# Copyright (c) 2014 Hewlett-Packard Development Company, L.P.
#
#    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 hashlib
import os

from oslo_concurrency import lockutils
from oslo_log import log as logging
import six
import yaml

from tempest import clients
from tempest.common import cred_provider
from tempest.common import fixed_network
from tempest import config
from tempest import exceptions

CONF = config.CONF
LOG = logging.getLogger(__name__)


def read_accounts_yaml(path):
    with open(path, 'r') as yaml_file:
        accounts = yaml.load(yaml_file)
    return accounts


class PreProvisionedCredentialProvider(cred_provider.CredentialProvider):

    def __init__(self, identity_version=None, name=None):
        super(PreProvisionedCredentialProvider, self).__init__(
            identity_version=identity_version, name=name)
        if (CONF.auth.test_accounts_file and
                os.path.isfile(CONF.auth.test_accounts_file)):
            accounts = read_accounts_yaml(CONF.auth.test_accounts_file)
            self.use_default_creds = False
        else:
            accounts = {}
            self.use_default_creds = True
        self.hash_dict = self.get_hash_dict(accounts)
        self.accounts_dir = os.path.join(lockutils.get_lock_path(CONF),
                                         'test_accounts')
        self._creds = {}

    @classmethod
    def _append_role(cls, role, account_hash, hash_dict):
        if role in hash_dict['roles']:
            hash_dict['roles'][role].append(account_hash)
        else:
            hash_dict['roles'][role] = [account_hash]
        return hash_dict

    @classmethod
    def get_hash_dict(cls, accounts):
        hash_dict = {'roles': {}, 'creds': {}, 'networks': {}}
        # Loop over the accounts read from the yaml file
        for account in accounts:
            roles = []
            types = []
            resources = []
            if 'roles' in account:
                roles = account.pop('roles')
            if 'types' in account:
                types = account.pop('types')
            if 'resources' in account:
                resources = account.pop('resources')
            temp_hash = hashlib.md5()
            temp_hash.update(six.text_type(account).encode('utf-8'))
            temp_hash_key = temp_hash.hexdigest()
            hash_dict['creds'][temp_hash_key] = account
            for role in roles:
                hash_dict = cls._append_role(role, temp_hash_key,
                                             hash_dict)
            # If types are set for the account append the matching role
            # subdict with the hash
            for type in types:
                if type == 'admin':
                    hash_dict = cls._append_role(CONF.identity.admin_role,
                                                 temp_hash_key, hash_dict)
                elif type == 'operator':
                    hash_dict = cls._append_role(
                        CONF.object_storage.operator_role, temp_hash_key,
                        hash_dict)
                elif type == 'reseller_admin':
                    hash_dict = cls._append_role(
                        CONF.object_storage.reseller_admin_role,
                        temp_hash_key,
                        hash_dict)
            # Populate the network subdict
            for resource in resources:
                if resource == 'network':
                    hash_dict['networks'][temp_hash_key] = resources[resource]
                else:
                    LOG.warning('Unknown resource type %s, ignoring this field'
                                % resource)
        return hash_dict

    def is_multi_user(self):
        # Default credentials is not a valid option with locking Account
        if self.use_default_creds:
            raise exceptions.InvalidConfiguration(
                "Account file %s doesn't exist" % CONF.auth.test_accounts_file)
        else:
            return len(self.hash_dict['creds']) > 1

    def is_multi_tenant(self):
        return self.is_multi_user()

    def _create_hash_file(self, hash_string):
        path = os.path.join(os.path.join(self.accounts_dir, hash_string))
        if not os.path.isfile(path):
            with open(path, 'w') as fd:
                fd.write(self.name)
            return True
        return False

