import pandas as pd
import networkx as nx

def analyze_trace(source_node):
    df = pd.read_csv("data/network_topology.csv")
    
    # Build directed graph from the CSV
    G = nx.from_pandas_edgelist(df, source='Source', target='Target', create_using=nx.DiGraph())

    # Get all nodes
    nodes = list(G.nodes())

    # Default: no path found
    path = ["Unknown"]

    # Attempt to find path to CoreNetwork
    target_node = "CoreNetwork"
    if source_node in G and target_node in G:
        try:
            path = nx.shortest_path(G, source=source_node, target=target_node)
        except nx.NetworkXNoPath:
            path = ["No path to CoreNetwork"]

    return path, nodes