pytrace/server/app/api/endpoints_graph.py

from fastapi import APIRouter, HTTPException
from pytrace.core.registry import NodeRegistry
from pytrace.core.executor import WorkflowExecutor
from pytrace.model.graph import WorkflowGraph, Node, Edge
from ..models.graph import GraphExecuteRequest

router = APIRouter()

@router.get("/plugins")
async def get_plugins():
    """
    Gets the list of all available (registered) nodes and their specifications.
    This is used by the frontend to populate the node palette.
    """
    specs = NodeRegistry.get_all_specs()
    
    # The old protocol expects a dictionary keyed by node type string.
    plugins = {
        spec.type: {
            "display_name": spec.name,
            "category": spec.category,
            "description": spec.description,
            "node_type": spec.node_type.value,
            "class_name": spec.type, # Using the unique type string as class_name
            "inputs": [p.dict() for p in spec.inputs],
            "outputs": [p.dict() for p in spec.outputs],
            "param_schema": [p.dict() for p in spec.params],
        }
        for spec in specs
    }
    
    return {
        "plugins": plugins,
        "total": len(plugins),
        "categories": NodeRegistry.get_categories()
    }

@router.post("/execute")
async def execute_graph(request: GraphExecuteRequest):
    """
    Executes a workflow graph.
    """
    try:
        # 1. Build the WorkflowGraph from the request
        graph = WorkflowGraph(name="Execution Graph")
        for node_data in request.nodes:
            graph.add_node(Node(
                id=node_data.id,
                type=node_data.type,
                name=node_data.name,
                params=node_data.params
            ))
        for edge_data in request.edges:
            graph.add_edge(Edge(
                source_id=edge_data.source_node,
                source_port=edge_data.source_port,
                target_id=edge_data.target_node,
                target_port=edge_data.target_port
            ))
            
        # 2. Instantiate the executor and run the graph
        executor = WorkflowExecutor()
        results = executor.execute(graph, initial_inputs=request.initial_inputs)
        
        # 3. Return the results
        return {
            "success": True,
            "results": results
        }
    except Exception as e:
        import traceback
        raise HTTPException(
            status_code=500,
            detail={
                "error": str(e),
                "type": type(e).__name__,
                "traceback": traceback.format_exc()
            }
        )