1 files changed, 95 insertions, 0 deletions
diff --git a/prompt/prompt.go b/prompt/prompt.go
new file mode 100644
index 0000000..395d4bd
--- /dev/null
+++ b/prompt/prompt.go
@@ -0,0 +1,95 @@
+package prompt
+
+import (
+	"bufio"
+	"dtail/logger"
+	"fmt"
+	"os"
+	"strings"
+)
+
+// Answer is a user input of a prompt question.
+type Answer struct {
+	// Long version of the expected user input
+	Long string
+	// Short version of the expected user input
+	Short string
+	// Runs when user input matches
+	Callback func()
+	// Runs after Callback and after logging resumes
+	EndCallback func()
+
+	AskAgain bool
+}
+
+// Prompt used for interactive user input.
+type Prompt struct {
+	question string
+	answers  []Answer
+}
+
+func (p *Prompt) askString() string {
+	var sb strings.Builder
+
+	sb.WriteString(p.question)
+	sb.WriteString("? (")
+
+	var ax []string
+	for _, a := range p.answers {
+		ax = append(ax, fmt.Sprintf("%s=%s", a.Short, a.Long))
+	}
+
+	sb.WriteString(strings.Join(ax, ","))
+	sb.WriteString("): ")
+
+	return sb.String()
+}
+
+// New returns a new prompt.
+func New(question string) *Prompt {
+	return &Prompt{question: question}
+}
+
+// Add an answer.
+func (p *Prompt) Add(answer Answer) {
+	p.answers = append(p.answers, answer)
+}
+
+// Ask a question.
+func (p *Prompt) Ask() {
+	reader := bufio.NewReader(os.Stdin)
+	logger.Pause()
+
+	for {
+		fmt.Print(p.askString())
+		answerStr, _ := reader.ReadString('\n')
+
+		if a, ok := p.answer(strings.TrimSpace(answerStr)); ok {
+			if a.Callback != nil {
+				a.Callback()
+			}
+
+			if !a.AskAgain {
+				logger.Resume()
+				if a.EndCallback != nil {
+					a.EndCallback()
+				}
+				return
+			}
+		}
+	}
+}
+
+func (p *Prompt) answer(answerStr string) (*Answer, bool) {
+	for _, a := range p.answers {
+		switch answerStr {
+		case a.Long:
+			return &a, true
+		case a.Short:
+			return &a, true
+		default:
+		}
+	}
+
+	return nil, false
+}