API: Add preset listing for sampler overrides

Querying the overrides list endpoint now returns the selected preset
and a list of presets to use.

Signed-off-by: kingbri <bdashore3@proton.me>

common/sampling.py

@@ -313,17 +313,20 @@ class BaseSamplerRequest(BaseModel):
         return {**gen_params, **kwargs}
 
 
+class SamplerOverridesContainer(BaseModel):
+    selected_preset: Optional[str] = None
+    overrides: dict = {}
+
+
 # Global for default overrides
-overrides = {}
+overrides_container = SamplerOverridesContainer()
 
 
 def overrides_from_dict(new_overrides: dict):
     """Wrapper function to update sampler overrides"""
 
-    global overrides
-
     if isinstance(new_overrides, dict):
-        overrides = prune_dict(new_overrides)
+        overrides_container.overrides = prune_dict(new_overrides)
     else:
         raise TypeError("New sampler overrides must be a dict!")
 
@@ -333,6 +336,7 @@ def overrides_from_file(preset_name: str):
 
     preset_path = pathlib.Path(f"sampler_overrides/{preset_name}.yml")
     if preset_path.exists():
+        overrides_container.selected_preset = preset_path.stem
         with open(preset_path, "r", encoding="utf8") as raw_preset:
             preset = yaml.safe_load(raw_preset)
             overrides_from_dict(preset)
@@ -347,18 +351,27 @@ def overrides_from_file(preset_name: str):
         raise FileNotFoundError(error_message)
 
 
+def get_all_presets():
+    """Fetches all sampler override presets from the overrides directory"""
+
+    override_directory = pathlib.Path("sampler_overrides")
+    preset_files = map(lambda file: file.stem, override_directory.glob("*.yml"))
+
+    return preset_files
+
+
 # TODO: Maybe move these into the class
 # Classmethods aren't recognized in pydantic default_factories
 def get_default_sampler_value(key, fallback=None):
     """Gets an overridden default sampler value"""
 
-    return unwrap(overrides.get(key, {}).get("override"), fallback)
+    return unwrap(overrides_container.overrides.get(key, {}).get("override"), fallback)
 
 
 def apply_forced_sampler_overrides(params: BaseSamplerRequest):
     """Forcefully applies overrides if specified by the user"""
 
-    for var, value in overrides.items():
+    for var, value in overrides_container.overrides.items():
         override = value.get("override")
         original_value = getattr(params, var, None)