chore: Lift and shift code of Video Block from edx-platform

This commit contains original code copied from edx-platform.
Purpose of keeping the first commit with original code is to get help in the review process.
Reviewer just needs to open the second commit and code changes will be clearly visible.

Author: farhan

xblocks_contrib/video/ajax_handler_mixin.py

@@ -0,0 +1,45 @@
+# NOTE: Code has been copied from the following source file
+# https://github.com/openedx/edx-platform/blob/master/xmodule/x_module.py#L739
+
+class XModuleToXBlockMixin:
+    """
+    Common code needed by XModule and XBlocks converted from XModules.
+    """
+    @property
+    def ajax_url(self):
+        """
+        Returns the URL for the ajax handler.
+        """
+        return self.runtime.handler_url(self, 'xmodule_handler', '', '').rstrip('/?')
+
+    @XBlock.handler
+    def xmodule_handler(self, request, suffix=None):
+        """
+        XBlock handler that wraps `handle_ajax`
+        """
+        class FileObjForWebobFiles:
+            """
+            Turn Webob cgi.FieldStorage uploaded files into pure file objects.
+
+            Webob represents uploaded files as cgi.FieldStorage objects, which
+            have a .file attribute.  We wrap the FieldStorage object, delegating
+            attribute access to the .file attribute.  But the files have no
+            name, so we carry the FieldStorage .filename attribute as the .name.
+
+            """
+            def __init__(self, webob_file):
+                self.file = webob_file.file
+                self.name = webob_file.filename
+
+            def __getattr__(self, name):
+                return getattr(self.file, name)
+
+        # WebOb requests have multiple entries for uploaded files.  handle_ajax
+        # expects a single entry as a list.
+        request_post = MultiDict(request.POST)
+        for key in set(request.POST.keys()):
+            if hasattr(request.POST[key], "file"):
+                request_post[key] = list(map(FileObjForWebobFiles, request.POST.getall(key)))
+
+        response_data = self.handle_ajax(suffix, request_post)
+        return Response(response_data, content_type='application/json', charset='UTF-8')

xblocks_contrib/video/bumper_utils.py

@@ -0,0 +1,149 @@
+# NOTE: Code has been copied from the following source files
+# https://github.com/openedx/edx-platform/blob/master/xmodule/video_block/bumper_utils.py
+"""
+Utils for video bumper
+"""
+
+
+import copy
+import json
+import logging
+from collections import OrderedDict
+from datetime import datetime, timedelta
+
+import pytz
+from django.conf import settings
+
+from .video_utils import set_query_parameter
+
+try:
+    import edxval.api as edxval_api
+except ImportError:
+    edxval_api = None
+
+log = logging.getLogger(__name__)
+
+
+def get_bumper_settings(video):
+    """
+    Get bumper settings from video instance.
+    """
+    bumper_settings = copy.deepcopy(getattr(video, 'video_bumper', {}))
+
+    # clean up /static/ prefix from bumper transcripts
+    for lang, transcript_url in bumper_settings.get('transcripts', {}).items():
+        bumper_settings['transcripts'][lang] = transcript_url.replace("/static/", "")
+
+    return bumper_settings
+
+
+def is_bumper_enabled(video):
+    """
+    Check if bumper enabled.
+
+    - Feature flag ENABLE_VIDEO_BUMPER should be set to True
+    - Do not show again button should not be clicked by user.
+    - Current time minus periodicity must be greater that last time viewed
+    - edxval_api should be presented
+
+    Returns:
+         bool.
+    """
+    bumper_last_view_date = getattr(video, 'bumper_last_view_date', None)
+    utc_now = datetime.utcnow().replace(tzinfo=pytz.utc)
+    periodicity = settings.FEATURES.get('SHOW_BUMPER_PERIODICITY', 0)
+    has_viewed = any([
+        video.bumper_do_not_show_again,
+        (bumper_last_view_date and bumper_last_view_date + timedelta(seconds=periodicity) > utc_now)
+    ])
+    is_studio = getattr(video.runtime, "is_author_mode", False)
+    return bool(
+        not is_studio and
+        settings.FEATURES.get('ENABLE_VIDEO_BUMPER') and
+        get_bumper_settings(video) and
+        edxval_api and
+        not has_viewed
+    )
+
+
+def bumperize(video):
+    """
+    Populate video with bumper settings, if they are presented.
+    """
+    video.bumper = {
+        'enabled': False,
+        'edx_video_id': "",
+        'transcripts': {},
+        'metadata': None,
+    }
+
+    if not is_bumper_enabled(video):
+        return
+
+    bumper_settings = get_bumper_settings(video)
+
+    try:
+        video.bumper['edx_video_id'] = bumper_settings['video_id']
+        video.bumper['transcripts'] = bumper_settings['transcripts']
+    except (TypeError, KeyError):
+        log.warning(
+            "Could not retrieve video bumper information from course settings"
+        )
+        return
+
+    sources = get_bumper_sources(video)
+    if not sources:
+        return
+
+    video.bumper.update({
+        'metadata': bumper_metadata(video, sources),
+        'enabled': True,  # Video poster needs this.
+    })
+
+
+def get_bumper_sources(video):
+    """
+    Get bumper sources from edxval.
+
+    Returns list of sources.
+    """
+    try:
+        val_profiles = ["desktop_webm", "desktop_mp4"]
+        val_video_urls = edxval_api.get_urls_for_profiles(video.bumper['edx_video_id'], val_profiles)
+        bumper_sources = [url for url in [val_video_urls[p] for p in val_profiles] if url]
+    except edxval_api.ValInternalError:
+        # if no bumper sources, nothing will be showed
+        log.warning(
+            "Could not retrieve information from VAL for Bumper edx Video ID: %s.", video.bumper['edx_video_id']
+        )
+        return []
+
+    return bumper_sources
+
+
+def bumper_metadata(video, sources):
+    """
+    Generate bumper metadata.
+    """
+    transcripts = video.get_transcripts_info(is_bumper=True)
+    unused_track_url, bumper_transcript_language, bumper_languages = video.get_transcripts_for_student(transcripts)
+
+    metadata = OrderedDict({
+        'saveStateUrl': video.ajax_url + '/save_user_state',
+        'showCaptions': json.dumps(video.show_captions),
+        'sources': sources,
+        'streams': '',
+        'transcriptLanguage': bumper_transcript_language,
+        'transcriptLanguages': bumper_languages,
+        'transcriptTranslationUrl': set_query_parameter(
+            video.runtime.handler_url(video, 'transcript', 'translation/__lang__').rstrip('/?'), 'is_bumper', 1
+        ),
+        'transcriptAvailableTranslationsUrl': set_query_parameter(
+            video.runtime.handler_url(video, 'transcript', 'available_translations').rstrip('/?'), 'is_bumper', 1
+        ),
+        'publishCompletionUrl': set_query_parameter(
+            video.runtime.handler_url(video, 'publish_completion', '').rstrip('?'), 'is_bumper', 1
+        ),
+    })
+
+    return metadata

