#    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.


import logging
import os

from copy import deepcopy
from toscaparser.common.exception import ExceptionCollector
from toscaparser.common.exception import InvalidTemplateVersion
from toscaparser.common.exception import MissingRequiredFieldError
from toscaparser.common.exception import UnknownFieldError
from toscaparser.common.exception import ValidationError
from toscaparser.elements.entity_type import update_definitions
from toscaparser.extensions.exttools import ExtTools
import toscaparser.imports
from toscaparser.prereq.csar import CSAR
from toscaparser.repositories import Repository
from toscaparser.topology_template import TopologyTemplate
from toscaparser.substitution_mappings import SubstitutionMappings
from toscaparser.utils.gettextutils import _
import toscaparser.utils.yamlparser

# TOSCA template key names
SECTIONS = (DEFINITION_VERSION, DEFAULT_NAMESPACE, TEMPLATE_NAME,
            TOPOLOGY_TEMPLATE, TEMPLATE_AUTHOR, TEMPLATE_VERSION,
            DESCRIPTION, IMPORTS, DSL_DEFINITIONS, TYPES, NODE_TYPES,
            RELATIONSHIP_TYPES, RELATIONSHIP_TEMPLATES,
            CAPABILITY_TYPES, ARTIFACT_TYPES, DATA_TYPES, INTERFACE_TYPES,
            POLICY_TYPES, GROUP_TYPES, REPOSITORIES) = \
           ('tosca_definitions_version', 'tosca_default_namespace',
            'template_name', 'topology_template', 'template_author',
            'template_version', 'description', 'imports', 'dsl_definitions',
            'types', 'node_types', 'relationship_types', 'relationship_templates',
            'capability_types', 'artifact_types', 'data_types',
            'interface_types', 'policy_types', 'group_types', 'repositories')
# Sections that are specific to individual template versions
SPECIAL_SECTIONS = (METADATA, DECORATORS) = ('metadata', 'decorators')

log = logging.getLogger("tosca.model")

YAML_LOADER = toscaparser.utils.yamlparser.load_yaml


class ToscaTemplate(object):
    exttools = ExtTools()
    strict = False

    MAIN_TEMPLATE_VERSIONS = ['tosca_simple_yaml_1_0',
                              'tosca_simple_yaml_1_2',
                              'tosca_simple_yaml_1_3']

    VALID_TEMPLATE_VERSIONS = MAIN_TEMPLATE_VERSIONS + exttools.get_versions()

    ADDITIONAL_SECTIONS = {'tosca_simple_yaml_1_0': SPECIAL_SECTIONS,
                           'tosca_simple_yaml_1_2': SPECIAL_SECTIONS,
                           'tosca_simple_yaml_1_3': SPECIAL_SECTIONS}

    ADDITIONAL_SECTIONS.update(exttools.get_sections())

    '''Load the template data.'''
    def __init__(self, path=None, parsed_params=None, a_file=True,
                 yaml_dict_tpl=None, import_resolver=None, verify=True):

        ExceptionCollector.start()
        self.a_file = a_file
        self.input_path = None
        self.path = None
        self.tpl = None
        self.import_resolver = import_resolver
        self.nested_tosca_tpls = {}
        self.nested_topologies = {}
        if path:
            self.input_path = path
            # don't validate or load if yaml_dict_tpl was set
            if yaml_dict_tpl:
                self.path = path
            else:
                self.path = self._get_path(path)
                self.tpl = YAML_LOADER(self.path, self.a_file)

        if yaml_dict_tpl:
            self.tpl = yaml_dict_tpl

        if not path and not yaml_dict_tpl:
            ExceptionCollector.appendException(
                ValueError(_('No path or yaml_dict_tpl was provided. '
                             'There is nothing to parse.')))

        if self.tpl:
            self.parsed_params = parsed_params
            self._validate_field()
            self.version = self._tpl_version()
            # XXX causes imports to be loaded twice
            self.description = self._tpl_description()
            self.topology_template = self._topology_template()
            self.repositories = self._tpl_repositories()
            if self.topology_template.tpl:
                self.inputs = self._inputs()
                self.relationship_templates = self._relationship_templates()
                self.outputs = self._outputs()
                self.policies = self._policies()
                self._handle_nested_tosca_templates_with_topology()
                # now that all the node templates have been loaded we can validated the relationships between them
                self.topology_template.validate_relationships(self.strict)
                for nested in self.nested_topologies.values():
                    nested.validate_relationships(self.strict)


