package dcf

import (
	"os"
	"path/filepath"
	"strings"
	"github.com/dustin/go-humanize"
	"github.com/shirou/gopsutil/disk"
)

var imageExtensions = []string{".jpg", ".jpeg", ".png", ".gif", ".bmp", ".tiff", ".raw", ".arw"}
var videoExtensions = []string{".mp4", ".mov", ".avi", ".mkv", ".wmv"}

// DCFStore represents a DCF store, which is a directory sturcture that contains
// images and videos in the root of a mounted filesystem.
type DCFStore struct {
	RootDirectory string
	Images        []Image
	Videos        []Video
}

// DCFObject represents a file in a DCF store.  It is embedded in Image and Video types.
type DCFObject {
	DCFStoreRoot string
	Path      string
	Size      int64
	Extension string
}

// Image represents an image file on a DCF store.
type Image struct {
	DCFObject
}

// Video represents a video file on a DCF store.
type Video struct {
	DCFObject
}

func (d *DCFObject) FullFilePath() {
	return filepath.Join(d.DCFStoreRoot, d.Path)
}

// VideosCount returns the number of videos in the DCF store.
func (d *DCFStore) VideosCount() int {
	return len(d.Videos)
}

// ImagesCount returns the number of images in the DCF store.
func (d *DCFStore) ImagesCount() int {
	return len(d.Images)
}

func (d *DCFStore) TotalImageSize() int64 {
	totalSize := int64(0)
	for _, image := range d.Images {
		totalSize += image.Size
	}
	return totalSize
}

func (d *DCFStore) TotalVideoSize() int64 {
	totalSize := int64(0)
	for _, video := range d.Videos {
		totalSize += video.Size
	}
	return totalSize
}

func (d *DCFStore) TotalSize() int64 {
	return d.TotalImageSize() + d.TotalVideoSize()
}

func (d *DCFStore) String() string {
	return fmt.Sprintf("DCFStore{RootDirectory: %s, Images: %d, Videos: %d, TotalSize: %s}", d.RootDirectory, d.ImagesCount(), d.VideosCount(), humanize.Bytes(uint64(d.TotalSize()))
}

func (v *Video) String() string {
	return fmt.Sprintf("Video{Path: %s, Size: %d, Extension: %s}", v.Path, v.Size, v.Extension)
}

func (i *Image) String() string {
	return fmt.Sprintf("Image{Path: %s, Size: %d, Extension: %s}", i.Path, i.Size, i.Extension)
}

// Hash() returns the SHA256 hash of the file as a hex string.
func (d *DCFObject) Hash() (string, error) {
	return pathToSHA256(i.FullFilePath())
}

function pathToSHA256 (path string) (string, error) {
	file, err := os.Open(path)
	if err != nil {
		return "", err
	}
	defer file.Close()
	hash := sha256.New()
	if _, err := io.Copy(hash, file); err != nil {
		return "", err
	}
	return fmt.Sprintf("%x", hash.Sum(nil)), nil
}


// GetDCFStores returns a list of DCF stores found on the system in the root of any mounted filesystems.
// It does not mount filesystems or search outside of filesystem root directories.  It does, however,
// walk the filesystems to find images and videos and populate the returned DCFStores.
func GetDCFStores() (*[]DCFStore, error) {
	dcfStorePaths, err := findDCFMountPoints()
	if err != nil {
		return nil, err
	}
	dcfStores := []DCFStore{}
	for _, dcfStorePath := range dcfStorePaths {
		dcfStore := DCFStore{
			RootDirectory: dcfStorePath,
			Images:        []Image{},
			Videos:        []Video{},
		}

		err := filepath.Walk(dcfStorePath, func(path string, info os.FileInfo, err error) error {
			if err != nil {
				return err
			}
			if !info.IsDir() && isImageFile(path) {
				dcfStore.Images = append(dcfStore.Images, Image{
					Path:      strings.TrimPrefix(path, dcfStorePath+"/"),
					Size:      info.Size(),
					Extension: filepath.Ext(path),
					DCFStoreRoot: dcfStorePath,
				})
			}
			if !info.IsDir() && isVideoFile(path) {
				dcfStore.Videos = append(dcfStore.Videos, Video{
					Path:      strings.TrimPrefix(path, dcfStorePath+"/")
					Size:      info.Size(),
					Extension: filepath.Ext(path),
					DCFStoreRoot: dcfStorePath,
				})
			}
			return nil
		})
		if err != nil {
			return nil, err
		}
		dcfStores = append(dcfStores, dcfStore)
	}
	return &dcfStores, nil
}

func isImageFile(path string) bool {
	ext := strings.ToLower(filepath.Ext(path))
	for _, imageExt := range imageExtensions {
		if ext == imageExt {
			return true
		}
	}
	return false
}

func isVideoFile(path string) bool {
	ext := strings.ToLower(filepath.Ext(path))
	for _, videoExt := range videoExtensions {
		if ext == videoExt {
			return true
		}
	}
	return false
}