From 20b2ca2ea536ec5814c746d34c398ec3f6912d3c Mon Sep 17 00:00:00 2001
From: Pavel Sviderski <me@psviderski.name>
Date: Wed, 2 Apr 2025 16:31:26 +1000
Subject: [PATCH] feat(ctx): interactive ctx command to switch between cluster
 contexts

---
 cmd/uncloud/context/ls.go   |  4 +-
 cmd/uncloud/context/root.go | 10 +++--
 cmd/uncloud/context/use.go  | 79 +++++++++++++++++++++++++++++++++++++
 3 files changed, 87 insertions(+), 6 deletions(-)
 create mode 100644 cmd/uncloud/context/use.go

diff --git a/cmd/uncloud/context/ls.go b/cmd/uncloud/context/ls.go
index 81b7ecc8..b91de526 100644
--- a/cmd/uncloud/context/ls.go
+++ b/cmd/uncloud/context/ls.go
@@ -15,8 +15,8 @@ func NewListCommand() *cobra.Command {
 	var clusterContext string
 
 	cmd := &cobra.Command{
-		Use:     "list",
-		Aliases: []string{"ls"},
+		Use:     "ls",
+		Aliases: []string{"list"},
 		Short:   "List available cluster contexts.",
 		RunE: func(cmd *cobra.Command, args []string) error {
 			uncli := cmd.Context().Value("cli").(*cli.CLI)
diff --git a/cmd/uncloud/context/root.go b/cmd/uncloud/context/root.go
index 25cba7bc..dd333de8 100644
--- a/cmd/uncloud/context/root.go
+++ b/cmd/uncloud/context/root.go
@@ -1,22 +1,24 @@
 package context
 
 import (
+	"github.com/psviderski/uncloud/internal/cli"
 	"github.com/spf13/cobra"
 )
 
 func NewRootCommand() *cobra.Command {
 	cmd := &cobra.Command{
-		Use:     "context",
-		Aliases: []string{"ctx"},
+		Use:     "ctx",
+		Aliases: []string{"context"},
 		Short:   "Switch between different cluster contexts. Contains subcommands to manage contexts.",
 		RunE: func(cmd *cobra.Command, args []string) error {
-			// TODO
-			return nil
+			uncli := cmd.Context().Value("cli").(*cli.CLI)
+			return selectContext(uncli)
 		},
 	}
 
 	cmd.AddCommand(
 		NewListCommand(),
+		NewUseCommand(),
 	)
 
 	return cmd
diff --git a/cmd/uncloud/context/use.go b/cmd/uncloud/context/use.go
new file mode 100644
index 00000000..fd34e03a
--- /dev/null
+++ b/cmd/uncloud/context/use.go
@@ -0,0 +1,79 @@
+package context
+
+import (
+	"fmt"
+	"maps"
+	"slices"
+
+	"github.com/charmbracelet/huh"
+	"github.com/psviderski/uncloud/internal/cli"
+	"github.com/spf13/cobra"
+)
+
+func NewUseCommand() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "use [CONTEXT]",
+		Short: "Switch to a different cluster context.",
+		Long: "Switch to a different cluster context. If no context is provided, " +
+			"a list of available contexts will be displayed for selection.",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			uncli := cmd.Context().Value("cli").(*cli.CLI)
+
+			if len(args) == 1 {
+				return uncli.SetCurrentContext(args[0])
+			}
+
+			return selectContext(uncli)
+		},
+	}
+
+	return cmd
+}
+
+func selectContext(uncli *cli.CLI) error {
+	if uncli.Config == nil {
+		return fmt.Errorf("context management is not available: Uncloud configuration file is not being used")
+	}
+	if len(uncli.Config.Contexts) == 0 {
+		return fmt.Errorf("no contexts found in Uncloud config (%s)", uncli.Config.Path)
+	}
+
+	contextNames := slices.Sorted(maps.Keys(uncli.Config.Contexts))
+
+	var selected string
+	form := huh.NewForm(
+		huh.NewGroup(
+			huh.NewSelect[string]().
+				Title("Select a cluster context").
+				Options(buildContextOptions(contextNames, uncli.Config.CurrentContext)...).
+				Value(&selected),
+		),
+	)
+	if err := form.Run(); err != nil {
+		return fmt.Errorf("select cluster context: %w", err)
+	}
+
+	if err := uncli.SetCurrentContext(selected); err != nil {
+		return fmt.Errorf("set current cluster context: %w", err)
+	}
+
+	fmt.Printf("Current cluster context is now '%s'.\n", selected)
+	return nil
+}
+
+func buildContextOptions(contexts []string, current string) []huh.Option[string] {
+	options := make([]huh.Option[string], len(contexts))
+
+	for i, ctx := range contexts {
+		opt := huh.NewOption(ctx, ctx)
+		if ctx == current {
+			opt.Key += " (current)"
+			opt = opt.Selected(true)
+		}
+
+		options[i] = opt
+	}
+
+	options[1].Selected(true)
+	return options
+}