(err)
				return
			}

			if _, err := io.Copy(tarWriter, content); err != nil {
				pipeWriter.CloseWithError(err)
				return
			}
		}
	}()

	return pipeReader
}