Address validation issues in oai.samvera

See: #498

metadata_mapper/mappers/oai/samvera_mapper.py

@@ -3,12 +3,70 @@
 
 class SamveraRecord(OaiRecord):
 
+    TYPES = {
+        "img": "image",
+        "txt": "text"
+    }
+
+    TYPES_BASEURL = "http://id.loc.gov/vocabulary/resourceTypes/"
+
     def UCLDC_map(self):
         return {
-            'is_shown_at': self.source_metadata.get('isShownAt'),
-            'is_shown_by': self.source_metadata.get('isShownBy')
+            "alternativeTitle": self.map_alternative_title,
+            "type": self.map_type,
         }
 
+    def map_alternative_title(self) -> list:
+        value = self.source_metadata.get("alternative")
+
+        if isinstance(value, list):
+            return value
+
+        return [value]
+
+    def map_is_shown_at(self) -> str:
+        value = self.source_metadata.get("isShownAt")
+
+        if isinstance(value, list):
+            return value[0]
+        elif isinstance(value, str):
+            return value
+        return None
+
+    def map_is_shown_by(self) -> str:
+        value = self.source_metadata.get("object")
+
+        if isinstance(value, list):
+            return value[0]
+        elif isinstance(value, str):
+            return value
+        return None
+
+    def map_type(self) -> list:
+        """
+        Iterates the `type` values. If they are part of the controlled vocabulary
+        defined by `TYPES_BASEURL`, then they are mapped to the HR value.
+
+        Returns:
+            list
+        """
+        types = self.source_metadata.get("type", [])
+        if isinstance(types, str):
+            types = [types]
+
+        type_list = []
+        for t in types:
+            mapped_type = None
+            for (type_k, type_v) in self.TYPES.items():
+                if mapped_type:
+                    break
+                if t == f"{self.TYPES_BASEURL}{type_k}":
+                    mapped_type = type_v
+            if not mapped_type:
+                mapped_type = t.replace(self.TYPES_BASEURL, "")
+            type_list.append(mapped_type.lower())
+        return type_list
+
 
 class SamveraVernacular(OaiVernacular):
     record_cls = SamveraRecord