Merge pull request #191 from dxe/fix-eventbrite-image-crop

Fix EB image crop
dxe · Jan 28, 2023 · 7ec7789 · 7ec7789
2 parents 18f0139 + 53adced
commit 7ec7789
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Showing 2 changed files with 45 additions and 16 deletions.
diff --git a/event_sync/eventbrite_api.go b/event_sync/eventbrite_api.go
@@ -132,7 +132,10 @@ func createEventbriteImage(event model.ExternalEvent, chapter model.ChapterWithT
 		return "", err
 	}
 
-	imageId, err := notifyEventbriteOfNewImage(chapter.EventbriteToken, uploadData.UploadToken)
+	imageId, err := notifyEventbriteOfNewImage(chapter.EventbriteToken, uploadData.UploadToken, image.Width, image.Height)
+	if err != nil {
+		return "", err
+	}
 
 	return imageId, nil
 }
@@ -374,7 +377,7 @@ func uploadImageToEventbrite(image Image, data EventbriteUploadData) error {
 	return nil
 }
 
-func notifyEventbriteOfNewImage(token string, uploadToken string) (string, error) {
+func notifyEventbriteOfNewImage(token string, uploadToken string, width int, height int) (string, error) {
 	path := eventbriteAPIBaseURL + "/media/upload/?token=" + token
 
 	type topLeft struct {
@@ -397,15 +400,31 @@ func notifyEventbriteOfNewImage(token string, uploadToken string) (string, error
 		ID string `json:"id"`
 	}
 
+	// Eventbrite requires an image with a 2:1 aspect ratio, but that may not always be what Facebook provides.
+	// So we must crop the image vertically or horizontally using the center.
+	var x, y = 1, 1
+	var finalWidth, finalHeight = width, height
+	cropHeight := width / 2
+	if cropHeight > height {
+		// If cropped height is greater than actual height, we need to crop horizontally instead.
+		cropWidth := height * 2
+		x = (width - cropWidth) / 2
+		finalWidth = cropWidth
+	} else {
+		// Else crop vertically.
+		y = (height - cropHeight) / 2
+		finalHeight = cropHeight
+	}
+
 	req := reqBody{
 		UploadToken: uploadToken,
 		CropMask: cropMask{
 			TopLeft: topLeft{
-				X: 1,
-				Y: 1,
+				X: x,
+				Y: y,
 			},
-			Width:  1280,
-			Height: 640,
+			Width:  finalWidth,
+			Height: finalHeight,
 		},
 	}
 

diff --git a/event_sync/facebook_api.go b/event_sync/facebook_api.go
@@ -1,14 +1,15 @@
 package event_sync
 
 import (
+	"bytes"
 	"errors"
+	"github.com/dxe/adb/model"
+	"image"
 	"io/ioutil"
 	"net/http"
 	"path"
 	"strconv"
 	"strings"
-
-	"github.com/dxe/adb/model"
 )
 
 const facebookAPIBaseURL = "https://graph.facebook.com/v4.0"
@@ -55,6 +56,8 @@ type FacebookCover struct {
 type Image struct {
 	Buffer []byte
 	Name   string
+	Width  int
+	Height int
 }
 
 func getFacebookEvents(page model.ChapterWithToken) ([]FacebookEvent, error) {
@@ -82,26 +85,33 @@ func getFacebookEvent(page model.ChapterWithToken, eventID string) (FacebookEven
 }
 
 func downloadImageFromFacebook(imageUrl string) (Image, error) {
-	var image Image
+	var outputImage Image
 
 	resp, err := http.Get(imageUrl)
 	if err != nil {
-		return image, err
+		return outputImage, err
 	}
 
 	defer resp.Body.Close()
 
 	if resp.StatusCode != http.StatusOK {
-		return image, errors.New("failed to get image from Facebook. Status: " + strconv.Itoa(resp.StatusCode))
+		return outputImage, errors.New("failed to get image from Facebook. Status: " + strconv.Itoa(resp.StatusCode))
+	}
+
+	outputImage.Buffer, err = ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return outputImage, err
 	}
 
-	image.Buffer, err = ioutil.ReadAll(resp.Body)
+	img, _, err := image.Decode(bytes.NewReader(outputImage.Buffer))
 	if err != nil {
-		return image, err
+		return outputImage, err
 	}
+	outputImage.Width = img.Bounds().Dx()
+	outputImage.Height = img.Bounds().Dy()
 
-	image.Name = path.Base(imageUrl)
-	image.Name = image.Name[:strings.Index(image.Name, "?")]
+	pathBase := path.Base(imageUrl)
+	outputImage.Name = pathBase[:strings.Index(pathBase, "?")]
 
-	return image, nil
+	return outputImage, nil
 }