xblocks_contrib/video/cache_utils.py

@@ -0,0 +1,102 @@
+# NOTE: Code has been copied from the following source files
+# https://github.com/openedx/edx-platform/blob/master/openedx/core/lib/cache_utils.py
+"""
+Utilities related to caching.
+"""
+
+
+import itertools
+
+import wrapt
+from django.utils.encoding import force_str
+
+from edx_django_utils.cache import RequestCache
+
+
+def request_cached(namespace=None, arg_map_function=None, request_cache_getter=None):
+    """
+    A function decorator that automatically handles caching its return value for
+    the duration of the request. It returns the cached value for subsequent
+    calls to the same function, with the same parameters, within a given request.
+
+    Notes:
+        - We convert arguments and keyword arguments to their string form to build the cache key. So if you have
+          args/kwargs that can't be converted to strings, you're gonna have a bad time (don't do it).
+        - Cache key cardinality depends on the args/kwargs. So if you're caching a function that takes five arguments,
+          you might have deceptively low cache efficiency.  Prefer functions with fewer arguments.
+        - WATCH OUT: Don't use this decorator for instance methods that take in a "self" argument that changes each
+          time the method is called. This will result in constant cache misses and not provide the performance benefit
+          you are looking for. Rather, change your instance method to a class method.
+        - Benchmark, benchmark, benchmark! If you never measure, how will you know you've improved? or regressed?
+
+    Arguments:
+        namespace (string): An optional namespace to use for the cache. By default, we use the default request cache,
+            not a namespaced request cache. Since the code automatically creates a unique cache key with the module and
+            function's name, storing the cached value in the default cache, you won't usually need to specify a
+            namespace value.
+            But you can specify a namespace value here if you need to use your own namespaced cache - for example,
+            if you want to clear out your own cache by calling RequestCache(namespace=NAMESPACE).clear().
+            NOTE: This argument is ignored if you supply a ``request_cache_getter``.
+        arg_map_function (function: arg->string): Function to use for mapping the wrapped function's arguments to
+            strings to use in the cache key. If not provided, defaults to force_text, which converts the given
+            argument to a string.
+        request_cache_getter (function: args, kwargs->RequestCache): Function that returns the RequestCache to use.
+            If not provided, defaults to edx_django_utils.cache.RequestCache.  If ``request_cache_getter`` returns None,
+            the function's return values are not cached.
+
+    Returns:
+        func: a wrapper function which will call the wrapped function, passing in the same args/kwargs,
+              cache the value it returns, and return that cached value for subsequent calls with the
+              same args/kwargs within a single request.
+    """
+    @wrapt.decorator
+    def decorator(wrapped, instance, args, kwargs):
+        """
+        Arguments:
+            args, kwargs: values passed into the wrapped function
+        """
+        # Check to see if we have a result in cache.  If not, invoke our wrapped
+        # function.  Cache and return the result to the caller.
+        if request_cache_getter:
+            request_cache = request_cache_getter(args if instance is None else (instance,) + args, kwargs)
+        else:
+            request_cache = RequestCache(namespace)
+
+        if request_cache:
+            cache_key = _func_call_cache_key(wrapped, arg_map_function, *args, **kwargs)
+            cached_response = request_cache.get_cached_response(cache_key)
+            if cached_response.is_found:
+                return cached_response.value
+
+        result = wrapped(*args, **kwargs)
+
+        if request_cache:
+            request_cache.set(cache_key, result)
+
+        return result
+
+    return decorator
+
+
+def _func_call_cache_key(func, arg_map_function, *args, **kwargs):
+    """
+    Returns a cache key based on the function's module,
+    the function's name, a stringified list of arguments
+    and a stringified list of keyword arguments.
+    """
+    arg_map_function = arg_map_function or force_str
+
+    converted_args = list(map(arg_map_function, args))
+    converted_kwargs = list(map(arg_map_function, _sorted_kwargs_list(kwargs)))
+
+    cache_keys = [func.__module__, func.__name__] + converted_args + converted_kwargs
+    return '.'.join(cache_keys)
+
+
+def _sorted_kwargs_list(kwargs):
+    """
+    Returns a unique and deterministic ordered list from the given kwargs.
+    """
+    sorted_kwargs = sorted(kwargs.items())
+    sorted_kwargs_list = list(itertools.chain(*sorted_kwargs))
+    return sorted_kwargs_list

