# -*- coding: utf-8 -*-
# _state/aptkey.py
"""
Manage apt keys
"""
from __future__ import absolute_import, print_function, unicode_literals

from base64 import b64encode, b64decode
from binascii import Error as binasciiError

def __virtual__():
    """Only load if 'pkg' (aptpkg) module has necessary functions"""

    if not 'pkg.add_repo_key' in __salt__ or not 'pkg.get_repo_keys' in __salt__:
        return False, "'pkg.add_repo_key' and 'pkg.get_repo_keys' functions are required"
    return True

def _get_fingerprints(input_text):
    """Get fingerprint(s) for given text

    :param str input_text: text to get fingerprint(s) from it

    :return:
        A list of found fingerprint(s)
    :rtype list:

    """
    fingerprints = []
    cmd = 'apt-key adv --with-fingerprint --with-colons --dry-run -'
    out = __salt__['cmd.run_stdout'](cmd, stdin=input_text, python_shell=False)
    for line in out.split('\n'):
        line = line.split(':')
        if line[0] == 'fpr':
            fingerprints.append(line[-2])
    return fingerprints


def added(name, key_text=None, key_url=None):
    """Ensure that given key added to APT's key storage

    :param str name:
        Just an ID, it does not used at all.
    :param str key_text:
        Key to add as a plain text or base64-encoded.
    :param str key_url:
        URL from which key should be fetched. Supported URLs: salt://, http://,
        https:// and file://.

    Examples:

    .. code-block:: yaml

        # Base64 encoded key
        {% set repo_key = salt['hashutil.base64_b64encode'](repo.key) %}
        linux_repo_ubuntu_key:
          aptkey.added:
            - key_text: {{ repo_key }}

    .. code-block:: yaml

        # Plaintext key
        linux_repo_ubuntu_key:
          aptkey.added:
            - key_text: '{{ repo.key | replace("\n", "\\n") }}'

    .. code-block:: yaml

        linux_repo_ubuntu_key:
          aptkey.added:
            - key_url: 'https://example.com/key.asc'
    """
    ret = {'name': name,
           'result': None if __opts__['test'] else True,
           'changes': {},
           'comment': ''}

    if not key_text and not key_url:
        ret['result'] = False,
        ret['comment'] = 'No key to add provided'
        return ret
    if key_text and key_url:
        ret['result'] = False
        ret['comment'] = 'Only one of key_text or key_url is permitted'
        return ret

    # If key_url provided fetch it before proceeding
    if key_url:
        # This only supports salt://, http://, https:// and file:// URLs
        key_text = __salt__['cp.get_url'](key_url, dest=None)

    # Try to apply base64 decoding to key_text, just in case...
    try:
        # Decode key_text if it is base64 encoded string
        decoded_key_text = b64decode(key_text)
        # the simplest available check that given string was base64 encoded
        if b64encode(decoded_key_text) == key_text:
            key_text = decoded_key_text
    except TypeError, binasciiError: # the first is for py2, the second for py3
        pass

    # Get apt's keys and their fingerprints
    apt_keys = __salt__['pkg.get_repo_keys']()
    apt_fingerprints = [key.get('fingerprint') for _, key in apt_keys.items()]

    key_fingerprints = _get_fingerprints(key_text)
    # If any of given fingerprints does not present in apt keys
    # then add all of them
    if not set(key_fingerprints).issubset(set(apt_fingerprints)):
        if __opts__['test']:
            ret['result'] = None
            ret['changes'] = {'key': key_text}
            return ret

        success = __salt__['pkg.add_repo_key'](text=key_text)
        if success:
            ret['result'] = True
            ret['changes'] = {'key': key_text}
        else:
            ret['result'] = False
            ret['comment'] = 'Key was not added because of errors'
    return ret