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

# Copyright: Ansible Project
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)

DOCUMENTATION = r"""
---
module: ec2_vpc_igw
version_added: 1.0.0
short_description: Manage an AWS VPC Internet gateway
description:
    - Manage an AWS VPC Internet gateway.
author: Robert Estelle (@erydo)
options:
  internet_gateway_id:
    version_added: 7.0.0
    description:
      - The ID of Internet Gateway to manage.
    required: false
    type: str
  vpc_id:
    description:
      - The VPC ID for the VPC to attach (when O(state=present)).
      - VPC ID can also be provided to find the internet gateway to manage that the VPC is attached to.
    required: false
    type: str
  state:
    description:
      - Create or terminate the IGW.
    default: present
    choices: [ 'present', 'absent' ]
    type: str
  force_attach:
    version_added: 7.0.0
    description:
      - Force attaching VPC to O(vpc_id).
      - Setting this option to true will detach an existing VPC attachment and attach to the supplied O(vpc_id).
      - Ignored when O(state=absent).
      - O(vpc_id) must be specified when O(force_attach=true).
    default: false
    type: bool
  detach_vpc:
    version_added: 7.0.0
    description:
      - Remove attached VPC from gateway.
    default: false
    type: bool
notes:
- Support for O(purge_tags) was added in release 1.3.0.
extends_documentation_fragment:
  - amazon.aws.common.modules
  - amazon.aws.region.modules
  - amazon.aws.tags
  - amazon.aws.boto3
"""

EXAMPLES = r"""
# Note: These examples do not set authentication details, see the AWS Guide for details.

# Ensure that the VPC has an Internet Gateway.
# The Internet Gateway ID is can be accessed via {{igw.gateway_id}} for use in setting up NATs etc.
- name: Create Internet gateway
  amazon.aws.ec2_vpc_igw:
    vpc_id: vpc-abcdefgh
    state: present
  register: igw

- name: Create Internet gateway with tags
  amazon.aws.ec2_vpc_igw:
    vpc_id: vpc-abcdefgh
    state: present
    tags:
      Tag1: tag1
      Tag2: tag2
  register: igw

- name: Create a detached gateway
  amazon.aws.ec2_vpc_igw:
    state: present
  register: igw

- name: Change the VPC the gateway is attached to
  amazon.aws.ec2_vpc_igw:
    internet_gateway_id: igw-abcdefgh
    vpc_id: vpc-stuvwxyz
    force_attach: true
    state: present
  register: igw

- name: Delete Internet gateway using the attached vpc id
  amazon.aws.ec2_vpc_igw:
    state: absent
    vpc_id: vpc-abcdefgh
  register: vpc_igw_delete

- name: Delete Internet gateway with gateway id
  amazon.aws.ec2_vpc_igw:
    state: absent
    internet_gateway_id: igw-abcdefgh
  register: vpc_igw_delete

- name: Delete Internet gateway ensuring attached VPC is correct
  amazon.aws.ec2_vpc_igw:
    state: absent
    internet_gateway_id: igw-abcdefgh
    vpc_id: vpc-abcdefgh
  register: vpc_igw_delete
"""

RETURN = r"""
changed:
  description: If any changes have been made to the Internet Gateway.
  type: bool
  returned: always
  sample:
    changed: false
gateway_id:
  description: The unique identifier for the Internet Gateway.
  type: str
  returned: O(state=present)
  sample:
    gateway_id: "igw-XXXXXXXX"
tags:
  description: The tags associated the Internet Gateway.
  type: dict
  returned: O(state=present)
  sample:
    tags:
      "Ansible": "Test"
vpc_id:
  description: The VPC ID associated with the Internet Gateway.
  type: str
  returned: O(state=present)
  sample:
    vpc_id: "vpc-XXXXXXXX"
"""

try:
    import botocore
except ImportError:
    pass  # caught by AnsibleAWSModule

from ansible.module_utils.common.dict_transformations import camel_dict_to_snake_dict

from ansible_collections.amazon.aws.plugins.module_utils.ec2 import ensure_ec2_tags
from ansible_collections.amazon.aws.plugins.module_utils.modules import AnsibleAWSModule
from ansible_collections.amazon.aws.plugins.module_utils.retries import AWSRetry
from ansible_collections.amazon.aws.plugins.module_utils.tagging import boto3_tag_list_to_ansible_dict
from ansible_collections.amazon.aws.plugins.module_utils.tagging import boto3_tag_specifications
from ansible_collections.amazon.aws.plugins.module_utils.transformation import ansible_dict_to_boto3_filter_list
from ansible_collections.amazon.aws.plugins.module_utils.waiters import get_waiter