        ExceptionCollector.stop()
        if verify:
            self.verify_template()

    def _topology_template(self):
        return TopologyTemplate(self._tpl_topology_template(),
                                self._get_all_custom_defs(),
                                self.parsed_params,
                                self)

    def _inputs(self):
        return self.topology_template.inputs

    @property
    def nodetemplates(self):
        return self.topology_template.nodetemplates

    def _relationship_templates(self):
        return self.topology_template.relationship_templates

    def _outputs(self):
        return self.topology_template.outputs

    def _tpl_version(self):
        return self.tpl.get(DEFINITION_VERSION)

    def _tpl_description(self):
        desc = self.tpl.get(DESCRIPTION)
        if desc:
            return desc.rstrip()

    def _tpl_imports(self):
        return self.tpl.get(IMPORTS)

    def _tpl_repositories(self):
        repositories = {}
        assert self.topology_template # sets self.nested_tosca_tpls
        for filename, tosca_tpl in self.nested_tosca_tpls.items():
            repositories.update(tosca_tpl.get(REPOSITORIES) or {})
        repositories.update(self.tpl.get(REPOSITORIES) or {})
        # we need to update the template because it is passed directly to the import loader
        self.tpl[REPOSITORIES] = repositories
        if self.import_resolver:
            get_repository = self.import_resolver.get_repository
        else:
            get_repository = Repository
        return {name:get_repository(name, val) for name, val in repositories.items()}

    def _tpl_relationship_templates(self):
        topology_template = self._tpl_topology_template()
        return topology_template.get(RELATIONSHIP_TEMPLATES)

    def _tpl_topology_template(self):
        return self.tpl.get(TOPOLOGY_TEMPLATE)

    def _policies(self):
        return self.topology_template.policies

    def _get_all_custom_defs(self, imports=None, path=None):
        types = [TYPES, NODE_TYPES, CAPABILITY_TYPES, RELATIONSHIP_TYPES,
                 DATA_TYPES, ARTIFACT_TYPES, INTERFACE_TYPES, POLICY_TYPES, GROUP_TYPES]
        custom_defs_final = {}

        custom_defs, nested_imports = self._get_custom_types(
            types, imports, path)
        if custom_defs:
            custom_defs_final.update(custom_defs)
        if nested_imports:
            for a_file, nested_import in nested_imports.items():
                import_defs = self._get_all_custom_defs(
                    nested_import, a_file)
                custom_defs_final.update(import_defs)

        return custom_defs_final

    def _get_custom_types(self, type_definitions, imports=None,
                          path=None):
        """Handle custom types defined in imported template files

        This method loads the custom type definitions referenced in "imports"
        section of the TOSCA YAML template.
        """

        custom_defs = {}
        nested_imports = None
        type_defs = []
        if not isinstance(type_definitions, list):
            type_defs.append(type_definitions)
        else:
            type_defs = type_definitions

        if imports is None:
            imports = self._tpl_imports()

        if imports:
            if path is None:
                path = getattr(imports, "baseDir", self.path)
            imported = toscaparser.imports.\
                ImportsLoader(imports, path, type_defs, self.tpl, self.import_resolver)

            nested_tosca_tpls = imported.get_nested_tosca_tpls()
            self._update_nested_tosca_tpls(nested_tosca_tpls)

            nested_imports = imported.get_nested_imports()
            imported_custom_defs = imported.get_custom_defs()
            if imported_custom_defs:
                custom_defs.update(imported_custom_defs)

        # Handle custom types defined in current template file
        for type_def in type_defs:
            inner_custom_types = self.tpl.get(type_def)
            if inner_custom_types:
                custom_defs.update(inner_custom_types)
        return custom_defs, nested_imports

    def _update_nested_tosca_tpls(self, nested_tosca_tpls):
        for tpl in nested_tosca_tpls:
            # add every import (even if it doesn't have a topology)
            filename, tosca_tpl = list(tpl.items())[0]
            if filename not in self.nested_tosca_tpls:
                self.nested_tosca_tpls.update(tpl)

    def _handle_nested_tosca_templates_with_topology(self):
        for filename, tosca_tpl in self.nested_tosca_tpls.items():
            topology_tpl = tosca_tpl.get(TOPOLOGY_TEMPLATE)
            if topology_tpl:
                custom_types = self._get_all_custom_defs().copy()
                custom_types.update(tosca_tpl.get('node_types', {})) # XXX isn't this redundant?
                self.nested_topologies[filename] = TopologyTemplate(
                                topology_tpl, custom_types, None, self)

