cli: throttle 'new version available' notification to once per day (#1809)

Record the last time we emitted the update-available notification in
`$XDG_CONFIG_HOME/ns/version-notify`, and skip both the remote version
check and the notification on subsequent invocations within 24h. The
throttle is global across all commands (`nsc`, `ns`, ...).

---------

Co-authored-by: Amp <amp@ampcode.com>

Author: hugosantos

internal/cli/fncobra/do.go

@@ -5,18 +5,25 @@
 package fncobra
 
 import (
+	"bytes"
 	"context"
 	"fmt"
+	"os"
+	"path/filepath"
+	"time"
 
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 	"namespacelabs.dev/foundation/internal/cli/version"
 	"namespacelabs.dev/foundation/internal/cli/versioncheck"
 	"namespacelabs.dev/foundation/internal/compute"
 	"namespacelabs.dev/foundation/internal/console"
+	"namespacelabs.dev/foundation/internal/workspace/dirs"
 	"namespacelabs.dev/foundation/std/tasks"
 )
 
+const updateNotifyInterval = 24 * time.Hour
+
 type CmdHandler func(context.Context, []string) error
 
 type ArgsParser interface {
@@ -41,6 +48,10 @@ func DeferCheckVersion(ctx context.Context, command string) {
 		return
 	}
 
+	if !shouldNotifyUpdate() {
+		return
+	}
+
 	compute.On(ctx).BestEffort(tasks.Action(command+".check-updated"), func(ctx context.Context) error {
 		status, err := versioncheck.CheckRemote(ctx, ver, command)
 		if err != nil {
@@ -54,6 +65,7 @@ func DeferCheckVersion(ctx context.Context, command string) {
 
 		if status.NewVersion {
 			compute.On(ctx).Cleanup(tasks.Action(command+".check-updated.notify").LogLevel(1), func(ctx context.Context) error {
+				_ = markUpdateNotified()
 				fmt.Fprintf(console.Info(ctx), "\n\n  A new version of %s is available (%s).\n\n", command, status.Version)
 				return nil
 			})
@@ -63,6 +75,37 @@ func DeferCheckVersion(ctx context.Context, command string) {
 	})
 }
 
+func updateNotifyPath() (string, error) {
+	return dirs.ConfigSubdir("version-notify")
+}
+
+func shouldNotifyUpdate() bool {
+	path, err := updateNotifyPath()
+	if err != nil {
+		return true
+	}
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return true
+	}
+	last, err := time.Parse(time.RFC3339, string(bytes.TrimSpace(data)))
+	if err != nil {
+		return true
+	}
+	return time.Since(last) >= updateNotifyInterval
+}
+
+func markUpdateNotified() error {
+	path, err := updateNotifyPath()
+	if err != nil {
+		return err
+	}
+	if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
+		return err
+	}
+	return os.WriteFile(path, []byte(time.Now().UTC().Format(time.RFC3339)), 0644)
+}
+
 func RunInContext(ctx context.Context, handler func(context.Context) error) error {
 	ctx, cancel := WithSigIntCancel(ctx)
 	defer cancel()