@AWSRetry.jittered_backoff(retries=10, delay=10)
def describe_igws_with_backoff(connection, **params):
    paginator = connection.get_paginator("describe_internet_gateways")
    return paginator.paginate(**params).build_full_result()["InternetGateways"]


def describe_vpcs_with_backoff(connection, **params):
    paginator = connection.get_paginator("describe_vpcs")
    return paginator.paginate(**params).build_full_result()["Vpcs"]


class AnsibleEc2Igw:
    def __init__(self, module, results):
        self._module = module
        self._results = results
        self._connection = self._module.client("ec2", retry_decorator=AWSRetry.jittered_backoff())
        self._check_mode = self._module.check_mode

    def process(self):
        internet_gateway_id = self._module.params.get("internet_gateway_id")
        vpc_id = self._module.params.get("vpc_id")
        state = self._module.params.get("state", "present")
        tags = self._module.params.get("tags")
        purge_tags = self._module.params.get("purge_tags")
        force_attach = self._module.params.get("force_attach")
        detach_vpc = self._module.params.get("detach_vpc")

        if state == "present":
            self.ensure_igw_present(internet_gateway_id, vpc_id, tags, purge_tags, force_attach, detach_vpc)
        elif state == "absent":
            self.ensure_igw_absent(internet_gateway_id, vpc_id)

    def get_matching_igw(self, vpc_id, gateway_id=None):
        """
        Returns the internet gateway found.
            Parameters:
                vpc_id (str): VPC ID
                gateway_id (str): Internet Gateway ID, if specified
            Returns:
                igw (dict): dict of igw found, None if none found
        """
        try:
            # If we know the gateway_id, use it to avoid bugs with using filters
            # See https://github.com/ansible-collections/amazon.aws/pull/766
            if not gateway_id:
                filters = ansible_dict_to_boto3_filter_list({"attachment.vpc-id": vpc_id})
                igws = describe_igws_with_backoff(self._connection, Filters=filters)
            else:
                igws = describe_igws_with_backoff(self._connection, InternetGatewayIds=[gateway_id])
        except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
            self._module.fail_json_aws(e)

        igw = None
        if len(igws) > 1:
            self._module.fail_json(msg=f"EC2 returned more than one Internet Gateway for VPC {vpc_id}, aborting")
        elif igws:
            igw = camel_dict_to_snake_dict(igws[0])

        return igw

    def get_matching_vpc(self, vpc_id):
        """
        Returns the virtual private cloud found.
            Parameters:
                vpc_id (str): VPC ID
            Returns:
                vpc (dict): dict of vpc found, None if none found
        """
        try:
            vpcs = describe_vpcs_with_backoff(self._connection, VpcIds=[vpc_id])
        except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
            # self._module.fail_json(msg=f"{str(e)}")
            if "InvalidVpcID.NotFound" in str(e):
                self._module.fail_json(msg=f"VPC with Id {vpc_id} not found, aborting")
            self._module.fail_json_aws(e)

        vpc = None
        if len(vpcs) > 1:
            self._module.fail_json(msg=f"EC2 returned more than one VPC for {vpc_id}, aborting")
        elif vpcs:
            vpc = camel_dict_to_snake_dict(vpcs[0])

        return vpc

    @staticmethod
    def get_igw_info(igw, vpc_id):
        return {
            "gateway_id": igw["internet_gateway_id"],
            "tags": boto3_tag_list_to_ansible_dict(igw["tags"]),
            "vpc_id": vpc_id,
        }

    def detach_vpc(self, igw_id, vpc_id):
        try:
            self._connection.detach_internet_gateway(aws_retry=True, InternetGatewayId=igw_id, VpcId=vpc_id)

            self._results["changed"] = True
        except botocore.exceptions.WaiterError as e:
            self._module.fail_json_aws(e, msg="Unable to detach VPC.")

    def attach_vpc(self, igw_id, vpc_id):
        try:
            self._connection.attach_internet_gateway(aws_retry=True, InternetGatewayId=igw_id, VpcId=vpc_id)

            # Ensure the gateway is attached before proceeding
            waiter = get_waiter(self._connection, "internet_gateway_attached")
            waiter.wait(InternetGatewayIds=[igw_id])

            self._results["changed"] = True
        except botocore.exceptions.WaiterError as e:
            self._module.fail_json_aws(e, msg="Failed to attach VPC.")

