# Copyright [2017] [Red Hat, Inc.]
#
# 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.

# Implement ConfigMapHash and SecretHash equivalents
# Based on https://github.com/kubernetes/kubernetes/pull/49961

from __future__ import (absolute_import, division, print_function)
__metaclass__ = type

import json
import hashlib

try:
    import string
    maketrans = string.maketrans
except AttributeError:
    maketrans = str.maketrans

try:
    from collections import OrderedDict
except ImportError:
    from orderreddict import OrderedDict


def sorted_dict(unsorted_dict):
    result = OrderedDict()
    for (k, v) in sorted(unsorted_dict.items()):
        if isinstance(v, dict):
            v = sorted_dict(v)
        result[k] = v
    return result


def generate_hash(resource):
    # Get name from metadata
    resource['name'] = resource.get('metadata', {}).get('name', '')
    if resource['kind'] == 'ConfigMap':
        marshalled = marshal(sorted_dict(resource), ['data', 'kind', 'name'])
        del(resource['name'])
        return encode(marshalled)
    if resource['kind'] == 'Secret':
        marshalled = marshal(sorted_dict(resource), ['data', 'kind', 'name', 'type'])
        del(resource['name'])
        return encode(marshalled)
    raise NotImplementedError


def marshal(data, keys):
    ordered = OrderedDict()
    for key in keys:
        ordered[key] = data.get(key, "")
    return json.dumps(ordered, separators=(',', ':')).encode('utf-8')


def encode(resource):
    return hashlib.sha256(resource).hexdigest()[:10].translate(maketrans("013ae", "ghkmt"))