xblocks_contrib/video/content.py

@@ -0,0 +1,60 @@
+# NOTE: Original code has been copied from the following file: 
+# https://github.com/openedx/edx-platform/blob/farhan/extract-video-xblock/xmodule/contentstore/content.py#L28
+
+
+class StaticContent:  # lint-amnesty, pylint: disable=missing-class-docstring
+    def __init__(self, loc, name, content_type, data, last_modified_at=None, thumbnail_location=None, import_path=None,
+                 length=None, locked=False, content_digest=None):
+        self.location = loc
+        self.name = name  # a display string which can be edited, and thus not part of the location which needs to be fixed  # lint-amnesty, pylint: disable=line-too-long
+        self.content_type = content_type
+        self._data = data
+        self.length = length
+        self.last_modified_at = last_modified_at
+        self.thumbnail_location = thumbnail_location
+        # optional information about where this file was imported from. This is needed to support import/export
+        # cycles
+        self.import_path = import_path
+        self.locked = locked
+        self.content_digest = content_digest
+
+    @staticmethod
+    def compute_location(course_key, path, revision=None, is_thumbnail=False):  # lint-amnesty, pylint: disable=unused-argument
+        """
+        Constructs a location object for static content.
+
+        - course_key: the course that this asset belongs to
+        - path: is the name of the static asset
+        - revision: is the object's revision information
+        - is_thumbnail: is whether or not we want the thumbnail version of this
+            asset
+        """
+        path = path.replace('/', '_')
+        return course_key.make_asset_key(
+            'asset' if not is_thumbnail else 'thumbnail',
+            AssetLocator.clean_keeping_underscores(path)
+        ).for_branch(None)
+
+    @staticmethod
+    def get_location_from_path(path):
+        """
+        Generate an AssetKey for the given path (old c4x/org/course/asset/name syntax)
+        """
+        try:
+            return AssetKey.from_string(path)
+        except InvalidKeyError:
+            # TODO - re-address this once LMS-11198 is tackled.
+            if path.startswith('/') or path.endswith('/'):
+                # try stripping off the leading slash and try again
+                return AssetKey.from_string(path.strip('/'))
+
+    @staticmethod
+    def serialize_asset_key_with_slash(asset_key):
+        """
+        Legacy code expects the serialized asset key to start w/ a slash; so, do that in one place
+        :param asset_key:
+        """
+        url = str(asset_key)
+        if not url.startswith('/'):
+            url = '/' + url  # TODO - re-address this once LMS-11198 is tackled.
+        return url