    def ensure_igw_absent(self, igw_id, vpc_id):
        igw = self.get_matching_igw(vpc_id, gateway_id=igw_id)
        if igw is None:
            return self._results

        igw_vpc_id = ""

        if len(igw["attachments"]) > 0:
            igw_vpc_id = igw["attachments"][0]["vpc_id"]

        if vpc_id and (igw_vpc_id != vpc_id):
            self._module.fail_json(msg=f"Supplied VPC ({vpc_id}) does not match found VPC ({igw_vpc_id}), aborting")

        if self._check_mode:
            self._results["changed"] = True
            return self._results

        try:
            self._results["changed"] = True

            if igw_vpc_id:
                self.detach_vpc(igw["internet_gateway_id"], igw_vpc_id)

            self._connection.delete_internet_gateway(aws_retry=True, InternetGatewayId=igw["internet_gateway_id"])
        except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
            self._module.fail_json_aws(e, msg="Unable to delete Internet Gateway")

        return self._results

    def ensure_igw_present(self, igw_id, vpc_id, tags, purge_tags, force_attach, detach_vpc):
        igw = None

        if igw_id:
            igw = self.get_matching_igw(None, gateway_id=igw_id)
        elif vpc_id:
            igw = self.get_matching_igw(vpc_id)

        if igw is None:
            if self._check_mode:
                self._results["changed"] = True
                self._results["gateway_id"] = None
                return self._results

            if vpc_id:
                self.get_matching_vpc(vpc_id)

            try:
                create_params = {}
                if tags:
                    create_params["TagSpecifications"] = boto3_tag_specifications(tags, types="internet-gateway")
                response = self._connection.create_internet_gateway(aws_retry=True, **create_params)

                # Ensure the gateway exists before trying to attach it or add tags
                waiter = get_waiter(self._connection, "internet_gateway_exists")
                waiter.wait(InternetGatewayIds=[response["InternetGateway"]["InternetGatewayId"]])
                self._results["changed"] = True

                igw = camel_dict_to_snake_dict(response["InternetGateway"])

                if vpc_id:
                    self.attach_vpc(igw["internet_gateway_id"], vpc_id)
            except botocore.exceptions.WaiterError as e:
                self._module.fail_json_aws(e, msg="No Internet Gateway exists.")
            except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
                self._module.fail_json_aws(e, msg="Unable to create Internet Gateway")
        else:
            igw_vpc_id = None

            if len(igw["attachments"]) > 0:
                igw_vpc_id = igw["attachments"][0]["vpc_id"]

                if detach_vpc:
                    if self._check_mode:
                        self._results["changed"] = True
                        self._results["gateway_id"] = igw["internet_gateway_id"]
                        return self._results

                    self.detach_vpc(igw["internet_gateway_id"], igw_vpc_id)

                elif igw_vpc_id != vpc_id:
                    if self._check_mode:
                        self._results["changed"] = True
                        self._results["gateway_id"] = igw["internet_gateway_id"]
                        return self._results

                    if force_attach:
                        self.get_matching_vpc(vpc_id)

                        self.detach_vpc(igw["internet_gateway_id"], igw_vpc_id)
                        self.attach_vpc(igw["internet_gateway_id"], vpc_id)
                    else:
                        self._module.fail_json(msg="VPC already attached, but does not match requested VPC.")

            elif vpc_id:
                if self._check_mode:
                    self._results["changed"] = True
                    self._results["gateway_id"] = igw["internet_gateway_id"]
                    return self._results

                self.get_matching_vpc(vpc_id)
                self.attach_vpc(igw["internet_gateway_id"], vpc_id)

        # Modify tags
        self._results["changed"] |= ensure_ec2_tags(
            self._connection,
            self._module,
            igw["internet_gateway_id"],
            resource_type="internet-gateway",
            tags=tags,
            purge_tags=purge_tags,
            retry_codes="InvalidInternetGatewayID.NotFound",
        )

        # Update igw
        igw = self.get_matching_igw(vpc_id, gateway_id=igw["internet_gateway_id"])
        igw_info = self.get_igw_info(igw, vpc_id)
        self._results.update(igw_info)

        return self._results


def main():
    argument_spec = dict(
        internet_gateway_id=dict(),
        vpc_id=dict(),
        state=dict(default="present", choices=["present", "absent"]),
        tags=dict(required=False, type="dict", aliases=["resource_tags"]),
        purge_tags=dict(default=True, type="bool"),
        force_attach=dict(default=False, type="bool"),
        detach_vpc=dict(default=False, type="bool"),
    )

    required_if = [
        ("force_attach", True, ("vpc_id",), False),
        ("state", "absent", ("internet_gateway_id", "vpc_id"), True),
        ("detach_vpc", True, ("internet_gateway_id", "vpc_id"), True),
    ]

    mutually_exclusive = [("force_attach", "detach_vpc")]

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

    results = dict(changed=False)
    igw_manager = AnsibleEc2Igw(module=module, results=results)
    igw_manager.process()

    module.exit_json(**results)


if __name__ == "__main__":
    main()
