cmd/mbf: set window title

This displays ongoing and complete cures via the notify channel.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/mbf/cache.go

@@ -5,6 +5,7 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
+	"strconv"
 	"testing"
 
 	"hakurei.app/check"
@@ -38,18 +39,32 @@ type cache struct {
 	base, mirror string
 }
 
+// writeTitle sets title of the terminal connected to [message.Msg].
+func writeTitle(msg message.Msg, s string) {
+	msg.Suspend()
+	w := msg.GetLogger().Writer()
+	_, _ = w.Write([]byte("\x1b]0;" + s + "\a"))
+	msg.Resume()
+}
+
 // open opens the underlying [pkg.Cache].
 func (cache *cache) open() (err error) {
 	if cache.c != nil {
 		return os.ErrInvalid
 	}
 
+	var hostname string
+	if hostname, err = os.Hostname(); err != nil {
+		return
+	}
+
 	var base *check.Absolute
 	if cache.base, err = filepath.Abs(cache.base); err != nil {
 		return
 	} else if base, err = check.NewAbs(cache.base); err != nil {
 		return
 	}
+	var notify chan bool
 
 	if cache.idle {
 		cache.attr.Flags |= pkg.CSchedIdle
@@ -65,6 +80,8 @@ func (cache *cache) open() (err error) {
 	}
 	if cache.color {
 		cache.attr.Flags |= pkg.CColourOutput
+		notify = make(chan bool, 1<<12)
+		cache.attr.Notify = notify
 	}
 
 	done := make(chan struct{})
@@ -109,6 +126,29 @@ func (cache *cache) open() (err error) {
 		cache.c.SetExternal(r)
 	}
 
+	if cache.attr.Notify != nil {
+		cache.msg.Suspend()
+		_, _ = cache.msg.GetLogger().Writer().Write([]byte("\x1b[22;0t"))
+		cache.msg.Resume()
+
+		prefix := hostname + ": mbf "
+		go func() {
+			var n, nc uint64
+			for enter := range notify {
+				if enter {
+					n++
+					nc++
+				} else {
+					nc--
+				}
+
+				writeTitle(cache.msg, prefix+
+					"("+strconv.FormatUint(nc, 10)+
+					" of "+strconv.FormatUint(n, 10)+")")
+			}
+		}()
+	}
+
 	if cache.qemu != nil {
 		var pathname *check.Absolute
 		pathname, _, err = cache.c.Cure(cache.qemu)
@@ -129,6 +169,11 @@ func (cache *cache) open() (err error) {
 func (cache *cache) Close() {
 	if cache.c != nil {
 		cache.c.Close()
+		if cache.attr.Notify != nil {
+			cache.msg.Suspend()
+			_, _ = cache.msg.GetLogger().Writer().Write([]byte("\x1b[23;0t"))
+			cache.msg.Resume()
+		}
 	}
 }