    @lockutils.synchronized('test_accounts_io', external=True)
    def _get_free_hash(self, hashes):
        # Cast as a list because in some edge cases a set will be passed in
        hashes = list(hashes)
        if not os.path.isdir(self.accounts_dir):
            os.mkdir(self.accounts_dir)
            # Create File from first hash (since none are in use)
            self._create_hash_file(hashes[0])
            return hashes[0]
        names = []
        for _hash in hashes:
            res = self._create_hash_file(_hash)
            if res:
                return _hash
            else:
                path = os.path.join(os.path.join(self.accounts_dir,
                                                 _hash))
                with open(path, 'r') as fd:
                    names.append(fd.read())
        msg = ('Insufficient number of users provided. %s have allocated all '
               'the credentials for this allocation request' % ','.join(names))
        raise exceptions.InvalidConfiguration(msg)

    def _get_match_hash_list(self, roles=None):
        hashes = []
        if roles:
            # Loop over all the creds for each role in the subdict and generate
            # a list of cred lists for each role
            for role in roles:
                temp_hashes = self.hash_dict['roles'].get(role, None)
                if not temp_hashes:
                    raise exceptions.InvalidConfiguration(
                        "No credentials with role: %s specified in the "
                        "accounts ""file" % role)
                hashes.append(temp_hashes)
            # Take the list of lists and do a boolean and between each list to
            # find the creds which fall under all the specified roles
            temp_list = set(hashes[0])
            for hash_list in hashes[1:]:
                temp_list = temp_list & set(hash_list)
            hashes = temp_list
        else:
            hashes = self.hash_dict['creds'].keys()
        # NOTE(mtreinish): admin is a special case because of the increased
        # privlege set which could potentially cause issues on tests where that
        # is not expected. So unless the admin role isn't specified do not
        # allocate admin.
        admin_hashes = self.hash_dict['roles'].get(CONF.identity.admin_role,
                                                   None)
        if ((not roles or CONF.identity.admin_role not in roles) and
                admin_hashes):
            useable_hashes = [x for x in hashes if x not in admin_hashes]
        else:
            useable_hashes = hashes
        return useable_hashes

    def _sanitize_creds(self, creds):
        temp_creds = creds.copy()
        temp_creds.pop('password')
        return temp_creds

    def _get_creds(self, roles=None):
        if self.use_default_creds:
            raise exceptions.InvalidConfiguration(
                "Account file %s doesn't exist" % CONF.auth.test_accounts_file)
        useable_hashes = self._get_match_hash_list(roles)
        free_hash = self._get_free_hash(useable_hashes)
        clean_creds = self._sanitize_creds(
            self.hash_dict['creds'][free_hash])
        LOG.info('%s allocated creds:\n%s' % (self.name, clean_creds))
        return self._wrap_creds_with_network(free_hash)

    @lockutils.synchronized('test_accounts_io', external=True)
    def remove_hash(self, hash_string):
        hash_path = os.path.join(self.accounts_dir, hash_string)
        if not os.path.isfile(hash_path):
            LOG.warning('Expected an account lock file %s to remove, but '
                        'one did not exist' % hash_path)
        else:
            os.remove(hash_path)
            if not os.listdir(self.accounts_dir):
                os.rmdir(self.accounts_dir)

    def get_hash(self, creds):
        for _hash in self.hash_dict['creds']:
            # Comparing on the attributes that are expected in the YAML
            init_attributes = creds.get_init_attributes()
            hash_attributes = self.hash_dict['creds'][_hash].copy()
            if ('user_domain_name' in init_attributes and 'user_domain_name'
                    not in hash_attributes):
                # Allow for the case of domain_name populated from config
                domain_name = CONF.auth.default_credentials_domain_name
                hash_attributes['user_domain_name'] = domain_name
            if all([getattr(creds, k) == hash_attributes[k] for
                   k in init_attributes]):
                return _hash
        raise AttributeError('Invalid credentials %s' % creds)

    def remove_credentials(self, creds):
        _hash = self.get_hash(creds)
        clean_creds = self._sanitize_creds(self.hash_dict['creds'][_hash])
        self.remove_hash(_hash)
        LOG.info("%s returned allocated creds:\n%s" % (self.name, clean_creds))

    def get_primary_creds(self):
        if self._creds.get('primary'):
            return self._creds.get('primary')
        net_creds = self._get_creds()
        self._creds['primary'] = net_creds
        return net_creds

