Add backend video image validations - EDUCATOR-45

cms/djangoapps/contentstore/views/videos.py

@@ -16,6 +16,7 @@ from boto import s3
 from django.conf import settings
 from django.contrib.auth.decorators import login_required
 from django.contrib.staticfiles.storage import staticfiles_storage
+from django.core.files.images import get_image_dimensions
 from django.http import HttpResponse, HttpResponseNotFound
 from django.utils.translation import ugettext as _
 from django.utils.translation import ugettext_noop
@@ -153,19 +154,69 @@ def videos_handler(request, course_key_string, edx_video_id=None):
         return videos_post(course, request)
 
 
+def validate_video_image(image_file):
+    """
+    Validates video image file.
+
+    Arguments:
+        image_file: The selected image file.
+
+   Returns:
+        error (String or None): If there is error returns error message otherwise None.
+    """
+    error = None
+
+    if not all(hasattr(image_file, attr) for attr in ['name', 'content_type', 'size']):
+        error = _('The image must have name, content type, and size information.')
+    elif image_file.content_type not in settings.VIDEO_IMAGE_SUPPORTED_FILE_FORMATS.values():
+        error = _('This image file type is not supported. Supported file types are {supported_file_formats}.').format(
+            supported_file_formats=settings.VIDEO_IMAGE_SUPPORTED_FILE_FORMATS.keys()
+        )
+    elif image_file.size > settings.VIDEO_IMAGE_SETTINGS['VIDEO_IMAGE_MAX_BYTES']:
+        error = _('This image file must be smaller than {image_max_size}.').format(
+            image_max_size=settings.VIDEO_IMAGE_MAX_FILE_SIZE_MB
+        )
+    elif image_file.size < settings.VIDEO_IMAGE_SETTINGS['VIDEO_IMAGE_MIN_BYTES']:
+        error = _('This image file must be larger than {image_min_size}.').format(
+            image_min_size=settings.VIDEO_IMAGE_MIN_FILE_SIZE_KB
+        )
+    else:
+        try:
+            image_file_width, image_file_height = get_image_dimensions(image_file)
+        except TypeError:
+            return _('This image file is corrupted.')
+        image_file_aspect_ratio = abs(image_file_width / float(image_file_height) - settings.VIDEO_IMAGE_ASPECT_RATIO)
+        if image_file_aspect_ratio > settings.VIDEO_IMAGE_ASPECT_RATIO_ERROR_MARGIN:
+            error = _('This image file must have an aspect ratio of {video_image_aspect_ratio_text}.').format(
+                video_image_aspect_ratio_text=settings.VIDEO_IMAGE_ASPECT_RATIO_TEXT
+            )
+        elif image_file_width < settings.VIDEO_IMAGE_MIN_WIDTH or image_file_height < settings.VIDEO_IMAGE_MIN_HEIGHT:
+            error = _('The minimum allowed image resolution is {image_file_min_width}x{image_file_min_height}.').format(
+                image_file_min_width=settings.VIDEO_IMAGE_MIN_WIDTH,
+                image_file_min_height=settings.VIDEO_IMAGE_MIN_HEIGHT
+            )
+        else:
+            try:
+                image_file.name.encode('ascii')
+            except UnicodeEncodeError:
+                error = _('The image file name can only contain letters, numbers, hyphens (-), and underscores (_).')
+    return error
+
+
 @expect_json
 @login_required
 @require_POST
 def video_images_handler(request, course_key_string, edx_video_id=None):
     if 'file' not in request.FILES:
-        return JsonResponse({"error": _(u'No file provided for video image')}, status=400)
+        return JsonResponse({'error': _(u'No file provided for video image')}, status=400)
 
     image_file = request.FILES['file']
-    file_name = request.FILES['file'].name
+    error = validate_video_image(image_file)
+    if error:
+        return JsonResponse({'error': error}, status=400)
 
