# -*- coding: utf-8 -*-
'''
:maintainer:    SaltStack
:maturity:      new
:platform:      all

.. versionadded:: Nitrogen

States for managing Hashicorp Vault. Currently handles policies. Configuration
instructions are documented in the execution module docs.
'''
from __future__ import absolute_import
import logging
import difflib

log = logging.getLogger(__name__)


def policy_present(name, rules):
    '''
    Ensure a Vault policy with the given name and rules is present.

    name
        The name of the policy

    rules
        Rules formatted as in-line HCL


    .. code-block:: yaml
    demo-policy:
      vault.policy_present:
        - name: foo/bar
        - rules: |
            path "secret/top-secret/*" {
              policy = "deny"
            }
            path "secret/not-very-secret/*" {
              policy = "write"
            }

    '''
    url = "v1/sys/policy/{0}".format(name)
    response = __utils__['vault.make_request']('GET', url)
    try:
        if response.status_code == 200:
            return _handle_existing_policy(name, rules, response.json()['rules'])
        elif response.status_code == 404:
            return _create_new_policy(name, rules)
        else:
            response.raise_for_status()
    except Exception as e:
        return {
            'name': name,
            'changes': None,
            'result': False,
            'comment': 'Failed to get policy: {0}'.format(e)
        }


def _create_new_policy(name, rules):
    if __opts__['test']:
        return {
            'name': name,
            'changes': {name: {'old': '', 'new': rules}},
            'result': None,
            'comment': 'Policy would be created'
        }

    payload = {'rules': rules}
    url = "v1/sys/policy/{0}".format(name)
    response = __utils__['vault.make_request']('PUT', url, json=payload)
    if response.status_code != 204:
        return {
            'name': name,
            'changes': None,
            'result': False,
            'comment': 'Failed to create policy: {0}'.format(response.reason)
        }

    return {
        'name': name,
        'result': True,
        'changes': {name: {'old': None, 'new': rules}},
        'comment': 'Policy was created'
    }


def _handle_existing_policy(name, new_rules, existing_rules):
    ret = {'name': name}
    if new_rules == existing_rules:
        ret['result'] = True
        ret['changes'] = None
        ret['comment'] = 'Policy exists, and has the correct content'
        return ret

    change = ''.join(difflib.unified_diff(existing_rules.splitlines(True), new_rules.splitlines(True)))
    if __opts__['test']:
        ret['result'] = None
        ret['changes'] = {name: {'change': change}}
        ret['comment'] = 'Policy would be changed'
        return ret

    payload = {'rules': new_rules}

    url = "v1/sys/policy/{0}".format(name)
    response = __utils__['vault.make_request']('PUT', url, json=payload)
    if response.status_code != 204:
        return {
            'name': name,
            'changes': None,
            'result': False,
            'comment': 'Failed to change policy: {0}'.format(response.reason)
        }

    ret['result'] = True
    ret['changes'] = {name: {'change': change}}
    ret['comment'] = 'Policy was updated'

    return ret
