import xml.etree.ElementTree as ET


KEY_DESCRIPTION = 'description'
"""Description (short) of an element"""
KEY_DETAILED_DESCRIPTION = 'detailed_description'
"""Description (short) of an element"""
KEY_ITEM_ID = 'id'
"""The human readable item id"""
KEY_LAST_CHANGE = 'last_change'
"""Date of the last change"""
KEY_SOURCE = 'source'
"""The source of a relation"""
KEY_SPEC_DATA = 'data'
"""A dict holding the data definition (key is the unique id of the data definition). Note this is not the datatype, but a reference to the datatype"""
KEY_START_EXECUTION_FROM_LEVEL = 'start_execution_from_level'
"""The level, of an spec object from where on the test should be executed"""
KEY_SYSTEM_TYPE_UID = 'system_type_uid'
"""The unique id of the corresponding type"""
KEY_SYSTEM_UID = 'system_uid'
"""A unique id"""
KEY_TARGET = 'target'
"""The target of a relation"""
KEY_XML_TAG = 'xml_tag'
"""The tag of the original xml object"""

PREFIX = '{http://www.omg.org/spec/ReqIF/20110401/reqif.xsd}'
TAG_CHILDREN = '%sCHILDREN' % PREFIX
TAG_DEFINITION = '%sDEFINITION' % PREFIX
TAG_OBJECT = '%sOBJECT' % PREFIX
TAG_OBJECT_REF = '%sSPEC-OBJECT-REF' % PREFIX
TAG_PROPERTIES = '%sPROPERTIES' % PREFIX
TAG_SOURCE = '%sSOURCE' % PREFIX
TAG_SPECIFIED_VALUES = '%sSPECIFIED-VALUES' % PREFIX
TAG_SPEC_ATTRIBUTES = '%sSPEC-ATTRIBUTES' % PREFIX
TAG_TARGET = '%sTARGET' % PREFIX
TAG_THE_VALUE = 'THE-VALUE'
TAG_TYPE = '%sTYPE' % PREFIX
TAG_VALUES = '%sVALUES' % PREFIX


class base_object(dict):
    ATTRIB_KEY_DESC = 'DESC'
    ATTRIB_KEY_IDENTIFIER = 'IDENTIFIER'
    ATTRIB_KEY_LONG_NAME = 'LONG-NAME'
    ATTRIB_KEY_LAST_CHANGE = 'LAST-CHANGE'
    ATTRIB_DATA = {KEY_DESCRIPTION: ATTRIB_KEY_LONG_NAME,
                   KEY_DETAILED_DESCRIPTION: ATTRIB_KEY_DESC,
                   KEY_LAST_CHANGE: ATTRIB_KEY_LAST_CHANGE,
                   KEY_SYSTEM_UID: ATTRIB_KEY_IDENTIFIER}

    def __init__(self, xml_object):
        dict.__init__(self)
        for key in self.ATTRIB_DATA:
            data = xml_object.attrib.get(self.ATTRIB_DATA[key])
            if data is not None:
                self[key] = data
        self[KEY_XML_TAG] = xml_object.tag
        type_obj = xml_object.find(TAG_TYPE)
        if type_obj is not None:
            self[KEY_SYSTEM_TYPE_UID] = type_obj[0].text

    def __str__(self):
        keys = self.keys()
        keys.sort()
        rv = ''
        for key in keys:
            rv += '%s: %s\n' % (key, self[key])
        return rv


class datatype(base_object):
    ATTRIB_KEY_KEY = 'KEY'

    def __init__(self, xml_datatype_object):
        base_object.__init__(self, xml_datatype_object)
        self.enmu_dict = dict()
        if 'ENUMERATION' in self[KEY_XML_TAG]:
            for child in xml_datatype_object.find(TAG_SPECIFIED_VALUES):
                key = child.attrib[self.ATTRIB_KEY_IDENTIFIER]
                value = None
                if child.find(TAG_PROPERTIES) is not None:
                    try:
                        value = int(child.find(TAG_PROPERTIES)[0].attrib.get(self.ATTRIB_KEY_KEY))
                    except ValueError:
                        value = child.find(TAG_PROPERTIES)[0].attrib.get(self.ATTRIB_KEY_KEY)
                value = value or child.attrib[self.ATTRIB_KEY_LONG_NAME]
                self.enmu_dict[key] = value