        # if a nodetemplate should be substituted, set its sub_mapping_tosca_template
        for nodetemplate in self.nodetemplates:
            if "substitute" not in nodetemplate.directives:
                continue
            for topology in self.nested_topologies.values():
                if not topology.substitution_mappings:
                    continue
                if topology.substitution_mappings.type == nodetemplate.type:
                    # the node template's properties treated as inputs
                    inputs = self._get_params_for_nested_template(nodetemplate)
                    # create a new substitution mapping object for the mapped node
                    # XXX SubstitutionMappings is just a simple wrapper around the def dict, only performs validation
                    # and sub_mapping_tosca_template is never unused!
                    nodetemplate.sub_mapping_tosca_template = SubstitutionMappings(
                        topology.substitution_mappings.sub_mapping_def,
                        topology,
                        inputs,
                        topology.outputs,
                        nodetemplate,
                        topology.custom_defs)
                    break

    def _validate_field(self):
        version = self._tpl_version()
        if not version:
            ExceptionCollector.appendException(
                MissingRequiredFieldError(what='Template',
                                          required=DEFINITION_VERSION))
        else:
            self._validate_version(version)
            self.version = version

        for name in self.tpl:
            if (name not in SECTIONS and
               name not in self.ADDITIONAL_SECTIONS.get(version, ())):
                ExceptionCollector.appendException(
                    UnknownFieldError(what='Template', field=name))

    def _validate_version(self, version):
        if version not in self.VALID_TEMPLATE_VERSIONS:
            ExceptionCollector.appendException(
                InvalidTemplateVersion(
                    what=version,
                    valid_versions='", "'. join(self.VALID_TEMPLATE_VERSIONS)))
        else:
            if version not in self.MAIN_TEMPLATE_VERSIONS:
                update_definitions(self.exttools, version, YAML_LOADER)

    def _get_path(self, path):
        if path.lower().endswith('.yaml') or path.lower().endswith('.yml'):
            return path
        elif path.lower().endswith(('.zip', '.csar')):
            # a CSAR archive
            csar = CSAR(path, self.a_file)
            if csar.validate():
                csar.decompress()
                self.a_file = True  # the file has been decompressed locally
                return os.path.join(csar.temp_dir, csar.get_main_template())
        else:
            ExceptionCollector.appendException(
                ValueError(_('"%(path)s" is not a valid file.')
                           % {'path': path}))

    def verify_template(self):
        if ExceptionCollector.exceptionsCaught():
            if self.input_path:
                raise ValidationError(
                    message=(_('\nThe input "%(path)s" failed validation with '
                               'the following error(s): \n\n\t')
                             % {'path': self.input_path}) +
                    '\n\t'.join(ExceptionCollector.getExceptionsReport()))
            else:
                raise ValidationError(
                    message=_('\nThe pre-parsed input failed validation with '
                              'the following error(s): \n\n\t') +
                    '\n\t'.join(ExceptionCollector.getExceptionsReport()))
        else:
            if self.input_path:
                msg = (_('The input "%(path)s" successfully passed '
                         'validation.') % {'path': self.input_path})
            else:
                msg = _('The pre-parsed input successfully passed validation.')

            log.info(msg)

    def _is_sub_mapped_node(self, nodetemplate, tosca_tpl):
        """Return True if the nodetemple is substituted."""
        # NOTE(ueha): Since condition "not nodetemplate.sub_mapping_tosca_\
        #             template" was deleted as a fix for bug/1883220, there is
        #             some possibility of breaking something on translator side
        #             that current tests not coverd.
        #             And this enhancement does not align with TOSCA standard
        #             but needed for ETSI NFV-SOL 001.
        if (nodetemplate and
                self.get_sub_mapping_node_type(tosca_tpl) == nodetemplate.type
                and len(nodetemplate.interfaces) < 1):
            return True
        else:
            return False

    def _get_params_for_nested_template(self, nodetemplate):
        """Return total params for nested_template."""
        parsed_params = {input.name : input for input in self.topology_template.inputs}
        if nodetemplate:
            parsed_params.update(nodetemplate.get_properties())
        return list(parsed_params.values())

    def _has_substitution_mappings(self):
        """Return True if the template has valid substitution mappings."""
        return self.topology_template is not None and \
            self.topology_template.substitution_mappings is not None
