implement POST /emoji for apiV4 (#5868)

app/emoji.go

@@ -0,0 +1,156 @@
+// Copyright (c) 2017 Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package app
+
+import (
+	"bytes"
+	"image"
+	"image/color/palette"
+	"image/draw"
+	"image/gif"
+	_ "image/jpeg"
+	"image/png"
+	"io"
+	"mime/multipart"
+	"net/http"
+
+	"github.com/disintegration/imaging"
+	"github.com/mattermost/platform/model"
+)
+
+const (
+	MaxEmojiFileSize = 1000 * 1024 // 1 MB
+	MaxEmojiWidth    = 128
+	MaxEmojiHeight   = 128
+)
+
+func CreateEmoji(sessionUserId string, emoji *model.Emoji, multiPartImageData *multipart.Form) (*model.Emoji, *model.AppError) {
+	// wipe the emoji id so that existing emojis can't get overwritten
+	emoji.Id = ""
+
+	// do our best to validate the emoji before committing anything to the DB so that we don't have to clean up
+	// orphaned files left over when validation fails later on
+	emoji.PreSave()
+	if err := emoji.IsValid(); err != nil {
+		return nil, err
+	}
+
+	if emoji.CreatorId != sessionUserId {
+		return nil, model.NewAppError("createEmoji", "api.emoji.create.other_user.app_error", nil, "", http.StatusForbidden)
+	}
+
+	if result := <-Srv.Store.Emoji().GetByName(emoji.Name); result.Err == nil && result.Data != nil {
+		return nil, model.NewAppError("createEmoji", "api.emoji.create.duplicate.app_error", nil, "", http.StatusBadRequest)
+	}
+
+	if imageData := multiPartImageData.File["image"]; len(imageData) == 0 {
+		err := model.NewLocAppError("Context", "api.context.invalid_body_param.app_error", map[string]interface{}{"Name": "createEmoji"}, "")
+		err.StatusCode = http.StatusBadRequest
+		return nil, err
+	} else if err := UploadEmojiImage(emoji.Id, imageData[0]); err != nil {
+		return nil, err
+	}
+
+	if result := <-Srv.Store.Emoji().Save(emoji); result.Err != nil {
+		return nil, result.Err
+	} else {
+		return result.Data.(*model.Emoji), nil
+	}
+}
+
+func UploadEmojiImage(id string, imageData *multipart.FileHeader) *model.AppError {
+	file, err := imageData.Open()
+	if err != nil {
+		return model.NewAppError("uploadEmojiImage", "api.emoji.upload.open.app_error", nil, "", http.StatusBadRequest)
+	}
+	defer file.Close()
+
+	buf := bytes.NewBuffer(nil)
+	io.Copy(buf, file)
+
+	// make sure the file is an image and is within the required dimensions
+	if config, _, err := image.DecodeConfig(bytes.NewReader(buf.Bytes())); err != nil {
+		return model.NewAppError("uploadEmojiImage", "api.emoji.upload.image.app_error", nil, "", http.StatusBadRequest)
+	} else if config.Width > MaxEmojiWidth || config.Height > MaxEmojiHeight {
+		data := buf.Bytes()
+		newbuf := bytes.NewBuffer(nil)
+		if info, err := model.GetInfoForBytes(imageData.Filename, data); err != nil {
+			return err
+		} else if info.MimeType == "image/gif" {
+			if gif_data, err := gif.DecodeAll(bytes.NewReader(data)); err != nil {
+				return model.NewAppError("uploadEmojiImage", "api.emoji.upload.large_image.gif_decode_error", nil, "", http.StatusBadRequest)
+			} else {
+				resized_gif := resizeEmojiGif(gif_data)
+				if err := gif.EncodeAll(newbuf, resized_gif); err != nil {
+					return model.NewAppError("uploadEmojiImage", "api.emoji.upload.large_image.gif_encode_error", nil, "", http.StatusBadRequest)
+				}
+				if err := WriteFile(newbuf.Bytes(), getEmojiImagePath(id)); err != nil {
+					return err
+				}
+			}
+		} else {
+			if img, _, err := image.Decode(bytes.NewReader(data)); err != nil {
+				return model.NewAppError("uploadEmojiImage", "api.emoji.upload.large_image.decode_error", nil, "", http.StatusBadRequest)
+			} else {
+				resized_image := resizeEmoji(img, config.Width, config.Height)
+				if err := png.Encode(newbuf, resized_image); err != nil {
+					return model.NewAppError("uploadEmojiImage", "api.emoji.upload.large_image.encode_error", nil, "", http.StatusBadRequest)
+				}
+				if err := WriteFile(newbuf.Bytes(), getEmojiImagePath(id)); err != nil {
+					return err
+				}
+			}
+		}
+	} else {
+		if err := WriteFile(buf.Bytes(), getEmojiImagePath(id)); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func resizeEmojiGif(gifImg *gif.GIF) *gif.GIF {
+	// Create a new RGBA image to hold the incremental frames.
+	firstFrame := gifImg.Image[0].Bounds()
+	b := image.Rect(0, 0, firstFrame.Dx(), firstFrame.Dy())
+	img := image.NewRGBA(b)
+
+	resizedImage := image.Image(nil)
+	// Resize each frame.
+	for index, frame := range gifImg.Image {
+		bounds := frame.Bounds()
+		draw.Draw(img, bounds, frame, bounds.Min, draw.Over)
+		resizedImage = resizeEmoji(img, firstFrame.Dx(), firstFrame.Dy())
+		gifImg.Image[index] = imageToPaletted(resizedImage)
+	}
+	// Set new gif width and height
+	gifImg.Config.Width = resizedImage.Bounds().Dx()
+	gifImg.Config.Height = resizedImage.Bounds().Dy()
+	return gifImg
+}
+
+func getEmojiImagePath(id string) string {
+	return "emoji/" + id + "/image"
+}
+
+func resizeEmoji(img image.Image, width int, height int) image.Image {
+	emojiWidth := float64(width)
+	emojiHeight := float64(height)
+
+	var emoji image.Image
+	if emojiHeight <= MaxEmojiHeight && emojiWidth <= MaxEmojiWidth {
+		emoji = img
+	} else {
+		emoji = imaging.Fit(img, MaxEmojiWidth, MaxEmojiHeight, imaging.Lanczos)
+	}
+	return emoji
+}
+
+func imageToPaletted(img image.Image) *image.Paletted {
+	b := img.Bounds()
+	pm := image.NewPaletted(b, palette.Plan9)
+	draw.FloydSteinberg.Draw(pm, b, img, image.ZP)
+	return pm
+}