    def xml_obj_to_value(self, xml_obj):
        if 'STRING' in self[KEY_XML_TAG]:
            data = xml_obj.attrib.get(TAG_THE_VALUE)
            return data
        elif 'INTEGER' in self[KEY_XML_TAG]:
            data = xml_obj.attrib.get(TAG_THE_VALUE)
            return int(data)
        elif 'BOOLEAN' in self[KEY_XML_TAG]:
            data = xml_obj.attrib.get(TAG_THE_VALUE)
            if data.lower() == 'false':
                return False
            else:
                return True
        elif 'ENUMERATION' in self[KEY_XML_TAG]:
            if xml_obj.find(TAG_VALUES) is not None:
                return self.enmu_dict.get(xml_obj.find(TAG_VALUES)[0].text)


class datatype_dict(dict):
    def __init__(self, xml_datatypes_object):
        dict.__init__(self)
        for child in xml_datatypes_object:
            dt = datatype(child)
            self[dt[KEY_SYSTEM_UID]] = dt

    def __str__(self):
        rv = ''
        for key in self:
            rv += str(self[key]) + '\n'
        return rv


class spec_type(base_object):
    def __init__(self, xml_spec_type_object):
        base_object.__init__(self, xml_spec_type_object)
        self[KEY_SPEC_DATA] = dict()
        for child in xml_spec_type_object.find(TAG_SPEC_ATTRIBUTES):
            a = base_object(child)
            self[KEY_SPEC_DATA][a[KEY_SYSTEM_UID]] = a


class spec_types_dict(dict):
    def __init__(self, xml_spec_types_object):
        dict.__init__(self)
        for child in xml_spec_types_object:
            st = spec_type(child)
            self[st[KEY_SYSTEM_UID]] = st

    def __str__(self):
        rv = ''
        for key in self:
            rv += str(self[key]) + '\n'
        return rv


class spec_object(base_object):
    def __init__(self, xml_object, spec_types, data_types):
        base_object.__init__(self, xml_object)
        try:
            for child in xml_object.find(TAG_VALUES):
                attr_id = child.find(TAG_DEFINITION)[0].text
                stype = spec_types[self[KEY_SYSTEM_TYPE_UID]]
                if attr_id in stype[KEY_SPEC_DATA]:
                    spec_attr = stype[KEY_SPEC_DATA][attr_id]
                    data_type = data_types[spec_attr[KEY_SYSTEM_TYPE_UID]]
                    self[spec_attr[KEY_DESCRIPTION]] = data_type.xml_obj_to_value(child)
        except TypeError:
            pass


class spec_objects(dict):
    def __init__(self, xml_object, spec_types, data_types):
        dict.__init__(self)
        for child in xml_object:
            so = spec_object(child, spec_types, data_types)
            self[so[KEY_SYSTEM_UID]] = so

    def __str__(self):
        rv = ''
        for key in self:
            rv += str(self[key]) + '\n'
        return rv


class spec_relation(spec_object):
    def __init__(self, xml_object, spec_types, data_types):
        spec_object.__init__(self, xml_object, spec_types, data_types)
        self[KEY_SOURCE] = xml_object.find(TAG_SOURCE).find(TAG_OBJECT_REF).text
        self[KEY_TARGET] = xml_object.find(TAG_TARGET).find(TAG_OBJECT_REF).text


class spec_relations(list):
    def __init__(self, xml_object, spec_types, data_types):
        list.__init__(self)
        for child in xml_object:
            self.append(spec_relation(child, spec_types, data_types))

    def __str__(self):
        rv = ''
        for key in self:
            rv += str(self[key]) + '\n'
        return rv


class id_tree(str):
    def __init__(self, system_uid):
        str.__init__(system_uid)
        self.children = list()

    def append(self, child):
        self.children.append(child)

    def get_flat_id_tree(self):
        """
        This method returns an ordered but flat list of all id_tree elements.
        """
        obj_list = list()
        for child in self.children:
            obj_list.append(child)
            obj_list.extend(child.get_flat_id_tree())
        return obj_list

    def executed_or_has_executed_children(self, item_type_id, execution_level, get_spec_object_method, default_execution_level):
        spec_obj = get_spec_object_method(str(self))
        if spec_obj[KEY_SYSTEM_TYPE_UID] == item_type_id:
            if execution_level >= spec_obj.get(KEY_START_EXECUTION_FROM_LEVEL, default_execution_level):
                return True
        for child in self.children:
            if child.executed_or_has_executed_children(item_type_id, execution_level, get_spec_object_method, default_execution_level):
                return True
        return False


class specification(spec_object):
    def __init__(self, xml_object, spec_types, data_types, spec_objects):
        spec_object.__init__(self, xml_object, spec_types, data_types)
        self._spec_objects = spec_objects
        self.children = list()
        self._add_hirarchy_objects(xml_object.find(TAG_CHILDREN), self.children)

