# Copyright 2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"). You
# may not use this file except in compliance with the License. A copy of
# the License is located at
#
# http://aws.amazon.com/apache2.0/
#
# or in the "license" file accompanying this file. This file 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 botocore.compat import six

from ebcli.objects.conversionconfiguration import ConversionConfiguration
from ebcli.objects.exceptions import InvalidSyntaxError
from ebcli.resources.strings import prompts

ENVIRONMENT_VAR_NAMESPACE = 'aws:elasticbeanstalk:application:environment'
CLOUDFORMATION_TEMPLATE = 'aws:cloudformation:template:parameter'
DATABASE_NAMESPACE = 'aws:rds:dbinstance'


class EnvironmentSettings(ConversionConfiguration):
    def collect_changes(self, usr_model):
        """
        Grabs all things in the usr_model that are different and
       returns just the changes
        :param usr_model: User model, key-value style
        :return: api_model
        """

        self.api_model = self.remove_unwanted_settings()
        self.ignore_default_resource_names()

        changes = []
        remove = []

        option_settings = self.api_model['OptionSettings']
        usr_options = usr_model['settings']
        for setting in option_settings:
            # Compare value for given optionName
            namespace = setting['Namespace']
            option = setting['OptionName']
            resource_name = None
            if 'ResourceName' in setting:
                resource_name = setting['ResourceName']
                key = resource_name + '.' + namespace
            else:
                key = namespace

            try:
                usr_value = usr_options[key][option]
                del usr_options[key][option]

                # If they dont match, take the user value
                if 'Value' in setting:
                    if setting['Value'] != usr_value:
                        setting['Value'] = usr_value
                        if usr_value:
                            changes.append(setting)
                        else:
                            remove.append(
                                _get_option_setting_dict(
                                    namespace,
                                    option,
                                    None,
                                    resource_name
                                )
                            )
                else:
                    if usr_value is not None:
                        setting['Value'] = usr_value
                        changes.append(setting)

            except KeyError:
                # user removed setting. We want to add to remove list
                d = _get_option_setting_dict(
                    namespace,
                    option,
                    None,
                    resource_name
                )
                remove.append(d)

        # Now we look for added options:
        for namespace, options in six.iteritems(usr_options):
            if options:
                namespace, resource_name = \
                    _get_namespace_and_resource_name(namespace)
                for option, value in six.iteritems(options):
                    if value is not None:
                        changes.append(_get_option_setting_dict(
                            namespace, option, value, resource_name))

        return changes, remove

    def convert_api_to_usr_model(self):
        """
        Convert an api model with Namespaces to a User model as a key-value system
        Remove unwanted entries
        :return: a user model
        """
        self.api_model = self.remove_unwanted_settings()
        self.ignore_default_resource_names()

        usr_model = dict()
        # Grab only data we care about
        self._copy_api_entry('ApplicationName', usr_model)
        self._copy_api_entry('EnvironmentName', usr_model)
        self._copy_api_entry('DateUpdated', usr_model)
        self._copy_api_entry('PlatformArn', usr_model)
        usr_model['settings'] = dict()
        usr_model_settings = usr_model['settings']

        for setting in self.api_model['OptionSettings']:
            namespace = setting['Namespace']

            if 'ResourceName' in setting:
                namespace = setting['ResourceName'] + '.' + namespace
            if namespace not in usr_model_settings:
                usr_model_settings[namespace] = dict()

            key = setting['OptionName']
            if 'Value' in setting:
                value = setting['Value']
            else:
                value = None

            usr_model_settings[namespace][key] = value

        return usr_model

    def remove_unwanted_settings(self):
        option_settings = self.api_model['OptionSettings']
        self.api_model['OptionSettings'] = [
            setting for setting in option_settings if
            setting['Namespace'] != ENVIRONMENT_VAR_NAMESPACE and
            setting['Namespace'] != CLOUDFORMATION_TEMPLATE and
            not (setting['Namespace'] == DATABASE_NAMESPACE
                 and (setting['OptionName'] == 'DBEngineVersion' or
                      setting['OptionName'] == 'DBUser' or
                      setting['OptionName'] == 'DBEngine' or
                      setting['OptionName'] == 'DBPassword'))

            ]
        return self.api_model

    def ignore_default_resource_names(self):
        option_settings = self.api_model['OptionSettings']
        for setting in option_settings:
            if 'ResourceName' in setting and setting['ResourceName'] in \
                    ['AWSEBAutoScalingGroup',
                     'AWSEBAutoScalingLaunchConfiguration',
                     'AWSEBEnvironmentName',
                     'AWSEBLoadBalancer',
                     'AWSEBRDSDatabase',
                     'AWSEBSecurityGroup',
                     'AWSEBV2LoadBalancer'
                     'AWSEBV2LoadBalancerListener',
                     'AWSEBV2LoadBalancerTargetGroup'
                     ]:
                del setting['ResourceName']

    @staticmethod
    def convert_usr_model_to_api(settings):
        """
        Convert a key-value based User model to api with namespaces
        :return: an api model
        """
        changes = []
        for (resource_namespace, options) in settings.items():
            namespace, resource_name = _get_namespace_and_resource_name(resource_namespace)
            if isinstance(options,dict):
                for(option_name, value) in options.items():
                    changes.append(_get_option_setting_dict(namespace, option_name, value, resource_name))
            else:
                for option_name in options:
                    changes.append(_get_option_setting_dict(namespace, option_name, None, resource_name))
        return changes



def _get_option_setting_dict(namespace, optionname, value, resource_name):
    d = {'Namespace': namespace, 'OptionName': optionname}
    if resource_name:
        d['ResourceName'] = resource_name
    if value is not None:
        d['Value'] = value
    return d


def _get_namespace_and_resource_name(namespace):
    if '.' not in namespace:
        return namespace, None
    else:
        parts = namespace.split('.')
        if len(parts) > 2:
            raise InvalidSyntaxError(prompts['update.invalidsyntax'])
        return parts[1], parts[0]