# Copyright 2014: Mirantis Inc.
# All Rights Reserved.
#
#    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 functools
import os
import re

from glanceclient import exc as glance_exc
from novaclient import exceptions as nova_exc
import six

from rally.common.i18n import _
from rally.common import objects
from rally import consts
from rally import exceptions
from rally import osclients
from rally.plugins.openstack.context.nova import flavors as flavors_ctx
from rally.task import types
from rally.verification.tempest import tempest

# TODO(boris-42): make the validators usable as a functions as well.
# At the moment validators can only be used as decorators.


class ValidationResult(object):

    def __init__(self, is_valid, msg=None):
        self.is_valid = is_valid
        self.msg = msg


def validator(fn):
    """Decorator that constructs a scenario validator from given function.

    Decorated function should return ValidationResult on error.

    :param fn: function that performs validation
    :returns: rally scenario validator
    """
    def wrap_given(*args, **kwargs):
        """Dynamic validation decorator for scenario.

        :param args: the arguments of the decorator of the benchmark scenario
        ex. @my_decorator("arg1"), then args = ("arg1",)
        :param kwargs: the keyword arguments of the decorator of the scenario
        ex. @my_decorator(kwarg1="kwarg1"), then kwargs = {"kwarg1": "kwarg1"}
        """
        @functools.wraps(fn)
        def wrap_validator(config, clients, deployment):
            # NOTE(amaretskiy): validator is successful by default
            return (fn(config, clients, deployment, *args, **kwargs) or
                    ValidationResult(True))

        def wrap_scenario(scenario):
            # TODO(boris-42): remove this in future.
            wrap_validator.permission = getattr(fn, "permission",
                                                consts.EndpointPermission.USER)

            scenario._meta_setdefault("validators", [])
            scenario._meta_get("validators").append(wrap_validator)
            return scenario

        return wrap_scenario

    return wrap_given


@validator
def number(config, clients, deployment, param_name, minval=None, maxval=None,
           nullable=False, integer_only=False):
    """Checks that parameter is number that pass specified condition.

    Ensure a parameter is within the range [minval, maxval]. This is a
    closed interval so the end points are included.

    :param param_name: Name of parameter to validate
    :param minval: Lower endpoint of valid interval
    :param maxval: Upper endpoint of valid interval
    :param nullable: Allow parameter not specified, or paramater=None
    :param integer_only: Only accept integers
    """

    val = config.get("args", {}).get(param_name)

    num_func = float
    if integer_only:
        # NOTE(boris-42): Force check that passed value is not float, this is
        #                 important cause int(float_numb) won't raise exception
        if type(val) == float:
            return ValidationResult(False,
                                    "%(name)s is %(val)s which hasn't int type"
                                    % {"name": param_name, "val": val})
        num_func = int

    # None may be valid if the scenario sets a sensible default.
    if nullable and val is None:
        return ValidationResult(True)

    try:
        number = num_func(val)
        if minval is not None and number < minval:
            return ValidationResult(
                False,
                "%(name)s is %(val)s which is less than the minimum "
                "(%(min)s)"
                % {"name": param_name, "val": number, "min": minval})
        if maxval is not None and number > maxval:
            return ValidationResult(
                False,
                "%(name)s is %(val)s which is greater than the maximum "
                "(%(max)s)"
                % {"name": param_name, "val": number, "max": maxval})
        return ValidationResult(True)
    except (ValueError, TypeError):
        return ValidationResult(
            False,
            "%(name)s is %(val)s which is not a valid %(type)s"
            % {"name": param_name, "val": val, "type": num_func.__name__})


def _file_access_ok(filename, mode, param_name, required=True):
    if not filename:
        return ValidationResult(not required,
                                "Parameter %s required" % param_name)
    if not os.access(os.path.expanduser(filename), mode):
        return ValidationResult(
            False, "Could not open %(filename)s with mode %(mode)s "
            "for parameter %(param_name)s"
            % {"filename": filename, "mode": mode, "param_name": param_name})
    return ValidationResult(True)


@validator
def file_exists(config, clients, deployment, param_name, mode=os.R_OK,
                required=True):
    """Validator checks parameter is proper path to file with proper mode.

