"""
Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
SPDX-License-Identifier: MIT-0

Permission is hereby granted, free of charge, to any person obtaining a copy of this
software and associated documentation files (the "Software"), to deal in the Software
without restriction, including without limitation the rights to use, copy, modify,
merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
OFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

"""

from aws_cdk import (
    core as cdk,
    aws_elasticloadbalancingv2 as alb,
    aws_wafv2 as waf,
)
import jsii


class RstudioWafStack(cdk.Stack):
    def __init__(
        self,
        scope: cdk.Construct,
        id: str,
        instance: str,
        allowed_ips: str,
        rstudio_load_balancer_arn: list,
        **kwargs,
    ) -> None:
        super().__init__(scope, id, **kwargs)

        allowed_ips = self.node.try_get_context("allowed_ips")
        allowed_ip_list = []

        if allowed_ips is None:
            print(
                "List of allowed IP addresses is not provided, will default to ALLOW all IPs"
            )
        else:
            allowed_ip_list = allowed_ips.split(",")

        if allowed_ip_list == [""]:  # IP list is empty
            is_allowed_ips_set = False
        else:
            is_allowed_ips_set = True

        waf_rules = []

        waf_rules.append(
            waf.CfnWebACL.RuleProperty(
                name=f"RStudio-AWSManagedRulesAdminProtectionRuleSet-{instance}",
                statement=waf.CfnWebACL.StatementProperty(
                    managed_rule_group_statement=waf.CfnWebACL.ManagedRuleGroupStatementProperty(
                        vendor_name="AWS", name="AWSManagedRulesAdminProtectionRuleSet"
                    )
                ),
                visibility_config=waf.CfnWebACL.VisibilityConfigProperty(
                    sampled_requests_enabled=True,
                    cloud_watch_metrics_enabled=True,
                    metric_name=f"RStudio-AWSManagedRulesAdminProtectionRuleSet-{instance}",
                ),
                priority=0,
                override_action=waf.CfnWebACL.OverrideActionProperty(none={}),
            )
        )

        waf_rules.append(
            waf.CfnWebACL.RuleProperty(
                name=f"RStudio-AWSManagedRulesAmazonIpReputationList-{instance}",
                statement=waf.CfnWebACL.StatementProperty(
                    managed_rule_group_statement=waf.CfnWebACL.ManagedRuleGroupStatementProperty(
                        vendor_name="AWS", name="AWSManagedRulesAmazonIpReputationList"
                    )
                ),
                visibility_config=waf.CfnWebACL.VisibilityConfigProperty(
                    sampled_requests_enabled=True,
                    cloud_watch_metrics_enabled=True,
                    metric_name=f"RStudio-AWSManagedRulesAmazonIpReputationList-{instance}",
                ),
                priority=1,
                override_action=waf.CfnWebACL.OverrideActionProperty(none={}),
            )
        )

        waf_rules.append(
            waf.CfnWebACL.RuleProperty(
                name=f"RStudio-RateLimitRule-{instance}",
                statement=waf.CfnWebACL.StatementProperty(
                    rate_based_statement=waf.CfnWebACL.RateBasedStatementProperty(
                        aggregate_key_type="IP", limit=1200
                    )
                ),
                visibility_config=waf.CfnWebACL.VisibilityConfigProperty(
                    sampled_requests_enabled=True,
                    cloud_watch_metrics_enabled=True,
                    metric_name=f"Rstudio-RateLimit-{instance}",
                ),
                priority=2,
                action=waf.CfnWebACL.RuleActionProperty(block={}),
            )
        )

        # Add IP whitelist bits here
        @jsii.implements(waf.CfnRuleGroup.IPSetReferenceStatementProperty)
        class IPSetReferenceStatement:
            @property
            def arn(self):
                return self._arn

            @arn.setter
            def arn(self, value):
                self._arn = value

        if is_allowed_ips_set:
            allowed_ipset = waf.CfnIPSet(
                self,
                id=f"allowedipset-{instance}",
                description="allowedipset rstudio",
                scope="REGIONAL",
                addresses=allowed_ip_list,
                ip_address_version="IPV4",
            )

            ip_set_ref_stmnt = IPSetReferenceStatement()
            ip_set_ref_stmnt.arn = allowed_ipset.attr_arn

            waf_rules.append(
                waf.CfnWebACL.RuleProperty(
                    name=f"allowiprule-{instance}",
                    priority=3,
                    statement=waf.CfnWebACL.StatementProperty(
                        ip_set_reference_statement=ip_set_ref_stmnt
                    ),
                    visibility_config=waf.CfnWebACL.VisibilityConfigProperty(
                        sampled_requests_enabled=True,
                        cloud_watch_metrics_enabled=False,
                        metric_name="webacl_ip_list_metric",
                    ),
                    action=waf.CfnWebACL.RuleActionProperty(allow={}),
                )
            )

            rstudio_web_acl = waf.CfnWebACL(
                self,
                id=f"RStudio-waf-web-acl-{instance}",
                default_action=waf.CfnWebACL.DefaultActionProperty(block={}),
                scope="REGIONAL",
                visibility_config=waf.CfnWebACL.VisibilityConfigProperty(
                    cloud_watch_metrics_enabled=True,
                    metric_name=f"rstudio-waf-{instance}",
                    sampled_requests_enabled=True,
                ),
                rules=waf_rules,
            )
        else:
            rstudio_web_acl = waf.CfnWebACL(
                self,
                id=f"RStudio-waf-web-acl-{instance}",
                default_action=waf.CfnWebACL.DefaultActionProperty(allow={}),
                scope="REGIONAL",
                visibility_config=waf.CfnWebACL.VisibilityConfigProperty(
                    cloud_watch_metrics_enabled=True,
                    metric_name=f"rstudio-waf-{instance}",
                    sampled_requests_enabled=True,
                ),
                rules=waf_rules,
            )

        i = 1
        for arn in rstudio_load_balancer_arn:
            rstudio_web_acl_assoc = waf.CfnWebACLAssociation(
                self,
                f"RStudio{i}-WebAclAssociation-{instance}",
                resource_arn=arn,
                web_acl_arn=rstudio_web_acl.attr_arn,
            )
            i += 1