func bedrockMiddleware()

in bedrock/bedrock.go [191:245]
46 lines of code
9 McCabe index (conditional complexity)

func bedrockMiddleware(signer *v4.Signer, cfg aws.Config) option.Middleware {
	return func(r *http.Request, next option.MiddlewareNext) (res *http.Response, err error) {
		var body []byte
		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.Method == http.MethodPost && DefaultEndpoints[r.URL.Path] {
				model := gjson.GetBytes(body, "model").String()
				stream := gjson.GetBytes(body, "stream").Bool()

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

				var path string
				if stream {
					path = fmt.Sprintf("/model/%s/invoke-with-response-stream", model)
				} else {
					path = fmt.Sprintf("/model/%s/invoke", model)
				}

				r.URL.Path = path
			}

			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))
		}

		ctx := r.Context()
		credentials, err := cfg.Credentials.Retrieve(ctx)
		if err != nil {
			return nil, err
		}

		hash := sha256.Sum256(body)
		err = signer.SignHTTP(ctx, credentials, r, hex.EncodeToString(hash[:]), "bedrock", cfg.Region, time.Now())
		if err != nil {
			return nil, err
		}

		return next(r)
	}
}