    Ensure a file exists and can be accessed with the specified mode.
    Note that path to file will be expanded before access checking.

    :param param_name: Name of parameter to validate
    :param mode: Access mode to test for. This should be one of:
        * os.F_OK (file exists)
        * os.R_OK (file is readable)
        * os.W_OK (file is writable)
        * os.X_OK (file is executable)

        If multiple modes are required they can be added, eg:
            mode=os.R_OK+os.W_OK
    :param required: Boolean indicating whether this argument is required.
    """

    return _file_access_ok(config.get("args", {}).get(param_name), mode,
                           param_name, required)


def check_command_dict(command):
    """Check command-specifying dict `command', raise ValueError on error."""

    # NOTE(pboldin): Here we check for the values not for presence of the keys
    # due to template-driven configuration generation that can leave keys
    # defined but values empty.
    if command.get("interpreter"):
        script_file = command.get("script_file")
        if script_file:
            command["script_file"] = os.path.expanduser(script_file)
            if "script_inline" in command:
                raise ValueError(
                    "Exactly one of script_inline or script_file with "
                    "interpreter is expected: %r" % command)
        # User tries to upload a shell? Make sure it is same as interpreter
        interpreter = command.get("interpreter")
        interpreter = (interpreter[-1]
                       if isinstance(interpreter, (tuple, list))
                       else interpreter)
        if (command.get("local_path") and
           command.get("remote_path") != interpreter):
            raise ValueError(
                "When uploading an interpreter its path should be as well"
                " specified as the `remote_path' string: %r" % command)
    elif not command.get("remote_path"):
        # No interpreter and no remote command to execute is given
        raise ValueError(
            "Supplied dict specifies no command to execute,"
            " either interpreter or remote_path is required: %r" % command)


@validator
def valid_command(config, clients, deployment, param_name, required=True):
    """Checks that parameter is a proper command-specifying dictionary.

    Ensure that the command dictionary is a proper command-specifying
    dictionary described in `vmtasks.VMTasks.boot_runcommand_delete' docstring.

    :param param_name: Name of parameter to validate
    :param required: Boolean indicating that the command dictionary is required
    """
    # TODO(pboldin): Make that a `jsonschema' check once generic validator
    # is available.

    command = config.get("args", {}).get(param_name)
    if command is None:
        return ValidationResult(not required,
                                "Command dicitionary is required")
    try:
        check_command_dict(command)
    except ValueError as e:
        return ValidationResult(False, str(e))

    for key in "script_file", "local_path":
        if command.get(key):
            return _file_access_ok(
                filename=command[key],
                mode=os.R_OK,
                param_name=param_name + "." + key,
                required=True)

    return ValidationResult(True)


def _get_validated_image(config, clients, param_name):
    image_context = config.get("context", {}).get("images", {})
    image_args = config.get("args", {}).get(param_name)
    image_ctx_name = image_context.get("image_name")

    if not image_args:
        msg = _("Parameter %s is not specified.") % param_name
        return (ValidationResult(False, msg), None)
    if "image_name" in image_context:
        # NOTE(rvasilets) check string is "exactly equal to" a regex
        # or image name from context equal to image name from args
        if "regex" in image_args:
            match = re.match(image_args.get("regex"), image_ctx_name)
        if image_ctx_name == image_args.get("name") or (
                "regex" in image_args and match):
            image = {
                "size": image_context.get("min_disk", 0),
                "min_ram": image_context.get("min_ram", 0),
                "min_disk": image_context.get("min_disk", 0)
            }
            return (ValidationResult(True), image)
    try:
        image_id = types.ImageResourceType.transform(
            clients=clients, resource_config=image_args)
        image = clients.glance().images.get(image=image_id).to_dict()
        return (ValidationResult(True), image)
    except (glance_exc.HTTPNotFound, exceptions.InvalidScenarioArgument):
        message = _("Image '%s' not found") % image_args
        return (ValidationResult(False, message), None)