-    # TODO: Image file validation
     with closing(image_file):
-        image_url = update_video_image(edx_video_id, course_key_string, image_file, file_name)
+        image_url = update_video_image(edx_video_id, course_key_string, image_file, image_file.name)
         LOGGER.info(
             'VIDEOS: Video image uploaded for edx_video_id [%s] in course [%s]', edx_video_id, course_key_string
         )

cms/envs/common.py

@@ -1350,3 +1350,20 @@ PROFILE_IMAGE_SIZES_MAP = {
 ###################### VIDEO IMAGE STORAGE ######################
 
 VIDEO_IMAGE_DEFAULT_FILENAME = 'images/video-images/default_video_image.png'
+VIDEO_IMAGE_SUPPORTED_FILE_FORMATS = {
+    '.bmp': 'image/bmp',
+    '.bmp2': 'image/x-ms-bmp',   # PIL gives x-ms-bmp format
+    '.gif': 'image/gif',
+    '.jpg': 'image/jpeg',
+    '.jpeg': 'image/jpeg',
+    '.png': 'image/png'
+}
+VIDEO_IMAGE_MAX_FILE_SIZE_MB = '2 MB'
+VIDEO_IMAGE_MIN_FILE_SIZE_KB = '2 KB'
+VIDEO_IMAGE_MAX_WIDTH = 1280
+VIDEO_IMAGE_MAX_HEIGHT = 720
+VIDEO_IMAGE_MIN_WIDTH = 640
+VIDEO_IMAGE_MIN_HEIGHT = 360
+VIDEO_IMAGE_ASPECT_RATIO = 16 / 9.0
+VIDEO_IMAGE_ASPECT_RATIO_TEXT = '16:9'
+VIDEO_IMAGE_ASPECT_RATIO_ERROR_MARGIN = 0.1

cms/envs/test.py

@@ -338,6 +338,8 @@ INSTALLED_APPS += ('openedx.core.djangoapps.api_admin',)
 
 ########################## VIDEO IMAGE STORAGE ############################
 VIDEO_IMAGE_SETTINGS = dict(
+    VIDEO_IMAGE_MAX_BYTES=2 * 1024 * 1024,    # 2 MB
+    VIDEO_IMAGE_MIN_BYTES=2 * 1024,       # 2 KB
     STORAGE_KWARGS=dict(
         location=MEDIA_ROOT,
         base_url=MEDIA_URL,

lms/envs/common.py

@@ -2567,6 +2567,8 @@ TIME_ZONE_DISPLAYED_FOR_DEADLINES = 'UTC'
 ########################## VIDEO IMAGE STORAGE ############################
 
 VIDEO_IMAGE_SETTINGS = dict(
+    VIDEO_IMAGE_MAX_BYTES=2 * 1024 * 1024,    # 2 MB
+    VIDEO_IMAGE_MIN_BYTES=2 * 1024,       # 2 KB
     # Backend storage
     # STORAGE_CLASS='storages.backends.s3boto.S3BotoStorage',
     # STORAGE_KWARGS=dict(bucket='video-image-bucket'),

openedx/core/djangoapps/profile_images/tests/helpers.py

@@ -11,7 +11,7 @@ from PIL import Image
 
 
 @contextmanager
-def make_image_file(dimensions=(320, 240), extension=".jpeg", force_size=None, orientation=None):
+def make_image_file(dimensions=(320, 240), prefix='tmp', extension='.jpeg', force_size=None, orientation=None):
     """
     Yields a named temporary file created with the specified image type and
     options.
@@ -21,9 +21,13 @@ def make_image_file(dimensions=(320, 240), extension=".jpeg", force_size=None, o
 
     The temporary file will be closed and deleted automatically upon exiting
     the `with` block.
+
+    prefix - To add prefix to random image file name, after adding will be like <custom-prefix><random-name>.png
+            otherwise by default `tmp` is added making file name tmp<random-name>.png.
+
     """
     image = Image.new('RGB', dimensions, "green")
-    image_file = NamedTemporaryFile(suffix=extension)
+    image_file = NamedTemporaryFile(prefix=prefix, suffix=extension)
     try:
         if orientation and orientation in xrange(1, 9):
             exif_bytes = piexif.dump({'0th': {piexif.ImageIFD.Orientation: orientation}})