import sys
sys.path.append("../wrappers")
from wrappers import modelverse as mv
from commons import *


class EdgeAdd(object):
    def __init__(self):
        self._from_node = ""
        self._to_node = ""

    def execute(self, model, from_node, to_node, local):
        self._from_node = from_node
        self._to_node = to_node

        if local:
            mv.transformation_execute_MANUAL("graph_ops/add_edge", {"gm":model}, {"gm":model},
                                             callback=self._callback)
        else:
            from_type = get_node_type(model, self._from_node)
            to_type = get_node_type(model, self._to_node)
            for m in all_models():
                nodes_from = all_nodes_with_type(m, from_type)
                nodes_to = all_nodes_with_type(m, to_type)
                for nf in nodes_from:
                    for nt in nodes_to:
                        self.execute(m, nf, nt, local=True)

    def _callback(self, model):
        mv.instantiate(model, "gm/Edge", ("gm/"+self._from_node, "gm/"+self._to_node), ID="e")


class EdgeDel(object):
    def __init__(self):
        self._edge = ""

    def execute(self, model, edge, local, check_last=False):
        self._edge = edge
        from_node = mv.read_association_source(model, edge)[0]
        to_node = mv.read_association_destination(model, edge)[0]
        from_type = get_node_type(model, from_node)
        to_type = get_node_type(model, to_node)

        if local:
            mv.transformation_execute_MANUAL("graph_ops/del_edge", {"gm":model}, {"gm":model},
                                             callback=self._callback)
        if check_last:
            # check if this association was the last one in all example models
            # if yes, delete it from all instance models as well to preserve their validity
            remaining_instances = 0

            for m in all_example_models():
                nodes_from = all_nodes_with_type(m, from_type)
                nodes_to = all_nodes_with_type(m, to_type)
                for nf in nodes_from:
                    for nt in nodes_to:
                        edges = get_associations_between(m, nf, nt)
                        remaining_instances += len(edges)
            if remaining_instances == 0:
                for m in all_instance_models():
                    nodes_from = all_nodes_with_type(m, from_type)
                    nodes_to = all_nodes_with_type(m, to_type)
                    for nf in nodes_from:
                        for nt in nodes_to:
                            edges = get_associations_between(m, nf, nt)
                            for edge in edges:
                                self.execute(m, edge, local=True)

        else:
            for m in all_models():
                nodes_from = all_nodes_with_type(m, from_type)
                nodes_to = all_nodes_with_type(m, to_type)
                for nf in nodes_from:
                    for nt in nodes_to:
                        edges = get_associations_between(m, nf, nt)
                        for edge in edges:
                            self.execute(m, edge, local=True)

    def _callback(self, model):
        mv.delete_element(model, "gm/"+self._edge)