metadata writer: some progress

src/photools3/metadata_writer.py

@@ -70,32 +70,39 @@ class MetadataWriter:
     def sidecar_path(self) -> Path:
         return Path()
 
-    @property
-    def metadata(self) -> XmpMetadata:
+    def get_metadata(self, *args, **kwargs) -> Any:
         try:
             with exiftool.ExifToolHelper() as exif:
                 metadata = exif.get_metadata([str(self.path)])[0]
         except Exception as exc:  # noqa: BLE001
             log.error(f"Could not read metadata from {self.path}: {exc}")
         assert metadata
-        return metadata
+        return metadata.get(*args, **kwargs)
 
-    def set_metadata(self):
+    def set_metadata(self, metadata_tags: dict[str, Any]) -> bool:
         if self.sidecar_path.exists():
             params = ["-overwrite_original"]
         else:
             params = ["-o", "%f.xmp"]
-        # TODO
+        try:
+            with exiftool.ExifToolHelper() as exif:
+                exif.set_tags(
+                    [str(self.sidecar_path)], tags=metadata_tags, params=params
+                )
+        except Exception as exc:  # noqa
+            log.error(f"Could not write metadata to file {self.sidecar_path}: {exc}")
+            return False
+        return True
 
     def write_caption(self, caption: Caption):
-        existing = self.metadata.get(XMP_KEYS_CAPTION[0], "")
+        existing = self.get_metadata(XMP_KEYS_CAPTION[0], "")
         is_existing_prefixed = _is_prefixed(existing)
         if existing and is_existing_prefixed:
             return
         elif existing and not is_existing_prefixed:
             caption = f"{existing}. {_prefixed(caption)}"
         metadata_tags = {key: caption for key in XMP_KEYS_CAPTION}
-        # TODO
+        self.set_metadata(metadata_tags)
 
     def write_keywords(self, keywords: Keywords): ...