From 55d61fceb2f70209c29e6cc0dab4087a2b7b4312 Mon Sep 17 00:00:00 2001
From: Dan Brown <ssddanbrown@googlemail.com>
Date: Sat, 26 Mar 2022 12:32:08 +0000
Subject: [PATCH] Added manual image thumbnail exif orientation handling

Uses original image data to extract orientation exif to apply image
transformations before scaling and save. Manually done due to issues
with exif data loss during the existing Invervention image path.

For #1854
---
 app/Uploads/ImageService.php | 46 ++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/app/Uploads/ImageService.php b/app/Uploads/ImageService.php
index e755be7e6..ee414aacb 100644
--- a/app/Uploads/ImageService.php
+++ b/app/Uploads/ImageService.php
@@ -5,6 +5,7 @@ namespace BookStack\Uploads;
 use BookStack\Exceptions\ImageUploadException;
 use ErrorException;
 use Exception;
+use GuzzleHttp\Psr7\Utils;
 use Illuminate\Contracts\Cache\Repository as Cache;
 use Illuminate\Contracts\Filesystem\FileNotFoundException;
 use Illuminate\Contracts\Filesystem\Filesystem as Storage;
@@ -14,6 +15,7 @@ use Illuminate\Support\Facades\DB;
 use Illuminate\Support\Facades\Log;
 use Illuminate\Support\Str;
 use Intervention\Image\Exception\NotSupportedException;
+use Intervention\Image\Image as InterventionImage;
 use Intervention\Image\ImageManager;
 use League\Flysystem\Util;
 use Psr\SimpleCache\InvalidArgumentException;
@@ -308,6 +310,8 @@ class ImageService
             throw new ImageUploadException(trans('errors.cannot_create_thumbs'));
         }
 
+        $this->orientImageToOriginalExif($thumb, $imageData);
+
         if ($keepRatio) {
             $thumb->resize($width, $height, function ($constraint) {
                 $constraint->aspectRatio();
@@ -328,6 +332,48 @@ class ImageService
         return $thumbData;
     }
 
+    /**
+     * Orientate the given intervention image based upon the given original image data.
+     * Intervention does have an `orientate` method but the exif data it needs is lost before it
+     * can be used (At least when created using binary string data) so we need to do some
+     * implementation on our side to use the original image data.
+     * Bulk of logic taken from: https://github.com/Intervention/image/blob/b734a4988b2148e7d10364b0609978a88d277536/src/Intervention/Image/Commands/OrientateCommand.php
+     * Copyright (c) Oliver Vogel, MIT License
+     */
+    protected function orientImageToOriginalExif(InterventionImage $image, string $originalData): void
+    {
+        if (!extension_loaded('exif')) {
+            return;
+        }
+
+        $stream = Utils::streamFor($originalData)->detach();
+        $orientation = exif_read_data($stream)['Orientation'] ?? null;
+
+        switch ($orientation) {
+            case 2:
+                $image->flip();
+                break;
+            case 3:
+                $image->rotate(180);
+                break;
+            case 4:
+                $image->rotate(180)->flip();
+                break;
+            case 5:
+                $image->rotate(270)->flip();
+                break;
+            case 6:
+                $image->rotate(270);
+                break;
+            case 7:
+                $image->rotate(90)->flip();
+                break;
+            case 8:
+                $image->rotate(90);
+                break;
+        }
+    }
+
     /**
      * Get the raw data content from an image.
      *