import re
from wrappers import modelverse as mv


class Attribute(object):
    """
    Helper class for attribute representation as key value pair
    """
    def __init__(self, key, val):
        self.key = key
        self.val = val

    def __eq__(self, other):
        if other.key == self.key and other.val == self.val:
            return True
        return False

    def __repr__(self):
        return "{}={}".format(self.key, self.val)


def all_models():
    """ Returns a list of paths of all example- and instance models """
    return all_instance_models() + all_example_models()

def all_instance_models():
    """ Returns a list of paths of all instance models """
    try:
        instance_models = mv.model_list("models/instance")
    except mv.UnknownLocation:
        # no instance models
        return []
    instance_models_full = ["models/instance/"+m for m in instance_models]
    return instance_models_full

def all_example_models():
    """ Returns a list of paths of all example models """
    try:
        example_models = mv.model_list("models/example")
    except mv.UnknownLocation:
        # no example models
        return []
    example_models_full = ["models/example/"+exm for exm in example_models]
    return example_models_full

def all_consyn_models():
    """ Returns a list of paths of all concrete syntax models """
    try:
        consyn_models = mv.model_list("models/consyn")
    except mv.UnknownLocation:
        return []
    consyn_models_full = ["models/consyn/"+csm for csm in consyn_models]
    return consyn_models_full

def all_nodes_with_type(model, typ):
    """ Returns a list of nodes in model model with type typ """
    all_nodes = mv.all_instances(model, "Node")
    ret = [node for node in all_nodes if mv.read_attrs(model, node)["typeID"] == typ]
    return ret

def get_node_type(model, node_id):
    """ Returns the type attribute of node in model as string"""
    return mv.read_attrs(model, node_id)["typeID"]

def get_available_types():
    """ Returns a list of all types of nodes in all example models """
    types = []
    for m in all_example_models():
        nodes = mv.all_instances(m, "Node")
        for node in nodes:
            typ = get_node_type(m, node)
            types.append(typ)
    return list(set(types))

def count_occurences(node_type, model):
    """ Returns the number of occurences of a node with type node_type in a model """
    ctr = 0
    all_nodes = mv.all_instances(model, "Node")
    for node in all_nodes:
        typ = get_node_type(model, node)
        if typ == node_type:
            ctr += 1
    return ctr

def get_associations_between(model, node1, node2):
    """ Returns a list of association IDs between the nodes node1 and node2 """
    edges_n1 = mv.read_outgoing(model, node1, "Edge")
    edges_n1.update(mv.read_incoming(model, node1, "Edge"))
    edges_n2 = mv.read_outgoing(model, node2, "Edge")
    edges_n2.update(mv.read_incoming(model, node2, "Edge"))
    return list(edges_n1.intersection(edges_n2))

def get_all_attributes_of_type(model, node_type):
    # type: (str, str) -> list(Attribute)
    """ Returns a list of attributes of a node with type node_type in a model """
    ret = []
    node_attribute_links = mv.all_instances(model, "NodeAttribute")
    for link in node_attribute_links:
        src_node = mv.read_association_source(model, link)[0]
        src_typ = mv.read_attrs(model, src_node)["typeID"]
        if src_typ != node_type:
            continue
        attr_node_name = mv.read_association_destination(model, link)[0]
        attr_dict = mv.read_attrs(model, attr_node_name)
        attr = Attribute(attr_dict["key"], attr_dict["value"])
        ret.append(attr)
    return ret

def get_attributes_of_node(model, node_id):
    # type: (str, str) -> list(Attribute)
    """ Returns a list of attributes of a specific node with id node_id """
    ret = []
    outgoings = mv.read_outgoing(model, node_id, "NodeAttribute")
    if not outgoings:
        return []
    for link in outgoings:
        dest = mv.read_association_destination(model, link)[0]
        attr_dict = mv.read_attrs(model, dest)
        attr = Attribute(attr_dict["key"], attr_dict["value"])
        ret.append(attr)
    return ret

def model_contains_type(model, node_type):
    """
    True if some node in model is typed by node_type, False otherwise.
    """
    all_types = all_nodes_with_type(model, node_type)
    if not all_types:
        return False
    return True

def has_edge_to_type(model, node_id, node_type):
    """
    True if the node identified by node_id is connected to a node of type type_id, False otherwise.
    """
    outgoings = mv.read_outgoing(model, node_id, "Edge")
    dest_ids = [mv.read_association_destination(model, edge)[0] for edge in outgoings]
    dest_types = [get_node_type(model, _node_id) for _node_id in dest_ids]

    # also need to check incomings of node_id
    incomings = mv.read_incoming(model, node_id, "Edge")
    src_ids = [mv.read_association_source(model, edge)[0] for edge in incomings]
    src_types = [get_node_type(model, _node_id) for _node_id in src_ids]

    return node_type in dest_types + src_types

def is_edge_supported(from_type, to_type):
    """
    True if an association between from_type and to_type exists in any example model
    False otherwise
    """
    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:
                assocs = get_associations_between(m, nf, nt)
                if assocs:
                    # somewhere in an example model, there is such an association
                    return True
    return False

def new_instance_model():
    """
    Adds a new, empty instance model to the Modelverse.
    Returns the name of the new model
    """
    existing_models = all_instance_models()
    idx = 1
    nums = []
    for model in existing_models:
        m = model.split("/")[-1]
        try:
            idx = int(re.search(r'\d+', m).group())
            nums.append(idx)
        except AttributeError:
            pass
    if nums:
        idx = sorted(nums)[-1] + 1
    im = "models/instance/im{}".format(idx)
    print("Adding new instance model {}".format(im))
    mv.model_add(im, "formalisms/graphMM")
    mid = mv.instantiate(im, "Model")
    mv.attr_assign(im, mid, "is_example", False)
    mv.attr_assign(im, mid, "descr", "")
    return im

def new_example_model():
    """
    Adds a new, empty example model to the Modelverse.
    Returns the name of the new model
    """
    existing_models = all_example_models()
    idx = 1
    nums = []
    for model in existing_models:
        m = model.split("/")[-1]
        try:
            idx = int(re.search(r'\d+', m).group())
            nums.append(idx)
        except AttributeError:
            pass
    if nums:
        idx = sorted(nums)[-1] + 1
    exm = "models/example/ex{}".format(idx)
    print("Adding new example model {}".format(exm))
    mv.model_add(exm, "formalisms/graphMM")
    mid = mv.instantiate(exm, "Model")
    mv.attr_assign(exm, mid, "is_example", True)
    mv.attr_assign(exm, mid, "descr", "")
    return exm