feat: Import from modulestore APIs (#36540)

This PR is addressed at adding the functionality to import
modulestore-based content to the learning-core based learning
package.

Partof: openedx/frontend-app-authoring#1681

Author: NiedielnitsevIvan

cms/djangoapps/import_from_modulestore/api.py

@@ -0,0 +1,45 @@
+"""
+API for course to library import.
+"""
+from typing import Sequence
+
+from opaque_keys.edx.keys import LearningContextKey, UsageKey
+
+from .helpers import cancel_incomplete_old_imports
+from .models import Import as _Import
+from .tasks import import_staged_content_to_library_task, save_legacy_content_to_staged_content_task
+from .validators import validate_usage_keys_to_import
+
+
+def stage_content_for_import(source_key: LearningContextKey, user_id: int) -> _Import:
+    """
+    Create a new import event to import a course to a library and save course to staged content.
+    """
+    import_from_modulestore = _Import.objects.create(source_key=source_key, user_id=user_id)
+    cancel_incomplete_old_imports(import_from_modulestore)
+    save_legacy_content_to_staged_content_task.delay_on_commit(import_from_modulestore.uuid)
+    return import_from_modulestore
+
+
+def import_staged_content_to_library(
+    usage_ids: Sequence[str | UsageKey],
+    import_uuid: str,
+    target_learning_package_id: int,
+    user_id: int,
+    composition_level: str,
+    override: bool,
+) -> None:
+    """
+    Import staged content to a library from staged content.
+    """
+    validate_usage_keys_to_import(usage_ids)
+    import_staged_content_to_library_task.apply_async(
+        kwargs={
+            'usage_key_strings': usage_ids,
+            'import_uuid': import_uuid,
+            'learning_package_id': target_learning_package_id,
+            'user_id': user_id,
+            'composition_level': composition_level,
+            'override': override,
+        },
+    )

cms/djangoapps/import_from_modulestore/constants.py

@@ -0,0 +1,5 @@
+"""
+Constants for import_from_modulestore app
+"""
+
+IMPORT_FROM_MODULESTORE_STAGING_PURPOSE = "import_from_modulestore"

cms/djangoapps/import_from_modulestore/data.py

@@ -1,6 +1,10 @@
 """
 This module contains the data models for the import_from_modulestore app.
 """
+from collections import namedtuple
+from enum import Enum
+from openedx.core.djangoapps.content_libraries import api as content_libraries_api
+
 from django.db.models import TextChoices
 from django.utils.translation import gettext_lazy as _
 
@@ -18,3 +22,33 @@ class ImportStatus(TextChoices):
     IMPORTING_FAILED = 'importing_failed', _('Failed to import staged content')
     IMPORTED = 'imported', _('Successfully imported content')
     CANCELED = 'canceled', _('Canceled')
+
+
+class CompositionLevel(Enum):
+    """
+    Enumeration of composition levels for course content.
+    Defines the different levels of composition for course content,
+    including chapters, sequentials, verticals, and xblocks.
+    It also categorizes these levels into complicated and flat
+    levels for easier processing.
+    """
+
+    CHAPTER = content_libraries_api.ContainerType.Section
+    SEQUENTIAL = content_libraries_api.ContainerType.Subsection
+    VERTICAL = content_libraries_api.ContainerType.Unit
+    COMPONENT = 'component'
+    OLX_COMPLEX_LEVELS = [
+        VERTICAL.olx_tag,
+        SEQUENTIAL.olx_tag,
+        CHAPTER.olx_tag,
+    ]
+
+    @classmethod
+    def values(cls):
+        """
+        Returns all levels of composition levels.
+        """
+        return [composition_level.value for composition_level in cls]
+
+
+PublishableVersionWithMapping = namedtuple('PublishableVersionWithMapping', ['publishable_version', 'mapping'])