add suggestions

Signed-off-by: kshamajain99 <[email protected]>

cmd/main.go

@@ -13,6 +13,7 @@ import (
 	apiserver "github.com/argoproj/argo-cd/cmd/argocd-server/commands"
 	util "github.com/argoproj/argo-cd/cmd/argocd-util/commands"
 	cli "github.com/argoproj/argo-cd/cmd/argocd/commands"
+	cmdutil "github.com/argoproj/argo-cd/cmd/util"
 )
 
 const (
@@ -27,6 +28,8 @@ func main() {
 		binaryName = val
 	}
 	switch binaryName {
+	case "argocd", "argocd-linux-amd64", "argocd-darwin-amd64", "argocd-windows-amd64.exe":
+		command = cli.NewCommand()
 	case "argocd-util", "argocd-util-linux-amd64", "argocd-util-darwin-amd64", "argocd-util-windows-amd64.exe":
 		command = util.NewCommand()
 	case "argocd-server":
@@ -38,6 +41,10 @@ func main() {
 	case "argocd-dex":
 		command = dex.NewCommand()
 	default:
+		if suggestionsString := cmdutil.FindSuggestions(binaryName); suggestionsString != "" {
+			fmt.Printf("unknown command %q for %s\n", binaryName, suggestionsString)
+			os.Exit(1)
+		}
 		// default is argocd cli
 		command = cli.NewCommand()
 	}

cmd/util/suggest.go

@@ -0,0 +1,82 @@
+package util
+
+import (
+	"fmt"
+	"strings"
+)
+
+const (
+	minSuggestionsDistance = 3
+)
+
+var (
+	argocdCommands = []string{"argocd-util", "argocd-server", "argocd-application-controller", "argocd-repo-server", "argocd-dex"}
+)
+
+func FindSuggestions(binaryName string) string {
+	suggestionsString := ""
+	if suggestions := SuggestionsFor(binaryName); len(suggestions) > 0 {
+		suggestionsString += "\n\nDid you mean this?\n"
+		for _, s := range suggestions {
+			suggestionsString += fmt.Sprintf("\t%v\n", s)
+		}
+	}
+	return suggestionsString
+}
+
+// Logic from https://github.com/spf13/cobra/blob/master/command.go#L721
+// Modified suggestion by prefix to suggest when either binary Name is
+// prefix to command name or command name is prefix to binary name
+// Added suggestions by substring
+// SuggestionsFor provides suggestions for the binary name.
+func SuggestionsFor(binaryName string) []string {
+	var suggestions []string
+	for _, cmdName := range argocdCommands {
+		levenshteinDistance := ld(binaryName, cmdName, true)
+		suggestByLevenshtein := levenshteinDistance <= minSuggestionsDistance
+		suggestByPrefix := strings.HasPrefix(strings.ToLower(cmdName), strings.ToLower(binaryName)) ||
+			strings.HasPrefix(strings.ToLower(binaryName), strings.ToLower(cmdName))
+		suggestBySubstring := strings.Contains(cmdName, binaryName)
+		if suggestByLevenshtein || suggestByPrefix || suggestBySubstring {
+			suggestions = append(suggestions, cmdName)
+		}
+	}
+	return suggestions
+}
+
+// Logic from https://github.com/spf13/cobra/blob/master/cobra.go#L165
+// ld compares two strings and returns the levenshtein distance between them.
+func ld(s, t string, ignoreCase bool) int {
+	if ignoreCase {
+		s = strings.ToLower(s)
+		t = strings.ToLower(t)
+	}
+	d := make([][]int, len(s)+1)
+	for i := range d {
+		d[i] = make([]int, len(t)+1)
+	}
+	for i := range d {
+		d[i][0] = i
+	}
+	for j := range d[0] {
+		d[0][j] = j
+	}
+	for j := 1; j <= len(t); j++ {
+		for i := 1; i <= len(s); i++ {
+			if s[i-1] == t[j-1] {
+				d[i][j] = d[i-1][j-1]
+			} else {
+				min := d[i-1][j]
+				if d[i][j-1] < min {
+					min = d[i][j-1]
+				}
+				if d[i-1][j-1] < min {
+					min = d[i-1][j-1]
+				}
+				d[i][j] = min + 1
+			}
+		}
+
+	}
+	return d[len(s)][len(t)]
+}