#!/usr/bin/python
# -*- coding: utf-8 -*-

# Copyright: (c) 2018, JR Kerkstra <jrkerkstra@example.org>
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)

DOCUMENTATION = r"""
---
module: redshift_cross_region_snapshots
version_added: 1.0.0
short_description: Manage Redshift Cross Region Snapshots
description:
  - Manage Redshift Cross Region Snapshots. Supports KMS-Encrypted Snapshots.
  - For more information, see U(https://docs.aws.amazon.com/redshift/latest/mgmt/working-with-snapshots.html#cross-region-snapshot-copy)
author:
  - JR Kerkstra (@captainkerk)
options:
  cluster_name:
    description:
      - The name of the cluster to configure cross-region snapshots for.
    required: true
    aliases: [ "cluster" ]
    type: str
  state:
    description:
      - Create or remove the cross-region snapshot configuration.
    choices: [ "present", "absent" ]
    default: present
    type: str
  region:
    description:
      - "The cluster's region."
    required: true
    aliases: [ "source" ]
    type: str
  destination_region:
    description:
      - The region to copy snapshots to.
    required: true
    aliases: [ "destination" ]
    type: str
  snapshot_copy_grant:
    description:
      - A grant for Amazon Redshift to use a master key in the I(destination_region).
      - See U(http://boto3.readthedocs.io/en/latest/reference/services/redshift.html#Redshift.Client.create_snapshot_copy_grant)
    aliases: [ "copy_grant" ]
    type: str
  snapshot_retention_period:
    description:
      - The number of days to keep cross-region snapshots for.
    required: true
    aliases: [ "retention_period" ]
    type: int
extends_documentation_fragment:
  - amazon.aws.region.modules
  - amazon.aws.common.modules
  - amazon.aws.boto3
"""

EXAMPLES = r"""
- name: configure cross-region snapshot on cluster `johniscool`
  community.aws.redshift_cross_region_snapshots:
    cluster_name: johniscool
    state: present
    region: us-east-1
    destination_region: us-west-2
    retention_period: 1

- name: configure cross-region snapshot on kms-encrypted cluster
  community.aws.redshift_cross_region_snapshots:
    cluster_name: whatever
    state: present
    region: us-east-1
    destination: us-west-2
    copy_grant: 'my-grant-in-destination'
    retention_period: 10

- name: disable cross-region snapshots, necessary before most cluster modifications (rename, resize)
  community.aws.redshift_cross_region_snapshots:
    cluster_name: whatever
    state: absent
    region: us-east-1
    destination_region: us-west-2
"""

RETURN = r""" # """

from ansible_collections.community.aws.plugins.module_utils.modules import AnsibleCommunityAWSModule as AnsibleAWSModule


class SnapshotController(object):
    def __init__(self, client, cluster_name):
        self.client = client
        self.cluster_name = cluster_name

    def get_cluster_snapshot_copy_status(self):
        response = self.client.describe_clusters(ClusterIdentifier=self.cluster_name)
        return response["Clusters"][0].get("ClusterSnapshotCopyStatus")

    def enable_snapshot_copy(self, destination_region, grant_name, retention_period):
        if grant_name:
            self.client.enable_snapshot_copy(
                ClusterIdentifier=self.cluster_name,
                DestinationRegion=destination_region,
                RetentionPeriod=retention_period,
                SnapshotCopyGrantName=grant_name,
            )
        else:
            self.client.enable_snapshot_copy(
                ClusterIdentifier=self.cluster_name,
                DestinationRegion=destination_region,
                RetentionPeriod=retention_period,
            )

    def disable_snapshot_copy(self):
        self.client.disable_snapshot_copy(ClusterIdentifier=self.cluster_name)

    def modify_snapshot_copy_retention_period(self, retention_period):
        self.client.modify_snapshot_copy_retention_period(
            ClusterIdentifier=self.cluster_name, RetentionPeriod=retention_period
        )


def requesting_unsupported_modifications(actual, requested):
    if (
        actual["SnapshotCopyGrantName"] != requested["snapshot_copy_grant"]
        or actual["DestinationRegion"] != requested["destination_region"]
    ):
        return True
    return False


def needs_update(actual, requested):
    if actual["RetentionPeriod"] != requested["snapshot_retention_period"]:
        return True
    return False


def run_module():
    argument_spec = dict(
        cluster_name=dict(type="str", required=True, aliases=["cluster"]),
        state=dict(type="str", choices=["present", "absent"], default="present"),
        region=dict(type="str", required=True, aliases=["source"]),
        destination_region=dict(type="str", required=True, aliases=["destination"]),
        snapshot_copy_grant=dict(type="str", aliases=["copy_grant"]),
        snapshot_retention_period=dict(type="int", required=True, aliases=["retention_period"]),
    )

    module = AnsibleAWSModule(
        argument_spec=argument_spec,
        supports_check_mode=True,
    )

    result = dict(
        changed=False,
        message="",
    )
    connection = module.client("redshift")

    snapshot_controller = SnapshotController(client=connection, cluster_name=module.params.get("cluster_name"))

    current_config = snapshot_controller.get_cluster_snapshot_copy_status()
    if current_config is not None:
        if module.params.get("state") == "present":
            if requesting_unsupported_modifications(current_config, module.params):
                message = (
                    "Cannot modify destination_region or grant_name. Please disable cross-region snapshots, and re-run."
                )
                module.fail_json(msg=message, **result)
            if needs_update(current_config, module.params):
                result["changed"] = True
                if not module.check_mode:
                    snapshot_controller.modify_snapshot_copy_retention_period(
                        module.params.get("snapshot_retention_period")
                    )
        else:
            result["changed"] = True
            if not module.check_mode:
                snapshot_controller.disable_snapshot_copy()
    else:
        if module.params.get("state") == "present":
            result["changed"] = True
            if not module.check_mode:
                snapshot_controller.enable_snapshot_copy(
                    module.params.get("destination_region"),
                    module.params.get("snapshot_copy_grant"),
                    module.params.get("snapshot_retention_period"),
                )
    module.exit_json(**result)


def main():
    run_module()


if __name__ == "__main__":
    main()