def _get_flavor_from_context(config, flavor_value):
    if "flavors" not in config.get("context", {}):
        raise exceptions.InvalidScenarioArgument("No flavors context")

    flavors = [flavors_ctx.FlavorConfig(**f)
               for f in config["context"]["flavors"]]
    resource = types.obj_from_name(resource_config=flavor_value,
                                   resources=flavors, typename="flavor")
    flavor = flavors_ctx.FlavorConfig(**resource)
    flavor.id = "<context flavor: %s>" % flavor.name
    return (ValidationResult(True), flavor)


def _get_validated_flavor(config, clients, param_name):
    flavor_value = config.get("args", {}).get(param_name)
    if not flavor_value:
        msg = "Parameter %s is not specified." % param_name
        return (ValidationResult(False, msg), None)
    try:
        flavor_id = types.FlavorResourceType.transform(
            clients=clients, resource_config=flavor_value)
        flavor = clients.nova().flavors.get(flavor=flavor_id)
        return (ValidationResult(True), flavor)
    except (nova_exc.NotFound, exceptions.InvalidScenarioArgument):
        try:
            return _get_flavor_from_context(config, flavor_value)
        except exceptions.InvalidScenarioArgument:
            pass
        message = _("Flavor '%s' not found") % flavor_value
        return (ValidationResult(False, message), None)


@validator
def validate_share_proto(config, clients, deployment):
    """Validates value of share protocol for creation of Manila share."""
    allowed = ("NFS", "CIFS", "GLUSTERFS", "HDFS", )
    share_proto = config.get("args", {}).get("share_proto")
    if six.text_type(share_proto).upper() not in allowed:
        message = _("Share protocol '%(sp)s' is invalid, allowed values are "
                    "%(allowed)s.") % {"sp": share_proto,
                                       "allowed": "', '".join(allowed)}
        return ValidationResult(False, message)


@validator
def image_exists(config, clients, deployment, param_name, nullable=False):
    """Returns validator for image_id

    :param param_name: defines which variable should be used
                       to get image id value.
    :param nullable: defines image id param is required
    """
    image_value = config.get("args", {}).get(param_name)
    if not image_value and nullable:
        return ValidationResult(True)
    return _get_validated_image(config, clients, param_name)[0]


@validator
def flavor_exists(config, clients, deployment, param_name):
    """Returns validator for flavor

    :param param_name: defines which variable should be used
                       to get flavor id value.
    """
    return _get_validated_flavor(config, clients, param_name)[0]


@validator
def image_valid_on_flavor(config, clients, deployment, flavor_name,
                          image_name):
    """Returns validator for image could be used for current flavor

    :param flavor_name: defines which variable should be used
                       to get flavor id value.
    :param image_name: defines which variable should be used
                       to get image id value.

    """
    valid_result, flavor = _get_validated_flavor(config, clients, flavor_name)
    if not valid_result.is_valid:
        return valid_result

    valid_result, image = _get_validated_image(config, clients, image_name)
    if not valid_result.is_valid:
        return valid_result

    if flavor.ram < (image["min_ram"] or 0):
        message = _("The memory size for flavor '%s' is too small "
                    "for requested image '%s'") % (flavor.id, image["id"])
        return ValidationResult(False, message)

    if flavor.disk:
        if (image["size"] or 0) > flavor.disk * (1024 ** 3):
            message = _("The disk size for flavor '%s' is too small "
                        "for requested image '%s'") % (flavor.id, image["id"])
            return ValidationResult(False, message)

        if (image["min_disk"] or 0) > flavor.disk:
            message = _("The disk size for flavor '%s' is too small "
                        "for requested image '%s'") % (flavor.id, image["id"])
            return ValidationResult(False, message)


@validator
def network_exists(config, clients, deployment, network_name):
    """Validator checks that network with network_name exist."""

