config: added links for thumbnails

invenio_rdm_records/services/config.py

@@ -11,9 +11,15 @@
 
 """RDM Record Service."""
 
+import itertools
+from copy import deepcopy
 from os.path import splitext
+from pathlib import Path
 
 from flask import current_app
+from invenio_app_rdm.records_ui.previewer.iiif_simple import (
+    previewable_extensions as image_extensions,
+)
 from invenio_communities.communities.records.api import Community
 from invenio_drafts_resources.services.records.components import (
     DraftMediaFilesComponent,
@@ -41,12 +47,20 @@
     SearchOptionsMixin,
     ServiceConfig,
 )
-from invenio_records_resources.services.base.links import Link, NestedLinks
+from invenio_records_resources.services.base.links import (
+    Link,
+    NestedLinks,
+    preprocess_vars,
+)
 from invenio_records_resources.services.files.links import FileLink
 from invenio_records_resources.services.files.schema import FileSchema
 from invenio_records_resources.services.records.config import (
     RecordServiceConfig as BaseRecordServiceConfig,
 )
+from invenio_records_resources.services.records.links import (
+    RecordLink,
+    pagination_links,
+)
 from invenio_records_resources.services.records.params import (
     FacetsParam,
     PaginationParam,
@@ -55,6 +69,7 @@
 from invenio_requests.services.requests import RequestItem, RequestList
 from invenio_requests.services.requests.config import RequestSearchOptions
 from requests import Request
+from werkzeug.exceptions import NotFound
 
 from invenio_rdm_records.records.processors.tiles import TilesProcessor
 
@@ -142,6 +157,36 @@ def lock_edit_published_files(service, identity, record=None, draft=None):
     return True
 
 
+def record_thumbnail_sizes():
+    """Return configured sizes for thumbnails."""
+    return current_app.config["APP_RDM_RECORD_THUMBNAIL_SIZES"]
+
+
+def record_thumbnail(size, record=None, **kwargs):
+    """Generate the URL for a record's thumbnail."""
+    # Verify against allowed thumbnail sizes
+    if size not in current_app.config["APP_RDM_RECORD_THUMBNAIL_SIZES"]:
+        raise NotFound("Thumbnail size not allowed")
+
+    files = record.files
+    default_preview = files.get("default_preview")
+    file_entries = files.entries
+    if file_entries:
+        # Verify file has allowed extension and selects default preview file if present else the first valid file
+        file_key = next(
+            (
+                key
+                for key in itertools.chain([default_preview], file_entries)
+                if key and Path(key).suffix[1:] in image_extensions
+            ),
+            None,
+        )
+        if file_key:
+            return f"{file_key}/full/{size},/0/default.png"
+
+    raise NotFound("Thumbnail not found")
+
+
 class RecordPIDLink(Link):
     """Record PID link."""
 
@@ -295,6 +340,36 @@ class RDMFileRecordServiceConfig(FileServiceConfig, ConfiguratorMixin):
     file_schema = FileSchema
 
 
+class RDMThumbnailLink(RecordLink):
+    """RDM thumbnail links dictionary."""
+
+    def __init__(self, *args, sizes=None, **kwargs):
+        """Constructor."""
+        self._sizes = sizes
+        super().__init__(*args, **kwargs)
+
+    def expand(self, obj, context):
+        """Expand the thumbs size dictionary of URIs."""
+        vars = {}
+        vars.update(deepcopy(context))
+        self.vars(obj, vars)
+        if self._vars_func:
+            self._vars_func(obj, vars)
+        vars = preprocess_vars(vars)
+
+        thumbnail_links = {}
+        for size in self._sizes():
+            try:
+                thumbnail_url = record_thumbnail(size, record=obj)
+                thumbnail_links[str(size)] = (
+                    self._uritemplate.expand(**vars) + thumbnail_url
+                )
+            except NotFound:
+                # Handle the case where the thumbnail does not exist
+                thumbnail_links[str(size)] = None
+        return thumbnail_links
+
+
 # Helper link definitions
 record_doi_link = ConditionalLink(
     cond=is_datacite_test,
@@ -455,6 +530,10 @@ class RDMRecordServiceConfig(RecordServiceConfig, ConfiguratorMixin):
             if_=RecordLink("{+api}/records/{id}/media-files"),
             else_=RecordLink("{+api}/records/{id}/draft/media-files"),
         ),
+        "thumbnails": RDMThumbnailLink(
+            "{+api}/iiif/record:{id}:",
+            sizes=record_thumbnail_sizes,
+        ),
         "archive": ConditionalLink(
             cond=is_record,
             if_=RecordLink(