import networkx as nx


class Graph(object):
    NODE_TYPE_KEY = "nodeType"
    not_allowed_node = type('NotAllowedNode', (Exception, ), {})

    def __init__(self, user=None):
        self.user = user
        self.nodes = {}
        self.nx_graph = nx.DiGraph()
        self.params = {}

    @classmethod
    def parse_graph(cls, json_graph, nodes_cls, common_params={}):

        graph = cls(user=json_graph['owner'])

        for node in json_graph['nodes']:
            node = nodes_cls.parse(node, graph)
            graph.add_node(node)

        for link in json_graph['links']:
            source_node = graph.get_node(link['source'])
            target_node = graph.get_node(link["target"])
            graph.add_edge(source_node, target_node)

        for key in common_params:
            graph.set_common_param(key, common_params[key])
        return graph

    def run(self, **kwargs):
        # Lineal execution. Study graph theory for more complexity. ##############
        for node in self.nx_graph:
            self.nodes[node].super_run()
        ##########################################################################

    def add_node(self, node):
        self.nx_graph.add_node(node.id)
        self.nodes[node.id] = node

    def change_node(self, node_id, value):
        self.nodes[node_id] = value

    def add_edge(self, source_node, target_node):
        self.nx_graph.add_edge(source_node.id, target_node.id)

    def get_node(self, node_id):
        return self.nodes[node_id]

    def set_param(self, key, value):
        self.params[key] = value

    def set_common_param(self, key, value):
        self.set_param(key, value)
        for node in self.nodes:
            self.nodes[node].set_param(key, value)

    def get_leaves(self):
        leaves = [x for x in self.nx_graph.nodes() if self.nx_graph.out_degree(x) == 0 and self.nx_graph.in_degree(x) == 1]
        if len(self.nx_graph.nodes()) == 1:
            leaves = self.nx_graph.nodes()
        return leaves

    def get_roots(self):
        roots = [x for x in self.nx_graph.nodes() if self.nx_graph.in_degree(x) == 0]
        return roots