feat: UDT palette theming

1 files changed, 58 insertions, 0 deletions

diff --git a/deckit/theme.py b/deckit/theme.py
new file mode 100644
index 0000000..7aa347b
--- /dev/null
+++ b/deckit/theme.py
@@ -0,0 +1,58 @@
+"""Read UDT's palette output and render it as CSS custom properties.
+
+UDT writes the structural palette to ~/.config/rofi/udt/palette.rasi and the
+wallpaper accent to ~/.cache/udt/udt-accent.rasi. deck-it reads both rather
+than restating the colours, so a scheme or wallpaper change reaches the tablet.
+"""
+
+import re
+from pathlib import Path
+
+PALETTE_LINE = re.compile(r"^\s*([a-z0-9]+)\s*:\s*(#[0-9a-fA-F]{6,8});", re.M)
+ACCENT = re.compile(r"accent:\s*(#[0-9a-fA-F]{6,8})")
+
+PALETTE_PATH = Path.home() / ".config" / "rofi" / "udt" / "palette.rasi"
+ACCENT_PATH = Path.home() / ".cache" / "udt" / "udt-accent.rasi"
+
+# Catppuccin Macchiato, used before UDT has ever generated its files.
+FALLBACK = {
+    "base": "#24273a", "mantle": "#1e2030", "crust": "#181926",
+    "surface0": "#363a4f", "surface1": "#494d64", "surface2": "#5b6078",
+    "text": "#cad3f5", "subtext0": "#a5adcb", "subtext1": "#b8c0e0",
+    "overlay0": "#6e738d", "red": "#ed8796", "green": "#a6da95",
+    "yellow": "#eed49f", "teal": "#8bd5ca", "blue": "#8aadf4",
+    "lavender": "#b7bdf8", "peach": "#f5a97f", "mauve": "#c6a0f6",
+    "accent": "#b7bdf8",
+}
+
+
+def parse_palette(text: str) -> dict[str, str]:
+    return dict(PALETTE_LINE.findall(text))
+
+
+def parse_accent(text: str) -> str | None:
+    m = ACCENT.search(text)
+    return m[1] if m else None
+
+
+def css(colors: dict, accent: str | None) -> str:
+    lines = [":root {"]
+    lines += [f"  --udt-{name}: {value};" for name, value in colors.items()]
+    lines.append(f"  --udt-accent: {accent or FALLBACK['accent']};")
+    lines.append("}")
+    return "\n".join(lines) + "\n"
+
+
+def load() -> str:
+    """Render the live UDT palette as CSS, falling back if it is not installed."""
+    try:
+        colors = parse_palette(PALETTE_PATH.read_text())
+    except OSError:
+        colors = {}
+    if not colors:
+        colors = dict(FALLBACK)
+    try:
+        accent = parse_accent(ACCENT_PATH.read_text())
+    except OSError:
+        accent = None
+    return css(colors, accent)