refactor: urfave v3

vendor/github.com/urfave/cli/v3/value_source.go

@@ -0,0 +1,145 @@
+package cli
+
+import (
+	"fmt"
+	"os"
+	"strings"
+)
+
+// ValueSource is a source which can be used to look up a value,
+// typically for use with a cli.Flag
+type ValueSource interface {
+	fmt.Stringer
+	fmt.GoStringer
+
+	// Lookup returns the value from the source and if it was found
+	// or returns an empty string and false
+	Lookup() (string, bool)
+}
+
+// ValueSourceChain contains an ordered series of ValueSource that
+// allows for lookup where the first ValueSource to resolve is
+// returned
+type ValueSourceChain struct {
+	Chain []ValueSource
+}
+
+func NewValueSourceChain(src ...ValueSource) ValueSourceChain {
+	return ValueSourceChain{
+		Chain: src,
+	}
+}
+
+func (vsc *ValueSourceChain) Append(other ValueSourceChain) {
+	vsc.Chain = append(vsc.Chain, other.Chain...)
+}
+
+func (vsc *ValueSourceChain) EnvKeys() []string {
+	vals := []string{}
+
+	for _, src := range vsc.Chain {
+		if v, ok := src.(*envVarValueSource); ok {
+			vals = append(vals, v.Key)
+		}
+	}
+
+	return vals
+}
+
+func (vsc *ValueSourceChain) String() string {
+	s := []string{}
+
+	for _, vs := range vsc.Chain {
+		s = append(s, vs.String())
+	}
+
+	return strings.Join(s, ",")
+}
+
+func (vsc *ValueSourceChain) GoString() string {
+	s := []string{}
+
+	for _, vs := range vsc.Chain {
+		s = append(s, vs.GoString())
+	}
+
+	return fmt.Sprintf("&ValueSourceChain{Chain:{%[1]s}}", strings.Join(s, ","))
+}
+
+func (vsc *ValueSourceChain) Lookup() (string, bool) {
+	s, _, ok := vsc.LookupWithSource()
+	return s, ok
+}
+
+func (vsc *ValueSourceChain) LookupWithSource() (string, ValueSource, bool) {
+	for _, src := range vsc.Chain {
+		if value, found := src.Lookup(); found {
+			return value, src, true
+		}
+	}
+
+	return "", nil, false
+}
+
+// envVarValueSource encapsulates a ValueSource from an environment variable
+type envVarValueSource struct {
+	Key string
+}
+
+func (e *envVarValueSource) Lookup() (string, bool) {
+	return os.LookupEnv(strings.TrimSpace(string(e.Key)))
+}
+
+func (e *envVarValueSource) String() string { return fmt.Sprintf("environment variable %[1]q", e.Key) }
+func (e *envVarValueSource) GoString() string {
+	return fmt.Sprintf("&envVarValueSource{Key:%[1]q}", e.Key)
+}
+
+func EnvVar(key string) ValueSource {
+	return &envVarValueSource{
+		Key: key,
+	}
+}
+
+// EnvVars is a helper function to encapsulate a number of
+// envVarValueSource together as a ValueSourceChain
+func EnvVars(keys ...string) ValueSourceChain {
+	vsc := ValueSourceChain{Chain: []ValueSource{}}
+
+	for _, key := range keys {
+		vsc.Chain = append(vsc.Chain, &envVarValueSource{Key: key})
+	}
+
+	return vsc
+}
+
+// fileValueSource encapsulates a ValueSource from a file
+type fileValueSource struct {
+	Path string
+}
+
+func (f *fileValueSource) Lookup() (string, bool) {
+	data, err := os.ReadFile(f.Path)
+	return string(data), err == nil
+}
+
+func (f *fileValueSource) String() string { return fmt.Sprintf("file %[1]q", f.Path) }
+func (f *fileValueSource) GoString() string {
+	return fmt.Sprintf("&fileValueSource{Path:%[1]q}", f.Path)
+}
+
+func File(path string) ValueSource {
+	return &fileValueSource{Path: path}
+}
+
+// Files is a helper function to encapsulate a number of
+// fileValueSource together as a ValueSourceChain
+func Files(paths ...string) ValueSourceChain {
+	vsc := ValueSourceChain{Chain: []ValueSource{}}
+
+	for _, path := range paths {
+		vsc.Chain = append(vsc.Chain, &fileValueSource{Path: path})
+	}
+
+	return vsc
+}