import operator
import ifcopenshell.util.element

from xml.dom.minidom import parse


class exception(Exception):
    pass


def error(msg):
    raise exception(msg)


class facet_evaluation:
    """
    The evaluation of a facet with data from IFC. Converts to bool and has a human readable string format.
    """

    def __init__(self, success, str):
        self.success = success
        self.str = str

    def __bool__(self):
        return self.success

    def __str__(self):
        return self.str


class meta_facet(type):
    """
    A metaclass for automatically registering facets in a map to be instantiated based on XML tagnames.
    """

    facets = {}

    def __new__(cls, clsname, bases, attrs):
        newclass = super(meta_facet, cls).__new__(cls, clsname, bases, attrs)
        meta_facet.facets[clsname] = newclass
        return newclass


class facet(metaclass=meta_facet):
    """
    The base class for IDS facets. IDS facets are functors constructed from
    XML nodes that return True or False. A getattr method is provided for
    conveniently extracting XML child node text content.
    """

    def __init__(self, node):
        self.node = node

    def __getattr__(self, k):
        try:
            v = self.node.getElementsByTagName(k)[0]
        except IndexError:
            v = None
        if v:
            elems = [n for n in v.childNodes if n.nodeType == n.ELEMENT_NODE]
            if elems:
                return restriction(elems[0])
            else:
                return v.firstChild.nodeValue.strip()
        else:
            return None

    def __iter__(self):
        for k in self.parameters:
            yield k, getattr(self, k)

    def __str__(self):
        di = dict(list(self))
        for k, v in di.items():
            if isinstance(v, str) and not len(v):
                di[k] = "not specified"
        return self.message % di


class entity(facet):
    """
    The IDS entity facet currently *with* inheritance
    """

    parameters = ["name", "predefinedtype"]
    
    def __call__(self, inst, logger):
        # @nb with inheritance
        if self.predefinedtype and hasattr(inst, "PredefinedType"):
            # logger.debug("Testing if entity predefinedtype '%s' == '%s'", inst.PredefinedType, self.predefinedtype)
            self.message = "an entity name '%(name)s' of predefined type '%(predefinedtype)s'"
            return facet_evaluation(inst.is_a(self.name) and inst.PredefinedType == self.predefinedtype, self.message % {"name": inst.is_a(), "predefinedtype": inst.PredefinedType})
        else:
            self.message = "an entity name '%(name)s'"
            return facet_evaluation(inst.is_a(self.name), self.message % {"name": inst.is_a()})
        

class classification(facet):
    """
    The IDS classification facet by traversing the HasAssociations inverse attribute
    """

    parameters = ["system", "value"]
    message = "a classification reference '%(value)s' from '%(system)s'"

    def __call__(self, inst, logger):
        refs = []
        for association in inst.HasAssociations:
            if association.is_a("IfcRelAssociatesClassification"):
                cref = association.RelatingClassification
                refs.append((cref.ReferencedSource.Name, cref.ItemReference))

        return facet_evaluation(
            (self.system, self.value) in refs,
            # @todo
            "[classification_eval_todo]",
        )


class property(facet):
    """
    The IDS property facet implenented using `ifcopenshell.util.element`
    """

    parameters = ["name", "propertyset", "value"]
    
    # import pdb;pdb.set_trace()
    message = "a property '%(name)s' in '%(propertyset)s' with value '%(value)s'"

    def __call__(self, inst, logger):
        props = ifcopenshell.util.element.get_psets(inst)
        pset = props.get(self.propertyset)
        val = pset.get(self.name) if pset else None
        logger.debug("Testing if property %s == %s", val, self.value)

        di = {
            "name": self.name,
            "propertyset": self.propertyset,
            "value": val,
        }

        if val is not None:
            msg = self.message % di
        else:
            if pset:
                msg = "a set '%(propertyset)s', but no property '%(name)s'" % di
            else:
                msg = "no set '%(propertyset)s'" % di

        return facet_evaluation(val == self.value, msg)


class material(facet):
    """
    The IDS material facet 
    """
    parameters = ["name", "value"]
    message = "a material '%(name)s with value '%(value)s'"

    def __call__(self, inst, logger):
        material_relations = [rel for rel in inst.HasAssociations if rel.is_a("IfcRelAssociatesMaterial")]
        names = []
        for rel in material_relations:
            # @todo not all subtypes of IfcMaterial handled
            if rel.RelatingMaterial.is_a() == "IfcMaterialLayerSetUsage":
                layers = rel.RelatingMaterial.ForLayerSet.MaterialLayers
                names = [layer.Material.Name for layer in layers]
            elif rel.RelatingMaterial.is_a() == "IfcMaterial":
                names.append(rel.RelatingMaterial.Name)
        
        return facet_evaluation(
            0,
            # @todo
            "[material_eval_todo]",
        )


