Move Slack Import to App Layer. (#5135)

1 files changed, 190 insertions, 1 deletions

diff --git a/app/file.go b/app/file.go
index 93a286a14..a4419bde8 100644
--- a/app/file.go
+++ b/app/file.go
@@ -5,11 +5,17 @@ package app
 
 import (
 	"bytes"
+	_ "image/gif"
 	"crypto/sha256"
 	"encoding/base64"
 	"fmt"
+	"image"
+	"image/color"
+	"image/draw"
+	"image/jpeg"
 	"io"
 	"io/ioutil"
+	"net/http"
 	"net/url"
 	"os"
 	"path"
@@ -20,8 +26,33 @@ import (
 	l4g "github.com/alecthomas/log4go"
 	"github.com/mattermost/platform/model"
 	"github.com/mattermost/platform/utils"
-
+	"github.com/disintegration/imaging"
 	s3 "github.com/minio/minio-go"
+	"github.com/rwcarlsen/goexif/exif"
+	_ "golang.org/x/image/bmp"
+)
+
+const (
+	/*
+	  EXIF Image Orientations
+	  1        2       3      4         5            6           7          8
+
+	  888888  888888      88  88      8888888888  88                  88  8888888888
+	  88          88      88  88      88  88      88  88          88  88      88  88
+	  8888      8888    8888  8888    88          8888888888  8888888888          88
+	  88          88      88  88
+	  88          88  888888  888888
+	*/
+	Upright            = 1
+	UprightMirrored    = 2
+	UpsideDown         = 3
+	UpsideDownMirrored = 4
+	RotatedCWMirrored  = 5
+	RotatedCCW         = 6
+	RotatedCCWMirrored = 7
+	RotatedCW          = 8
+
+	MaxImageSize = 6048 * 4032 // 24 megapixels, roughly 36MB as a raw image
 )
 
 func ReadFile(path string) ([]byte, *model.AppError) {
@@ -338,3 +369,161 @@ func GeneratePublicLinkHash(fileId, salt string) string {
 
