func vertexMiddleware()

in vertex/vertex.go [57:107]
41 lines of code
11 McCabe index (conditional complexity)

func vertexMiddleware(region, projectID string) sdkoption.Middleware {
	return func(r *http.Request, next sdkoption.MiddlewareNext) (*http.Response, error) {
		if r.Body != nil {
			body, err := io.ReadAll(r.Body)
			if err != nil {
				return nil, err
			}
			r.Body.Close()

			if !gjson.GetBytes(body, "anthropic_version").Exists() {
				body, _ = sjson.SetBytes(body, "anthropic_version", DefaultVersion)
			}

			if r.URL.Path == "/v1/messages" && r.Method == http.MethodPost {
				if projectID == "" {
					return nil, fmt.Errorf("no projectId was given and it could not be resolved from credentials")
				}

				model := gjson.GetBytes(body, "model").String()
				stream := gjson.GetBytes(body, "stream").Bool()

				body, _ = sjson.DeleteBytes(body, "model")

				specifier := "rawPredict"
				if stream {
					specifier = "streamRawPredict"
				}

				r.URL.Path = fmt.Sprintf("/v1/projects/%s/locations/%s/publishers/anthropic/models/%s:%s", projectID, region, model, specifier)
			}

			if r.URL.Path == "/v1/messages/count_tokens" && r.Method == http.MethodPost {
				if projectID == "" {
					return nil, fmt.Errorf("no projectId was given and it could not be resolved from credentials")
				}

				r.URL.Path = fmt.Sprintf("/v1/projects/%s/locations/%s/publishers/anthropic/models/count-tokens:rawPredict", projectID, region)
			}

			reader := bytes.NewReader(body)
			r.Body = io.NopCloser(reader)
			r.GetBody = func() (io.ReadCloser, error) {
				_, err := reader.Seek(0, 0)
				return io.NopCloser(reader), err
			}
			r.ContentLength = int64(len(body))
		}

		return next(r)
	}
}