mistral: Adopt new strategy for ObservationContext

Relates to gh-2518

Signed-off-by: Thomas Vitale <[email protected]>

Author: ThomasVitale

Diff for: models/spring-ai-mistral-ai/src/main/java/org/springframework/ai/mistralai/MistralAiEmbeddingModel.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2023-2024 the original author or authors.
+ * Copyright 2023-2025 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -28,7 +28,6 @@
 import org.springframework.ai.embedding.AbstractEmbeddingModel;
 import org.springframework.ai.embedding.Embedding;
 import org.springframework.ai.embedding.EmbeddingOptions;
-import org.springframework.ai.embedding.EmbeddingOptionsBuilder;
 import org.springframework.ai.embedding.EmbeddingRequest;
 import org.springframework.ai.embedding.EmbeddingResponse;
 import org.springframework.ai.embedding.EmbeddingResponseMetadata;
@@ -110,12 +109,16 @@ public MistralAiEmbeddingModel(MistralAiApi mistralAiApi, MetadataMode metadataM
 
 	@Override
 	public EmbeddingResponse call(EmbeddingRequest request) {
-		var apiRequest = createRequest(request);
+		// Before moving any further, build the final request Prompt,
+		// merging runtime and default options.
+		EmbeddingRequest embeddingRequest = buildEmbeddingRequest(request);
+
+		var apiRequest = createRequest(embeddingRequest);
 
 		var observationContext = EmbeddingModelObservationContext.builder()
 			.embeddingRequest(request)
 			.provider(MistralAiApi.PROVIDER_NAME)
-			.requestOptions(buildRequestOptions(apiRequest))
+			.requestOptions(embeddingRequest.getOptions())
 			.build();
 
 		return EmbeddingModelObservationDocumentation.EMBEDDING_MODEL_OPERATION
@@ -146,20 +149,29 @@ public EmbeddingResponse call(EmbeddingRequest request) {
 			});
 	}
 
+	private EmbeddingRequest buildEmbeddingRequest(EmbeddingRequest embeddingRequest) {
+		// Process runtime options
+		MistralAiEmbeddingOptions runtimeOptions = null;
+		if (embeddingRequest.getOptions() != null) {
+			runtimeOptions = ModelOptionsUtils.copyToTarget(embeddingRequest.getOptions(), EmbeddingOptions.class,
+					MistralAiEmbeddingOptions.class);
+		}
+
+		// Define request options by merging runtime options and default options
+		MistralAiEmbeddingOptions requestOptions = ModelOptionsUtils.merge(runtimeOptions, this.defaultOptions,
+				MistralAiEmbeddingOptions.class);
+
+		return new EmbeddingRequest(embeddingRequest.getInstructions(), requestOptions);
+	}
+
 	private DefaultUsage getDefaultUsage(MistralAiApi.Usage usage) {
 		return new DefaultUsage(usage.promptTokens(), usage.completionTokens(), usage.totalTokens(), usage);
 	}
 
-	@SuppressWarnings("unchecked")
 	private MistralAiApi.EmbeddingRequest<List<String>> createRequest(EmbeddingRequest request) {
-		var embeddingRequest = new MistralAiApi.EmbeddingRequest<>(request.getInstructions(),
-				this.defaultOptions.getModel(), this.defaultOptions.getEncodingFormat());
-
-		if (request.getOptions() != null) {
-			embeddingRequest = ModelOptionsUtils.merge(request.getOptions(), embeddingRequest,
-					MistralAiApi.EmbeddingRequest.class);
-		}
-		return embeddingRequest;
+		MistralAiEmbeddingOptions requestOptions = (MistralAiEmbeddingOptions) request.getOptions();
+		return new MistralAiApi.EmbeddingRequest<>(request.getInstructions(), requestOptions.getModel(),
+				requestOptions.getEncodingFormat());
 	}
 
 	@Override
@@ -168,10 +180,6 @@ public float[] embed(Document document) {
 		return this.embed(document.getFormattedContent(this.metadataMode));
 	}
 
-	private EmbeddingOptions buildRequestOptions(MistralAiApi.EmbeddingRequest<List<String>> request) {
-		return EmbeddingOptionsBuilder.builder().withModel(request.model()).build();
-	}
-
 	/**
 	 * Use the provided convention for reporting observation data
 	 * @param observationConvention The provided convention