Improve usability and better output formatting for gosndc

Description

Related Issue

#188 (closed)

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

cli/cmd/prompt.go

@@ -47,7 +47,9 @@ import (
 
 // PromptCompleter provides completion for a device
 type PromptCompleter struct {
-	yangSchemaCompleterMap map[uuid.UUID]*completer.YangSchemaCompleter
+	yangSchemaCompleterMap   map[uuid.UUID]*completer.YangSchemaCompleter
+	currentDeviceSuggestions []prompt.Suggest
+	history                  []string
 }
 
 // NewPromptCompleter returns a new promptCompleter
@@ -76,6 +78,8 @@ func (pc *PromptCompleter) Run() {
 		prompt.OptionPrefixTextColor(prompt.Cyan),
 		prompt.OptionCompletionWordSeparator(completer.YangSchemaCompletionSeperator),
 		prompt.OptionShowCompletionAtStart(),
+		prompt.OptionCompletionOnDown(),
+		prompt.OptionHistory(pc.history),
 		prompt.OptionSuggestionBGColor(prompt.DarkGray),
 		prompt.OptionSuggestionTextColor(prompt.LightGray),
 		prompt.OptionDescriptionTextColor(prompt.DarkGray),
@@ -128,11 +132,11 @@ func filterFlagSlice(input []string) (commandSlice []string, flagSlice []string)
 func deviceGetCompletion(c *PromptCompleter, d prompt.Document, inputSplit []string) []prompt.Suggest {
 	switch inputLen := len(inputSplit); inputLen {
 	case 2:
-		return devicePrompt(d)
+		return devicePrompt(c, d)
 	case 3:
 		id, err := uuid.Parse(inputSplit[inputLen-1])
 		if err != nil {
-			return devicePrompt(d)
+			return devicePrompt(c, d)
 		}
 		if c, ok := c.yangSchemaCompleterMap[id]; ok {
 			return c.Complete(d)
@@ -151,7 +155,7 @@ func deviceGetCompletion(c *PromptCompleter, d prompt.Document, inputSplit []str
 		}
 		id, err := uuid.Parse(inputSplit[inputLen-2])
 		if err != nil {
-			return devicePrompt(d)
+			return devicePrompt(c, d)
 		}
 		if yc, ok := c.yangSchemaCompleterMap[id]; ok {
 			return yc.Complete(d)
@@ -162,15 +166,15 @@ func deviceGetCompletion(c *PromptCompleter, d prompt.Document, inputSplit []str
 	return []prompt.Suggest{}
 }
 
-func devicePrompt(d prompt.Document) []prompt.Suggest {
-	spinner, _ := pterm.DefaultSpinner.Start("Requesting devices from controller.")
-	devices, err := getDevices()
-	if err != nil {
-		spinner.Fail(err)
-		return prompt.FilterHasPrefix(devices, d.GetWordBeforeCursor(), true)
+func devicePrompt(c *PromptCompleter, d prompt.Document) []prompt.Suggest {
+	if c.currentDeviceSuggestions == nil {
+		var err error
+		c.currentDeviceSuggestions, err = getDevices()
+		if err != nil {
+			return prompt.FilterHasPrefix(c.currentDeviceSuggestions, d.GetWordBeforeCursor(), true)
+		}
 	}
-	spinner.Success()
-	return prompt.FilterHasPrefix(devices, d.GetWordBeforeCursor(), true)
+	return prompt.FilterHasPrefix(c.currentDeviceSuggestions, d.GetWordBeforeCursor(), true)
 }
 
 func cobraCommandCompletion(currCmd *cobra.Command, d prompt.Document, inputFlags []string, loaded []prompt.Suggest) []prompt.Suggest {
@@ -204,6 +208,9 @@ func completionBasedOnCmd(c *PromptCompleter, cmd *cobra.Command, inputSplit []s
 	case deviceShowCmd:
 		devices, _ := getDevices()
 		return devices
+	case deviceCmd:
+		c.currentDeviceSuggestions = nil
+		return cobraCommandCompletion(cmd, d, inputFlags, []prompt.Suggest{})
 	default:
 		return cobraCommandCompletion(cmd, d, inputFlags, []prompt.Suggest{})
 	}