Organize backend into product executable and shared Go modules

backend/shared/ratelimit/config.go

@@ -0,0 +1,38 @@
+package ratelimit
+
+import (
+	"strings"
+	"time"
+
+	"git.sendico.io/tech/sxchnge/shared/errors"
+)
+
+const (
+	MinWindow = time.Second
+	MaxWindow = 24 * time.Hour
+	MaxLimit  = 10000
+)
+
+type WindowConfig struct {
+	Limit  int    `yaml:"limit"`
+	Window string `yaml:"window"`
+}
+
+type Window struct {
+	Limit  int
+	Window time.Duration
+}
+
+func ResolveWindow(raw WindowConfig, field string) (Window, error) {
+	if raw.Limit < 1 || raw.Limit > MaxLimit {
+		return Window{}, merrors.InvalidArgument("rate limit must be between 1 and 10000", field+".limit")
+	}
+	window, err := time.ParseDuration(strings.TrimSpace(raw.Window))
+	if err != nil {
+		return Window{}, merrors.InvalidArgument("rate limit window must be a valid duration", field+".window")
+	}
+	if window < MinWindow || window > MaxWindow {
+		return Window{}, merrors.InvalidArgument("rate limit window must be between 1s and 24h", field+".window")
+	}
+	return Window{Limit: raw.Limit, Window: window}, nil
+}