    def get_alt_creds(self):
        if self._creds.get('alt'):
            return self._creds.get('alt')
        net_creds = self._get_creds()
        self._creds['alt'] = net_creds
        return net_creds

    def get_creds_by_roles(self, roles, force_new=False):
        roles = list(set(roles))
        exist_creds = self._creds.get(six.text_type(roles).encode(
            'utf-8'), None)
        # The force kwarg is used to allocate an additional set of creds with
        # the same role list. The index used for the previously allocation
        # in the _creds dict will be moved.
        if exist_creds and not force_new:
            return exist_creds
        elif exist_creds and force_new:
            new_index = six.text_type(roles).encode('utf-8') + '-' + \
                six.text_type(len(self._creds)).encode('utf-8')
            self._creds[new_index] = exist_creds
        net_creds = self._get_creds(roles=roles)
        self._creds[six.text_type(roles).encode('utf-8')] = net_creds
        return net_creds

    def clear_creds(self):
        for creds in self._creds.values():
            self.remove_credentials(creds)

    def get_admin_creds(self):
        return self.get_creds_by_roles([CONF.identity.admin_role])

    def is_role_available(self, role):
        if self.use_default_creds:
            return False
        else:
            if self.hash_dict['roles'].get(role):
                return True
            return False

    def admin_available(self):
        return self.is_role_available(CONF.identity.admin_role)

    def _wrap_creds_with_network(self, hash):
        creds_dict = self.hash_dict['creds'][hash]
        credential = cred_provider.get_credentials(
            identity_version=self.identity_version, **creds_dict)
        net_creds = cred_provider.TestResources(credential)
        net_clients = clients.Manager(credentials=credential)
        compute_network_client = net_clients.compute_networks_client
        net_name = self.hash_dict['networks'].get(hash, None)
        try:
            network = fixed_network.get_network_from_name(
                net_name, compute_network_client)
        except exceptions.InvalidConfiguration:
            network = {}
        net_creds.set_resources(network=network)
        return net_creds


class NonLockingCredentialProvider(PreProvisionedCredentialProvider):
    """Credentials provider which always returns the first and second
    configured accounts as primary and alt users.
    This credential provider can be used in case of serial test execution
    to preserve the current behaviour of the serial tempest run.
    """

    def _unique_creds(self, cred_arg=None):
        """Verify that the configured credentials are valid and distinct """
        try:
            user = self.get_primary_creds()
            alt_user = self.get_alt_creds()
            return getattr(user, cred_arg) != getattr(alt_user, cred_arg)
        except exceptions.InvalidCredentials as ic:
            msg = "At least one of the configured credentials is " \
                  "not valid: %s" % ic.message
            raise exceptions.InvalidConfiguration(msg)

    def is_multi_user(self):
        return self._unique_creds('username')

    def is_multi_tenant(self):
        return self._unique_creds('tenant_id')

    def get_primary_creds(self):
        if self._creds.get('primary'):
            return self._creds.get('primary')
        primary_credential = cred_provider.get_configured_credentials(
            credential_type='user', identity_version=self.identity_version)
        self._creds['primary'] = cred_provider.TestResources(
            primary_credential)
        return self._creds['primary']

    def get_alt_creds(self):
        if self._creds.get('alt'):
            return self._creds.get('alt')
        alt_credential = cred_provider.get_configured_credentials(
            credential_type='alt_user',
            identity_version=self.identity_version)
        self._creds['alt'] = cred_provider.TestResources(
            alt_credential)
        return self._creds['alt']

    def clear_creds(self):
        self._creds = {}

    def get_admin_creds(self):
        creds = cred_provider.get_configured_credentials(
            "identity_admin", fill_in=False)
        self._creds['admin'] = cred_provider.TestResources(creds)
        return self._creds['admin']

    def get_creds_by_roles(self, roles, force_new=False):
        msg = "Credentials being specified through the config file can not be"\
              " used with tests that specify using credentials by roles. "\
              "Either exclude/skip the tests doing this or use either an "\
              "test_accounts_file or dynamic credentials."
        raise exceptions.InvalidConfiguration(msg)