    def _add_hirarchy_objects(self, children, parent_list):
        for child in children:
            child_id = child.find('%s/%s' % (TAG_OBJECT, TAG_OBJECT_REF)).text
            child_tree_obj = id_tree(child_id)
            parent_list.append(child_tree_obj)
            next_children = child.find(TAG_CHILDREN)
            if next_children is not None:
                self._add_hirarchy_objects(next_children, child_tree_obj.children)

    def get_system_uid_list_by_type(self, type_id):
        """
        This method returns an ordered but flat list of all items of this specification with the specified type.
        """
        obj_list = list()
        for child in self.children:
            if self._spec_objects[child][KEY_SYSTEM_TYPE_UID] == type_id:
                obj_list.append(str(child))
            for item_id in child.get_flat_id_tree():
                if self._spec_objects[item_id][KEY_SYSTEM_TYPE_UID] == type_id:
                    obj_list.append(str(item_id))
        return obj_list


class specifications(list):
    def __init__(self, xml_object, spec_types, data_types, spec_objects):
        list.__init__(self)
        for child in xml_object:
            self.append(specification(child, spec_types, data_types, spec_objects))

    def __str__(self):
        rv = ''
        for i in self:
            rv += str(i) + '\n'
        return rv


class parse(object):
    TAG_HEADER_MAIN = '%sTHE-HEADER' % PREFIX
    TAG_HEADER_REQIF = '%sREQ-IF-HEADER' % PREFIX
    TAG_TITLE = '%sTITLE' % PREFIX
    TAG_COMMENT = '%sCOMMENT' % PREFIX

    TAG_CORE_CONTENT = '%sCORE-CONTENT' % PREFIX
    TAG_REQ_IF_CONTENT = '%sREQ-IF-CONTENT' % PREFIX
    TAG_DATATYPES = '%sDATATYPES' % PREFIX
    TAG_SPEC_RELATIONS = '%sSPEC-RELATIONS' % PREFIX
    TAG_SPEC_TYPES = '%sSPEC-TYPES' % PREFIX
    TAG_SPEC_OBJECTS = '%sSPEC-OBJECTS' % PREFIX
    TAG_SPECIFICATION = '%sSPECIFICATIONS' % PREFIX

    def __init__(self, filename):
        tree = ET.parse(filename)
        req_if = tree.getroot()

        self._title = req_if.find('./%s/%s/%s' % (self.TAG_HEADER_MAIN, self.TAG_HEADER_REQIF, self.TAG_TITLE)).text
        self._comment = req_if.find('./%s/%s/%s' % (self.TAG_HEADER_MAIN, self.TAG_HEADER_REQIF, self.TAG_COMMENT)).text

        xml_obj = req_if.find('./%s/%s/%s' % (self.TAG_CORE_CONTENT, self.TAG_REQ_IF_CONTENT, self.TAG_DATATYPES))
        self._datatypes = datatype_dict(xml_obj)
        xml_obj = req_if.find('./%s/%s/%s' % (self.TAG_CORE_CONTENT, self.TAG_REQ_IF_CONTENT, self.TAG_SPEC_TYPES))
        self._spec_types = spec_types_dict(xml_obj)
        xml_obj = req_if.find('./%s/%s/%s' % (self.TAG_CORE_CONTENT, self.TAG_REQ_IF_CONTENT, self.TAG_SPEC_OBJECTS))
        self._spec_objects = spec_objects(xml_obj, self._spec_types, self._datatypes)
        xml_obj = req_if.find('./%s/%s/%s' % (self.TAG_CORE_CONTENT, self.TAG_REQ_IF_CONTENT, self.TAG_SPEC_RELATIONS))
        try:
            self._relations = spec_relations(xml_obj, self._spec_types, self._datatypes)
        except TypeError:
            self._relations = []
        xml_obj = req_if.find('./%s/%s/%s' % (self.TAG_CORE_CONTENT, self.TAG_REQ_IF_CONTENT, self.TAG_SPECIFICATION))
        self._specifications = specifications(xml_obj, self._spec_types, self._datatypes, self._spec_objects)

    def __str__(self):
        rv = 'Title: %s' % self._title
        rv += 'Comment: %s' % self._comment
        rv += 'DATATYPES:\n----------\n'
        rv += str(self._datatypes)
        rv += str(self._spec_types)
        rv += '\n\n\nSPEC_OBJECTS:\n-------------\n'
        rv += str(self._spec_objects)
        rv += '\n\n\nSPECIFICATIONS:\n---------------\n'
        rv += str(self._specifications)
        return rv