From 17c1fccd9c6c8e59339f1970576ea1815c9fb454 Mon Sep 17 00:00:00 2001
From: iwilltry42 <iwilltry42@gmail.com>
Date: Fri, 5 Jun 2020 08:54:27 +0200
Subject: [PATCH] completion: add custom completion for 'get clusters'

---
 cmd/get/getCluster.go | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/cmd/get/getCluster.go b/cmd/get/getCluster.go
index 5d9535d5..fb298e57 100644
--- a/cmd/get/getCluster.go
+++ b/cmd/get/getCluster.go
@@ -58,6 +58,7 @@ func NewCmdGetCluster() *cobra.Command {
 			clusters := buildClusterList(cmd.Context(), args)
 			PrintClusters(clusters, clusterFlags)
 		},
+		ValidArgsFunction: validArgsFunc,
 	}
 
 	// add flags
@@ -70,6 +71,31 @@ func NewCmdGetCluster() *cobra.Command {
 	return cmd
 }
 
+// validArgsFunc is used for shell completion: proposes the list of existing clusters
+func validArgsFunc(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+
+	var completions []string
+	var clusters []*k3d.Cluster
+	clusters, err := k3cluster.GetClusters(context.Background(), runtimes.SelectedRuntime)
+	if err != nil {
+		log.Errorln("Failed to get list of clusters for shell completion")
+		return nil, cobra.ShellCompDirectiveError
+	}
+
+clusterLoop:
+	for _, cluster := range clusters {
+		for _, arg := range args {
+			if arg == cluster.Name { // only clusters, that are not in the args yet
+				continue clusterLoop
+			}
+		}
+		if strings.HasPrefix(cluster.Name, toComplete) {
+			completions = append(completions, cluster.Name)
+		}
+	}
+	return completions, cobra.ShellCompDirectiveDefault
+}
+
 func buildClusterList(ctx context.Context, args []string) []*k3d.Cluster {
 	var clusters []*k3d.Cluster
 	var err error