Support more OpenAI embedding models

embedding.go

@@ -12,8 +12,15 @@ import (
 )
 
 const (
-	baseURLOpenAI              = "https://api.openai.com/v1"
-	embeddingModelOpenAI3Small = "text-embedding-3-small"
+	baseURLOpenAI = "https://api.openai.com/v1"
+)
+
+type EmbeddingModelOpenAI string
+
+const (
+	EmbeddingModelOpenAI2Ada   EmbeddingModelOpenAI = "text-embedding-ada-002"
+	EmbeddingModelOpenAI3Small EmbeddingModelOpenAI = "text-embedding-3-small"
+	EmbeddingModelOpenAI3Large EmbeddingModelOpenAI = "text-embedding-3-large"
 )
 
 type openAIResponse struct {
@@ -28,13 +35,12 @@ type openAIResponse struct {
 // The API key is read from the environment variable "OPENAI_API_KEY".
 func CreateEmbeddingsDefault() EmbeddingFunc {
 	apiKey := os.Getenv("OPENAI_API_KEY")
-	return CreateEmbeddingsOpenAI(apiKey)
+	return CreateEmbeddingsOpenAI(apiKey, EmbeddingModelOpenAI3Small)
 }
 
-// CreateEmbeddingsDefault returns a function that creates embeddings for a document
-// using OpenAI`s "text-embedding-3-small" model via their API.
-// The model supports a maximum document length of 8191 tokens.
-func CreateEmbeddingsOpenAI(apiKey string) EmbeddingFunc {
+// CreateEmbeddingsOpenAI returns a function that creates embeddings for a document
+// using the OpenAI API.
+func CreateEmbeddingsOpenAI(apiKey string, model EmbeddingModelOpenAI) EmbeddingFunc {
 	// We don't set a default timeout here, although it's usually a good idea.
 	// In our case though, the library user can set the timeout on the context,
 	// and it might have to be a long timeout, depending on the document size.
@@ -44,7 +50,7 @@ func CreateEmbeddingsOpenAI(apiKey string) EmbeddingFunc {
 		// Prepare the request body.
 		reqBody, err := json.Marshal(map[string]string{
 			"input": document,
-			"model": embeddingModelOpenAI3Small,
+			"model": string(model),
 		})
 		if err != nil {
 			return nil, fmt.Errorf("couldn't marshal request body: %w", err)