Initial commit

lib/client/errors.go

@@ -0,0 +1,49 @@
+package client
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strings"
+)
+
+// APIError is returned for every non-2xx API response. Validation contains
+// field-specific messages for 422 responses; Message contains ordinary API
+// error strings.
+type APIError struct {
+	StatusCode int
+	Message    string
+	Validation map[string]string
+	Body       string
+}
+
+// Error implements error using the API message or HTTP status.
+func (e *APIError) Error() string {
+	switch {
+	case e.Message != "":
+		return fmt.Sprintf("gardomatic API: %s (%d)", e.Message, e.StatusCode)
+	case len(e.Validation) != 0:
+		return fmt.Sprintf("gardomatic API: validation failed (%d)", e.StatusCode)
+	default:
+		return fmt.Sprintf("gardomatic API: request failed (%d)", e.StatusCode)
+	}
+}
+
+func newAPIError(response *http.Response, body []byte) *APIError {
+	apiError := &APIError{
+		StatusCode: response.StatusCode,
+		Body:       strings.TrimSpace(string(body)),
+	}
+
+	var envelope struct {
+		Error json.RawMessage `json:"error"`
+	}
+	if err := json.Unmarshal(body, &envelope); err != nil || len(envelope.Error) == 0 {
+		return apiError
+	}
+	if err := json.Unmarshal(envelope.Error, &apiError.Message); err == nil {
+		return apiError
+	}
+	_ = json.Unmarshal(envelope.Error, &apiError.Validation)
+	return apiError
+}