# Copyright 2012 Managed I.T.
#
# Author: Kiall Mac Innes <kiall@managedit.ie>
#
# 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 os
import pkg_resources
import json
from designateclient import exceptions


def resource_string(*args, **kwargs):
    if len(args) == 0:
        raise ValueError()

    package = kwargs.pop('package', None)

    if not package:
        package = 'designateclient'

    resource_path = os.path.join('resources', *args)

    if not pkg_resources.resource_exists(package, resource_path):
        raise exceptions.ResourceNotFound('Could not find the requested '
                                          'resource: %s' % resource_path)

    return pkg_resources.resource_string(package, resource_path)


def load_schema(version, name, package=None):
    schema_string = resource_string('schemas', version, '%s.json' % name,
                                    package=package)

    return json.loads(schema_string)


def get_item_properties(item, fields, mixed_case_fields=[], formatters={}):
    """Return a tuple containing the item properties.

    :param item: a single item resource (e.g. Server, Tenant, etc)
    :param fields: tuple of strings with the desired field names
    :param mixed_case_fields: tuple of field names to preserve case
    :param formatters: dictionary mapping field names to callables
        to format the values
    """
    row = []

    for field in fields:
        if field in formatters:
            row.append(formatters[field](item))
        else:
            if field in mixed_case_fields:
                field_name = field.replace(' ', '_')
            else:
                field_name = field.lower().replace(' ', '_')
            if not hasattr(item, field_name) and \
                    (isinstance(item, dict) and field_name in item):
                data = item[field_name]
            else:
                data = getattr(item, field_name, '')
            if data is None:
                data = ''
            row.append(data)
    return tuple(row)


def get_columns(data):
    """
    Some row's might have variable count of columns, ensure that we have the
    same.

    :param data: Results in [{}, {]}]
    """
    columns = set()

    def _seen(col):
        columns.add(str(col))

    map(lambda item: map(_seen, item.keys()), data)
    return list(columns)
