package daemon

import (
	"fmt"
	"path"
	"sort"

	"github.com/docker/docker/api/types"
	"github.com/docker/docker/api/types/filters"
	"github.com/docker/docker/container"
	"github.com/docker/docker/image"
	"github.com/docker/docker/layer"
	"github.com/docker/docker/reference"
)

var acceptedImageFilterTags = map[string]bool{
	"dangling": true,
	"label":    true,
	"before":   true,
	"since":    true,
}

// byCreated is a temporary type used to sort a list of images by creation
// time.
type byCreated []*types.Image

func (r byCreated) Len() int           { return len(r) }
func (r byCreated) Swap(i, j int)      { r[i], r[j] = r[j], r[i] }
func (r byCreated) Less(i, j int) bool { return r[i].Created < r[j].Created }

// Map returns a map of all images in the ImageStore
func (daemon *Daemon) Map() map[image.ID]*image.Image {
	return daemon.imageStore.Map()
}

// Images returns a filtered list of images. filterArgs is a JSON-encoded set
// of filter arguments which will be interpreted by api/types/filters.
// filter is a shell glob string applied to repository names. The argument
// named all controls whether all images in the graph are filtered, or just
// the heads.
func (daemon *Daemon) Images(filterArgs, filter string, all bool, withExtraAttrs bool) ([]*types.Image, error) {
	var (
		allImages    map[image.ID]*image.Image
		err          error
		danglingOnly = false
	)

	imageFilters, err := filters.FromParam(filterArgs)
	if err != nil {
		return nil, err
	}
	if err := imageFilters.Validate(acceptedImageFilterTags); err != nil {
		return nil, err
	}

	if imageFilters.Include("dangling") {
		if imageFilters.ExactMatch("dangling", "true") {
			danglingOnly = true
		} else if !imageFilters.ExactMatch("dangling", "false") {
			return nil, fmt.Errorf("Invalid filter 'dangling=%s'", imageFilters.Get("dangling"))
		}
	}
	if danglingOnly {
		allImages = daemon.imageStore.Heads()
	} else {
		allImages = daemon.imageStore.Map()
	}

	var beforeFilter, sinceFilter *image.Image
	err = imageFilters.WalkValues("before", func(value string) error {
		beforeFilter, err = daemon.GetImage(value)
		return err
	})
	if err != nil {
		return nil, err
	}

	err = imageFilters.WalkValues("since", func(value string) error {
		sinceFilter, err = daemon.GetImage(value)
		return err
	})
	if err != nil {
		return nil, err
	}

	images := []*types.Image{}
	var imagesMap map[*image.Image]*types.Image
	var layerRefs map[layer.ChainID]int
	var allLayers map[layer.ChainID]layer.Layer
	var allContainers []*container.Container

	var filterTagged bool
	if filter != "" {
		filterRef, err := reference.ParseNamed(filter)
		if err == nil { // parse error means wildcard repo
			if _, ok := filterRef.(reference.NamedTagged); ok {
				filterTagged = true
			}
		}
	}

	for id, img := range allImages {
		if beforeFilter != nil {
			if img.Created.Equal(beforeFilter.Created) || img.Created.After(beforeFilter.Created) {
				continue
			}
		}

		if sinceFilter != nil {
			if img.Created.Equal(sinceFilter.Created) || img.Created.Before(sinceFilter.Created) {
				continue
			}
		}

		if imageFilters.Include("label") {
			// Very old image that do not have image.Config (or even labels)
			if img.Config == nil {
				continue
			}
			// We are now sure image.Config is not nil
			if !imageFilters.MatchKVList("label", img.Config.Labels) {
				continue
			}
		}

		layerID := img.RootFS.ChainID()
		var size int64
		if layerID != "" {
			l, err := daemon.layerStore.Get(layerID)
			if err != nil {
				return nil, err
			}

			size, err = l.Size()
			layer.ReleaseAndLog(daemon.layerStore, l)
			if err != nil {
				return nil, err
			}
		}

		newImage := newImage(img, size)

		for _, ref := range daemon.referenceStore.References(id.Digest()) {
			if filter != "" { // filter by tag/repo name
				if filterTagged { // filter by tag, require full ref match
					if ref.String() != filter {
						continue
					}
				} else if matched, err := path.Match(filter, ref.Name()); !matched || err != nil { // name only match, FIXME: docs say exact
					continue
				}
			}
			if _, ok := ref.(reference.Canonical); ok {
				newImage.RepoDigests = append(newImage.RepoDigests, ref.String())
			}
			if _, ok := ref.(reference.NamedTagged); ok {
				newImage.RepoTags = append(newImage.RepoTags, ref.String())
			}
		}
		if newImage.RepoDigests == nil && newImage.RepoTags == nil {
			if all || len(daemon.imageStore.Children(id)) == 0 {

				if imageFilters.Include("dangling") && !danglingOnly {
					//dangling=false case, so dangling image is not needed
					continue
				}
				if filter != "" { // skip images with no references if filtering by tag
					continue
				}
				newImage.RepoDigests = []string{"<none>@<none>"}
				newImage.RepoTags = []string{"<none>:<none>"}
			} else {
				continue
			}
		} else if danglingOnly && len(newImage.RepoTags) > 0 {
			continue
		}

		if withExtraAttrs {
			// lazyly init variables
			if imagesMap == nil {
				allContainers = daemon.List()
				allLayers = daemon.layerStore.Map()
				imagesMap = make(map[*image.Image]*types.Image)
				layerRefs = make(map[layer.ChainID]int)
			}

			// Get container count
			newImage.Containers = 0
			for _, c := range allContainers {
				if c.ImageID == id {
					newImage.Containers++
				}
			}

			// count layer references
			rootFS := *img.RootFS
			rootFS.DiffIDs = nil
			for _, id := range img.RootFS.DiffIDs {
				rootFS.Append(id)
				chid := rootFS.ChainID()
				layerRefs[chid]++
				if _, ok := allLayers[chid]; !ok {
					return nil, fmt.Errorf("layer %v was not found (corruption?)", chid)
				}
			}
			imagesMap[img] = newImage
		}

		images = append(images, newImage)
	}

	if withExtraAttrs {
		// Get Shared and Unique sizes
		for img, newImage := range imagesMap {
			rootFS := *img.RootFS
			rootFS.DiffIDs = nil

			newImage.Size = 0
			newImage.SharedSize = 0
			for _, id := range img.RootFS.DiffIDs {
				rootFS.Append(id)
				chid := rootFS.ChainID()

				diffSize, err := allLayers[chid].DiffSize()
				if err != nil {
					return nil, err
				}

				if layerRefs[chid] > 1 {
					newImage.SharedSize += diffSize
				} else {
					newImage.Size += diffSize
				}
			}
		}
	}

	sort.Sort(sort.Reverse(byCreated(images)))

	return images, nil
}

func newImage(image *image.Image, virtualSize int64) *types.Image {
	newImage := new(types.Image)
	newImage.ParentID = image.Parent.String()
	newImage.ID = image.ID().String()
	newImage.Created = image.Created.Unix()
	newImage.Size = -1
	newImage.VirtualSize = virtualSize
	newImage.SharedSize = -1
	newImage.Containers = -1
	if image.Config != nil {
		newImage.Labels = image.Config.Labels
	}
	return newImage
}