from src.helper.debug_printer import debug_print
from src.helper.check_eulerian import check_directed_eulerian, check_non_directed_eulerian
import networkx as nx
import osmnx as ox

def find_eulerian(G, debug_mode, path=False, start=None, directed=False):
    """
    Trouve et renvoit un chemin ou un cycle eulérien du graph G.
    Il est possible de spécifier le point de départ du cycle/chemin.
    Renvoie le chemin/cycle crée ou None si la demande n'est pas possible
    Parameters:
        G: Graph duquel on souhaite obtenir le chemin/cycle eulérien
        debug_mode: Indique si le debug est actif
        path: [OPTIONNEL | DEFAUT = False] True si on souhaite avoir
            un chemin eulérien. Faux pour avoir un cycle
        start: [OPTIONNEL | DEFAUT = None] Noeud NetworkX de départ
            du chemin/cycle. Un check est effectué si on souhaite un chemin
    """
    if (G == None):
        debug_print("[BASIC_EULER] Cannot procede: The graph is null")

    spots = None

    if (directed):
        spots = check_directed_eulerian(G)
    else:
        spots = check_non_directed_eulerian(G)

    if (spots == None):
        debug_print("[BASIC_EULER] This is not an Eulerian graph: Cannot create path or cycle", debug_mode)
        return None

    if (path):
        if (start != spots[0] and start != spots[1]):
            # We just want to warn the user that the start position is invalid for this graph
            debug_print("[BASIC_EULER] The starting position inputted is not a suitable start for an eulerian path", debug_mode)
            start = spots[0]
        
        # We return a list and not an iterator
        return [u for u, _ in nx.eulerian_path(G, source=start)]
    else:
        # This condition is a bit overkill but you never know
        if (spots[0] != None or spots[1] != None):
            debug_print("[BASIC_EULER] Cannot create cycle on this eulerian graph", debug_mode)
            return None

        # We return a list and not an iterator
        return [u for u, _ in nx.eulerian_circuit(G, source=start)]