    network = config.get("args", {}).get(network_name, "private")

    networks = [net.label for net in
                clients.nova().networks.list()]
    if network not in networks:
        message = _("Network with name %(network)s not found. "
                    "Available networks: %(networks)s") % {
                        "network": network,
                        "networks": networks
        }
        return ValidationResult(False, message)


@validator
def external_network_exists(config, clients, deployment, network_name):
    """Validator checks that external network with given name exists."""
    ext_network = config.get("args", {}).get(network_name)
    if not ext_network:
        return ValidationResult(True)

    networks = [net.name for net in clients.nova().floating_ip_pools.list()]

    if networks and isinstance(networks[0], dict):
        networks = [n["name"] for n in networks]

    if ext_network not in networks:
        message = _("External (floating) network with name %(network)s "
                    "not found. "
                    "Available networks: %(networks)s") % {
                        "network": ext_network,
                        "networks": networks}
        return ValidationResult(False, message)


@validator
def tempest_tests_exists(config, clients, deployment):
    """Validator checks that specified test exists."""
    args = config.get("args", {})

    if "test_name" in args:
        tests = [args["test_name"]]
    else:
        tests = args.get("test_names", [])

    if not tests:
        return ValidationResult(False,
                                _("Parameter 'test_name' or 'test_names' "
                                  "should be specified."))
    verifier = tempest.Tempest(
        deployment["uuid"],
        source=config.get("context", {}).get("tempest", {}).get("source"))
    if not verifier.is_installed():
        try:
            verifier.install()
        except tempest.TempestSetupFailure as e:
            return ValidationResult(False, e)
    if not verifier.is_configured():
        verifier.generate_config_file()

    allowed_tests = verifier.discover_tests()

    for i, test in enumerate(tests):
        if not test.startswith("tempest.api."):
            tests[i] = "tempest.api." + test

    wrong_tests = set(tests) - allowed_tests

    if wrong_tests:
        message = (_("One or more tests not found: '%s'") %
                   "', '".join(sorted(wrong_tests)))
        return ValidationResult(False, message)


@validator
def tempest_set_exists(config, clients, deployment):
    """Validator that check that tempest set_name is valid."""
    set_name = config.get("args", {}).get("set_name")

    if not set_name:
        return ValidationResult(False, "`set_name` is not specified.")

    if set_name not in (list(consts.TempestTestsSets) +
                        list(consts.TempestTestsAPI)):
        message = _("There is no tempest set with name '%s'.") % set_name
        return ValidationResult(False, message)


@validator
def required_parameters(config, clients, deployment, *required_params):
    """Validator for checking required parameters are specified.

    :param *required_params: list of required parameters
    """
    missing = set(required_params) - set(config.get("args", {}))
    if missing:
        message = _("%s parameters are not defined in "
                    "the benchmark config file") % ", ".join(missing)
        return ValidationResult(False, message)


@validator
def required_services(config, clients, deployment, *required_services):
    """Validator checks if specified OpenStack services are available.

    :param *required_services: list of services names
    """
    available_services = list(clients.services().values())

    if consts.Service.NOVA_NET in required_services:
        nova = osclients.Clients(
            objects.Endpoint(**deployment["admin"])).nova()
        for service in nova.services.list():
            if (service.binary == consts.Service.NOVA_NET and
                    service.status == "enabled"):
                available_services.append(consts.Service.NOVA_NET)

    for service in required_services:
        if service not in consts.Service:
            return ValidationResult(False, _("Unknown service: %s") % service)
        if service not in available_services:
            return ValidationResult(
                False, _("Service is not available: %s") % service)


@validator
def required_neutron_extensions(config, clients, deployment,
                                *required_extensions):
    """Validator checks if the specified Neutron extension is available

    :param required_extensions: list of Neutron extensions
    """
    extensions = clients.neutron().list_extensions().get("extensions", [])
    aliases = map(lambda x: x["alias"], extensions)
    for extension in required_extensions:
        if extension not in aliases:
            msg = (_("Neutron extension %s is not configured") % extension)
            return ValidationResult(False, msg)


@validator
def required_cinder_services(config, clients, deployment, service_name):
    """Validator checks that specified Cinder service is available.

