[SE-3520] Adds waffle flag to enable overriding existing transcripts on import

edxval/api.py

@@ -19,6 +19,7 @@
 from lxml.etree import Element, SubElement
 from pysrt.srtexc import Error
 
+from edxval.config.waffle import OVERRIDE_EXISTING_IMPORTED_TRANSCRIPTS
 from edxval.exceptions import (
     InvalidTranscriptFormat,
     InvalidTranscriptProvider,
@@ -42,7 +43,13 @@
 )
 from edxval.serializers import TranscriptPreferenceSerializer, TranscriptSerializer, VideoSerializer
 from edxval.transcript_utils import Transcript
-from edxval.utils import THIRD_PARTY_TRANSCRIPTION_PLANS, TranscriptFormat, create_file_in_fs, get_transcript_format
+from edxval.utils import (
+    THIRD_PARTY_TRANSCRIPTION_PLANS,
+    TranscriptFormat,
+    create_file_in_fs,
+    get_transcript_format,
+    is_duplicate_file,
+)
 
 logger = logging.getLogger(__name__)
 
@@ -1155,54 +1162,71 @@ def import_transcript_from_fs(edx_video_id, language_code, file_name, provider,
         static_dir (str): The Directory to retrieve transcript file.
     """
     file_format = None
-    transcript_data = get_video_transcript_data(edx_video_id, language_code)
+    existing_transcript = VideoTranscript.get_or_none(edx_video_id, language_code)
 
-    # First check if transcript record does not exist.
-    if not transcript_data:
-        # Read file from import file system and attach it to transcript record in DS.
-        try:
-            with resource_fs.open(combine(static_dir, file_name), 'r', encoding='utf-8-sig') as f:
-                file_content = f.read()
-        except ResourceNotFound:
-            # Don't raise exception in case transcript file is not found in course OLX.
-            logger.warning(
-                '[edx-val] "%s" transcript "%s" for video "%s" is not found.',
-                language_code,
-                file_name,
-                edx_video_id
-            )
-            return
-        except UnicodeDecodeError:
-            # Don't raise exception in case transcript contains non-utf8 content.
-            logger.warning(
-                '[edx-val] "%s" transcript "%s" for video "%s" contains a non-utf8 file content.',
-                language_code,
-                file_name,
-                edx_video_id
-            )
-            return
+    # check if the transcript exists and if it does, make sure that overriding
+    # existing transcripts is enabled before proceeding to import it
+    if (existing_transcript and
+            not OVERRIDE_EXISTING_IMPORTED_TRANSCRIPTS.is_enabled()):
+        return
 
-        # Get file format from transcript content.
-        try:
-            file_format = get_transcript_format(file_content)
-        except Error:
-            # Don't raise exception, just don't create transcript record.
-            logger.warning(
-                '[edx-val] Error while getting transcript format for video=%s -- language_code=%s --file_name=%s',
-                edx_video_id,
-                language_code,
-                file_name
-            )
-            return
-
-        # Create transcript record.
-        create_video_transcript(
-            video_id=edx_video_id,
-            language_code=language_code,
-            file_format=file_format,
-            content=ContentFile(file_content.encode('utf-8')),
-            provider=provider
+    # Read file from import file system and attach it to transcript record in DS.
+    try:
+        with resource_fs.open(combine(static_dir, file_name), 'r', encoding='utf-8-sig') as f:
+            file_content = f.read()
+    except ResourceNotFound:
+        # Don't raise exception in case transcript file is not found in course OLX.
+        logger.warning(
+            '[edx-val] "%s" transcript "%s" for video "%s" is not found.',
+            language_code,
+            file_name,
+            edx_video_id
+        )
+        return
+    except UnicodeDecodeError:
+        # Don't raise exception in case transcript contains non-utf8 content.
+        logger.warning(
+            '[edx-val] "%s" transcript "%s" for video "%s" contains a non-utf8 file content.',
+            language_code,
+            file_name,
+            edx_video_id
         )
+        return
+
+    # change file content to utf8
+    utf8_encoded_file_content = file_content.encode('utf-8')
+    new_transcript_content_file = ContentFile(utf8_encoded_file_content)
+
+    # check if transcript content already exists, and if it does, make sure
+    # the transcript isn't a duplicate transcript to the already existing one
+    if (existing_transcript and
+            is_duplicate_file(new_transcript_content_file, existing_transcript.transcript.file)):
+        return
+
+    # Get file format from transcript content.
+    try:
+        file_format = get_transcript_format(file_content)
+    except Error:
+        # Don't raise exception, just don't create transcript record.
+        logger.warning(
+            '[edx-val] Error while getting transcript format for video=%s -- language_code=%s --file_name=%s',
+            edx_video_id,
+            language_code,
+            file_name
+        )
+        return
+
+    # Create transcript record.
+    create_or_update_video_transcript(
+        video_id=edx_video_id,
+        language_code=language_code,
+        metadata={
+            'provider': provider,
+            'file_format': file_format,
+            'language_code': language_code,
+        },
+        file_data=new_transcript_content_file,
+    )
 
