feat: add support for multimodal embeddings in vertex

vertexai/multi_embedding.go

@@ -0,0 +1,95 @@
+package vertexai
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/url"
+
+	"github.com/milosgajdos/go-embeddings/request"
+)
+
+// MultiEmbeddingRequest is multimodal embedding request.
+type MultiEmbeddingRequest struct {
+	Instances []MultiInstance `json:"instances"`
+	Params    *MultiParams    `json:"parameters,omitempty"`
+}
+
+// MultiInstance contains the request payload.
+type MultiInstance struct {
+	Text  *string `json:"text,omitempty"`
+	Image any     `json:"image,omitempty"`
+}
+
+// ImageGCS contains GCS URI to image file.
+type ImageGCS struct {
+	URI string `json:"gcsUri"`
+}
+
+// ImageBase64 contains image encoded as base64 string.
+type ImageBase64 struct {
+	Bytes string `json:"bytesBase64Encoded"`
+}
+
+// MultiParams are additional API request parameters.
+type MultiParams struct {
+	Dimension uint `json:"dimension"`
+}
+
+// MultiEmbedddingResponse received from API.
+type MultiEmbedddingResponse struct {
+	Predictions []MultiPrediction `json:"predictions"`
+	ModelID     string            `json:"deployedModelId"`
+}
+
+// MultiPrediction for a given request.
+type MultiPrediction struct {
+	Image []float64 `json:"imageEmbedding"`
+	Text  []float64 `json:"textEmbedding"`
+}
+
+// MultiEmbeddings returns multimodal embeddings for every object in EmbeddingRequest.
+func (c *Client) MultiEmbeddings(ctx context.Context, embReq *MultiEmbeddingRequest) (*MultiEmbedddingResponse, error) {
+	u, err := url.Parse(c.baseURL + "/" + c.projectID + "/" + ModelURI + "/" + c.modelID + EmbedAction)
+	if err != nil {
+		return nil, err
+	}
+
+	var body = &bytes.Buffer{}
+	enc := json.NewEncoder(body)
+	enc.SetEscapeHTML(false)
+	if err := enc.Encode(embReq); err != nil {
+		return nil, err
+	}
+
+	if c.token == "" {
+		var err error
+		c.token, err = GetToken(c.tokenSrc)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	options := []request.Option{
+		request.WithBearer(c.token),
+	}
+
+	req, err := request.NewHTTP(ctx, http.MethodPost, u.String(), body, options...)
+	if err != nil {
+		return nil, err
+	}
+
+	resp, err := c.doRequest(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	e := new(MultiEmbedddingResponse)
+	if err := json.NewDecoder(resp.Body).Decode(e); err != nil {
+		return nil, err
+	}
+
+	return e, nil
+}