    It uses Cinder client with admin permissions to call 'cinder service-list'
    call

    :param service_name: Cinder service name
    """

    admin_client = osclients.Clients(
        objects.Endpoint(**deployment["admin"])).cinder()

    for service in admin_client.services.list():
        if (service.binary == six.text_type(service_name) and
                service.state == six.text_type("up")):
            return ValidationResult(True)

    msg = _("%s service is not available") % service_name
    return ValidationResult(False, msg)


@validator
def required_clients(config, clients, deployment, *components, **kwargs):
    """Validator checks if specified OpenStack clients are available.

    :param *components: list of client components names
    :param **kwargs: optional parameters:
                     admin - bool, whether to use admin clients
    """
    if kwargs.get("admin", False):
        clients = osclients.Clients(objects.Endpoint(**deployment["admin"]))

    for client_component in components:
        try:
            getattr(clients, client_component)()
        except ImportError:
            return ValidationResult(
                False,
                _("Client for %s is not installed. To install it run "
                  "`pip install -r"
                  " optional-requirements.txt`") % client_component)


@validator
def required_contexts(config, clients, deployment, *context_names):
    """Validator checks if required benchmark contexts are specified.

    :param *context_names: list of context names that should be specified
    """
    missing_contexts = set(context_names) - set(config.get("context", {}))
    if missing_contexts:
        message = (_("The following contexts are required but missing from "
                     "the benchmark configuration file: %s") %
                   ", ".join(missing_contexts))
        return ValidationResult(False, message)


@validator
def required_openstack(config, clients, deployment, admin=False, users=False):
    """Validator that requires OpenStack admin or (and) users.

    This allows us to create 4 kind of benchmarks:
    1) not OpenStack related (validator is not specified)
    2) requires OpenStack admin
    3) requires OpenStack admin + users
    4) requires OpenStack users

    :param admin: requires OpenStack admin
    :param users: requires OpenStack users
    """

    if not (admin or users):
        return ValidationResult(
            False, _("You should specify admin=True or users=True or both."))

    if deployment["admin"] and deployment["users"]:
        return ValidationResult(True)

    if deployment["admin"]:
        if users and not config.get("context", {}).get("users"):
            return ValidationResult(False,
                                    _("You should specify 'users' context"))
        return ValidationResult(True)

    if deployment["users"] and admin:
        return ValidationResult(False, _("Admin credentials required"))


@validator
def volume_type_exists(config, clients, deployment, param_name):
    """Returns validator for volume types.

       check_types: defines variable to be used as the flag to determine if
                    volume types should be checked for existence.
    """
    val = config.get("args", {}).get(param_name)
    if val:
        volume_types_list = clients.cinder().volume_types.list()
        if len(volume_types_list) < 1:
            message = (_("Must have at least one volume type created "
                         "when specifying use of volume types."))
            return ValidationResult(False, message)


@validator
def restricted_parameters(config, clients, deployment, param_names,
                          subdict=None):
    """Validates that parameters is not set.

    :param param_names: parameter or parameters list to be validated.
    :param subdict: sub-dict of "config" to search for param_names. if
                    not defined - will search in "config"
    """
    if not isinstance(param_names, (list, tuple)):
        param_names = [param_names]

    restricted_params = []
    for param_name in param_names:
        args = config.get("args", {})
        a_dict, a_key = (args, subdict) if subdict else (config, "args")
        if param_name in a_dict.get(a_key, {}):
            restricted_params.append(param_name)
    if restricted_params:
        msg = (_("You can't specify parameters '%(params)s' in '%(a_dict)s'")
               % {"params": ", ".join(restricted_params),
                  "a_dict": subdict if subdict else "args"})
        return ValidationResult(False, msg)
