Minor adjustment plus added missing implementation.

Signed-off-by: Ralph Gasser <[email protected]>

vitrivr-engine-module-fes/src/main/kotlin/org/vitrivr/engine/base/features/external/implementations/classification/ImageClassification.kt

@@ -10,10 +10,13 @@ import org.vitrivr.engine.core.model.content.element.ContentElement
 import org.vitrivr.engine.core.model.content.element.ImageContent
 import org.vitrivr.engine.core.model.content.element.TextContent
 import org.vitrivr.engine.core.model.descriptor.struct.LabelDescriptor
+import org.vitrivr.engine.core.model.descriptor.vector.FloatVectorDescriptor
+import org.vitrivr.engine.core.model.metamodel.Analyser
 import org.vitrivr.engine.core.model.metamodel.Analyser.Companion.merge
 import org.vitrivr.engine.core.model.metamodel.Schema
 import org.vitrivr.engine.core.model.query.Query
 import org.vitrivr.engine.core.model.query.bool.SimpleBooleanQuery
+import org.vitrivr.engine.core.model.query.proximity.ProximityQuery
 import org.vitrivr.engine.core.model.retrievable.Retrievable
 import org.vitrivr.engine.core.model.types.Value
 import org.vitrivr.engine.core.operators.Operator
@@ -67,23 +70,53 @@ class ImageClassification : ExternalFesAnalyser<ContentElement<*>, LabelDescript
      */
     override fun newExtractor(field: Schema.Field<ContentElement<*>, LabelDescriptor>, input: Operator<Retrievable>, context: IndexContext) = ImageClassificationExtractor(input, field, this, merge(field, context))
 
+    /**
+     * Generates and returns a new [Retriever] instance for this [ImageClassification].
+     *
+     * @param field The [Schema.Field] to create an [Retriever] for.
+     * @param query The [Query] to use with the [Retriever].
+     * @param context The [QueryContext] to use with the [Retriever].
+     *
+     * @return A new [Retriever] instance for this [Analyser]
+     */
     override fun newRetrieverForQuery(field: Schema.Field<ContentElement<*>, LabelDescriptor>, query: Query, context: QueryContext): Retriever<ContentElement<*>, LabelDescriptor> {
         require(field.analyser == this) { "The field '${field.fieldName}' analyser does not correspond with this analyser. This is a programmer's error!" }
         require(query is SimpleBooleanQuery<*>) { "The query is not a boolean query. This is a programmer's error!" }
         return object : AbstractRetriever<ContentElement<*>, LabelDescriptor>(field, query, context){}
     }
 
+    /**
+     * Generates and returns a new [Retriever] instance for this [ImageClassification].
+     *
+     * Invoking this method involves converting the provided [FloatVectorDescriptor] into a [ProximityQuery] that can be used to retrieve similar [ImageContent] elements.
+     *
+     * @param field The [Schema.Field] to create an [Retriever] for.
+     * @param descriptors An array of [FloatVectorDescriptor] elements to use with the [Retriever]
+     * @param context The [QueryContext] to use with the [Retriever]
+     */
+    override fun newRetrieverForDescriptors(field: Schema.Field<ContentElement<*>, LabelDescriptor>, descriptors: Collection<LabelDescriptor>, context: QueryContext): Retriever<ContentElement<*>, LabelDescriptor> {
+        val descriptor = descriptors.firstOrNull()?.label ?: throw IllegalArgumentException("No label descriptor provided.")
+        val query = SimpleBooleanQuery(value = descriptor, attributeName = "label")
+        return newRetrieverForQuery(field, query, context)
+    }
+
+    /**
+     * Generates and returns a new [Retriever] instance for this [ImageClassification].
+     *
+     * Invoking this method involves converting the provided [ImageContent] and the [QueryContext] into a [FloatVectorDescriptor]
+     * that can be used to retrieve similar [ImageContent] elements.
+     *
+     * @param field The [Schema.Field] to create an [Retriever] for.
+     * @param content An array of [Content] elements to use with the [Retriever]
+     * @param context The [QueryContext] to use with the [Retriever]
+     */
     override fun newRetrieverForContent(
         field: Schema.Field<ContentElement<*>, LabelDescriptor>,
         content: Collection<ContentElement<*>>,
         context: QueryContext
     ): Retriever<ContentElement<*>, LabelDescriptor> {
-        val firstContent = content.first()
-        if (content.size != 1 || firstContent !is TextContent) {
-            throw IllegalArgumentException("The content does not match the expected type. This is a programmer's error!")
-        }
-        val query = SimpleBooleanQuery(value = Value.String(firstContent.content), attributeName = "label")
+        val first = content.filterIsInstance<TextContent>().firstOrNull() ?: throw IllegalArgumentException("The content does not contain any text.")
+        val query = SimpleBooleanQuery(value = Value.String(first.content), attributeName = "label")
         return newRetrieverForQuery(field, query, context)
-
     }
 }