In the middle of fixing router. A ton of circular dependencies. Moving over to a new design.

src/crewai/routers/pipeline_router.py

@@ -0,0 +1,76 @@
+from __future__ import annotations
+
+from typing import Any, Callable, Dict, List, Tuple, Union
+
+from pydantic import BaseModel
+
+from crewai.crew import Crew
+
+
+class PipelineRouter(BaseModel):
+    conditions: List[
+        Tuple[Callable[[Dict[str, Any]], bool], Union[Crew, "Pipeline"]]
+    ] = []
+    default: Union[Crew, "Pipeline", None] = None
+
+    def add_condition(
+        self,
+        condition: Callable[[Dict[str, Any]], bool],
+        next_stage: Union[Crew, "Pipeline"],
+    ):
+        """
+        Add a condition and its corresponding next stage to the router.
+
+        Args:
+            condition: A function that takes the input dictionary and returns a boolean.
+            next_stage: The Crew or Pipeline to execute if the condition is met.
+        """
+        self.conditions.append((condition, next_stage))
+
+    def set_default(self, default_stage: Union[Crew, "Pipeline"]):
+        """Set the default stage to be executed if no conditions are met."""
+        self.default = default_stage
+
+    def route(self, input_dict: Dict[str, Any]) -> Union[Crew, "Pipeline"]:
+        """
+        Evaluate the input against the conditions and return the appropriate next stage.
+
+        Args:
+            input_dict: The input dictionary to be evaluated.
+
+        Returns:
+            The next Crew or Pipeline to be executed.
+
+        Raises:
+            ValueError: If no conditions are met and no default stage was set.
+        """
+        for condition, next_stage in self.conditions:
+            if condition(input_dict):
+                self._update_trace(input_dict, next_stage)
+                return next_stage
+
+        if self.default is not None:
+            self._update_trace(input_dict, self.default)
+            return self.default
+
+        raise ValueError("No conditions were met and no default stage was set.")
+
+    def _update_trace(
+        self, input_dict: Dict[str, Any], next_stage: Union[Crew, "Pipeline"]
+    ):
+        """Update the trace to show that the input went through the router."""
+        if "trace" not in input_dict:
+            input_dict["trace"] = []
+        input_dict["trace"].append(
+            {
+                "router": self.__class__.__name__,
+                "next_stage": next_stage.__class__.__name__,
+            }
+        )
+
+
+# TODO: See if this is necessary
+from crewai.pipeline.pipeline import Pipeline
+
+# This line should be at the end of the file
+PipelineRouter.model_rebuild()