Notify with notify-send, preview outside kitty with xdg-open

kitty's OSC 99 notifications only worked inside kitty. Use notify-send
instead, passing the id of the previous notification with -r so each
one replaces the last rather than stacking. Outside kitty, where icat
cannot draw, open the candidate montage with xdg-open.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

2 files changed, 18 insertions, 9 deletions

diff --git a/README.md b/README.md
index 0de61a3..3e57d6d 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,8 @@ image stage. Pages land in the book-reader library as `NNN.png`.
 - Python 3, stdlib only
 - llama-server in router mode on `localhost:8181` serving `Gemma4-12B-qat-mtp`
 - `sd-cli` with Vulkan, models under `/data/LLM-models/SD`
-- ImageMagick 7 (`magick`), kitty (`kitty +kitten icat`), `$EDITOR`
+- ImageMagick 7 (`magick`), `$EDITOR`, `notify-send` (libnotify), and kitty for
+  inline previews (elsewhere candidates open with `xdg-open`)
 - `~/.config/book-reader.conf` with a `LIBRARY="..."` line
 
 ## Usage
diff --git a/fanfictioner b/fanfictioner
index 72c2e85..89a3fec 100755
--- a/fanfictioner
+++ b/fanfictioner
@@ -416,13 +416,18 @@ def log(msg):
             f.write(f"{time.strftime('%Y-%m-%d %H:%M:%S')} {msg}\n")
 
 
+NOTIFY_ID = None  # notify-send id of the last notification, replaced by the next one
+
+
 def notify(body):
-    """Desktop notification via kitty (OSC 99). One fixed id, so each replaces the last instead of
-    stacking; shown only while the terminal is unfocused."""
-    if sys.stdout.isatty():
-        body = re.sub(r"[\x00-\x1f\x7f]", " ", body)
-        print(f"\x1b]99;i=fanfictioner:d=0:o=unfocused;fanfictioner\x1b\\"
-              f"\x1b]99;i=fanfictioner:d=1:p=body;{body}\x1b\\", end="", flush=True)
+    """Desktop notification that replaces the previous one instead of stacking."""
+    global NOTIFY_ID
+    try:
+        out = subprocess.run(["notify-send", "-a", "fanfictioner", "-p", *(["-r", NOTIFY_ID] if NOTIFY_ID else []),
+                              "fanfictioner", body], capture_output=True, text=True, timeout=5).stdout.strip()
+    except (OSError, subprocess.TimeoutExpired):
+        return
+    NOTIFY_ID = out if out.isdigit() else None
 
 
 def editor(path):
@@ -470,8 +475,11 @@ def show(files, seed, d):
         print("montage failed, candidates:", *files, sep="\n")
         return
     print(m)
-    try:
-        subprocess.run(["kitty", "+kitten", "icat", str(fit(m))])
+    try:  # inline in kitty, else in the desktop's image viewer
+        if os.environ.get("KITTY_WINDOW_ID"):
+            subprocess.run(["kitty", "+kitten", "icat", str(fit(m))])
+        else:
+            subprocess.Popen(["xdg-open", str(m)], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
     except OSError as e:
         print(f"cannot show image: {e}")