Sequential Workflows

# Complete sequential workflow runner
class SequentialWorkflowRunner:
    def __init__(self, nodes: dict, edge_map: dict):
        """
        nodes: dict of node_id -> node function
        edge_map: dict of node_id -> {condition: next_node_id}
        """
        self.nodes = nodes
        self.edge_map = edge_map

    def run(self, workflow_name: str, initial_input: dict) -> dict:
        state = {
            "workflow": workflow_name,
            "input": initial_input,
            "data": {},
            "status": "running",
            "step": 0,
            "path": ["START"]
        }

        current_node = self.edge_map["START"]["*"]

        while current_node not in ("END", "ERROR") and state["step"] < 20:
            if current_node not in self.nodes:
                state["status"] = "failed"
                state["error"] = f"Node '{current_node}' not defined"
                break

            print(f"  [{state['step']+1}] Running node: {current_node}")
            try:
                # Execute the node — returns a condition string
                condition = self.nodes[current_node](state)
            except Exception as e:
                state["status"] = "failed"
                state["error"] = f"Node '{current_node}' raised: {e}"
                break

            state["path"].append(current_node)
            state["step"] += 1

            # Resolve next node
            transitions = self.edge_map.get(current_node, {"*": "END"})
            current_node = transitions.get(condition, transitions.get("*", "END"))

        state["status"] = "complete" if state["status"] == "running" else state["status"]
        state["final_node"] = state["path"][-1]
        return state

# Define simple nodes
def get_data(state):
    state["data"]["value"] = 42
    return "success"

def process_data(state):
    state["data"]["result"] = state["data"]["value"] * 2
    return "success"

def deliver_result(state):
    print(f"  Result: {state['data']['result']}")
    return "done"

nodes = {"get_data": get_data, "process_data": process_data, "deliver": deliver_result}
edges = {"START": {"*": "get_data"}, "get_data": {"success": "process_data"},
         "process_data": {"success": "deliver"}, "deliver": {"done": "END"}}

runner = SequentialWorkflowRunner(nodes, edges)
result = runner.run("data_pipeline", {"input_id": "X1"})
print(f"Status: {result['status']}, Path: {result['path']}")