 	return base64.RawURLEncoding.EncodeToString(hash.Sum(nil))
 }
+
+func DoUploadFile(teamId string, channelId string, userId string, rawFilename string, data []byte) (*model.FileInfo, *model.AppError) {
+	filename := filepath.Base(rawFilename)
+
+	info, err := model.GetInfoForBytes(filename, data)
+	if err != nil {
+		err.StatusCode = http.StatusBadRequest
+		return nil, err
+	}
+
+	info.Id = model.NewId()
+	info.CreatorId = userId
+
+	pathPrefix := "teams/" + teamId + "/channels/" + channelId + "/users/" + userId + "/" + info.Id + "/"
+	info.Path = pathPrefix + filename
+
+	if info.IsImage() {
+		// Check dimensions before loading the whole thing into memory later on
+		if info.Width*info.Height > MaxImageSize {
+			err := model.NewLocAppError("uploadFile", "api.file.upload_file.large_image.app_error", map[string]interface{}{"Filename": filename}, "")
+			err.StatusCode = http.StatusBadRequest
+			return nil, err
+		}
+
+		nameWithoutExtension := filename[:strings.LastIndex(filename, ".")]
+		info.PreviewPath = pathPrefix + nameWithoutExtension + "_preview.jpg"
+		info.ThumbnailPath = pathPrefix + nameWithoutExtension + "_thumb.jpg"
+	}
+
+	if err := WriteFile(data, info.Path); err != nil {
+		return nil, err
+	}
+
+	if result := <-Srv.Store.FileInfo().Save(info); result.Err != nil {
+		return nil, result.Err
+	}
+
+	return info, nil
+}
+
+func HandleImages(previewPathList []string, thumbnailPathList []string, fileData [][]byte) {
+	for i, data := range fileData {
+		go func(i int, data []byte) {
+			img, width, height := prepareImage(fileData[i])
+			if img != nil {
+				go generateThumbnailImage(*img, thumbnailPathList[i], width, height)
+				go generatePreviewImage(*img, previewPathList[i], width)
+			}
+		}(i, data)
+	}
+}
+
+func prepareImage(fileData []byte) (*image.Image, int, int) {
+	// Decode image bytes into Image object
+	img, imgType, err := image.Decode(bytes.NewReader(fileData))
+	if err != nil {
+		l4g.Error(utils.T("api.file.handle_images_forget.decode.error"), err)
+		return nil, 0, 0
+	}
+
+	width := img.Bounds().Dx()
+	height := img.Bounds().Dy()
+
+	// Fill in the background of a potentially-transparent png file as white
+	if imgType == "png" {
+		dst := image.NewRGBA(img.Bounds())
+		draw.Draw(dst, dst.Bounds(), image.NewUniform(color.White), image.Point{}, draw.Src)
+		draw.Draw(dst, dst.Bounds(), img, img.Bounds().Min, draw.Over)
+		img = dst
+	}
+
+	// Flip the image to be upright
+	orientation, _ := getImageOrientation(fileData)
+
+	switch orientation {
+	case UprightMirrored:
+		img = imaging.FlipH(img)
+	case UpsideDown:
+		img = imaging.Rotate180(img)
+	case UpsideDownMirrored:
+		img = imaging.FlipV(img)
+	case RotatedCWMirrored:
+		img = imaging.Transpose(img)
+	case RotatedCCW:
+		img = imaging.Rotate270(img)
+	case RotatedCCWMirrored:
+		img = imaging.Transverse(img)
+	case RotatedCW:
+		img = imaging.Rotate90(img)
+	}
+
+	return &img, width, height
+}
+
+func getImageOrientation(imageData []byte) (int, error) {
+	if exifData, err := exif.Decode(bytes.NewReader(imageData)); err != nil {
+		return Upright, err
+	} else {
+		if tag, err := exifData.Get("Orientation"); err != nil {
+			return Upright, err
+		} else {
+			orientation, err := tag.Int(0)
+			if err != nil {
+				return Upright, err
+			} else {
+				return orientation, nil
+			}
+		}
+	}
+}
+
+func generateThumbnailImage(img image.Image, thumbnailPath string, width int, height int) {
+	thumbWidth := float64(utils.Cfg.FileSettings.ThumbnailWidth)
+	thumbHeight := float64(utils.Cfg.FileSettings.ThumbnailHeight)
+	imgWidth := float64(width)
+	imgHeight := float64(height)
+
+	var thumbnail image.Image
+	if imgHeight < thumbHeight && imgWidth < thumbWidth {
+		thumbnail = img
+	} else if imgHeight/imgWidth < thumbHeight/thumbWidth {
+		thumbnail = imaging.Resize(img, 0, utils.Cfg.FileSettings.ThumbnailHeight, imaging.Lanczos)
+	} else {
+		thumbnail = imaging.Resize(img, utils.Cfg.FileSettings.ThumbnailWidth, 0, imaging.Lanczos)
+	}
+
+	buf := new(bytes.Buffer)
+	if err := jpeg.Encode(buf, thumbnail, &jpeg.Options{Quality: 90}); err != nil {
+		l4g.Error(utils.T("api.file.handle_images_forget.encode_jpeg.error"), thumbnailPath, err)
+		return
+	}
+
+	if err := WriteFile(buf.Bytes(), thumbnailPath); err != nil {
+		l4g.Error(utils.T("api.file.handle_images_forget.upload_thumb.error"), thumbnailPath, err)
+		return
+	}
+}
+
+func generatePreviewImage(img image.Image, previewPath string, width int) {
+	var preview image.Image
+	if width > int(utils.Cfg.FileSettings.PreviewWidth) {
+		preview = imaging.Resize(img, utils.Cfg.FileSettings.PreviewWidth, utils.Cfg.FileSettings.PreviewHeight, imaging.Lanczos)
+	} else {
+		preview = img
+	}
+
+	buf := new(bytes.Buffer)
+
+	if err := jpeg.Encode(buf, preview, &jpeg.Options{Quality: 90}); err != nil {
+		l4g.Error(utils.T("api.file.handle_images_forget.encode_preview.error"), previewPath, err)
+		return
+	}
+
+	if err := WriteFile(buf.Bytes(), previewPath); err != nil {
+		l4g.Error(utils.T("api.file.handle_images_forget.upload_preview.error"), previewPath, err)
+		return
+	}
+}