ncmpcpp: Add on-song-change script

Now the cover image and artist + title shows on song change.

terminal/ncmpcpp/default.nix

@@ -10,6 +10,8 @@
       '';
     };
 
+    xdg.configFile."ncmpcpp/on-song-change.sh".source = ./on-song-change.sh;
+
     programs.ncmpcpp = {
       enable = true;
 
@@ -138,7 +140,7 @@
         autocenter_mode = "yes";
         allow_for_physical_item_deletion = "no";
         mouse_support = "no";
-        execute_on_song_change = "~/.config/mpd/mpdnotify";
+        execute_on_song_change = "~/.config/ncmpcpp/on-song-change.sh";
         mpd_crossfade_time = 3;
       };
     };

terminal/ncmpcpp/on-song-change.sh

@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+
+music_dir="$HOME/Music"
+fallback_image="$HOME/a.jpg"
+
+main () {
+    find_cover 2>/dev/null
+    send       2>/dev/null
+}
+
+find_cover () {
+    ext="$(mpc --format %file% current | sed 's/^.*\.//')"
+    if [ "$ext" != "flac" ]; then
+        ffmpeg -y -i "$(mpc --format "$music_dir"/%file% | head -n 1)" \
+        /tmp/cover.jpg && cover_path="/tmp/cover.jpg" && return
+    else
+        # ffmpeg doesn't work for flacs
+        metaflac --export-picture-to=/tmp/cover.jpg \
+        "$(mpc --format "$music_dir"/%file% current)" && cover_path="/tmp/cover.jpg" && return
+    fi
+    #without embedded images this is used as a fallback
+    file="$music_dir/$(mpc --format %file% current)"
+    album="${file%/*}"
+    #search for cover image
+    cover_path=$(find "$album"  -maxdepth 1 | grep -m 1 ".*\.\(jpg\|png\|gif\|bmp\)")
+}
+
+send () {
+    notify-send -i "${cover_path:-$fallback_image}" "Now Playing" "$(mpc current)"
+}
+
+main