 
 def create_transcript_objects(xml, edx_video_id, resource_fs, static_dir, external_transcripts):

edxval/config/waffle.py

@@ -0,0 +1,38 @@
+"""
+This module contains various configuration settings via
+waffle switches for edx's video abstraction layer.
+"""
+
+
+from edx_toggles.toggles.__future__ import WaffleFlag
+
+WAFFLE_NAMESPACE = 'edxval'
+
+
+def waffle_name(toggle_name):
+    """
+    Method to append waffle namespace to toggle's name
+
+    Reason behind not using f-strings is backwards compatibility
+    Since this is a method, it should be easy to change later on
+    """
+    return "{namespace}.{toggle_name}".format(
+        namespace=WAFFLE_NAMESPACE,
+        toggle_name=toggle_name,
+    )
+
+
+# .. toggle_name: OVERRIDE_EXISTING_IMPORTED_TRANSCRIPTS
+# .. toggle_implementation: WaffleFlag
+# .. toggle_default: False
+# .. toggle_description: Enables overriding existing transcripts when importing courses with already
+#   existing transcripts. The transcripts are compared using content hashing, and if the transcript
+#   being imported isn't a duplicate, but different in content, it overrides the existing one.
+#   Otherwise, if the transcript is a duplicate, with same content, it doesn't get uploaded.
+# .. toggle_use_cases: opt_in
+# .. toggle_creation_date: 2021-01-01
+# .. toggle_tickets: https://openedx.atlassian.net/browse/OSPR-5117
+OVERRIDE_EXISTING_IMPORTED_TRANSCRIPTS = WaffleFlag(
+    waffle_name('override_existing_imported_transcripts'),
+    module_name=__name__,
+)

edxval/models.py

@@ -447,6 +447,27 @@ def filename(self):
 
         return file_name
 
+    def save_transcript(self, file_data, file_format, file_name=None):
+        """
+        Saves Transcript Content to a Video Transcript File
+
+        Arguments:
+            file_data(InMemoryUploadedFile): Transcript content.
+            file_format(unicode): Transcript file format.
+        """
+        # generate transcript file name if not already given
+        if not file_name:
+            file_name = '{uuid}.{ext}'.format(uuid=uuid4().hex, ext=file_format)
+
+        # save the transcript file
+        if file_data:
+            self.transcript.save(file_name, file_data)
+        else:
+            self.transcript.name = file_name
+
+        # save the object
+        self.save()
+
     @classmethod
     def get_or_none(cls, video_id, language_code):
         """
@@ -476,18 +497,16 @@ def create(cls, video, language_code, file_format, content, provider):
             provider(unicode): Transcript provider.
         """
         video_transcript = cls(video=video, language_code=language_code, file_format=file_format, provider=provider)
-        with closing(content) as transcript_content:
-            try:
-                file_name = '{uuid}.{ext}'.format(uuid=uuid4().hex, ext=video_transcript.file_format)
-                video_transcript.transcript.save(file_name, transcript_content)
-                video_transcript.save()
-            except Exception:
-                logger.exception(
-                    '[VAL] Transcript save failed to storage for video_id "%s" language code "%s"',
-                    video.edx_video_id,
-                    language_code
-                )
-                raise
+
+        try:
+            video_transcript.save_transcript(content, file_format)
+        except Exception:
+            logger.exception(
+                '[VAL] Transcript save failed to storage for video_id "%s" language code "%s"',
+                video.edx_video_id,
+                language_code
+            )
+            raise
 
         return video_transcript
 
@@ -519,14 +538,7 @@ def create_or_update(cls, video, language_code, metadata, file_data=None):
         transcript_name = metadata.get('file_name')
 
         try:
-            if transcript_name:
-                video_transcript.transcript.name = transcript_name
-            elif file_data:
-                with closing(file_data) as transcript_file_data:
-                    file_name = '{uuid}.{ext}'.format(uuid=uuid4().hex, ext=video_transcript.file_format)
-                    video_transcript.transcript.save(file_name, transcript_file_data)
-
-            video_transcript.save()
+            video_transcript.save_transcript(file_data, video_transcript.file_format, file_name=transcript_name)
         except Exception:
             logger.exception(
                 '[VAL] Transcript save failed to storage for video_id "%s" language code "%s"',

edxval/settings.py

@@ -117,6 +117,7 @@
     # Third Party
     'rest_framework',
     'storages',
+    'waffle',
 
     # Our App
     'edxval',