#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

from toscaparser.common.exception import ExceptionCollector
from toscaparser.common.exception import UnknownFieldError
from toscaparser.common.exception import ValidationError
from toscaparser.elements.capabilitytype import CapabilityTypeDef
import toscaparser.elements.interfaces as ifaces
from toscaparser.elements.interfaces import InterfacesDef
from toscaparser.elements.relationshiptype import RelationshipType
from toscaparser.elements.statefulentitytype import StatefulEntityType


class NodeType(StatefulEntityType):
    '''TOSCA built-in node type.'''
    SECTIONS = (DERIVED_FROM, METADATA, PROPERTIES, VERSION, DESCRIPTION, ATTRIBUTES, REQUIREMENTS, CAPABILITIES, INTERFACES, ARTIFACTS) = \
               ('derived_from', 'metadata', 'properties', 'version',
                'description', 'attributes', 'requirements', 'capabilities',
                'interfaces', 'artifacts')

    def __init__(self, ntype, custom_def=None):
        super(NodeType, self).__init__(ntype, self.NODE_PREFIX, custom_def)
        self.ntype = ntype
        self.custom_def = custom_def
        self._validate_keys()

    @property
    def parent_type(self):
        '''Return a node this node is derived from.'''
        if not hasattr(self, 'defs'):
            return None
        pnode = self.derived_from(self.defs)
        if pnode:
            return NodeType(pnode, self.custom_def)

    @property
    def relationship(self):
        '''Return a dictionary of relationships to other node types.

        This method returns a dictionary of named relationships that nodes
        of the current node type (self) can have to other nodes (of specific
        types) in a TOSCA template.

        '''
        relationship = {}
        requires = self.get_all_requirements()
        if requires:
            # NOTE(sdmonov): Check if requires is a dict.
            # If it is a dict convert it to a list of dicts.
            # This is needed because currently the code below supports only
            # lists as requirements definition. The following check will
            # make sure if a map (dict) was provided it will be converted to
            # a list before proceeding to the parsing.
            if isinstance(requires, dict):
                requires = [{key: value} for key, value in requires.items()]

            keyword = None
            node_type = None
            for require in requires:
                for key, req in require.items():
                    if 'relationship' in req:
                        relation = req.get('relationship')
                        if 'type' in relation:
                            relation = relation.get('type')
                        node_type = req.get('node')
                        value = req
                        if node_type:
                            keyword = 'node'
                        else:
                            # If value is a dict and has a type key
                            # we need to lookup the node type using
                            # the capability type
                            value = req
                            if isinstance(value, dict):
                                captype = value['capability']
                                value = (self.
                                         _get_node_type_by_cap(key, captype))
                            relation = self._get_relation(key, value)
                            keyword = key
                            node_type = value
                rtype = RelationshipType(relation, keyword, self.custom_def)
                relatednode = NodeType(node_type, self.custom_def)
                relationship[rtype] = relatednode
        return relationship

    def _get_node_type_by_cap(self, key, cap):
        '''Find the node type that has the provided capability

        This method will lookup all node types if they have the
        provided capability.
        '''

        # Filter the node types
        node_types = [node_type for node_type in self.TOSCA_DEF.keys()
                      if node_type.startswith(self.NODE_PREFIX) and
                      node_type != 'tosca.nodes.Root']

        for node_type in node_types:
            node_def = self.TOSCA_DEF[node_type]
            if isinstance(node_def, dict) and 'capabilities' in node_def:
                node_caps = node_def['capabilities']
                for value in node_caps.values():
                    if isinstance(value, dict) and \
                            'type' in value and value['type'] == cap:
                        return node_type

    def _get_relation(self, key, ndtype):
        relation = None
        ntype = NodeType(ndtype)
        caps = ntype.get_capabilities()
        if caps and key in caps.keys():
            c = caps[key]
            for r in self.RELATIONSHIP_TYPE:
                rtypedef = ntype.TOSCA_DEF[r]
                for properties in rtypedef.values():
                    if c.type in properties:
                        relation = r
                        break
                if relation:
                    break
                else:
                    for properties in rtypedef.values():
                        if c.parent_type in properties:
                            relation = r
                            break
        return relation

    def get_capabilities_objects(self):
        '''Return a list of capability objects.'''
        typecapabilities = []
        caps = self.get_value(self.CAPABILITIES, None, True)
        if caps is None:
            caps = self.get_value(self.CAPABILITIES, None, True)
        if caps:
            for name, value in caps.items():
                ctype = value.get('type')
                cap = CapabilityTypeDef(name, ctype, self.type,
                                        self.custom_def)
                typecapabilities.append(cap)
        return typecapabilities

    def get_capabilities(self):
        '''Return a dictionary of capability name-objects pairs.'''
        return {cap.name: cap
                for cap in self.get_capabilities_objects()}

    @property
    def requirements(self):
        return self.get_value(self.REQUIREMENTS, None, True)

    def get_all_requirements(self):
        requires = self.requirements
        parent_node = self.parent_type
        if requires is None:
            requires = self.get_value(self.REQUIREMENTS, None, True)
            if parent_node is None:
                ExceptionCollector.appendException(
                    ValidationError(message="parent_node is "
                                    + str(parent_node)))
            else:
                parent_node = parent_node.parent_type
        if parent_node:
            while parent_node.type != 'tosca.nodes.Root':
                req = parent_node.get_value(self.REQUIREMENTS, None, True)
                for r in req:
                    if r not in requires:
                        requires.append(r)
                parent_node = parent_node.parent_type
        return requires

    @property
    def interfaces(self):
        return self.get_value(self.INTERFACES)

    @property
    def lifecycle_inputs(self):
        '''Return inputs to life cycle operations if found.'''
        inputs = []
        interfaces = self.interfaces
        if interfaces:
            for name, value in interfaces.items():
                if name == ifaces.LIFECYCLE:
                    for x, y in value.items():
                        if x == 'inputs':
                            for i in y.iterkeys():
                                inputs.append(i)
        return inputs

    @property
    def lifecycle_operations(self):
        '''Return available life cycle operations if found.'''
        ops = None
        interfaces = self.interfaces
        if interfaces:
            i = InterfacesDef(self.type, ifaces.LIFECYCLE)
            ops = i.lifecycle_ops
        return ops

    def get_capability(self, name):
        caps = self.get_capabilities()
        if caps and name in caps.keys():
            return caps[name].value

    def get_capability_type(self, name):
        captype = self.get_capability(name)
        if captype and name in captype.keys():
            return captype[name].value

    def _validate_keys(self):
        if self.defs:
            for key in self.defs.keys():
                if key not in self.SECTIONS:
                    ExceptionCollector.appendException(
                        UnknownFieldError(what='Nodetype"%s"' % self.ntype,
                                          field=key))
