input: better reusable prompt functions

1 files changed, 95 insertions, 11 deletions

diff --git a/input/prompt.go b/input/prompt.go
index 6036c062..c7887abb 100644
--- a/input/prompt.go
+++ b/input/prompt.go
@@ -4,23 +4,36 @@ import (
 	"bufio"
 	"fmt"
 	"os"
+	"strconv"
 	"strings"
+	"syscall"
+
+	"golang.org/x/crypto/ssh/terminal"
+
+	"github.com/MichaelMure/git-bug/util/interrupt"
 )
 
-func PromptValue(name string, preValue string) (string, error) {
-	return promptValue(name, preValue, false)
+// PromptValidator is a validator for a user entry
+type PromptValidator func(name string, value string) (complaint string, err error)
+
+// Required is a validator preventing a "" value
+func Required(name string, value string) (string, error) {
+	if value == "" {
+		return fmt.Sprintf("%s is empty", name), nil
+	}
+	return "", nil
 }
 
-func PromptValueRequired(name string, preValue string) (string, error) {
-	return promptValue(name, preValue, true)
+func Prompt(prompt, name string, validators ...PromptValidator) (string, error) {
+	return PromptDefault(prompt, name, "", validators...)
 }
 
-func promptValue(name string, preValue string, required bool) (string, error) {
+func PromptDefault(prompt, name, preValue string, validators ...PromptValidator) (string, error) {
 	for {
 		if preValue != "" {
-			_, _ = fmt.Fprintf(os.Stderr, "%s [%s]: ", name, preValue)
+			_, _ = fmt.Fprintf(os.Stderr, "%s [%s]: ", prompt, preValue)
 		} else {
-			_, _ = fmt.Fprintf(os.Stderr, "%s: ", name)
+			_, _ = fmt.Fprintf(os.Stderr, "%s: ", prompt)
 		}
 
 		line, err := bufio.NewReader(os.Stdin).ReadString('\n')
@@ -31,14 +44,85 @@ func promptValue(name string, preValue string, required bool) (string, error) {
 		line = strings.TrimSpace(line)
 
 		if preValue != "" && line == "" {
-			return preValue, nil
+			line = preValue
 		}
 
-		if required && line == "" {
-			_, _ = fmt.Fprintf(os.Stderr, "%s is empty\n", name)
-			continue
+		for _, validator := range validators {
+			complaint, err := validator(name, line)
+			if err != nil {
+				return "", err
+			}
+			if complaint != "" {
+				_, _ = fmt.Fprintln(os.Stderr, complaint)
+				continue
+			}
 		}
 
 		return line, nil
 	}
 }
+
+func PromptPassword(prompt, name string, validators ...PromptValidator) (string, error) {
+	termState, err := terminal.GetState(syscall.Stdin)
+	if err != nil {
+		return "", err
+	}
+
+	cancel := interrupt.RegisterCleaner(func() error {
+		return terminal.Restore(syscall.Stdin, termState)
+	})
+	defer cancel()
+
+	for {
+		_, _ = fmt.Fprintf(os.Stderr, "%s: ", prompt)
+
+		bytePassword, err := terminal.ReadPassword(syscall.Stdin)
+		// new line for coherent formatting, ReadPassword clip the normal new line
+		// entered by the user
+		fmt.Println()
+
+		if err != nil {
+			return "", err
+		}
+
+		pass := string(bytePassword)
+
+		for _, validator := range validators {
+			complaint, err := validator(name, pass)
+			if err != nil {
+				return "", err
+			}
+			if complaint != "" {
+				_, _ = fmt.Fprintln(os.Stderr, complaint)
+				continue
+			}
+		}
+
+		return pass, nil
+	}
+}
+
+func PromptChoice(prompt string, choices []string) (int, error) {
+	for {
+		for i, choice := range choices {
+			_, _ = fmt.Fprintf(os.Stderr, "[%d]: %s\n", i+1, choice)
+		}
+		_, _ = fmt.Fprintf(os.Stderr, "%s: ", prompt)
+
+		line, err := bufio.NewReader(os.Stdin).ReadString('\n')
+		fmt.Println()
+		if err != nil {
+			return 0, err
+		}
+
+		line = strings.TrimSpace(line)
+
+		index, err := strconv.Atoi(line)
+		if err != nil || index < 1 || index > len(choices) {
+			fmt.Println("invalid input")
+			continue
+		}
+
+		return index, nil
+	}
+}