package main

import (
	"fmt"
	"reflect"
	"strings"
	"time"

	"github.com/containers/storage"
	"github.com/docker/go-units"
	digest "github.com/opencontainers/go-digest"
	"github.com/pkg/errors"
	"github.com/projectatomic/libpod/cmd/podman/formats"
	"github.com/projectatomic/libpod/libpod"
	"github.com/projectatomic/libpod/libpod/common"
	"github.com/projectatomic/libpod/pkg/inspect"
	"github.com/urfave/cli"
)

type imagesTemplateParams struct {
	Repository string
	Tag        string
	ID         string
	Digest     digest.Digest
	Created    string
	Size       string
}

type imagesJSONParams struct {
	ID      string        `json:"id"`
	Name    []string      `json:"names"`
	Digest  digest.Digest `json:"digest"`
	Created time.Time     `json:"created"`
	Size    int64         `json:"size"`
}

type imagesOptions struct {
	quiet     bool
	noHeading bool
	noTrunc   bool
	digests   bool
	format    string
}

var (
	imagesFlags = []cli.Flag{
		cli.BoolFlag{
			Name:  "quiet, q",
			Usage: "display only image IDs",
		},
		cli.BoolFlag{
			Name:  "noheading, n",
			Usage: "do not print column headings",
		},
		cli.BoolFlag{
			Name:  "no-trunc, notruncate",
			Usage: "do not truncate output",
		},
		cli.BoolFlag{
			Name:  "digests",
			Usage: "show digests",
		},
		cli.StringFlag{
			Name:  "format",
			Usage: "Change the output format to JSON or a Go template",
		},
		cli.StringFlag{
			Name:  "filter, f",
			Usage: "filter output based on conditions provided (default [])",
		},
	}

	imagesDescription = "lists locally stored images."
	imagesCommand     = cli.Command{
		Name:                   "images",
		Usage:                  "list images in local storage",
		Description:            imagesDescription,
		Flags:                  imagesFlags,
		Action:                 imagesCmd,
		ArgsUsage:              "",
		UseShortOptionHandling: true,
	}
)

func imagesCmd(c *cli.Context) error {
	if err := validateFlags(c, imagesFlags); err != nil {
		return err
	}

	runtime, err := getRuntime(c)
	if err != nil {
		return errors.Wrapf(err, "Could not get runtime")
	}
	defer runtime.Shutdown(false)

	format := genImagesFormat(c.String("format"), c.Bool("quiet"), c.Bool("noheading"), c.Bool("digests"))

	opts := imagesOptions{
		quiet:     c.Bool("quiet"),
		noHeading: c.Bool("noheading"),
		noTrunc:   c.Bool("no-trunc"),
		digests:   c.Bool("digests"),
		format:    format,
	}

	var imageInput string
	if len(c.Args()) == 1 {
		imageInput = c.Args().Get(0)
	}
	if len(c.Args()) > 1 {
		return errors.New("'podman images' requires at most 1 argument")
	}

	params, err := runtime.ParseImageFilter(imageInput, c.String("filter"))
	if err != nil {
		return errors.Wrapf(err, "error parsing filter")
	}

	// generate the different filters
	labelFilter := generateImagesFilter(params, "label")
	beforeImageFilter := generateImagesFilter(params, "before-image")
	sinceImageFilter := generateImagesFilter(params, "since-image")
	danglingFilter := generateImagesFilter(params, "dangling")
	referenceFilter := generateImagesFilter(params, "reference")
	imageInputFilter := generateImagesFilter(params, "image-input")

	/*
		podman does not implement --all for images

		intermediate images are only generated during the build process.  they are
		children to the image once built. until buildah supports caching builds,
		it will not generate these intermediate images.
	*/

	images, err := runtime.GetImages(params, labelFilter, beforeImageFilter, sinceImageFilter, danglingFilter, referenceFilter, imageInputFilter)
	if err != nil {
		return errors.Wrapf(err, "could not get list of images matching filter")
	}

	return generateImagesOutput(runtime, images, opts)
}

func genImagesFormat(format string, quiet, noHeading, digests bool) string {
	if format != "" {
		// "\t" from the command line is not being recognized as a tab
		// replacing the string "\t" to a tab character if the user passes in "\t"
		return strings.Replace(format, `\t`, "\t", -1)
	}
	if quiet {
		return formats.IDString
	}
	format = "table {{.Repository}}\t{{.Tag}}\t"
	if noHeading {
		format = "{{.Repository}}\t{{.Tag}}\t"
	}
	if digests {
		format += "{{.Digest}}\t"
	}
	format += "{{.ID}}\t{{.Created}}\t{{.Size}}\t"
	return format
}

// imagesToGeneric creates an empty array of interfaces for output
func imagesToGeneric(templParams []imagesTemplateParams, JSONParams []imagesJSONParams) (genericParams []interface{}) {
	if len(templParams) > 0 {
		for _, v := range templParams {
			genericParams = append(genericParams, interface{}(v))
		}
		return
	}
	for _, v := range JSONParams {
		genericParams = append(genericParams, interface{}(v))
	}
	return
}

