feat: add configuration module with YAML loading and defaults

Made-with: Cursor

src/cursor_flasher/config.py

@@ -0,0 +1,72 @@
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Any
+
+import yaml
+
+
+@dataclass
+class Config:
+    pulse_color: str = "#FF9500"
+    pulse_width: int = 4
+    pulse_speed: float = 1.5
+    pulse_opacity_min: float = 0.3
+    pulse_opacity_max: float = 1.0
+
+    sound_enabled: bool = True
+    sound_name: str = "Glass"
+    sound_volume: float = 0.5
+
+    poll_interval: float = 0.5
+    cooldown: float = 3.0
+
+    auto_dismiss: int = 300
+
+
+FIELD_MAP: dict[str, dict[str, str]] = {
+    "pulse": {
+        "color": "pulse_color",
+        "width": "pulse_width",
+        "speed": "pulse_speed",
+        "opacity_min": "pulse_opacity_min",
+        "opacity_max": "pulse_opacity_max",
+    },
+    "sound": {
+        "enabled": "sound_enabled",
+        "name": "sound_name",
+        "volume": "sound_volume",
+    },
+    "detection": {
+        "poll_interval": "poll_interval",
+        "cooldown": "cooldown",
+    },
+    "timeout": {
+        "auto_dismiss": "auto_dismiss",
+    },
+}
+
+
+DEFAULT_CONFIG_PATH = Path.home() / ".cursor-flasher" / "config.yaml"
+
+
+def load_config(path: Path = DEFAULT_CONFIG_PATH) -> Config:
+    """Load config from YAML, falling back to defaults for missing values."""
+    if not path.exists():
+        return Config()
+
+    with open(path) as f:
+        raw = yaml.safe_load(f)
+
+    if not raw or not isinstance(raw, dict):
+        return Config()
+
+    overrides: dict[str, Any] = {}
+    for section, mapping in FIELD_MAP.items():
+        section_data = raw.get(section, {})
+        if not isinstance(section_data, dict):
+            continue
+        for yaml_key, field_name in mapping.items():
+            if yaml_key in section_data:
+                overrides[field_name] = section_data[yaml_key]
+
+    return Config(**overrides)