fs: Use --cutoff-mode hard,soft,catious instead of 3 --max-transfer-mode flags

Fixes #2672

fs/cutoffmode.go

@@ -0,0 +1,49 @@
+package fs
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/pkg/errors"
+)
+
+// CutoffMode describes the possible delete modes in the config
+type CutoffMode byte
+
+// MaxTransferMode constants
+const (
+	CutoffModeHard CutoffMode = iota
+	CutoffModeSoft
+	CutoffModeCautious
+	CutoffModeDefault = CutoffModeHard
+)
+
+var cutoffModeToString = []string{
+	CutoffModeHard:     "HARD",
+	CutoffModeSoft:     "SOFT",
+	CutoffModeCautious: "CAUTIOUS",
+}
+
+// String turns a LogLevel into a string
+func (m CutoffMode) String() string {
+	if m >= CutoffMode(len(cutoffModeToString)) {
+		return fmt.Sprintf("CutoffMode(%d)", m)
+	}
+	return cutoffModeToString[m]
+}
+
+// Set a LogLevel
+func (m *CutoffMode) Set(s string) error {
+	for n, name := range cutoffModeToString {
+		if s != "" && name == strings.ToUpper(s) {
+			*m = CutoffMode(n)
+			return nil
+		}
+	}
+	return errors.Errorf("Unknown cutoff mode %q", s)
+}
+
+// Type of the value
+func (m *CutoffMode) Type() string {
+	return "string"
+}