class boolean_logic:
    """
    Boolean conjunction over a collection of functions
    """

    def __init__(self, terms):
        self.terms = terms

    def __call__(self, *args):
        eval = [t(*args) for t in self.terms]
        join = [" and ", " or "][self.fold == any]
        return facet_evaluation(self.fold(eval), join.join(map(str, eval)))

    def __str__(self):
        return [" and ", " or "][self.fold == any].join(map(str, self.terms))


class boolean_and(boolean_logic):
    fold = all


class boolean_or(boolean_logic):
    fold = any


class restriction:
    """
    The value restriction from XSD implemented as a list of values and a containment test
    """

    def __init__(self, node):

        self.restriction_on = node.getAttribute("base")
        self.options = []
        self.type = []
        
        for n in node.childNodes:
            if n.nodeType == n.ELEMENT_NODE and n.tagName.endswith("enumeration"):
                self.options.append(n.getAttribute("value"))
                self.type = "enumeration"        
            elif n.nodeType == n.ELEMENT_NODE and (n.tagName.endswith("Inclusive") or n.tagName.endswith("Exclusive")):
                self.options.append(n.getAttribute("value"))
                self.type = "bounds"
            elif n.nodeType == n.ELEMENT_NODE and n.tagName.endswith("length"):
                self.options.append(n.getAttribute("value"))
                self.type = "length"
            elif n.nodeType == n.ELEMENT_NODE and n.tagName.endswith("pattern"):
                self.options.append(n.getAttribute("value"))
                self.type = "pattern"

    def __eq__(self, other):
        return other in self.options

    def __repr__(self):
        if self.type == "enumeration":
            return " or ".join(self.options)
        elif self.type == "bounds":
            self.options.sort()
            return "of type %s, having a value between %s and %s" % (self.restriction_on, self.options[0], self.options[1])
        elif self.type == "length":
            return "of type %s with a length of %s" % (self.restriction_on, self.options[0])
        elif self.type == "pattern":
            return "of type %s respecting pattern %s" % (self.restriction_on, self.options[0])


class specification:
    """
    Represents the XML <specification> node and its two children <applicability> and <requirements>
    """

    def __init__(self, node):
        def parse_rules(node):
            children = [n for n in node.childNodes if n.nodeType == n.ELEMENT_NODE]
            names = map(operator.attrgetter("tagName"), children)
            classes = map(meta_facet.facets.__getitem__, names)
            return [cls(n) for cls, n in zip(classes, children)]

        phrases = [n for n in node.childNodes if n.nodeType == n.ELEMENT_NODE]

        len(phrases) == 2 or error("expected two child nodes for <specification>")
        phrases[0].tagName == "applicability" or error("expected <applicability>")
        phrases[1].tagName == "requirements" or error("expected <requirements>")

        self.applicability, self.requirements = (boolean_and(parse_rules(phrase)) for phrase in phrases)

    def __call__(self, inst, logger):
        if self.applicability(inst, logger):
            valid = self.requirements(inst, logger)

            if valid:
                logger.info({'guid':inst.GlobalId, 'result':valid.success,'sentence':str(self) + "\n'" + inst.Name + "' (id:" + inst.GlobalId + ") has " + str(valid) + " so is compliant"})
            else:
                logger.error({'guid':inst.GlobalId, 'result':valid.success, 'sentence':str(self) + "\n'" + inst.Name + "' (id:" + inst.GlobalId + ") has " + str(valid) + " so is not compliant"})

    def __str__(self):
        return "Given an instance with %(applicability)s\nWe expect %(requirements)s" % self.__dict__


class ids:
    """
    Represents the XML root <ids> node and its <specification> childNodes.
    """

    def __init__(self, fn):
        dom = parse(fn)
        ids = dom.childNodes[0]
        ids.tagName == "ids" or error("expected <ids>")

        self.specifications = [
            specification(n) for n in ids.childNodes if n.nodeType == n.ELEMENT_NODE and n.tagName == "specification"
        ]

    def validate(self, ifc_file, logger):
        for spec in self.specifications:
            for elem in ifc_file.by_type("IfcObject"):
                spec(elem, logger)

if __name__ == "__main__":
    import sys, os
    import logging
    import ifcopenshell

    filename = os.path.join(os.getcwd(), "ids.txt")

    logger = logging.getLogger("IDS")
    logging.basicConfig(filename=filename, level=logging.INFO, format="%(message)s")
    logging.FileHandler(filename, mode='w')

    ids_file = ids(sys.argv[1])
    ifc_file = ifcopenshell.open(sys.argv[2])

    ids_file.validate(ifc_file, logger)
    
    print("Validated %s IDS requirements on %s IFC elements. Results saved to %s" % (len(ids_file.specifications[0].requirements.terms), len(ifc_file.by_type('IfcProduct')), filename))