add pdctl interactive mode autocomplete (#2785)

* add pdctl interactive mode autocomplete

Signed-off-by: jiashiwen <jiashiwen126@126.com>

tools/pd-ctl/pdctl/ctl.go

@@ -17,6 +17,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"strings"
 
 	"github.com/chzyer/readline"
 	"github.com/mattn/go-shellwords"
@@ -37,9 +38,10 @@ type CommandFlags struct {
 var (
 	commandFlags = CommandFlags{}
 
-	detach   bool
-	interact bool
-	version  bool
+	detach            bool
+	interact          bool
+	version           bool
+	readlineCompleter *readline.PrefixCompleter
 )
 
 func init() {
@@ -117,6 +119,7 @@ func getMainCmd(args []string) *cobra.Command {
 	rootCmd.ParseFlags(args)
 	rootCmd.SetOutput(os.Stdout)
 
+	readlineCompleter = readline.NewPrefixCompleter(genCompleter(rootCmd)...)
 	return rootCmd
 }
 
@@ -156,6 +159,7 @@ func loop() {
 	l, err := readline.NewEx(&readline.Config{
 		Prompt:            "\033[31m»\033[0m ",
 		HistoryFile:       "/tmp/readline.tmp",
+		AutoComplete:      readlineCompleter,
 		InterruptPrompt:   "^C",
 		EOFPrompt:         "^D",
 		HistorySearchFold: true,
@@ -190,3 +194,22 @@ func loop() {
 		Start(args)
 	}
 }
+
+func genCompleter(cmd *cobra.Command) []readline.PrefixCompleterInterface {
+	pc := []readline.PrefixCompleterInterface{}
+
+	for _, v := range cmd.Commands() {
+		if v.HasFlags() {
+			flagsPc := []readline.PrefixCompleterInterface{}
+			flagUsages := strings.Split(strings.Trim(v.Flags().FlagUsages(), " "), "\n")
+			for i := 0; i < len(flagUsages)-1; i++ {
+				flagsPc = append(flagsPc, readline.PcItem(strings.Split(strings.Trim(flagUsages[i], " "), " ")[0]))
+			}
+			flagsPc = append(flagsPc, genCompleter(v)...)
+			pc = append(pc, readline.PcItem(strings.Split(v.Use, " ")[0], flagsPc...))
+		} else {
+			pc = append(pc, readline.PcItem(strings.Split(v.Use, " ")[0], genCompleter(v)...))
+		}
+	}
+	return pc
+}

tools/pd-ctl/pdctl/ctl_test.go

@@ -0,0 +1,70 @@
+// Copyright 2020 TiKV Project Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pdctl
+
+import (
+	"testing"
+
+	"github.com/spf13/cobra"
+)
+
+func newCommand(usage, short string) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   usage,
+		Short: short,
+	}
+	return cmd
+}
+
+func TestGenCompleter(t *testing.T) {
+	var subCommand = []string{"testa", "testb", "testc", "testdef"}
+
+	rootCmd := &cobra.Command{
+		Use:   "roottest",
+		Short: "test root cmd",
+	}
+
+	cmdA := newCommand("testa", "test a command")
+	cmdB := newCommand("testb", "test b command")
+	cmdC := newCommand("testc", "test c command")
+	cmdDEF := newCommand("testdef", "test def command")
+
+	rootCmd.AddCommand(cmdA, cmdB, cmdC, cmdDEF)
+
+	pc := genCompleter(rootCmd)
+
+	for _, cmd := range subCommand {
+		runArray := []rune(cmd)
+		inPrefixArray := true
+		for _, v := range pc {
+			inPrefixArray = true
+			if len(runArray) != len(v.GetName())-1 {
+				continue
+			}
+			for i := 0; i < len(runArray); i++ {
+				if runArray[i] != v.GetName()[i] {
+					inPrefixArray = false
+				}
+			}
+			if inPrefixArray == true {
+				break
+			}
+		}
+
+		if inPrefixArray == false {
+			t.Errorf("%s not in prefix array", cmd)
+		}
+	}
+
+}