fix: rank udt-accent power icons by name order and size

find_icon merged all candidate names into one set and ranked across
them, so a later alternate name could beat the first name present, and
size directories spelled 48x48 or scalable were not parsed. Try the
names in order instead: the first with a match wins, and within a name
prefer -symbolic, then scalable, then the largest size directory.
Update the docstring and selftest comment to match, extend the selftest
with size and name-order cases.

Add the missing GPL-2.0-only SPDX line.

1 files changed, 59 insertions, 19 deletions

diff --git a/bin/udt-accent b/bin/udt-accent
index 53839b1..a862ae9 100755
--- a/bin/udt-accent
+++ b/bin/udt-accent
@@ -1,4 +1,5 @@
 #!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0-only
 # udt-accent: pick a Catppuccin Macchiato accent matching a wallpaper.
 # Copyright (C) 2026 Danilo M. <danix@danix.xyz>
 # Licensed under the GNU General Public License v2 only.
@@ -338,31 +339,42 @@ def icon_theme():
 
 
 def find_icon(theme, names, dirs=None):
-    """Absolute path to the first of `names` found in `theme`, else "".
-
-    A theme may ship an icon flat or as a symbolic variant at several sizes.
-    Prefer the symbolic variant, then the largest size directory, so the panel
-    gets a tintable silhouette. `dirs` is injectable for the selftest.
+    """Absolute path to the first of `names` present in `theme`, else "".
+
+    The names are tried in order: the first that has any match wins. For that
+    name a theme may ship the icon flat or as a symbolic variant at several
+    sizes. Prefer the symbolic variant, then the largest size directory, where
+    `16x16`, `24x24`, `48x48`, a plain `16`/`48` and `scalable` are all parsed
+    and `scalable` counts as larger than any pixel size. `dirs` is injectable
+    for the selftest.
     """
     if not theme:
         return ""
     dirs = ICON_DIRS if dirs is None else dirs
-    wanted = set(names) | {f"{name}-symbolic" for name in names}
-    matches = []
-    for base in dirs:
-        root = base / theme
-        if not root.is_dir():
-            continue
-        matches = [p for p in root.rglob("*.svg") if p.stem in wanted]
-        if matches:
-            break
 
     def rank(path):
         symbolic = path.stem.endswith("-symbolic")
-        sizes = [int(part) for part in path.parts if part.isdigit()]
-        return (symbolic, max(sizes, default=0))
-
-    return str(max(matches, key=rank)) if matches else ""
+        scalable = False
+        size = 0
+        for part in path.parts:
+            if part == "scalable":
+                scalable = True
+                continue
+            match = re.fullmatch(r"(\d+)(?:x\d+)?", part)
+            if match:
+                size = max(size, int(match.group(1)))
+        return (symbolic, scalable, size)
+
+    for name in names:
+        stems = {name, f"{name}-symbolic"}
+        for base in dirs:
+            root = base / theme
+            if not root.is_dir():
+                continue
+            matches = [p for p in root.rglob("*.svg") if p.stem in stems]
+            if matches:
+                return str(max(matches, key=rank))
+    return ""
 
 
 def power_icons():
@@ -516,7 +528,7 @@ def selftest():
 
     # Power icons: an unknown or empty theme resolves to empty, so the greeter
     # falls back to its bundled SVGs; a real theme prefers the symbolic variant
-    # and a name list is honoured in order.
+    # at the largest size, and a name list is tried in order.
     assert find_icon("", ["system-shutdown"]) == ""
     assert find_icon("no-such-theme-udt", ["system-shutdown"]) == ""
     with tempfile.TemporaryDirectory() as tmpdir:
@@ -534,6 +546,34 @@ def selftest():
         assert find_icon("probe", ["system-hibernate", "system-suspend-hibernate"],
                          dirs=[root]) == ""
 
+    # Among the sizes one name ships at, the largest directory wins. Both the
+    # WxH and plain-number spellings parse, and scalable is treated as largest.
+    with tempfile.TemporaryDirectory() as tmpdir:
+        root = Path(tmpdir) / "icons"
+        actions = root / "probe" / "actions"
+        for sub in ("16x16", "48x48"):
+            (actions / sub).mkdir(parents=True)
+            (actions / sub / "system-shutdown.svg").write_text("<svg/>")
+        got = find_icon("probe", ["system-shutdown"], dirs=[root])
+        assert got.endswith("actions/48x48/system-shutdown.svg"), got
+        (actions / "scalable").mkdir()
+        (actions / "scalable" / "system-shutdown.svg").write_text("<svg/>")
+        got = find_icon("probe", ["system-shutdown"], dirs=[root])
+        assert got.endswith("actions/scalable/system-shutdown.svg"), got
+
+    # The first name in the list that exists wins, even when a later name also
+    # has a match.
+    with tempfile.TemporaryDirectory() as tmpdir:
+        root = Path(tmpdir) / "icons"
+        base = root / "probe" / "actions" / "48"
+        base.mkdir(parents=True)
+        (base / "system-shutdown.svg").write_text("<svg/>")
+        (base / "system-reboot.svg").write_text("<svg/>")
+        got = find_icon("probe", ["system-shutdown", "system-reboot"], dirs=[root])
+        assert got.endswith("actions/48/system-shutdown.svg"), got
+        got = find_icon("probe", ["system-reboot", "system-shutdown"], dirs=[root])
+        assert got.endswith("actions/48/system-reboot.svg"), got
+
     with tempfile.TemporaryDirectory() as tmpdir:
         probe_image = Path(tmpdir) / "wall.png"
         probe_image.write_bytes(b"")