Implement AI Host functionality with model caching and job management

- Added ai_host.py to handle AI tasks with FastAPI integration.
- Introduced HostState and ModelCache classes for managing client connections and model loading.
- Implemented job submission and cancellation endpoints in the AI host.
- Enhanced tests for AI host functionality, including client tracking and job cancellation.
- Updated existing tests to accommodate changes in the operator and command structure.
- Refactored runtime commands to use request-based architecture instead of command-line arguments.
- Improved model loading logic to handle CUDA memory management and reuse models efficiently.

src/snapform/image_depth.py

@@ -26,8 +26,13 @@ IMAGE_NAME_SUFFIXES = (
 
 def image_depth_model_items(owner, context):
     from .models import model_enum_items
+    from .runtime import model_ready
 
-    return model_enum_items(owner, context)
+    return [
+        item
+        for item in model_enum_items(owner, context)
+        if model_ready(item[0])
+    ]
 
 
 _last_depth_plane_model = "BASE"
@@ -921,8 +926,13 @@ class RemoveImageBackground(bpy.types.Operator):
     @classmethod
     def poll(cls, context):
         from .operators import active_job
+        from .runtime import host_busy
 
-        return is_image_empty(context.object) and active_job() is None
+        return (
+            is_image_empty(context.object)
+            and active_job() is None
+            and not host_busy()
+        )
 
     def execute(self, context):
         from .operators import IMAGE_BACKGROUND_JOB
@@ -1001,7 +1011,7 @@ class ConvertImageToDepthPlane(bpy.types.Operator):
     snapform_process_res_factor: bpy.props.FloatProperty(
         name="Resolution Scale",
         description="Scale applied to the source image long-edge resolution",
-        default=0.5,
+        default=1.0,
         min=0.1,
         max=1.0,
         step=10,
@@ -1019,18 +1029,30 @@ class ConvertImageToDepthPlane(bpy.types.Operator):
         min=0,
         max=10,
     )
-
     @classmethod
     def poll(cls, context):
         from .operators import active_job
+        from .runtime import host_busy
 
-        return is_image_empty(context.object) and active_job() is None
+        return (
+            is_image_empty(context.object)
+            and active_job() is None
+            and not host_busy()
+        )
 
     def invoke(self, context, _event):
         global _last_depth_plane_model
 
         if not self.properties.is_property_set("snapform_model"):
-            self.snapform_model = _last_depth_plane_model
+            available_keys = [
+                item[0] for item in image_depth_model_items(self, context)
+            ]
+            if available_keys:
+                self.snapform_model = (
+                    _last_depth_plane_model
+                    if _last_depth_plane_model in available_keys
+                    else available_keys[0]
+                )
         return context.window_manager.invoke_props_dialog(self, width=340)
 
     def draw(self, context):
@@ -1038,21 +1060,32 @@ class ConvertImageToDepthPlane(bpy.types.Operator):
         layout.prop(self, "snapform_depth_source")
         if self.snapform_depth_source == "ESTIMATE":
             estimate_box = layout.box()
-            estimate_box.prop(self, "snapform_model")
-            estimate_box.prop(self, "snapform_use_ray_pose")
-            process_res = scaled_process_resolution(
-                context.object.data,
-                self.snapform_process_res_factor,
-            )
-            estimate_box.prop(
-                self,
-                "snapform_process_res_factor",
-                text=f"Resolution Scale ({process_res} px)",
-            )
-        layout.prop(self, "snapform_remove_background")
-        layout.prop(self, "snapform_displacement_via")
-        layout.prop(self, "snapform_unshaded")
-        layout.prop(self, "snapform_subdivision_level")
+            available_models = image_depth_model_items(self, context)
+            if not available_models:
+                estimate_box.label(text="No DA3 models installed", icon="ERROR")
+                estimate_box.label(text="Download one in Host > Models")
+            else:
+                estimate_box.prop(self, "snapform_model")
+                estimate_box.prop(self, "snapform_use_ray_pose")
+                process_res = scaled_process_resolution(
+                    context.object.data,
+                    self.snapform_process_res_factor,
+                )
+                estimate_box.prop(
+                    self,
+                    "snapform_process_res_factor",
+                    text=f"Resolution Scale ({process_res} px)",
+                )
+        settings_header, settings_body = layout.panel(
+            "snapform_depth_plane_options",
+            default_closed=True,
+        )
+        settings_header.label(text="Options")
+        if settings_body is not None:
+            settings_body.prop(self, "snapform_displacement_via")
+            settings_body.prop(self, "snapform_subdivision_level")
+            settings_body.prop(self, "snapform_remove_background")
+            settings_body.prop(self, "snapform_unshaded")
         layout.prop(self, "snapform_delete_original")
 
     def execute(self, context):