# Copyright 2019 Google LLC
#
# 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 re
from typing import List, Dict
from kubernetes.client.models import (V1ObjectMeta, V1ResourceRequirements,
                                      V1PersistentVolumeClaimSpec,
                                      V1PersistentVolumeClaim,
                                      V1TypedLocalObjectReference)

from ._resource_op import ResourceOp
from ._pipeline_param import (PipelineParam, match_serialized_pipelineparam,
                              sanitize_k8s_name)
from ._pipeline_volume import PipelineVolume

VOLUME_MODE_RWO = ["ReadWriteOnce"]
VOLUME_MODE_RWM = ["ReadWriteMany"]
VOLUME_MODE_ROM = ["ReadOnlyMany"]


class VolumeOp(ResourceOp):
  """Represents an op which will be translated into a resource template which will be creating a PVC.

  TODO(https://github.com/kubeflow/pipelines/issues/4822): Determine the
      stability level of this feature.

  Args:
    resource_name: A desired name for the PVC which will be created
    size: The size of the PVC which will be created
    storage_class: The storage class to use for the dynamically created PVC
    modes: The access modes for the PVC
    annotations: Annotations to be patched in the PVC
    data_source: May be a V1TypedLocalObjectReference, and then it is used
      in the data_source field of the PVC as is. Can also be a
      string/PipelineParam, and in that case it will be used as a
      VolumeSnapshot name (Alpha feature)
    volume_name: VolumeName is the binding reference to the PersistentVolume
      backing this claim.
    kwargs: See :py:class:`kfp.dsl.ResourceOp`

  Raises:
    ValueError: if k8s_resource is provided along with other arguments
                if k8s_resource is not a V1PersistentVolumeClaim
                if size is None
                if size is an invalid memory string (when not a
                    PipelineParam)
                if data_source is not one of (str, PipelineParam,
                    V1TypedLocalObjectReference)
    """

  def __init__(self,
               resource_name: str = None,
               size: str = None,
               storage_class: str = None,
               modes: List[str] = None,
               annotations: Dict[str, str] = None,
               data_source=None,
               volume_name=None,
               **kwargs):
    # Add size to attribute outputs
    self.attribute_outputs = {"size": "{.status.capacity.storage}"}

    if "k8s_resource" in kwargs:
      if resource_name or size or storage_class or modes or annotations:
        raise ValueError("You cannot provide k8s_resource along with "
                         "other arguments.")
      if not isinstance(kwargs["k8s_resource"], V1PersistentVolumeClaim):
        raise ValueError("k8s_resource in VolumeOp must be an instance"
                         " of V1PersistentVolumeClaim")
      super().__init__(**kwargs)
      self.volume = PipelineVolume(
          name=sanitize_k8s_name(self.name), pvc=self.outputs["name"])
      return

    if not size:
      raise ValueError("Please provide size")
    elif not match_serialized_pipelineparam(str(size)):
      self._validate_memory_string(size)

    if data_source and not isinstance(
        data_source, (str, PipelineParam, V1TypedLocalObjectReference)):
      raise ValueError("data_source can be one of (str, PipelineParam, "
                       "V1TypedLocalObjectReference).")
    if data_source and isinstance(data_source, (str, PipelineParam)):
      data_source = V1TypedLocalObjectReference(
          api_group="snapshot.storage.k8s.io",
          kind="VolumeSnapshot",
          name=data_source)

    # Set the k8s_resource
    if not match_serialized_pipelineparam(str(resource_name)):
      resource_name = sanitize_k8s_name(resource_name)
    pvc_metadata = V1ObjectMeta(
        name="{{workflow.name}}-%s" % resource_name, annotations=annotations)
    requested_resources = V1ResourceRequirements(requests={"storage": size})
    pvc_spec = V1PersistentVolumeClaimSpec(
        access_modes=modes or VOLUME_MODE_RWM,
        resources=requested_resources,
        storage_class_name=storage_class,
        data_source=data_source,
        volume_name=volume_name)
    k8s_resource = V1PersistentVolumeClaim(
        api_version="v1",
        kind="PersistentVolumeClaim",
        metadata=pvc_metadata,
        spec=pvc_spec)

    super().__init__(
        k8s_resource=k8s_resource,
        **kwargs,
    )
    self.volume = PipelineVolume(
        name=sanitize_k8s_name(self.name), pvc=self.outputs["name"])

  def _validate_memory_string(self, memory_string):
    """Validate a given string is valid for memory request or limit."""
    if re.match(r"^[0-9]+(E|Ei|P|Pi|T|Ti|G|Gi|M|Mi|K|Ki){0,1}$",
                memory_string) is None:
      raise ValueError("Invalid memory string. Should be an integer, " +
                       "or integer followed by one of " +
                       '"E|Ei|P|Pi|T|Ti|G|Gi|M|Mi|K|Ki"')