// generate the header based on the template provided
func (i *imagesTemplateParams) headerMap() map[string]string {
	v := reflect.Indirect(reflect.ValueOf(i))
	values := make(map[string]string)

	for i := 0; i < v.NumField(); i++ {
		key := v.Type().Field(i).Name
		value := key
		if value == "ID" {
			value = "Image" + value
		}
		values[key] = strings.ToUpper(splitCamelCase(value))
	}
	return values
}

// getImagesTemplateOutput returns the images information to be printed in human readable format
func getImagesTemplateOutput(runtime *libpod.Runtime, images []*storage.Image, opts imagesOptions) (imagesOutput []imagesTemplateParams) {
	var (
		lastID string
	)
	for _, img := range images {
		if opts.quiet && lastID == img.ID {
			continue // quiet should not show the same ID multiple times
		}
		createdTime := img.Created

		imageID := "sha256:" + img.ID
		if !opts.noTrunc {
			imageID = shortID(img.ID)
		}

		repository := "<none>"
		tag := "<none>"
		if len(img.Names) > 0 {
			arr := strings.Split(img.Names[0], ":")
			repository = arr[0]
			if len(arr) == 2 {
				tag = arr[1]
			}
		}

		imgData, _ := runtime.GetImageInspectInfo(*img)
		if imgData != nil {
			createdTime = *imgData.Created
		}

		params := imagesTemplateParams{
			Repository: repository,
			Tag:        tag,
			ID:         imageID,
			Digest:     imgData.Digest,
			Created:    units.HumanDuration(time.Since((createdTime))) + " ago",
			Size:       units.HumanSizeWithPrecision(float64(imgData.Size), 3),
		}
		imagesOutput = append(imagesOutput, params)
	}
	return
}

// getImagesJSONOutput returns the images information in its raw form
func getImagesJSONOutput(runtime *libpod.Runtime, images []*storage.Image) (imagesOutput []imagesJSONParams) {
	for _, img := range images {
		createdTime := img.Created

		imgData, _ := runtime.GetImageInspectInfo(*img)
		if imgData != nil {
			createdTime = *imgData.Created
		}

		params := imagesJSONParams{
			ID:      img.ID,
			Name:    img.Names,
			Digest:  imgData.Digest,
			Created: createdTime,
			Size:    imgData.Size,
		}
		imagesOutput = append(imagesOutput, params)
	}
	return
}

// generateImagesOutput generates the images based on the format provided
func generateImagesOutput(runtime *libpod.Runtime, images []*storage.Image, opts imagesOptions) error {
	if len(images) == 0 {
		return nil
	}

	var out formats.Writer

	switch opts.format {
	case formats.JSONString:
		imagesOutput := getImagesJSONOutput(runtime, images)
		out = formats.JSONStructArray{Output: imagesToGeneric([]imagesTemplateParams{}, imagesOutput)}
	default:
		imagesOutput := getImagesTemplateOutput(runtime, images, opts)
		out = formats.StdoutTemplateArray{Output: imagesToGeneric(imagesOutput, []imagesJSONParams{}), Template: opts.format, Fields: imagesOutput[0].headerMap()}

	}

	return formats.Writer(out).Out()
}

// generateImagesFilter returns an ImageFilter based on filterType
// to add more filters, define a new case and write what the ImageFilter function should do
func generateImagesFilter(params *libpod.ImageFilterParams, filterType string) libpod.ImageFilter {
	switch filterType {
	case "label":
		return func(image *storage.Image, info *inspect.ImageData) bool {
			if params == nil || params.Label == "" {
				return true
			}

			pair := strings.SplitN(params.Label, "=", 2)
			if val, ok := info.Labels[pair[0]]; ok {
				if len(pair) == 2 && val == pair[1] {
					return true
				}
				if len(pair) == 1 {
					return true
				}
			}
			return false
		}
	case "before-image":
		return func(image *storage.Image, info *inspect.ImageData) bool {
			if params == nil || params.BeforeImage.IsZero() {
				return true
			}
			return info.Created.Before(params.BeforeImage)
		}
	case "since-image":
		return func(image *storage.Image, info *inspect.ImageData) bool {
			if params == nil || params.SinceImage.IsZero() {
				return true
			}
			return info.Created.After(params.SinceImage)
		}
	case "dangling":
		return func(image *storage.Image, info *inspect.ImageData) bool {
			if params == nil || params.Dangling == "" {
				return true
			}
			if common.IsFalse(params.Dangling) && params.ImageName != "<none>" {
				return true
			}
			if common.IsTrue(params.Dangling) && params.ImageName == "<none>" {
				return true
			}
			return false
		}
	case "reference":
		return func(image *storage.Image, info *inspect.ImageData) bool {
			if params == nil || params.ReferencePattern == "" {
				return true
			}
			return libpod.MatchesReference(params.ImageName, params.ReferencePattern)
		}
	case "image-input":
		return func(image *storage.Image, info *inspect.ImageData) bool {
			if params == nil || params.ImageInput == "" {
				return true
			}
			return libpod.MatchesReference(params.ImageName, params.ImageInput)
		}
	default:
		fmt.Println("invalid filter type", filterType)
		return nil
	}
}