From 5c24ed7d2fcacabfaa979181aed956d8001a5ffb Mon Sep 17 00:00:00 2001
From: Dipankar Das <65275144+dipankardas011@users.noreply.github.com>
Date: Mon, 5 May 2025 21:32:38 +0530
Subject: [PATCH] feat(completion): add shell completion support

Introduce shell completion support for bash, zsh, and fish shells.
This includes a new `completion` command that generates the necessary
scripts for each shell.

Signed-off-by: Dipankar Das <65275144+dipankardas011@users.noreply.github.com>
---
 cmd/completion.go | 54 +++++++++++++++++++++++++++++++++++++++++++++++
 cmd/handler.go    |  1 +
 2 files changed, 55 insertions(+)
 create mode 100644 cmd/completion.go

diff --git a/cmd/completion.go b/cmd/completion.go
new file mode 100644
index 0000000..025110a
--- /dev/null
+++ b/cmd/completion.go
@@ -0,0 +1,54 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+func (k *KsctlCommand) ShellCompletion() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "completion [bash|zsh|fish]",
+		Short: "Generate shell completion scripts",
+		Long: `To load completions:
+
+Bash:
+
+  $ source <(ksctl completion bash)
+
+  # To load completions for each session, execute once:
+  # Linux:
+  $ ksctl completion bash > /etc/bash_completion.d/ksctl
+  # macOS:
+  $ ksctl completion bash > /usr/local/etc/bash_completion.d/ksctl
+
+Zsh:
+
+  $ echo "autoload -U compinit; compinit" >> ~/.zshrc
+  $ ksctl completion zsh > "${fpath[1]}/_ksctl"
+
+Fish:
+
+  $ ksctl completion fish | source
+
+  # To load completions for each session, execute once:
+  $ ksctl completion fish > ~/.config/fish/completions/ksctl.fish
+`,
+		Args: cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			switch args[0] {
+			case "bash":
+				return cmd.Root().GenBashCompletion(os.Stdout)
+			case "zsh":
+				return cmd.Root().GenZshCompletion(os.Stdout)
+			case "fish":
+				return cmd.Root().GenFishCompletion(os.Stdout, true)
+			default:
+				return fmt.Errorf("unsupported shell: %s", args[0])
+			}
+		},
+	}
+
+	return cmd
+}
diff --git a/cmd/handler.go b/cmd/handler.go
index d7f4ea5..1794729 100644
--- a/cmd/handler.go
+++ b/cmd/handler.go
@@ -26,6 +26,7 @@ func (k *KsctlCommand) CommandMapping() error {
 		c,
 		k.Version(),
 		k.SelfUpdate(),
+		k.ShellCompletion(),
 		cr,
 	)
 	cli.RegisterCommand(